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

Week 3 Notes

by: Austin Miller
Austin Miller
GPA 3.6

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

Week 3 Notes for BSC 216
Human Anatomy & Physiology II
Austin Hicks/Jason Pienaar
Class Notes
25 ?




Popular in Human Anatomy & Physiology II

Popular in Biological Sciences

This 8 page Class Notes was uploaded by Austin Miller on Monday January 18, 2016. The Class Notes belongs to BSC 216 at University of Alabama - Tuscaloosa taught by Austin Hicks/Jason Pienaar in Winter 2016. Since its upload, it has received 17 views. For similar materials see Human Anatomy & Physiology II in Biological Sciences at University of Alabama - Tuscaloosa.

Similar to BSC 216 at UA

Popular in Biological Sciences


Reviews for Week 3 Notes


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: 01/18/16
VESSELS & CIRCULATION Blood Vessels:  Arteries are the efferent pathways that carries blood away from the heart and branches out along the way  Veins are the afferent pathways that carry blood back to the heart and converge along the way  The only vessels that come in close contacts to tissues and exchange gas and nutrients are capillaries. Capillaries take the oxygen rich blood from the arteries, use what they need, and send the rest through the veins and back to the heart Structure of Blood Vessels: 1. Tunica intima (interna): a. Innermost tunic b. Direct contact with the blood c. Endothelium= squamous epithelial tissue d. Endothelium is slippery so it can minimize friction for the blood e. Internal elastic lamina is for distensibility 2. Tunica media: a. Middle tunic b. Circular smooth muscle along with elastin c. Controlled by sympathetic nervous system d. Vasoconstriction: smooth muscle contracts and lumen diameter is reduced e. Vasodilation: smooth muscle relaxes and lumen diameter increases f. Helps control blood pressure with it’s extensibility 3. Tunica externa (adventitia): a. Outermost tunic b. Collagen fibers responsible for protection and anchoring c. Possesses nerve fibers, lymphatic vessels d. Vasa vasorum is the network of tiny vessels that nourish the tunica externa and media Structure of Arteries: 1. Elastic arteries: thick-walled, near heart (aorta + branches) a. Lumen has the largest diameter of all arteries b. High in elastin content; present in all three tunics c. Elastin content allows expansion and retraction in response to blood from heart d. Will be directly off heart (aorta) to deal with the high pressure of blood being pumped from the ventricles 2. Muscular arteries: deliver blood to organs, these are most of our arteries a. Thickest tunica media of all vessels; intermediate lumen diameter b. More smooth muscle, less elastin in tunica media than elastic arteries c. Better at vasoconstriction (moving blood) 3. Arterioles: deliver blood to capillary beds within tissues a. Lumen has smallest diameter of all arteries b. Tunica media mostly smooth muscle; few elastin fibers 2 Structure of Veins: 1. Venules: result from convergence of capillaries a. Endothelium plus some surrounding connective tissue b. Highly porous (fluid and WBC’s freely move across walls) c. Larger venules have smooth muscle layers (tunica media) and thin tunica externa 2. Veins: result from the convergence of venules a. 3 tunics b. Walls thinner and lumens larger than arteries c. Very little smooth muscle in tunica media d. Thick tunica externa with thick collagen fibers and elastic fibers e. Blood pressure lower in veins but the large lumens provide little resistance to blood flow to return it to the heart f. Venous valves are extensions of the tunica intima (similar in structure to the semilunar valves of the heart) 3 Blood distribution in Cardiovascular System: Circulatory Routes: 4  As far as circulatory routes go, we see three different options in our body. 1. Simple Pathway- a. This pathway only sees one, single capillary bed and will travel from the heart  arteries  arterioles  capillaries  venules  and finally veins before retuning back to the heart b. This is the simplest, and most common pathway! 2. Portal System- a. Blood flows through two consecutive capillary networks before returning to the heart i. Between hypothalamus and anterior pituitary ii. In kidneys iii. Between intestines and liver 3. Arteriovenous anastomosis (shunt)- a. Artery flows directly into veins, bypassing capillaries i. In our fingers and toes to reduce heat loss (but can lead to frostbite) b. Venous anastomosis is the most common anastomosis where one vein empties directly into another. This is why vein blockage is less serious than arterial blockage. c. Arterial anastomosis is where two arteries merge and provide collateral (alternative) routes of blood supply to the desired tissue. This is in coronary circulation and around joints 5 (a) Simplest  pathway       (1 capillary  bed) (c)  Arteriovenou s       anastomosis      (shunt) (d) Venous (e) Arterial              anastomose anastomose s s Basic Terms of Circulation Physiology:  Blood flow- volume of blood flowing through a vessel, organ, or entire circulation in a goven period o For entire vascular system cardiac output = 5-6 L/min  Blood flow (F) ~ BP gradient (P)/Resistance (R) o This is the same as saying the greater the pressure difference between two points, the greater the flow. o The greater the resistance, the less the flow. 6  Pressure gradient (P) = Cardiac output (CO) x Peripheral Resistance (PR) o Cardiac output (CO) = stroke volume x heart rate o Stoke colume is the volume of blood expelled from the heart with each ventricular contraction aka how much blood is leaving the heart (b) Portal sure is the force per unit area exerted system by blood on a vessel wall (mmHg) and typically refers to arterial blood pressure in aorta and its       (2 capillary  beds)nches. We would NOT want to measure this in the veins since the venous bp is much lower. Blood flows from high to low pressure. Peripheral Resistance  Vessel radius: most powerful influence on blood flow o The only significant way of controlling peripheral resistance o Vasomotion- change in vessel radius  Vasoconstriction- by muscular effort that results in smooth muscle contraction  Vasodilation- by relaxation of the smooth muscle o Vessel radius affects blood velocity o Laminar flow- flows in layers, with the center flowing the fastest o Blood flow (F) is proportional to the fourth power of the radius (r)  Arterioles can constrict to one-third of fully relaxed radius  If r = 3mm, F = 81 mm/sec; If r = 1 mm, F = 1 mm/sec 7 8


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!"

Janice Dongeun University of Washington

"I used the money I made selling my notes & study guides to pay for spring break in Olympia, Washington...which was Sweet!"

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.