Lecture 3A Flashcards
Why is the Aortic wall distensible?
Because it has a large amount of elastic tissue
5 sections of the Aorta
- Ascending Aorta
- Aortic Arch
- Descending Aorta
- Thoracic Arch
- Abdominal Aorta
Where is blood pressure at its highest under normal conditions?
Ascending Aorta
Name the three layers of an artery
- Tunica Intima
- Tunica Media
- Tunica Externa (or adventitia)
What layer contains the CT of the artery?
Tunica externa
Which layer houses the endothelium of the artery
Tunica Intima
Which layer contains the smooth muscle and elastic tissue of an artery
Tunica Media
What is the site of the greatest resistance and largest pressure drop in the circulation?
Arterioles
What can induce a change in the the radius of an artery or arteriole
- Autonomic nervous system
- Circulating hormones (Angiotensin II, Vasopressin)
- Local Vasoactive substances
- Other (e.g. temperature)
which vessels have the greatest total cross-sectional and surface area?
Capillaries
Endothelial cells in capillaries may have small pores called what?
Fenestrations
Merged capillaries form what?
Venules –> Veins
Do arteries or veins have the thinner wall?
Veins
Which vessel (arteries or veins) operate under Lower pressures?
Veins
Which vessels contain the highest proportion of blood in the cardiovascular system at any given time
Veins
The superior and Inferior Vena cava are collectively called what?
Vena Cavae
What do the Vena Cavae do?
Drain deoxygenated into the right atrium
What is the largest vein in the body
Inferior Vena Cava
The inferior portion of the the Inferior Vena Cava begins at what juncture
Juncture of the Common Iliac veins
The superior vena cava is formed by what two veins?
The convergence of the Right and Left Brachiocephalic veins
The Celiac trunk of the abdominal aorta supplies blood to what structures (6)
- Liver
- Gallbladder
- Stomach
- Spleen
- Pancreas
- Duodenum
What branch of the abdominal aorta supplies blood to the small intestine and the large intestine
Superior Mesenteric
What branch of the abdominal aorta supplies blood to the Large Intestine and Rectum
Inferior Mesenteric
What is the Hepatic Portal System
- Blood from abdominal parts of GI system and spleen pass through this secondary venous system which drains in the liver before ultimately returning to the right atrium of the heart
