blood vessels Flashcards
what is the composition and function of tunica intima (interna) blood vessel layer
It is the inner lining made of edothelial cells and basement membrane for all blood vessels
its job is to reduce friction for blood flow
what is the composition and function of tunica media
It is the middle layer made of smooth muscle and elastic tissue for arteries, arterioles, and veins/venules
Its job is to allow the blood vessel to constrict
what is the composition and function of tunica adventitia (externa)
it is the outer layer made of collagen for arteries, arterioles, and veins/venules
Its job is to protect and anchor the blood vessels to surrounding structures
what is the anatomical difference between arteries and veins
arteries are located deep within the body and have thick walls, veins are closer to the surface and have thin walls
what are the functions of the arteries
- they transport oxygenated blood away from the heart to tissues, with the exception of the pulmonary artery that transports deoxygenated
- elastic arteries (conducting) act as pressure reservoirs
- muscular arteries (distributing) contract and dilate for blood flow
what are the functions of arterioles
- they push blood flow into the capillaries
- they are resistance vessels, meaning they can slow blood flow from their high resistance
what are the functions of capillaries
- they transport blood, nutrients, and oxygen
what are the location and functions of continuous capillaries
-location: muscles, skin, connective tissue, lungs, brain
-allow transport of h20, ions, and glucose
(have intracellular clefts to let things in)
what are the locations and functions of fenestrated capillaries
-location: kidneys, small intestine, endocrine glands
-allow transport of h20, ions, glucose, other SMALL solutes
(have intracellular clefts to let things in)
what are the locations and functions of sinusoid capillaries
-Location: bone marrow, spleen, liver
-allow transport of h20, ions, proteins, blood cells, small solutes
(have intracellular clefts to let things in)
how does blood flow through capillary beds and what mechanisms are used to alter it
blood flow is controlled by the diameter of terminal arteriole, arteriole will be dilated when blood needed and constricted to shunt away blood when not needed
-metarterioles connect arterioles to capillaries
-precapillary sphincters are used to increase/decrease blood flow depending on the bodys needs
what does vascular shunting do to get blood to the rest of the body and how is it done
blood will be diverted to active areas and diverted away from inactive areas, this is done by vasoconrtsiction and vasodilation
ex: sends blood to muscles and brain when working out
what are the three ways capillary exchange is done and how do they work
This is exchange from blood to interstitial fluid
diffusion: exchanges things from high to low concentration, either through endothelial cells or clefts/fenestrations
transcytosis: exchanges larger substances that cannot diffuse through on their own (hormones, antibodies)
Bulkflow: large number of molecules move together at a fast rate, high pressure to low pressure
what is the difference between hydrostatic pressure and osmotic pressure in capillary beds
hydrostatic is pushing water in/out
osmotic is sucking proteins in/out
what factors assist with blood being returned to the heart
-veins help to transport blood from tissues back to the heart
-skeletal muscle pump uses the skeletal muscles to push blood up by contracting
-respiratory pump pushes blood back to the heart by inhaling
-sympathetic venoconstriction helps by having smooth muscle constrict to push blood back up
how does resistance, viscosity, and vessel length impact blood flow
high resistance = low blood flow
high viscosity =high resistance = low blood flow
high vessel length = high resistance = low blood flow
how does blood vessel surface area impact velocity
high surface area will give low velocity of blood flow, this is good for the exchange of blood through capillaries
low surface area will give high velocity of blood flow
how do pressure gradients impact blood flow
blood flows from high to low pressure
there is small flow when there is not a big difference (40) in pressure
there is large flow when there is a big difference (80) in pressure
there is equal flow when there is only a 20 difference in pressure
there is no flow when there is the same pressure on both sides
how does vessel composition and compliance affect pressure in arteries in veins
veins have more compliance than arteries
high compliance when a large volume change causes a small pressure change
low compliance when a large volume change causes a large pressure change
what is the difference between systolic and diastolic pressure
systolic = high
diastolic = low
what is mean arterial pressure (MAP) and its factors
it is determined by cardiac output and total peripheral resistance
stroke volume, heart rate, and TPR increase MAP
MAP is low when blood goes away from the heart
what happens in hyper tension
you have high blood pressure
this is persistent in obese people
heart attack or heart failure can happen
what happens in hypo tension
you have low blood pressure
this usually happens with aging
shock (low oxygen, rapid breathing/pulse) can happen
how do edemas form
from a abnormal increase of interstitial fluid
if you have high plasma osmotic compared to interstitial do things leave/stay and is it neg/pos
it will be negative and things would stay
if you have high plasma hydrostatic compared to interstitial do things leave/stay and is it neg/pos
it will be positive and things will leave
