Blood Vessels Structure Flashcards
What is the artery wall,structure
Thick and muscular
What is the artery endothelium structure like
Present but folded
What is the artery lumen structure like
Narrow
What is the artery elastic content like
High
Does the artery have valves
No
What is the artery pressure like
High
When does pressure in arteries drop
When ventricles relax,but stays quite high due to elastic recoil of walls
In the artery what decreases with distance from the heart
Pressure,as there is resistance with blood flow due to friction with the larger surface area of walls and dissipation of energy in elastic recoil
Why are artery Walls thick
To resist pressure
In the artery what does the thick layer of elastic tissue stretch with
High pressure pulse then recoils maintaining pressure pushing blood out further and smooths out the flow
In the artery what does narrow lumen maintain
Pressure
In the artery what does thick muscle prevent
Rupture
What is the Wall structure like in the vein wall
Thin
What is the endothelium like in the vein
Present and not folded
What is the lumen structure like in the vein
Wide
What is the elastic content like in the vein
Low
Are ther valves in the vein?
Yes
In the vain what does a large volume result in
Low flow rate
What is the pressure like in the vein
Pressure is always low,
why do the vein walls not need thick muscle
Pressure is low
What are the vein walls squeezed by and why
The skeletal muscle and breathing movements to push blood
Why is the lumen wide
To fit large volume of blood and lower resistance
What do valves in veins ensure
No backflow
what is elastic recoil
the inherent resistance of a tissue to changes in shape, and the tendency of the tissue to revert to its original shape once deformed
what do capillaries form as exchange surfaces
capillary beds which are many branched capillaries
what is a capillaries diametre like
narrow to slow blood flow
what about capillaries narrow diametre maximises diffusion
red blood cells can only just fit through and are squashed against the walls
when comparing arterioles to arteries what is the muscle layer like when comparing the two
the arterioles muscle layer is thicker than arteries to help restrict blood flow inot the capillaries
what is the elastic layer like in the arterioles compared to the arteries
thinner than in the arteries as pressure is lower
what is wall thickness like in the arterioles compared to the arteries
thinner,as pressure is slightly lower
do arterioles have valves
no
do capillaries have a muscle layer
no
what is the structure of the capillaries elastic layer like
doesnt have one
what is the capillaries wall thickness like
one cell thick, consisting of only a lining layer
why is the capillary wall thickness advantageous
this provides a short diffusion distance for exchanging materials between the blood and cells
from right to left what makes up a capillary bed
artery,arterioles,capillaries,venules,vein
