Lec #7 Cardiovascular Flashcards
What is angiography?
- looking at blood vessels
How many layers do blood vessels have?
3 layers (tunics)
What are the 2 types of arteries?
Elastic (conducting)
Muscular (Distributing)
Which is larger elastic or conducting arteries
Elastic is largest artery in body
Elastic arteries are said to have ‘high compliance’ what does this mean?
- can stretch alot without tearing
What is the composition of muscular arteries?
- more smooth muscle than elastic fibers (can contract to inc blood pressure)
What is an anastomoses?
Union of 2 or more branches of arteries supplying the same region
- can occur between veins and arteries aswell
Which type of artery does not form anastomes?
end arteries do not
What are arterioles
- small arteries
Precapillary Sphincter
- controls blood flow into capillary beds.
What are capillaries/what do they do?
- exchange between blood and interstitial fluid (20 billion of them)
- lacks a tunica media and externa.
What does fenestrated mean?
- small holes
What is a capillary bed?
network of 10-100 capillaries from a single metarteriole.
- increases gas exchange (larger surface area)
What allows for the largest amount of gas exchange?
sinusoids
What are venules?
- drains the capillaries (2 types)
- Postcapillary (exchange of nutrients and waste) and Muscular venules (no exchange).
What does it mean when venules are ‘distensible’
distensible - good reservoir of blood (majority of blood in venous system)
What is the biggest vein in body?
IVC
What is biggest artery?
aorta
Which has a thinner tunica media? veins or arterys?
- veins have alot less smooth muscles/elastic tissue (therefore, thinner tunica media)
Which direction do the cusps in the veins point?
- towards the heart
What causes varicose veins?
- valves in veins not fully closing - blood can go backwards and cause vein to buldge.
Where is a majority of the blood in body stored?
majority in the venous system (good reservoirs - big lumens)
What forces determine the flow of tissues in the body?
Starling forces -> Hydrostatic (pushes fluid out) and osmotic forces (pulls fluid in)
How does filtration occur?
- Blood Hydrostatic Pressure (BHP) -> pushes fluid out of capillaries into interstitial fluid
Interstitial Fluid osmotic pressure (IFOP) - pulls fluid out of capillaries into interstitial fluid
