New User Special Price Expires in

Let's log you in.

Sign in with Facebook


Don't have a StudySoup account? Create one here!


Create a StudySoup account

Be part of our community, it's free to join!

Sign up with Facebook


Create your account
By creating an account you agree to StudySoup's terms and conditions and privacy policy

Already have a StudySoup account? Login here

Human Gross Anatomy Lecture 5 Part 2

by: Anais Ioschpe

Human Gross Anatomy Lecture 5 Part 2 BISC 2581

Marketplace > George Washington University > Anatomy > BISC 2581 > Human Gross Anatomy Lecture 5 Part 2
Anais Ioschpe

Preview These Notes for FREE

Get a free preview of these Notes, just enter your email below.

Unlock Preview
Unlock Preview

Preview these materials now for free

Why put in your email? Get access to more of this material and other relevant free materials for your school

View Preview

About this Document

GWU Human Gross Anatomy Lecture 5 notes from lecture, powerpoint, and handout.
Human Gross Anatomy
Jeffrey Rosenstein; Raymond Walsh;
Class Notes
25 ?




Popular in Human Gross Anatomy

Popular in Anatomy

This 11 page Class Notes was uploaded by Anais Ioschpe on Saturday January 30, 2016. The Class Notes belongs to BISC 2581 at George Washington University taught by Jeffrey Rosenstein; Raymond Walsh; in Spring 2016. Since its upload, it has received 60 views. For similar materials see Human Gross Anatomy in Anatomy at George Washington University.


Reviews for Human Gross Anatomy Lecture 5 Part 2


Report this Material


What is Karma?


Karma is the currency of StudySoup.

You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!

Date Created: 01/30/16
Human Gross Anatomy Lecture 5 Part II on 28/1/16 Introduction to the Upper Limb— Forearm Learning Objectives for the Lecture on Forearm 1) Identify the major anatomical features of an AP radiograph of the wrist and hand, and 2) Describe the articulations and movements at the wrist, midcarpal, metacarpophalangeal, and interphalangeal joints. 3) List the innervation and major actions of all the forearm muscles 4) Describe the boundaries and contents of the carpal tunnel 5) List the spinal nerve that controls flexion of the thumb and fingers at their interphalangeal joints 6) Explain why injury to the radial nerve in the axilla may lead to wrist drop 7) Describe the boundaries and bony floor of the anatomical snuffbox and the use of the anatomical small box in the physical diagnosis of scaphoid fractures. - Forearm • Anterior forearm: predominantly flexors— bringing something toward me (holding a bottle of wine and pulling the cork screw toward you)— Very large in size whereas the posterior forearm are very flat • Posterior forearm: predominantly extends. The two together are always working in opposite roles; as one extends the other flexes. • The forearm begins at the elbow region and continues to the area of the wrist. The bulk of the forearm is composed of fleshy muscles whose tendons extend to and through the wrist to the fingers. Their contractions permit the extensive movements of the wrist and fingers. Generally, the flexors for grasping and power grip are located on the anterior surface and the extensors for fine and controlled movement are the posterior surface. These compartments are roughly divided by the parallel bones radius and ulna and the interosseous membrane between. • The flexors and pronators in the anterior compartment are innervated mainly by the median nerve and its branches with one and one half exceptions (see below) and the extensors in the posterior compartment are innervated by the radial nerve, mostly by its deep branch. - Skeleton of Wrist and Hand • Since the forearm muscles act on the joints of the wrist and digits we must first examine the skeleton and joints. It is important to recognize that anatomically and medically the thumb is not a finger. Page 1 of 11 • In the hand, there are five digits, and they consist of the four fingers plus the thumb i.e, index, middle, ring, little. Notice that each digit has two equivalent names (e.g. index finger is digit #2). When you identify a digit of the hand in clinical notes, it is always advisable to include both names of the digit. This practice minimizes the possibility of incorrect identification of the digit by other medical personnel. • Carpals: The bones of the wrist (8 in total) - The carpals are traditionally divided into two rows (a proximal row and a distal row) of four carpals each. Proceeding from the most lateral carpal to the most medial carpal in the proximal row (that is, the row nearest the distal ends of the radius and ulna), the carpals of the proximal row are named scaphoid, lunate, triquetrum, and pisiform. Proceeding from the most lateral carpal to the most medial carpal of the distal row, the carpal of the distal row are named trapezium, trapezoid, capitate, and hamate. The images of trapezium and trapezoid partially overlap each other in an AP radiograph of the hand. • Metacarpals: the bones in the palm of the hand Page 2 of 11 - The five metacarpals are numbered in such a fashion that the 1st metacarpal (thumb) is the most lateral metacarpal and the 5th metacarpal (little) is the most medial metacarpal. Each metacarpal has a base, a shaft, and a head. The base forms the proximal end of the metacarpal, and the head forms the distal end. The heads of the 2nd to 5th metacarpals form the knuckles. Index finger (2nd metacarpal bone) • Phalanges: and the bones in the digits are called phalanges. - The phalanges of each finger are called the proximal, middle, and distal phalanges of the finger. The phalanges of the thumb have two, are called the proximal and distal phalanges of the thumb. Each phalanx has a base, a shaft, and a head. The base is the proximal end of the phalanx and the head is the distal end of the phalanx • The wrist joint: is a synovial joint in which the scaphoid, lunate and triquetrum articulate with the distal end of the radius and the articular disc of the distal radioulnar joint. The midcarpal joint is a synovial joint in which the carpals of the distal row articulate with the scaphoid, lunate, and triquetrum. The synovial cavity of the midcarpal joint is separate from that of the wrist joint. Page 3 of 11 - The wrist and midcarpal joints provide for four movements: flexion, extension, abduction, and adduction of the hand. The metacarpophalangeal (MP) joints each join the head of a metacarpal with the base of its corresponding proximal phalanx. Each MP joint provides for flexion, extension, abduction, and adduction of the proximal phalanx of the digit. • Abduction of each finger is the movement in which the finger moves in the plane of the hand away from the reference axial line that extends through the middle finger • Adduction is the reverse of the abduction movement. Page 4 of 11 •The carpometacarpal joint of the thumb is a synovial joint in which the trapezium articulates with the base of the 1st metacarpal. It provides for flexion, extension, abduction adduction and rotation of the thumb. Because the thumb’s palmar surface is oriented approximately 90◦ to that of the palmar surfaces of the fingers, flexion, extension, abduction, and adduction of the thumb is oriented at right angles to the corresponding movements of the MP joints of the fingers (e.g the thumb flexes across the palm). The interphalangeal (IP) joints provide only for flexion and extension of the more distal phalanx in both the fingers and thumb. •Distal radioulnar joint: located between the radial and distal bones, doesnt move. RECAP ON NERVES and MUSCLES •The major nerves of the upper limb: The axillary, musculocutaneous, median, ulnar, and radial nerves •The axillary nerve transmits: Only C5 and C6 nerve fibers and innervated only two muscles: deltoid and teres minor •The musculocutaneous nerve transmits: mainly C5 and C6 nerve fibers and innervates three muscles in the anterior surface of the arm: coracobrachialis, biceps brachii, and brachialis •The radial nerve transmits: Mainly C7 and C7 nerve fibers to the posterior arm and forearm muscle: triceps brachii Page 5 of 11 • The muscles of the forearm can be divided into two groups: the anterior forearm muscles and the posterior forearm muscles • A a group, the anterior forearm can: “the pronators”; pronate the forearm, flex, abduct, and adduct the hand, and flex its digits • As a group, the posterior forearm muscles can: “the supinators”; supinate the forearm, extend, abduct, and adduct the hand, extend its digits, and abduct the thumb - Musculature and Innervation In the forearm, the only nerves we are dealing with are the radial, median and ulnar. The • ulnar has a minor role in the forearm but innervates most of the muscles within the hand. The radial (extensors) and median (flexors) are responsible for almost all the innervation. The muscles of the forearm either operate the wrist or are extrinsic muscles of the digits as opposed to intrinsic muscles of the digits that arise and insert within the hand. It is best to group the muscles by compartment and nerve innervation. This involves memorization but helps you understand how the tendons that cross the wrist to enter the hand are arranged and how they evoke their specific movements (or lack of movement after a nerve injury). Muscles of the anterior (flexor) compartment of the forearm are all innervated by the median nerve except the flexor carpi ulnaris and the ulnar half of the flexor digitorum profunds which are innervated by the ulnar nerve Cubital fossa Page 6 of 11 • Superficial anterior compartment muscles: mostly arise from the medial epicondyl of the humerus - Pronator teres: flexes elbow and by its lateral radial attachment pronates the forearm - Flexor carpi radialis: by its distal attachment to the base of the second and third metacarpals felxes and abducts the wrist. Flexes the wrist on the left side (abduct the hand) - Palmaris longus: by its insertion into the palmar aponeurosis is a weak flexor of the wrist. The tendon that pops out when you make a fist. Value to this muscle is that you don't really need it, you can graft this tendon and repair other broken tendon of the hand. 85-90% of people have this muscle. - Flexor carpi ulnaris: by its attachments through the posiform to the hamate and base of the fifth metacarpal it flexes and adducts the wrist. Flexes the wrist on the right side (adduct the hand) - Flexor degitorum superficialis: lies slightly deeper than the above muscles and also has an origin from the radius. By its insertion on the middle phalanges of the fingers it flexes the proximal interphalangeal joints and contributes to metacarpophalangeal and wrist flexion. It goes through the wirst and breaks up into 4 tendons. These 4 tendons then insert onto the middle phalanx of the 4 digits. • Deep anterior compartment muscles - Flexor digitorum profundus: arises from the ulna and inserts on the distal phalanges of the fingers. It flexes the distal interphalangeal joint and contributes to flexon of MP and wrist. As it goes through the hand, it inserts into the distal phalanx and allows it to flex. • Has 4 parts, one to each of the digits. The that goes to the second and middle finger is innervated by the median nerve. The part that goes to the ring finger and little finger s innervated by the ulnar nerve. ** know for exam - Flexor pollicis longus: arises from the radius and inserts into the distal phalanx of the thumb It felzes the interphalangeal joint of the thumb. It flexes the interphalangeal joint of the thumb. Flexor of the thumb across the palm. - Pronator quadratus: by its origin from the distal ulna and insertion on the radius it is a strong pronator - Median nerve: as the median nerve extends into the forearm, it gives rise to a major branch called the anterior interosseous nerve. The median nerve and anterior interosseous branch innervate all the anterior forearm muscles except flexor carpi ulnaris and the medial half of flexor digitorum profundus. In the forearm, the ulnar nerve innervates flexor carpi ulnaris and the medial half of flexor digitorum profuncus. Page 7 of 11 Page 8 of 11 - Muscles of the posterior (extensor) compartment of the forearm • Superficial posterior compartment muscles: primarily arise from the lateral epicondyle and supracondylar ridge of the humerus. - Brachioradialis: by its insertion on the distal radius is a flexor at the elbow and pronates from supination, innervated by the radial nerve. Known as the tennis players muscle, as its the most used muscle for tennis players. - Extensor carpi radialis longus and brevis: by their insertion of the dorsum of the base of the second and third metacarpals they extend and abduct the wrist innervated by the radial nerve, and deep radial nerve respectively. Extensor carpi radialis longus arrise from the humerus, up on the supercondular ridge. • Tennis elbow: when the muscle gets stretched off the humerus - Extensor digitorum and extensor digit minimi: by the insertion of its tendons into the extensor hoods and proximal phalanges of the fingers of the finger, extends metacarpophlanageal and contributes to wrist extension— innervated by the deep radial nerve - Deep posterior compartment muscles: all are innervated by the deep radial nerve • Supinator: arise above from the lateral epocondyle of the humerus, then spiral laterally around the upper radius to attach to its anterior surface. Supinates the forearm in all positions of the elbow • Abductor pollicis longus: inserts into the anterior surface of the base of the first metacarpal. Abducts thumb and contributes to wrist abduction. Extensor pollicis breves: Arises from the radius and • inserts on the dorsum of the proximal phalanx joint • Extensor pollicis longus: aris from the ulna and inserts on the distal phalanx of the thumb and so extends its interphalangeal joint • Extensor indicis: contributes to extension at the metacarpophalangeal joint of the index finger Page 9 of 11 Tendons of the posterior side of the hand— Extensor hood RECAP - Extensor Compartment • Superficial layers - Brachiodialis (radia) - Extensor carpi radialis longus (radial) - Extensor carpi radials brevis (deep radial) - Extensor digitorum (deep radial) - Extensor digiti minimi (deep radial) - Extensor carpi ulnaris (deep radial) - Anconeus (radial) • Deep layer - Supinator (deep radial) - Abductor pollicis longus (deep radial) - Extensor pollicis brevis (deep radial) - Extensor pollicis longus (deep radial) - Extensor indicis (deep radial) Page 10 of 1 1 - Anatomical Snuffbox • The hallowed triangular area between the tendon of extensor pollicis longus medially and the tendons of abductor pollicis longus and extensor pollicis brevis laterally is called the anatomical snuffbox. • The skin of the anatomical snuffbox overlies the styloid process of the radius, the scaphoid, the trapezium, and the base of the 1st metacarpal. It is innervated by the superficial radial nerve (cutaneous). • The anatomically snuffbox is a highly clinically relevant surface anatomy feature because it is used to help diagnose a fractured scaphoid. - FOOSH (fall on an outstretched hand): The scaphoid is the most commonly fractures carpal. The patient commonly presents with a history of trauma to the wrist and a dull, persistent pain in the lateral part of the wrist. Tenderness upon the application of either direct or indirect pressure on the anatomical snuffbox is highly suggestive of a scaphoid fracture. This is because the scaphoid forms part of the bony floor of the anatomical snuffbox. The radial artery is also found in the floor. Indirect pressure can be applied by axial compression of the thumb toward the anatomical snuffbox • Scaphoid fractures are at risk of non-union of the fragments. This is because most of all of the scaphoid’s nutrient foramina are located on the surface of the distal half of the bone. If the fracture tears inner arteries and these inner arteries fail to reunite, the proximal fragment of the bone may suffer ischemic necrosis • Radial nerve passes through the snuff box. You can take your pulse on the snuffbox. Test to see if the radial nerve is damaged is apply pressure with a toothpick on the snuffbox and observe if the patient feels pain or pressure. Page 1 1 of 1


Buy Material

Are you sure you want to buy this material for

25 Karma

Buy Material

BOOM! Enjoy Your Free Notes!

We've added these Notes to your profile, click here to view them now.


You're already Subscribed!

Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'

Why people love StudySoup

Bentley McCaw University of Florida

"I was shooting for a perfect 4.0 GPA this semester. Having StudySoup as a study aid was critical to helping me achieve my goal...and I nailed it!"

Amaris Trozzo George Washington University

"I made $350 in just two days after posting my first study guide."

Jim McGreen Ohio University

"Knowing I can count on the Elite Notetaker in my class allows me to focus on what the professor is saying instead of just scribbling notes the whole time and falling behind."

Parker Thompson 500 Startups

"It's a great way for students to improve their educational experience and it seemed like a product that everybody wants, so all the people participating are winning."

Become an Elite Notetaker and start selling your notes online!

Refund Policy


All subscriptions to StudySoup are paid in full at the time of subscribing. To change your credit card information or to cancel your subscription, go to "Edit Settings". All credit card information will be available there. If you should decide to cancel your subscription, it will continue to be valid until the next payment period, as all payments for the current period were made in advance. For special circumstances, please email


StudySoup has more than 1 million course-specific study resources to help students study smarter. If you’re having trouble finding what you’re looking for, our customer support team can help you find what you need! Feel free to contact them here:

Recurring Subscriptions: If you have canceled your recurring subscription on the day of renewal and have not downloaded any documents, you may request a refund by submitting an email to

Satisfaction Guarantee: If you’re not satisfied with your subscription, you can contact us for further help. Contact must be made within 3 business days of your subscription purchase and your refund request will be subject for review.

Please Note: Refunds can never be provided more than 30 days after the initial purchase date regardless of your activity on the site.