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HUMBOLDT / Animal Science / ANSC 270 / How many ribs do you have altogether in your chest area?

How many ribs do you have altogether in your chest area?

How many ribs do you have altogether in your chest area?

Description

School: Humboldt State University
Department: Animal Science
Course: Human Anatomy
Professor: Michael king
Term: Winter 2015
Tags: Human Anatomy and Zool 270
Cost: 25
Name: Human Anatomy - All Lab Notes
Description: These are all the lab notes for the Human Anatomy course taught by Michael King during the Fall 2015 semester
Uploaded: 01/11/2016
62 Pages 39 Views 1 Unlocks
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Human Anatomy Lab Notes – August 25th 


How many ribs do you have altogether in your chest area?



Lab unavailable MW 11-2, but it is locked when not in use so you’ll need to find a building  monitor (11-4 is when they’re on duty), otherwise get a keycard from the main office (?)

Axial Region

Cranial – skull/brain case

Frontal – forehead region

Cervical – neck region

Thoracic – chest region, that portion that is surround by the rib cage

Abdominal – stomach/intestinal area

Pubic – waist/hips region

Appendicular Region

Axillary – armpit area

Brachial – upper arm region

Antebrachial – forearm region, term not used often

Carpal – wrist area

Inguinal – groin region, where leg meets trunk


What are the vertebrae in the neck region called?



Femoral – thigh area

Leg- specifically the lower leg/tibia region

Tarsal – Anklebones

Body Cavities

Cranial cavity – where the brain is

Spinal cavity – where the spinal cord is

Ventral Cavity – upper body

Thoracic cavity – area encased in rib cage

Pleural cavity – area where the lungs are

Mediastinum – area formed by the mediastinal septum (membrane), area  where the esophagus, trachea and heat/pericardial cavity

Pericardial cavity – heart is contained in its own sac within the  

mediastinum

Peritoneal cavity – area below ribs in the axial region

Planes of Section

*These planes can be placed in many different orientations along the body and  through specific organs, but follow these basic rules


Is the groin part of the trunk or leg?



Don't forget about the age old question of What is in the cytoplasm of bacterial cells?

Sagittal plane – longitudinal, running front to back

Midsagittal plane – runs directly through the middle of the body, gives us a  mirror image of both sides of the body (think Gamzee)

Transverse – cross-section (think Eridan)

Frontal (Coronal) – longitudinal, goes side to side, like most common human  anatomy diagrams/mannequins

Directional Couplets – relative terms that are opposites of each other, help us describe  where things are within the body Don't forget about the age old question of How does content play a role in the view of formal analysis?

Superior/Inferior – higher in the body/lower in the body

Anterior/Posterior – towards the front/towards the back

*These couplets are applied to all organisms, not just humans, and is regardless of  posture/walking orientation

Dorsal/Ventral – the back side/the belly side  

Cranial/Caudal – head end/tail end

Medial/Lateral – towards the middle of the body/towards the sides of the body Proximal/Distal – towards the trunk/away from the trunk (ex. the elbow is distal to  the shoulder but proximal to the wrist; *these terms are used in relation to a specific point  on the body)

Superficial/Deep – closer to the surface of the body/farther away and in among the  internal tissues of the body

Tissues

4 Different Types

Epithelial

Cover organs (ex. skin) and form linings (digestive tract, mouth, etc.) Connective

Most common, function as binding and support for organs and other  

structures (mostly)

Muscle

Nervous

Human Anatomy Lab Notes – August 27th 

Epithelial Tissues – Coverings and Linings

Functions  If you want to learn more check out We cannot use the element effect when?

Protective

Absorptive

Secretory

Sensory

Characteristics 

Mostly cellular

Free surface

Unattached on one side, faces the center of a hollow organ (that  side is called the “lumen”)

Avascular

No blood vessels present in these tissues

Basement membrane

What “glues” the epithelial tissues to the deeper connective tissues  underneath them

Naming of Epithelial Tissues 

Number of Cell Layers

First word in the tissue’s name

Simple – single cell layer in the tissue

Stratified – multiple layers of cells

Shape of Surface Cells

Squamous – Flat shape, squashed/thin appearance from above

Cuboidal – Cube shape, square appearance from above Don't forget about the age old question of What does federalism offer as advantages?

*Lining of a tubule has a different cuboidal shape when sliced

Columnar – Column shape, long rectangle appearance from above *Nuclei tend to be lined up along the bottom of these cells

*Basal cells are the ones that are actively dividing near the basement  membrane, and push the new cells up towards the surface where they get their appearance/name We also discuss several other topics like What are sigma and pi bond?

Special Types of ET cells

Pseudo-stratified cells

“False stratified”

Cells are all squished together in a disorganized way that makes it  look they are stratified

These cells are not organized together in even layers like  

stratified cells

These cells are only found in the airways, like the trachea, and they  have goblet cells included in the layers that produce mucus

Pseudo-stratified cell layers have a cilia border that carries away  dust and small particles that are trapped in the mucus, keeps the  trachea/lungs clean

Transitional cells

Cell type that is only found in the urinary bladder and ureters

Very stretchy, the cells look very “fluffy” and rounded, lots of space  between cells

Within the ureter, the lumen is arranged in folds extending into the  tubule We also discuss several other topics like What is the use of the phonograph?

Location of Cells 

Simple squamous

Found in the lungs, for gas exchange and diffusion to occur very rapidly Stratified squamous

Located in skin, mouth, esophagus, and vagina

 Stratified layers are necessary for more protection

Transitional

Found in urinary bladders and ureters

Very stretchy so the organ can expand and hold an increased volume

Simple Columnar

Large cells to hold a lot of organelles necessary for doing the work  involved in digesting foods and absorbing nutrients

Cuboidal

Found in the kidneys

Transporting nutrients into the bloodstream and transporting toxins out,  needs a thicker cell for a lot of activity happening within the cell

 Anatomy Lab – September 8th 

Form follows Function 

Selective Advantage to the form or the form may have worked well  for our ancestors!

Axial Skeleton

Vertebrae 

Vertebral Body

Area that is weight bearing

Intervertebral Disc

In between two vertebrae, constructed of fibrocartilage with  

hyaline cartilage in the center

Vertebral Arch

Together the arch and the body form the vertebral foramen, which  is what the spinal cord runs through

Spinous Process

Single process that extends posterior

Transverse Processes  

Two processes that extend laterally to the body

Articular process

Superior and Inferior articular extend between the transverse  and spinous, articulate with the articulars on the vertebrae above  and below them to allow for flexibility and movement

Vertebral Notch

Formed by the transverse processes on two vertebrae to construct the intervertebral foramen where the spinal nerves extend  out towards the body

Vertebral Column 

Cervical Vertebrae

7, form the neck

Smallest with small transverse processes and body, large vertebral foramen and two extra transverse foramen (for the vertebral  arteries)

∙ C1 – Atlas, supports the skull, has no vertebral body!

∙ C2 – Axis, articulates with the axis on its large spinous process, allows for rotation/movement of the skull

Thoracic

12, form the upper back

Changes in size down the vertebral column, spinous process  

extends downwards

Rib facets on the transverse processes and in between the  

vertebrae

Lumbar

5, form the lower back

Largest w/ broad body, support most of the upper body’s weight Very broad, short and flat spinous processes for muscle  

attachment

Very small vertebral foramen

Sacrum

5 fused vertebrae at the caudal-most portion of the spine

Holes that would be the intervertebral foramen (if it were unfused) Large facet on the side that is the auricular surface, articulates  with the pelvic girdle

Ox coxa (Coccyx)

The “tailbone” is three tiny vertebrae that are fused

*S-shape of the spine makes it flexible and act as a shock absorber, also  allows for a wide range of movement

Very helpful for our ancestors when running and leaping while  

hunting

Sternum & Ribs 

*The sternum and abdominal muscles help to support the curved S shape of the spine

Sternum

Manubrium

Upper portion of the sternum

Sternal (“jugular”) notch on the superior middle of the  

sternum

Clavicular notches are lateral to the sternal notch,  

articulate with the clavicle

Body

Main portion of the sternum

Xiphoid Process

Lower, small portion of the sternum

Ribs

True Ribs (1-7), attached to the sternum via costal cartilage  

(made of hyaline cartilage)

Floating ribs (8-12) don’t directly articulate with the sternum;  more costal cartilage connects them to the sternum (protect the  kidneys)

Head of the rib attaches at the vertebral body and at the  

transverse process by a tubercle  

Doesn’t move much, but can roll a little bit for expansion  

during inhalation

Anatomy Lab Notes – September 15th 

Appendicular Skeleton

* - on lab notes sheet, means “know left or right” of specific bone

Pectoral Girdle 

Connects with the axial skeleton at one place - the clavicular notches on the  sternum  

Everything else is attached and held together by muscles!

Scapula*

Relatively flat, thin bone that is concave (matches the curve of the ribcage) Subscapular fossa – “under the scapula” anterior depression, fits  together with ribcage

Glenoid fossa – Shoulder joint, articulates with the head of the humerus Axillary border- refers to the armpit region that it is closest too

Medial (vertebral) border

Superior border

Scapular spine – posterior ridge that ends in the acromion (which  articulates with the clavicle anteriorly)

Supraspinous fossa – depression above the scapular spine

Infraspinous fossa – large depression below the scapular spine

Coracoid process – smaller, anterior process that attaches to the brachii  muscles

Clavicles

Acromial end – articulates with the acromion on the scapula, vey flat end Sternal end – articulates with the sternum,  

Arm 

Humerus*

Anterior View 

Head of the humerus – most superior portion of the humerus

Greater tubercle – larger and more lateral to the humeral head

Lesser tubercle – smaller ridge of bone and more medial

Intertubercular groove – groove in between the tubercles, muscles run  along it

Deltoid tuberosity – rough patch of bone about halfway down the shaft of the humerus, the deltoid muscle attaches here

Capitulum – lateral condyle on the inferior portion of the humerus Trochlea – medial condyle of the humerus, looks like a “spool” of thread Epicondyles – two of them on either side and above the condyles Coronoid fossa – articulates with the coronoid process of the ulna, more  medial

Radial fossa – articulates with the head of the radius, more lateral Posterior View

Olecranon fossa – very large depression behind the trochlea

Radial groove  

Ulna*

Olecranon process – large, superior projection of the ulna

Semilunar (trochlear) notch – articulates with the trochlea of the  humerus

Coronoid process – smaller, inferior projection of the ulna

Radial notch – lateral-facing depression, articulates with the radial head

Radius*

Head – very flat

Ulnar notch – distal to the radial head, medially facing and articulates with the ulna

Styloid process – inferior-most projection of bone on the lateral side of the radius

Hand 

Carpals (Wrist) - “Some Lovers Try Positions That They Can’t Handle” Pisiform - Very small, round “pea”-shaped carpal bone

Scaphoid -  

Hamate – looks like Darth Vader’s head (??)

Metacarpals

Long bones in palm of hand

Thumb = MC 1  Pinky = MC 5

Phalanges

Proximal  Medial  Distal

Pelvic Girdle 

Os coxae

The two “hip” bones – each one is 3 bones completely fused together. Inlet of the pelvis – the “birth canal”, narrow in males and very wide in  females

This is a result of sexual dimorphism – evolution has selected for the  size differences of the hips in males and females

Ilium – superior bone, flares out like a wing

Iliac Crest – superior ridge of the ilium

Anterior-Superior iliac spine with an inferior iliac spine

below it

Acetabulum – hip socket, this is the point where the 3  

separate bones fuse to form the os coxa

Pubis – anterior bone of the os coxa  

Pubic ramus – superior and inferior ramus, join together at the

pubic symphysis

Pubic arch – narrow in males, wider angle in females

Ischium – posterior/inferior bone

Ischial tuberosity – posterior patch of rough bone, when the  

hamstrings attach

Obturator foramen – large hole formed by the pubis and  

ischium, most likely used to reduce the weight of the pelvis

Leg 

Femur*

Longest bone in the body, often has a high amount of variation between  individuals

Femoral Head

Fovea capitis – small pit on the femoral head

Femoral Neck – the offset neck creates the angle of the femur, aids  in walking/running  

Anterior View 

Greater trochanter – more superior and larger

Lesser trochanter – more inferior/posterior and smaller

Epicondyles – lateral and medial, superior to the two condyles

Condyles – smooth articulation surface for the tibia  

Tibia*

Condyles - articulate with the condyles of the femur, tibial condyles make  up the tibial head

Tibial tuberosity – large, anterior knob of bone on the tibia, muscle  attaches here

Medial malleolus – distal portion of the tibia, creates a small bump of  bone as the “ankle”

Fibula  

Small, very thin long bone that is mostly for muscle attachment and  stability (not very weight bearing)

Lateral malleolus – on the distal end of the fibula, creates the other bump of the “ankle”

Distal end of fibula is very flat and is shaped a bit like an arrowhead

Foot 

Tarsal (Ankle)

Talus – articulates with the tibia

Calcaneus – posterior-most projection of the tarsals, creates the “heel” Metatarsals

Make up the arch of the foot – like the metacarpals

Use the same Roman numbering system as in the hand (thumb = big toe) Phalanges

Big toe has only two phalanges; proximal phalanx is called the “hallux”

Anatomy Lab Notes – September 17th 

Articulations

Synovial Joints

Types

Gliding (“Plane”) Joint

Can move in any direction but they don’t move

very far – allows for increased flexibility

Hinge Joint

Axis through the joint like a door hinge– only a  

single axis of movement (ex. elbow, knee,  

etc.)

Pivot Joint

axis running straight down through the bone –  

another single axis of movement (ex. radius  

and ulna)

Condyloid Joint

bone fits together into the fossa of another  

bone – allows for two axis of movement  

(up/down, left/right) – ex. finger(phalanx and  

metacarpal)

Saddle Joint

 two U-shapes rotating around each other –  

only saddle joint is found at the metacarpals  

and carpals

Ball-and-Socket Joint

multiaxial – moving in all directions, can  

circumduct and rotate the arm

Shoulder Joint

Special Features 

Subacromial bursa – fluid-filled “pillow”, above the  

actual synovial joint helps to distribute the weight  

and cushion the joint

Tendon sheath – another bursa-like structure, helps  

to reduce friction during movement for the tendon as

it passes through the small area of the shoulder joint

Hip Joint

Special Features  

Greater trochanter

Has it’s own separate epiphyseal line

Fovea capitis

Small divot on head of femur, a small  

ligament attaches here

Helps to protect the blood vessels  

passing through which provide nutrients to the  

head of the femur

Head of the femur needs a large blood  

supply because it is dynamic and  

probably being remodeled often

Knee Joint

Special Features 

Meniscus

o Cartilaginous pads under each condyle of

the femur (two of them – lateral and  

medial)

o Conforms to the shape of the femoral  

condyles and helps distribute the weight  

away from a central spot

 Femur slides around in the fossa  

created by the meniscus

Collateral Ligaments

oTwo ligaments – fibular and tibial collateral  

ligament

 Large ligaments to provide stability

to sides of the knee

Cruciate ligaments

o Ligaments within the knee joint that  

cross over each other

o Anterior cruciate

 Crosses over from the medial side  

of the tibia to the lateral/posterior  

side of the femur

 Prevents hyperextension of the leg  

and the knee being displaced  

posteriorly (moving too far back)

o Posterior cruciate

 Prevents the knee from being  

displaced anteriorly (moving too far

forward) and prevents  

hyperflexsion

o Tendon of the quadriceps femoris  

muscle

 Goes over the patella and inserts  

on the tibial tuberosity (below the  

patella, this tendon is called the  

patellar ligament)

o Lots of fat pads around the knee for  

shock absorbency

Muscle Tissues

Skeletal 

Sometimes called “voluntary” muscle

Unique look  

Long skinny cells (aka muscle fibers) that can be as  

long as the entire muscle

Multinucleate – they have more than one nucleus per

cell because they’re so long, that it would be difficult for  one nucleus to control everything happening in the cell Well organized – skeletal muscle are composed of  

dense packs of myofibrils, this organization of myofibrils  results in distinctive striations of the muscle

Nucleus (in  

circle)

Striations of  

myofibrils  

(dark pink  

lines)

Individual muscle cell  

(wrapped in  

endomysium)

Cardiac 

Has some  

characteristics of  

skeletal muscle (hard and fast contractions) and  smooth muscle (is involuntary – most humans can’t  control their heart rate, etc.)

Single nucleus per cell and very well-organized Has light striations due to their myofibril organization Has an intercalated disc in between each cell (cells  

are interdigitated with each other) – very distinctive!! Cardiac muscle cells are sometimes branched between the  muscle fibers (but on our slides, we may not always see  them so don’t count on recognizing cardiac muscle  because of it)

Intercalated  

Disc (tiny  

horizontal lines

in black circles)

Smooth 

Sometimes called “involuntary” muscle – because it’s  associated with the digestive tract and blood vessels so it’s working all the time

Use waves of contraction to move food along, or to  constrict/dilate blood muscles

Not very distinctive – long, skinny cells that pointed at both ends to form a large sheet of muscle

One nucleus per cell – not multinucleated!

Smooth muscle lining the digestive tract is divided  up into two groups: circular muscle and longitudinal muscle (we’ll mostly focus on the circular)

Parts of a Muscle 

Structure  

Thickest part of a muscle is called the “belly” or the “head” All the connective tissue that wraps around individual parts of the muscle joins together at the end into a tendon! Tendons connect bone to muscle

Most tendons are round, but some are broad  

flat tendons called an aponeurosis

Ligaments connect bone to bone

Collagen of the tendon and muscle is heavily integrated  with the collagen of the periosteum (and all of the collagen connected to the bone)

Muscle cells are wrapped together into small bundles  called fascicles by the perimysium

Endomysium is the collagenous connective tissue  

that wraps around the individual muscle cell

Perimyseum is the collagenous CT sheath that wraps  

around the fascicle

Epimysium is the collagenous CT wrapping around all

of the fascicles/around the entire muscle

Action 

All a muscle can do is contract, so muscle pull on a bone or another muscle when contracting and shortening their  length (resulting in flexion); and when the muscle relaxes  this results in extension

Most extensors (muscles that are primarily involved in  extension) are on the dorsal surface

Most flexors (muscles that are primarily involved in flexion) are on the ventral surface  

This results in the body having opposing groups of  

muscles that pull on the same bone to result in  

opposite actions

The same muscle can’t extend and flex a  

particular joint – they can only do one thing or  

the other

Origin 

Insertion 

Naming 

Some muscles are named for their shape  

(Ex: deltoid – looks like an upside triangle (triangle is  

symbol for Greek letter “delta”; trapezoid – looks like  

a trapezoid)

Some muscles are named for their action  

(Ex: adductor magnus – large muscle in the thigh for  

adducting the leg to the medial line)

Some are named for their size

 (Ex: brevis muscles = small muscles; magnus =  

large muscles)

Some muscles are named for their location  

(Ex: biceps brachii – muscle found in the brachial or  

arm region; biceps femoris = muscle found in the  

thigh)

Named for the number of head/bellies

(Ex: “biceps” = two heads; “triceps” = three heads)

Named for their attachments

(Ex: sternocleidomastoid – origin is the sternum and  

clavicle; insertion is the mastoid process)

Muscular System 

Mammals have fewer bones but have a large amount of different  muscles to allow for a wide range of delicate to brute movements

Groups of muscles are very common for performing a specific  activity

(ex: 3 muscles are involved in the action of flexing the  elbow – each muscle plays a part depending on where the  arm is and what you’re trying to do)

Muscles that work together as a group to perform a specific task  are called synergists

As a result, the groups of muscles that oppose (do the  opposite action of) the synergists are called the  

antagonists

Masseter muscle

One of the main muscles involved in chewing

Origin is the zygomatic arch

Insertion is the angle & ramus of the mandible

Temporalis and masseter muscles are  

synergists (they work together for chewing  

(masseter moves mandible side to side for grinding 

herbivores/cows/sheep have large masseter muscles  

for chewing grasses)  

Temporalis muscle  

Temporalis moves mandible up and down to open your mouth as  far as possible  predators/carnivores have a large temporalis  muscle for clamping down)

Digastric muscle

“Di- = two heads”; one head is posterior, other is anterior Pulls the mandible down posteriorly to open your mouth

Platysma

Flat, thin sheet of muscle that runs over the front of the neck;  holds the trachea, esophagus, blood vessels etc. in the front of the  neck together

Buccinator

Horizontal muscle runs diagonally from the corner of the jaw to the  corner of the mouth (moves the lips posteriorly – used in smiling and  manipulating food around in our mouth!

Orbicularis oris

Surrounds the entire mouth (“oris” = oral cavity = mouth) Allows for puckering the lips This muscle and the buccinators  are antagonistic to each other!  

Orbicularis oculi  

Surrounds the entire eye (“oculi” = eye)

Allows for squinting

Anatomy Lab Notes – September 29th 

Shoulder & Trunk Muscles

*Learn origin and insertion of muscles with an asterisk next to them on lab  sheet!!

Shoulder Muscles

Trapezius

Broad flat sheath of muscle

Origin - all along the thoracic and cervical

Insertion - at the clavicle and scapular spine

Basic Action - Draws the scapula medially towards the spine (**You can also contract different areas of the muscle to  

draw the scapula in different direction – but we only care  

about the most basic actions of the muscle)

Latissimus Dorsii

Broad flat muscle, tucks underneath the armpit and tapers to a  point anteriorly for insertion

Origin - at lower thoracic and lumbar vertebra

Insertion - at Intertubercular groove of humerus

Basic Action - retracts and adducts the arm at the shoulder

Deltoid

Covers the shoulder joint and goes over the head of the humerus (like football shoulder pads)

Origin – at scapular spine and clavicle

Insertion – at deltoid tuberosity

Basic Action– abduction at the shoulder (lifts the arm upwards)

Rhomboid  

Deep to the trapezius, technically two muscles (r. major and r.  minor) but we’ll consider them as a single group

Origin – at the spines of the thoracic vertebrae

Insertion - at vertebral border of the scapula

Basic Action – causes the scapula to rotate; adducts the  scapula

Supraspinatus

Origin – Supraspinous fossa

Insertion – Greater tubercle of the humerus

Travels anteriorly over and down the top of the humeral  

head

Basic Action – abducts the humerus; synergist with the  deltoid muscle

Infraspinatus

Origin – Infraspinous fossa

Insertion – greater tubercle of humerus, at a different angle  than the supraspinatus does

Basic Action – adducts and laterally rotates the humerus;  antagonistic towards the supraspinatus

Teres Major  

Comes under the armpit anteriorly to the front of the humerus;  deep to the trapezius and latissimus dorsii

Origin – Inferior angle of the scapula

Insertion - Lesser tubercle of the humerus

Basic Action – retracts, adducts and medially rotates the arm  (rotates thumb towards the midline)

Teres Minor

Smaller and superior to teres major

Origin – axillary border of scapula

Insertion – grater tubercle of humerus

Under the armpit and comes around to the back of the humerus;  adductors; causes lateral rotation of the humerus

Erector Spinae

Group of muscles

Originate in the pelvic girdle and come all the way up to the back of  the head; run along a notch formed by the transverse and spinous processes  of the vertebrae

Serratus anterior

Origin on ribs 1-8 (have a “serrated” appearance) Wraps around the  armpit and under the scapula to insert on the medial border to the scapula Action = abducts the scapula  antagonistic with the rhomboid  muscles

Subscapularis –  

(not able to be seen in our cadavers because it’s underneath the  scapula and above ribs); origin at the subscapular fossa of the scapula  to insert on e lesser tubercle of humerus

Medial rotation of the humerus

Levator scapulae

Origin on cervical vertebrae C1-C4

Trunk Muscles

Pectoralis major – flat, broad sheath of muscle

Origin in multiple places along the clavicle, sternum and ribs 2-6; inserts at the greater tubercle of the humerus

Action adducts and protracts and medially rotates the arm

Pectoralis minor – deep to pectoralis major;  

origin at ribs 3-5 and inserts at the coracoid process of the scapula;  pulls the scapula down (“depresses the scapula”)

Intercostals

“in-between the ribs” muscles; thin sheets of muscle

External intercostals – angle upwards and diagonally left; action = pull  ribs out to expand during inhalation

Internal intercostals – angle downwards and diagonally right (opposite  the external i.c.)

Action = pull ribs in to collapse the rib cage during exhalation

3 layers of muscles that are angled in different directions along the lateral  sides of the trunk to allow for movement and strength (like plywood)

Obliques

Anterior trunk muscles; pretty similar to the intercostals (intercostal  muscles could be viewed as an extension of the obliques)

External obliques are lateral and angle down towards the pubis; thin sheet of muscle; insert along the linea alba (“white line” along the midline of the  body)

Internal obliques are deep to the external obliques and angle upwards to  form a “chevron” pointing towards the sternum

Transverse abdominus

Rectus abdominus  

Rectus = “straight”  

Maintains the spinal curvature in humans

Cells don’t go all the way up from origin to insertion, its divided into sections  (“the six-pack”) to increase the muscles strength

Anatomy Lab Notes – October 1st 

Arm Muscles

Brachial (Upper Arm) Muscles 

Biceps brachii*

Two-headed muscle, upper arm muscle

Origin on the scapula

Long head of tendon runs through the  

intertubercular groove and originates on  

supraglenoid tubercle;  

Tendon of short head on the coracoid process

Insertion is on the radial tuberosity – crosses over the  elbow!

Action at both the shoulder and elbow – flexion at the  elbow and supinate the forearm by pivoting the radius

Brachialis

Origin - halfway down the shaft of the humerus  

Inserts at the coronoid process of the ulna

Action - produces speed by contracting very close to the  elbow joint and flexing the forearm

Brachioradialis*

Muscle runs from the humerus to the end of the radius Origin on the supracondylar ridge of the humerus – higher  up than the other forearm muscles

Inserts on the styloid process of the radius

Action = flexes the forearm  

Triceps brachii*

Posterior – long head that crosses the shoulder joint (origin  on the infragelnoid tubercle)

Other two heads originate on the humerus

All insert on the olecranon process of the ulna

Action – 3 flexor muscles combined into one – flexes the  arm and forearm

Antebrachial (Forearm) muscles 

(**Muscles are named for their location and action!)

Posterior – extensor muscles are on the dorsal side 

Extensor carpi radialis

Medial – on the thumb side

Origin – lateral epicondyle of humerus

Insert at the metacarpals

Extensor carpi ulnaris

Lateral – on the pinky side

Origin – lateral epicondyle of humerus

Insert – on 5h metacarpal

Extensor digitorum

Muscle in the middle of the forearm – inserts on the  

phalanges

Origin – lateral epicondyle of humerus

Extensor pollicis (longus and brevis)

“Pollux” = thumb

Adductor – move thumb dorsally

Abductor pollicis longus

Lateral = abductor

Anterior – Flexors on the ventral side 

(**All muscles origin on the medial epicondyle of the humerus –  more power in the flexors than the extensors!)

Palmaris longus

Short belly with a long tendon; very superficial muscle and  is above the CT wrapping around the wrist!

In between the two flexors – not a “necessary muscle”  though  

Flexor carpi radialis

Radial/thumb side - lateral

Flexor carpi ulnaris

Ulnar/pinky finger side - medial

Flexor digitorum superficialis

Large forearm muscle – long tendons go all the way to the  digits and insert at the medial bone of the phalanges  

Flexor digitorum profundus

Very large muscle – tendon insert all the way at the  

terminal bone of the phalanges

Supinator

Runs in the opposite direction of the pronator muscles –  supinates the radius and is deep to the other forearm  muscles

Antagonistic to the pronator teres and quadratus

Synergist with biceps brachii for supinating the  

forearm

Pronator teres

Cuts across the forearm at an angle

Inserts on the lateral side of the radius -brings the radius  over the ulna into pronation position

Pronator quadratus

Flat muscle cuts across the forearm perpendicular to the  bone

Synergist with pronator teres – also brings radius  

over ulna

Anatomy Lab Notes – October 6th 

Muscles of the Leg and Hip 

Upper Leg 

Sartorius

Longest muscle in the body

Crosses at a diagonal angle from lateral to medial

Tensor fascia latae

“Tensing the fascia associated with the thigh” - Pulling on the  ilial-tibial tract  

Wrapped in a thick sheet of CT and is very lateral  

Quadriceps femoris group 

“Four heads” = four separate muscles with the same  insertion – through patella to the tibial tuberosity

Rectus femoris – “straight”, crosses over the hip  

joint to originate on the anterior inferior iliac spine

Vastus lateralis

Vastus medialis

Vastus intermedius – in between the vastus medialis  

and lateralis

Gracilis

The most medial muscle on the thigh, and is very slender! Crosses over the knee joint to insert on the medial tibia and  originates on the pubis

Hamstrings Group – all originate from the ischial tuberosity Medial

Semitendinosus – rounded tendon shape

Semimembranosus – very flat tendon shape

Lateral

Biceps femoris = “two headed muscle on the back of  

the femur”

Only muscle in hamstrings group to originate on the  

femur as well

Gluteal muscles – stabilize the hip joint

Gluteus maximus – lateral rotator of the femur

Gluteus medius – medial rotator and abductor of the femur Gluteus minimus – medial rotator and abductor of the  femur

Iliacus and Psoas major

Often named as one muscle group – “iliopsoas”, but we will learn  them separately  

These are the main “sitting up” muscles – very large!

Lower Leg  

Tibialis anterior

Fibularis group

Tendons of the muscle wrap around the fibula anteriorly  and insert onto the metatarsals

Gastrocnemius

Origin on the femoral condyles  crossing the knee and  ankle joints

Soleus

Deep to the gastrocnemius – same insertion on the  

calcaneus as the gastrocnemius

Origin on the tibia and fibular head – so it doesn’t cross  over the knee joint!

Heart and Great Vessels - see the Oct 7th Lecture Notes

Semilunar Valves don’t have chordae tendinae associated with  them, they are held closed by blood filling up their little “cups”  and weighing them down to form a seal

Some heart characteristics are left over from fetal development A small shunt is present between the pulmonary trunk and  the aorta – allowing fetal blood to bypass the developing lungs  since there’s no air in the womb – called the ligamentum  arteriosum

In-between the two atria – Interatrial septum has a small  depression that’s the remnants of the fossa ovalis

A “Trap door” in the fetus allowing blood to pass through  from the right side to the left side of the heart

Helped to “exercise” the left side of the heart – was sealed  closed by the pressure of blood entering from the  

pulmonary vein into the left side of the heart

Coronary arteries  

Leaving the base of the aorta and going to both sides of the  exterior heart

Supplies blood to the myocardium itself

Cardiac veins

Carry deoxy. Blood away from the myocardium and to the  coronary sinus (basically a large vein for draining old blood back  into the right atrium for re-circulation)

Anatomy Lab – October 13th 

Arteries and Veins 

Arteries – carrying high pressure blood away from the heart

Small lumen, thick wall (very muscular – holds its shape when  empty)

Wall has a wavy, elastic line on the interior – this is because of the  elastic ET

Veins – carrying low pressure blood in towards the heart

Large lumen, thin “leaky” wall (doesn’t hold its shape)

Major Arteries of the Body 

Coronary arteries

Branching off immediately from the base of the aorta – freshest,  most oxygenated blood is supplied to the heart itself

Aortic arch

3 arteries branch off form the arch

Brachiocephalic artery – supplies blood to the head and arm  

regions

This artery bifurcates into two arteries

Carotid artery – goes up to supply blood to neck  

and head

Internal carotid artery – supplies blood to the

brain

External carotid artery – blood to the neck  

and face

Subclavian artery – supplies blood to the shoulder  

and arm

This artery changes names depending on its  

location (right axillary artery from head of  

humerus to underneath the acromion  

process of scapula/ armpit region; right  

brachial artery from beneath the humeral  

head to the elbow)

Vertebral artery – go through the transverse foramina of the  cervical vertebrae

Below the heart 

Thoracic aorta

Intercostal arteries – serve the intercostal muscles, tiny vessels  between each rib

Abdominal aorta

Left and right renal arteries - paired branches to the kidneys

Testicular/Ovarian arteries – paired branches of arteries to the  reproductive organs (name changes depending on sex of  

cadaver)

Celiac artery

Short, unpaired artery that trifurcates (“three branches”); we’ll follow only one branch – hepatic artery (supplies blood to the liver) Superior mesenteric artery

Supplies blood to the upper intestines (artery is superior to the renal  arteries)

Inferior mesenteric artery

Supplies blood to lower intestines and rectum

Abdominal aorta bifurcates into the R & L common iliac arteries Each common iliac artery immediately bifurcates into an internal and external artery

Right external iliac artery  Right femoral artery

(* We’ll only learn the arteries above the knee)

Major veins of the body 

More veins than arteries in body!

Below the heart 

Femoral vein – directly beneath the artery (arteries and veins always run close together)

Great saphenous vein – medial to the femoral artery and very  superficial/just under the skin (used for blood vessel grafts in  surgery!)

Femoral and Great saphenous veins come together to form the  common iliac veins again

Common iliac veins come together to form the Inferior Vena Cava

Ovarian/testicular veins come together into the renal veins before  joining up with the inferior vena cava again

Hepatic veins are inside of the liver (the liver grows around the  inferior vena cava)

Blood from the digestive tract takes a different route – goes  

through the liver to drop off collected food nutrients for  

processing before going back to the heart  this nutrient-rich  blood is carried to the liver by the hepatic portal vein from  capillary bed to capillary bed (no heart involved so the blood  here is very low pressure!!)

Liver has two blood supplies coming in (hepatic portal  

vein and hepatic artery) and only one blood supply coming  out of it (hepatic vein)

Inferior Vena Cava passes through the diaphragm so it can bring  blood to the right atrium

Above the heart

Median cubital vein – small vein at elbow where a lot of IVs go Leads into the basilic vein then into the brachial veins  

Brachial vein also changes names based upon its location  axillary  vein  subclavian vein

Internal jugular vein – larger vessel, brings blood out of the brain External jugular vein – smaller vessel, brings blood out from the head and  face

Jugular veins join up with the subclavian vein to then reform the  superior vena cava

Azygos vein – brings blood out from the intercostal and back to the  superior vena cava

Anatomy Lab Notes – October 20th 

Blood and Lymph 

Blood is composed of:

55% - Plasma (liquid portion)

45% - formed elements/cells

Mostly erythrocytes (RBCs) and a small proportion of leukocytes (WBCs)  on the slide

Erythrocytes – very thin w/ no nucleus in the middle so they stain  white with a pink/light red ring

Leukocytes – stain dark blue because they have a nucleus in the  center

Neutrophil – common, ~60% of all leukocytes observed

Nucleus has a pinched, curled appearance  

Cell is much larger than an erythrocyte and is very  

transparent

Lymphocyte – common

Nucleus is very large in the cell with very little or small  

”halo” of cytoplasm surrounding it

Only slightly bigger than an erythrocyte

Monocyte – rare

Clear cytoplasm and is the biggest of the leukocytes Nucleus is often “kidney bean” shaped or bisected, but  not always!

Eosinophil – very rare

Large red/orange granules in the cytoplasm  

Nucleus has two lobes – sometimes looks like the cell  has two small nuclei

Basophils – very rare/rarest

Many large, dark blue granules in cytoplasm

*Platelets – aka “thrombocytes” small, fragmented  

appearance

Become “sticky” when they come into contact with  

collagenous fibers, help to plug holes and aid in clotting  

at an injury

Lymphatic System

An entirely separate vessel system from the circulatory system

This system carries lymph – the fluid’s name changes depending on its location In blood = plasma

Outside of cells – interstitial fluid

In lymphatic system = tissue fluid/lymph

Lymphatic system carries this fluid back into general circulation by dumping it  into the subclavian veins

However, the lymph is filtered by the lymph nodes before it goes back  into general circulation – gets rid of cell fragments and foreign invaders

Lymph Nodes

Composed of a meshwork of reticular fibers

These fibers carry many leukocytes that are available to fight pathogens  and other invaders (aka why you get swollen lymph nodes when you’re  sick)

Lymph is typically filtered two or three times by different lymph  

nodes to make sure there are as little pathogens in the lymph as  possible

Spleen – similar to a very large lymph node, filters out the blood for pathogens

Thoracic duct

Largest lymphatic vessel in the body, location where all of the lymphatic  vessels from the lower half of the body come together

Thymus gland and bone marrow are also grouped into the lymphatic system The thymus gland is very large in juveniles, but shrinks over time  Only found in juveniles, it’s nonexistent in adults

Thymus gland is the location where T-cells are produced from  

lymphocytes and “sensitized” or educated to protect against a specific  disease or pathogen

Blood Slide

Lymph Node Slide (Labeled reticular tissue)

Cadavers

Lymph Nodes

Spleen

Body Cavities 

Ventral Cavity

Thoracic cavity – bounded by rib cage

Pleural cavity – contains the lungs

Mediastinum – in between the pleural cavities

Pericardial Cavity – contains the heart

Peritoneal Cavity – below the thoracic

Diaphragm – thick membrane dividing the thoracic and  

peritoneal cavities

Membrane Terminology  

Visceral – membranes that line the organs themselves

Parietal – means “sides”, membranes that are lining the sides of the  cavities

Pleura 

Serous membranes that are within the pleural cavity 

Ex: serous membrane covering the lungs themselves –  

“visceral pleura”

Serous membrane lining the pleural cavity – “parietal  

pleura”

Pericardium 

Serous membranes that are within the pericardial cavity 

Membrane covering the heart (aka the epicardium) =  

“visceral pericardium”

Membrane lining the pericardial cavity – “parietal  

pericardium”

Peritoneum 

Serous membranes found within the peritoneal cavity 

Membranes covering the organs in the peritoneal cavity – “visceral peritoneum”

Membranes lining the peritoneal cavity – “parietal  

peritoneum”

These serous membranes have a small amount of serous fluid in between them – allowing the organs to slide smoothly along the  cavity’s walls

Head 

Nasal Cavity

Nasal concha – small trabeculae of bone that are covered in  nasal epithelium and mucus membranes; initial filter of air particles and  warms the air as you inhale

Olfactory epithelium is composed of the superior portion of the nasal  epithelium that is right beneath the cribiform plate of the Ethmoid bone - Opening of he auditory tube – allows for equalization of pressure in your  inner ear and at the tympanic membrane, hole is found at the very back of  the nasal cavity

Oral Cavity

Separation between these two cavities is the palate – “hard” palate is made of bone, “soft” palate is made of cartilage

Pharynx – receives both air and food from the nasal and oral cavities Nasopharynx – portion directly behind the nasal cavity

Oropharynx – portion directly behind the oral cavity

Laryngopharynx – portion directly behind the larynx

Glottis is an opening in the pharynx through which air travels through to  get to the trachea

Glottis is protected by the epiglottis – flap of cartilage that folds over when  swallowing food, protects against getting food/water into your airways Pharyngeal tonsils

Palatine tonsils – tonsils found right behind the oral cavity and below the  soft palate

Lingual tonsils – tonsils found at the back of the tongue

Larynx

Thyroid cartilage – hard cartilage found at the front of the larynx Thyroid gland sits right below it

Cricoid cartilage – small in the front and large in the back of the larynx Vocal fold – line of cartilage attached to the arytenoid cartilage, air is forced through the vocal folds and the vocal folds are tightened or loosened to  create sounds

Laryngeal prominence (“Adam’s apple”) – cartilaginous prominence  found on the thyroid cartilage that extends forwards during puberty,  extends the vocal folds and causes a deepening of the voice in males

Below the larynx is the trachea – cartilaginous C-shaped “rings” with a  small membranous portion in between the trachea and esophagus, allows  for expansion of the esophagus into the trachea when swallowing large  portions of food

Lower respiratory tract

Trachea bifurcates into two primary bronchi, one to each lung Primary bronchi brnch out multiple times – collectively called th  “bronchial tree”

Smallest section of the bronchial tree that still has cartilage  associated with are the bronchioles

Bronchioles have small alveoli that are covered in alveolar sacs (“Air  sacs”) at the end of them, this means that there is a large amount of  surface area available for gas exchange (gas exchange primarily happens  at the alveoli

Elastic fibers and capillaries are found on the surface of every single alveoli Elastic fibers squeeze air out of the sacs w/o much energy required Capillaries have deoxygenated  

Alveolus (“air sac”) is basically just one squamous cell thick, so they are  extremely thin, and there is a very small amount of space inbetween the  capillary wall and the alveolar epithelium that is filled with extracellular  fluid – space is called the respiratory membrane

Ventilation of the lungs

Inspiration – drawing air into the lungs

Intercostal muscles are relaxed – sternum is lying flat

Diaphragm is stretched upwards

Inspiration needs to have the volume of the thoracic cavity increased Contraction of the intercostal muscles pulls the ribs up and outwards,  and also causes the sternum to move up and out

Diaphragm is contracted and is drawn downwards (now it’s held taut like a  drum membrane)

Causes negative pressure which means the lungs expand to fill  up the space and automatically draws air into the lungs

Ribs do all the work – the lungs don’t do shit

Passive expiration – sitting, not consciously focusing on respiration Relaxing the external intercostals – collapses the rib cage and  sternum, makes the guts push upwards against the diaphragm Decreases the amount of volume in the thoracic cavity and air is  forced outwards

Active exspiration – running/physical activity, consciously focusing on  respiration

Contraction of the internal intercostals – squeezes the ribs together  and brings the sternum down and in vey quickly

Abdominal muscles (rectus abdominus, transverse abdominus and  obliques) are also contracted pulling the sternum down further and the  pushing the guts upwards

Quickly decreases the volume of the thoracic cavity and rapidly  forces air out

Anatomy Lab Notes – November 3rd 

Three primary brain vesicles form during embryonic development  Forebrain

Midbrain

Hindbrain

As development continues – forebrain and hindbrain each divide into two vesicles  

These 5 vesicles are called “secondary brain vesicles” Telencephalon – forms the adult cerebrum

Diencephalon - thalamus and hypothalamus

Mesencephalon – forms the adult midbrain

Metencephalon – pons and cerebellum

Myelencephalon – medulla oblongata

Brain - External Structures 

Brain Stem 

Cerebrum 

Very large “mushroom cap” over the brain stem

Mammals typically have much larger cerebrums  

compared to other animal species

Humans and marine mammals have the largest

cerebrums of mammals though

Medulla 

First “swelling” off of the brain stem

Controls basic survival functions - respiration, heart  

rate, hunger, thirst, sex drives

Pons 

Anterior bulge above the medulla – composed of a  

series of tracts that lead to the cerebellum

*Tracts = groups of neuronal fibers in the CNS

Carries info out of the brain stem and into the  

cerebellum via the cerebella peduncles and vice  

versa

Arbor vitae – branching of the white matter  

within the cerebellum

Midbrain 

This section hasn’t changed much evolutionarily or  

developmentally

Dorsally are four small lumps that are the corpora  

quadrigemina

Thalamus 

Superior to the midbrain/top of the brain stem

Directs information to various functional centers in  

the cerebrum and then retrieves info from those  

sections to send it to various body regions

Pineal gland 

Protrudes off the thalamus dorsally

Measures the amount of light and darkness in the  

environment

Produces melatonin when it’s dark out (like an  

internal body clock for determining day/night  

and seasons)

Hypothalamus 

Very important region!

Involved in the maintenance of homeostasis in the  

body

Two ways of achieving this

Rapid method - sends signals down the brain  

stem and into the spinal cord

Slow method – causes the pituitary gland to  

secrete and the various hormones it creates

Pituitary gland 

Aka “hypophysis”

“Master gland” and produces hormones that result in

long-term changes to the body over time

Brain - Internal Structures 

Surface of the cerebrum is composed of gray matter on the  surface and white matter on the inside (This is opposite of the  spinal cord!)

Gray matter – cell bodies and “naked” nerve fibers

Decision-making is occurring in the gray matter

White matter - myelinated neuronal fibers to speed up  signals  

Has the “wires” that connect the various parts of the  

brain and allow signals to travel around the entire  

brain

Gray matter – aka “cerebral cortex”

Large amount of gray matter in our brain is well condensed into the small package of the skull because it has many  convolutions/wrinkles on its surface!

This is very important for newborns so that their  

heads can fit through the birth canal during labor –  

even though newborn humans are fairly  

underdeveloped compared to the newborns of other  

animal species  

Gyrus – ridge of a wrinkle

Sulcus – groove of the wrinkle

Fissure - a particularly deep sulcus, these usually  

separate the portions of the brain into different lobes

These lobes have the same names as the skull  

bones that they are nearest to!

Lobes of the brain are divided into many  

different functional centers!! There’s no structural indication of these

centers, and we can’t see them in  

cadavers

The functional centers are slightly different in everyone and  there is a large amount of plasticity (flexibility) to the centers If something happens to one functional center in the brain,  another functional center of the brain can be “trained” to  start doing the ruined center’s job

**A lot of our cerebral cortex is devoted to motor control in the  feet, hands and the face!!

Cranial nerves 

Optic nerves enter the brain and cross at the optic  

chiasma!

Corpus callosum 

Transverse series of tracts that carries signals back and  forth between the right and left hemispheres of the  cerebrum

Pretty much makes up the entirety of the white matter in  the cerebrum

Septum pellucidum 

Thin sheet between corpus callosum and the fornix Underneath this sheet is a hollow inside of the cerebrum This hollow extends all the way down the central  

canal of the spinal cord and is usually filled with  

cerebral spinal fluid!

There are 4 ventricles in the brain  

Two lateral ventricles

A third ventricle  

Found at the top of the brain stem between the two

thalami

The two thalami are large groupings of neuronal cell  

bodies

Each thalamus has a medial projection that  

meet up with each other – called the  

intermediate mass

A fourth ventricle

Found underneath the cerebellum

Cerebral aqueduct – small canal connecting the  third and fourth ventricles

In all of these ventricles are a network of capillaries called  the choroid plexus and are covered in neuroglia The choroid plexus is constantly making new cerebral spinal fluid that is fresh and ultra-filtered by the  

neuroglia!

At the very top of the skull is the sagittal sinus

This is a venous sinus made of dura mater that collects  old CSF that is within the subarachnoid space

The CSF travels through projection called arachnoid  villi into the sinus

Sagittal sinus meets up with the transverse sinus at the  back of the skull before draining the venous blood and old  CSF into the jugular veins for entry into general  circulation

**Falx cerebri – projection of the sagittal sinus’s  dura mater down into the longitudinal fissure of the  cerebrum

Anatomy Lab Notes – November 5th 

Cranial Nerves 

*Know the name, Roman number, location and innervation

**Cranial nerves 1 – 6  we can see these on the actual  

specimens so these will be asked about on the practical

Cranial nerves 7-12  usually can’t be seen on the  

specimens (but they might be asked about in a  

general sense)

Olfactory nerve 

Cranial nerve I

Runs through the olfactory foramina on the cribriform plate and into the olfactory bulb

Very short nerves – once they pass through the  

olfactory bulb, they are a part of the CNS and  

become olfactory tracts

These are sensory nerves because they’re bringing  information in

Optic Nerve 

Cranial Nerve II

Both optic nerves cross over and come together at the  optic chiasma

Once they’re past the optic chiasma – they are  

considered part of the CNS and become the optic  

tract

Serves the retina of the eyeball - These are sensory nerves!

Oculomotor nerve  

Cranial nerve III

Comes out between the pons and the midbrain

It’s a motor nerve!

Deals with the extrinsic eye muscles – the muscles

on the actual eyeball that allow you to move your  

eye up, down, left, right, etc.

Trochlear nerve 

Cranial nerve IV

Goes to extrinsic eye muscles as well– it’s a motor nerve!

Trigeminal nerve 

Cranial nerve V

Large nerve with three branches going to the face

Both sensory and motor

Sensory - brining in sensory info/sensations from  

the skin

Motor – goes out to the superficial muscles of the  

face/skin  

Abducens nerve  

Cranial nerve VI  

Motor nerve - goes to extrinsic eye muscles too

Facial nerve

Cranial nerve VII

Goes to the deep facial muscles (ex. orbicularis oculi,  orbicularis oculi, etc.)

Both sensory and motor!

Vestibulocochlear nerve 

Cranial nerve VIII

Used to be the auditory nerve

Now its called the VB nerve because it also deals  

with equilibrium

Serves the vestibule and cochlea of the ear

Glossopharyngeal nerve 

Cranial nerve IX

Serves the tongue and pharynx muscles  

Both a sensory and motor!

Vagus nerve  

Cranial nerve X

Main nerve of the parasympathetic division of the ANS Autonomic nerve – works subconsciously

Innervates all of the viscera –all of the internal organs! Both sensory and motor!

Accessory nerve  

Cranial nerve XI

Aka the “spinal accessory”

Looks like a spinal nerve – but has a distinctive, “ladder like” branch going down the spinal cord

Serves two neck muscles – trapezius and  

sternocleidomastoid

Only a motor nerve!

Hypoglossal nerve  

Cranial nerve XII

Serves the muscles right underneath the tongue

Only a motor nerve!

Anatomy Lab Notes – November 10th 

Smell 

Simplest and oldest sensory system

Starts in the nasal cavity – at the very top of the cavity is the  olfactory epithelium

Olfactory nerves pass through the olfactory foramina of the  cribriform plate and into the olfactory bulb  at this point they  are considered a part of the CNS and are called the olfactory  tract

In the olfactory epithelium, there are cilia that are attached to  olfactory receptor cells  each cell is chemically attuned to a  different smell (although there are multiple cells that detect the  same smell)

If a smell triggers enough olfactory sensory cells that are  

matched to that smell, an action potential is generated

and information is sent to the brain about the smell

Taste 

Small papillae on the tongue

Each papillae has a deep groove surrounding it so that the taste buds along the side of the papillae are within this groove

A taste bud has about 50 – 100 taste cells that all detect the same  taste

However there are many different taste buds along each papillae  that detect 5 different tastes

Sweet

Sour

Salt

Bitter

Umami (detects glutamate – “savory”)

When a taste molecule comes into contact with the taste cell that has its  matching ion channel, the channel opens up and ions come rushing in If enough taste molecules bind with the taste cells, then an action  potential is generated and an electrical signal is sent to the brain  

The more taste molecules binding to taste cells, the more ions that come  in and the electrical signal being sent to the brain is amplified This amplifies the apparent “taste” of the food you’re eating

Eye 

**The entire structure of the eyeball is meant to enhance the light coming in so that an image can be formed by the brain

Retina - Light receptors that form the innermost layer at the back of the  eyeball

Two different kinds of light receptors

Rods – detect varying shades (light and dark/black and white) Cones –detect the three primary colors

These receptors use a lot of energy and are constantly receiving  and sending out information to the brain

As such they need a large blood supply, so the blood vessels  are actually in front of the retina and light receptors

Since the blood vessels are constantly there, the brain  

has adapted to “ignore” them and fill in the spaces  

blocked by the blood vessels

Optic disc – this is where the optic nerve comes out of the eyeball No sensory receptors present there – forms the “blind spot”

Pupil – determines how much light is allowed to come into the eyeball The pupil is simply a hole that can be made smaller or larger by the iris contracting or relaxing

Lens – changes its shape a little to bend and refracts the light to keep an  image in focus

Lens has multiple layers (like an onion) and when the  

suspensory ligaments attached to it pull on the lens, the lens  tightens up and flattens out  this bends the light a little bit When the ligaments are relaxed, the lens gets thicker in  

the middle and the light is bent a lot

*Ciliary muscles change the tension on the suspensory ligaments

Sclera – outer layer of the eyeball, white of the eye that holds the shape  of the eyeball together

Sclera is modified in the front to form the cornea

Cornea – clear portion of the sclera at the very front of the eyeball Cornea and sclera are formed from very durable connective  tissue!

Conjunctiva – very thin layer of epithelial tissue that faces the free  surface of the eyeball

Tears formed by the lacrimal glands wash over the conjunctiva  and help keep it clean

Choroid – black layer that is deep to the sclera and absorbs stray  light

Light passes through the conjunctiva and the cornea and then  through the anterior and posterior chambers (these chambers  are filled with aqueous humor) and then through the pupil

Light then passes through the vitreous humor – most of the “jelly” of  the eyeball

The retina is held in place by the vitreous humor

If the vitreous humor is shaken up too much, then the retina can  become detached and pull away from the back of the eyeball (ex. heavy blow to the head)

This also happens during aging as the vitreous humor dries up

Macula lutea – located at the very back of the eyeball  

Part of the eyeball that you’re using most of the time

Very center of the macula is the fovea centralis

This small depression allows for a shit-ton of sensory  

receptors to be packed into it (these sensory receptors are  all cones!)  

Primarily used for discerning fine detail and small  

color changes

Ear 

Formation of Sound waves

When you hit a tuning fork, the two tines are vibrating and  compresses the air molecules on one side and rarefracting the air  molecules on the other side  and then vice versa and this continues to  form a “ripples in the pond” effect on the air molecules

External ear – everything outside of the eardrum

Looks like a funnel – channels airborne vibration (aka sounds)  into the external auditory canal and straight to the tympanic membrane Tympanic membrane – very thin and flexible, but very tough  connective tissue

Incoming airborne vibrations (aka sounds) causes the eardrum to  vibrate – these vibrations are very small/weak though

Middle ear – where the auditory ossicles are

These ossicles give the weak vibrations from the eardrum a  mechanical advantage and amplify the vibrations

Auditory Ossicles are three, very tiny bones!

Inner ear – everything that is encased in bone and fluid-filled Stapes pushes against the oval window of the inner ear and  turns the vibrations from the air into vibrations in the fluid When you push against the oval window, the round window  bulges out and vice versa so that there is equilibrium in the  vibrating fluid

Auditory tube leads from the air-filled chamber of the middle  ear to the pharynx  allows for reduction/equilibrium in changing air pressures (ex. popping you ears during a flight)

Upper portion is the vestibular apparatus – used for  

equilibrium

Balance information comes out and goes to the brain through  the vestibular nerve

Lowe portion is the cochlea – the auditory bit

Information comes out of the cochlea through the cochlear  nerve

These two nerves join up and form the vestibulocochlear  nerve (cranial nerve VIII)

Cochlear tube is divided into three sections

Scala vestibule

Separated from the cochlear duct by a thin vestibular  

membrane

Cochlear duct (aka scala media) – where the actual sensory  receptors for hearing are located!

These sensory receptor cells are collectively called the  

spiral organ of Corti

Below the cochlear duct is scala tympani – separated by a much  thicker basilar membrane

Within the cochlear duct, there are very tiny hair cells that are  connected to the basilar membrane, and when this membrane vibrates,  the hair cells bend and generate an action potential  

Action potential goes to the brain, and the brain perceives the fine  details such as the tone, pitch, etc.

Transduction (Change of Mode in the ear)

Airborne Vibrations  Mechanical movement  Fluid-borne Vibrations  Mechanical movement  Chemical Signal  Action Potential

Human Anatomy Notes – November 12th 

Endocrine System

Other control system with a slower but longer-lasting effect on the body Releases its signal molecules directly into the blood system

Any signal molecule that is transported by the blood system is called a  hormone!

Results in seasonal, monthly, etc. changes in the body

Since the blood system is the supply transport system for every cell in the body –  every cell in the body has various hormone receptors on it!

Various glands are part of the endocrine system

Hypothalamus 

Pineal gland 

Pituitary gland 

aka hypophysis

Hangs off of the hypothalamus by a small stalk called the infundibulum  and rests within the stella turcica of the sphenoid bone

Separated into two lobes – anterior and posterior pituitary glands

Posterior pituitary gland (“neuro-hypophysis”) is very neural!

Neurosecretory neurons extend into the posterior pituitary glands  

to produce two hormones; the posterior pituitary gland only  

releases these hormones (it doesn’t make them itself)

Oxytocin – causes the contraction of smooth muscle in the  

uterus during labor and in sternal muscles (around the  

mammary glands for secreting milk)

Vasopressin – causes contraction of the smooth muscles in  

blood vessels – increasing blood pressure

Specifically affecting the kidneys – also called anti

diuretic hormone (ADH) and stops you from producing

urine to retain water

Anterior pituitary gland (“adeno-hypophysis”) is very glandular!

Multiple endocrine cells producing hormones are present

Also has neurosecretory neurons going into it

Hypothalamic – hypophysis portal system – small portal system  

going from capillary bed to capillary bed with no heart action in  

between

Anterior pituitary gland produces many hormones that are controlled in  their release by the hypothalamus

Growth hormone (GH) – affects the entire body

Prolactin (PRL)– targets the mammary glands to stimulate the growth  of the machinery that will later produce milk

Tropic hormones – target endocrine glands/this is why the pituitary gland is called the “master gland” because it makes different hormones that affect other endocrine glands

Thyroid stimulating hormone (TSH) – affects the thyroid

ACTH – affects the adrenal cortex for it to release its specific  

hormones

FSH and LH – affects the testes/ovaries to release sex hormones  

and gametes

Endorphins – affects pain receptors in the brain

Neurohypophsis

Adrenohypophysis

Thyroid gland 

Located just below the thyroid cartilage of the larynx and is wrapped around the  trachea

H-shaped – has two lobes on the side of the trachea but the central “isthmus” of the thyroid is very difficult to see and is almost non-existent

Very squishy and “soft” in appearance

Thyroid is composed of fluid-filled chambers called follicles - fluid inside the follicles  are thyroid hormones (T3 & T4)

These hormones are involved in metabolism and increase metabolic rate  Keeps you warm in the winter, but in the summer less of these  

hormones are secreted to keep you cool)

Single layer of cells surround the follicle are the follicular cells

Parafollicular cells are small groupings of cells found in the spaces in  between the follicles

Parafollicular cells make calcitonin - decreases blood calcium  

levels to maintain homeostasis after you eat something that is calcium rich

Calcitonin stimulates osteoblasts to store extra calcium in the

bone by building new bone cells

Follicle

Follicular cells

Parafollicular cells (at  

pointer)

Parathyroid glands 

Very subtle differences between these glands and the thyroid

They are very small glands that are attached to the back of the thyroid gland –  make parathyroid hormone (PTH) that increase blood calcium

If you haven’t had food and your body has low calcium levels, PTH  

stimulates osteoclasts to break down bone cells and release the stored excess calcium into the blood stream

Thymus 

Hormone produced here is thymosin – involved in the maturation of T -  lymphocytes, but we don’t really know what it does beyond that?

Present in juveniles but disappears with age and is completely gone in adults

Adrenal glands 

Found on/above the kidneys

Mostly triangular in shape

Outer region is called the adrenal cortex

Very glandular – looks like a homogenous mass of cells

There are separate zones within the adrenal cortex that make  

different hormones

Aldosterone – hormone that helps the body retain sodium and water

Excess water increases the fluid volume of blood and increases  

your blood pressure – high blood pressure is good for when you  

need to escape from something!

Cortisol – suppresses the immune system

If you’re in a fight or flight situation – you don’t want the  

inflammatory response to an injury to make your limbs inflexible  

and unable to move/run away from something

Also breaks down fats and proteins in the body to keep your

blood sugar levels high for increased energy

Androgens – male sex hormones (testosterone)

Both men and women make testosterone in their adrenal glands

Male sex hormones increase libido/sex drive, which may be  

important if people are dying all around you and you really need  

to make some offspring to continue on as the next generation pf  

the species

Inner region is called the adrenal medulla

Very neural - has a lot of modified neurons from post-sympathetic  

ganglion neurons in the sympathetic division of the ANS

Adrenal medulla produces similar hormones to what a post-sympathetic

ganglion does

Secretes epinephrine and norepinephrine directly into the blood  

stream

Same effect is generated – flight or fight response!

This effect lasts longer than the effect generated from the sympathetic  

nervous system

Adrenal  

medulla

Adrenal cortex

Pancreas 

Mostly a ducted, digestive gland – producing pancreatic juices that go into the  upper portion of the small intestine for digestion – juices are made by the acinar  cells

There are small groups of dissimilar cells called pancreatic islets – these are the  cells that are actually considered part of the endocrine system

Much lighter and larger compared to the other pancreatic cells around it These cells don’t have a duct, instead there is a blood vessel right next to  them that allows the pancreatic islets to release their hormonal secretions  directly into the blood stream

Main hormones produced here are insulin and glucagon

Insulin – decreases blood sugar levels when they’re higher than  

normal

Every cell in the body has insulin receptors because every  

cell needs sugar for functioning

More insulin receptors in the liver – so it takes in a lot of  

sugar to form a big storage molecule for excess sugar  

called glycogen

Glycogen is also found in the muscles as well

Glucagon – increases blood sugar levels when they’re lower than  

normal

Gets to the glycogen stored in the liver and muscles and  

gets it to release the excess sugar that it’s storing

Somatostatin

“Steady body” – antagonistic hormone to growth hormones  

– stops body growth!

Pancreatic islet (at  

pointer)

Acinar cells

Ovary/Testis 

Although the are primarily reproductive organs – they also produce sex hormones  that include them into the endocrine system too

Endocrine Reflex Pathway/Arc 

Chemical signals moving through the blood stream

Example:

Parathyroid glands sense the low calcium levels in the blood stream that  stimulate them to release PTH which targets three areas

Targets bone so that osteoclasts will break down bone cells and release  stored calcium

Targets the intestine to increase the rate of absorption for calcium from  the food

Targets the kidneys to activate Vitamin D and increase the rate of  

calcium reabsorption from the waste products of the digestive system As the calcium levels rise in the blood stream because of these three targeted areas  calcium ions travel back to the parathyroid glands and inhibit the  release of PTH

This endocrine reflex pathway/arc is a negative feedback loop!

Anatomy Lab Notes – November 17th 

Digestive System

Within the ventral cavity – “tube within a tube” structure

Pharynx – takes in both air and food

Food moves from the oral cavity to the oropharynx

Multiple salivary glands in the head – sublingual and  

pharyngeal salivary glands

Esophagus

Long muscular tube leading to the stomach – passes  

food through it by waves of contraction called  

peristalsis

Passes through the gastro-esophageal (aka cardiac)  

sphincter to get into the stomach

Stomach

Food is held in here by the pyloric sphincter being  closed

Mechanical and chemical digestion occurs in the  

stomach!

Stomach is very muscular with a large third  

layer of muscle being present – large ridges  

called rugae are found along the stomach wall  

Food churns around like in a washing machine  

with stomach acid and other digestive juices  

These digestive juices have a pH of 2 – very  

acidic!

All of this turns food bits into a thick soup-like  

mix called chyme – very easy to move this  

through the intestines!

No nutrients are absorbed in the stomach – however  cold water is absorbed very rapidly!

Small Intestine

**Majority of absorption occurs here as part of  

digestion – stomach acid is neutralized so that it  

doesn’t burn the small intestine!

Small intestine is very long but is folded up a lot so  that it will fit into the peritoneal cavity

The interior or the small intestine also has  

circular folds that increase the surface area  

and swirl the chime around to increase the  

amount of nutrients absorbed

Finger-like projections found on these  

circular folds are called villi and are  

covered in a brush border of microvilli –  

greatly increases the surface area!!

Segmentation – circular muscles contract in different  regions to separate the chyme into small pools 

opposing circular muscle groups contract to push a  little bit of chime from one “pool” into the next pool  causes a sloshing back-and-forth mixing of the  

chyme

This segmentation happens at the same time  

as peristalsis  transport muscle contraction  

moving all of the chime along through the  

digestive system

Duodenum – first part of the intestine coming off of  the stomach

Jejunum – difficult to distinguish from the other two  portions

Ileum - end of the small intestine that leads into the  large intestine

Ileocecal sphincter – sphincter between the  

ilium and the first part of the large intestine  

called the cecum

Peyer’s Patches

Lymphoid tissue found in the submucosa  

layer of the ileum  very recognizable  

and will be on test!

Greater omentum – overlies the small intestine,

helps keep the small intestine in place, warm  

and has fat all along it for energy storage

Large Intestine (aka colon)

Large intestine is almost always oriented in the same manner in every person

Large intestine is “bubbly” in appearance – small  pouches reabsorb water and form feces from  

undigested food and waste material

Sac at the very beginning of the large intestine  

is the cecum

Small dangly bit hanging off of the cecum

is the appendix

Portion of the large intestine going up is the  

ascending colon

Portion going across is the transverse colon

Portion going down is the descending colon

Descending colon ends in the rectum –  

very distinctive bend-shape here!

Rectum finally ends in the anal sphincters –  

terminal point of the digestive system!

4 layers to the digestive tract wall

**These layers can be in different concentrations  depending on where they are in the body (ex: not a whole  lot of digestion happening in the esophagus, so the mucosa layer is reduced but the muscularis externa layer is fairly  large)

Serosa

Serous membrane, outer-most layer of the digestive  tract

This is a continuous membrane – lines both the body  wall and the digestive tract as both the parietal  

peritoneum and visceral peritoneum respectively! Forms a double layer with connective tissue in  

between them – the mesenteries

Physical support to hold the digestive tract  

mostly in place and also the space where blood

vessels can pass through to bring nutrients and

blood to the gut

Muscularis externa

Muscular wall of the digestive tract – composed of  circular and longitudinal muscle

Submucosa

Mucosa

Mucous membrane facing the lumen of the digestive  tract

 Liver  Sinusoids

Creates bile, passes it through the hepatic duct and  into the gallbladder for storage  

Sinusoids – “little hollow” radiating from a central  vein (small white cracks in between groups of liver  cells)

These hollows are bringing all of the blood from the hepatic portal vein and from the hepatic  artery towards a central vein and into the liver  for processing

Bile and Blood are flowing counter-currently from  each other in the liver

Pancreas  Acinar Cells

Lobular, whitish organ that is long, skinny and in  between the liver and stomach is the pancreas

Makes digestive juices

Digestive juices pass through the pancreatic  duct, while bile passes through the common  bile duct  both are introduced into the  

duodenum of the small intestine

Anatomy Notes – December 8th 

Female Reproductive System 

Ovary

Follicle-Stimulating Hormone (FSH) stimulates the production of a  

follicle to surround an oocyte

Oocyte is so large that it needs the nutrient-rich fluid within the  

follicle to surround it so that it can grow and develop inside the  

ovary

Estrogens and progesterone are produced by the corpus luteum  

that forms after the follicle ruptures and expels the oocyte from  

the ovary

Infundibulum of the uterine tube

Ciliated funnel with finger-like projections that overlies the ovary so  that it 99% of the time, captures the released oocyte and draws it into the uterine (fallopian) tube

Uterus

Ova implants into the endometrium or inner wall of the uterus if it has  been fertilized

Myometrium is the thicker, external wall of the uterus that is  

composed of smooth muscle

Cervix

Opening to the uterus - sealed up by a mucoidal “plug” during the  non-fertile periods of the menstrual cycle

Vagina

Long tube leading up to the uterus and is made primarily of  

connective tissue so it is very flexible and can stretch

Has rugae or ridges that allow for more stretching

Vestibule  

Urethral opening, vaginal opening, glans clitoris and the prepuce are  all found here

Hymen may occasionally be found covering the vaginal opening

Region from the pubic mound and the anus is called the perineum The vestibule containing the external genitalia is found here  

Uterine Cycle 

Menstruation – sloughing off of the old endometrium

Proliferative phase – new endometrium begins to form

Secretory phase – occurs immediately at ovulation

Glands in uterus begin secreting nutritious secretions that would  

provide nutrients for the implanted ova and subsequent embryo

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