Blood Circulation Flashcards
What is the role of arteries in the body
carry oxygen-rich blood from your heart to your body
What are arterioles?
Smaller than arteries and connect to the capillaries
What do capilaries connect
Connect the arterioles to the veins
What is the role of veins
Carry blood back into the heart
Why is the muscle layer thicker in arteries
Thicker than veins so that constriction and dilation can occur to control volume of blood.
What is the muscle layer like in veins
Relatively thin so it cannot control the blood flow
What is the elastic layer like in arteries
Thicker than veins to help maintain blood pressure. The walls can stretch and recoil in response to the heart beat
What is the elastic layer like in veins
Relatively thin as the pressure is much lower
What is the wall thickness in arteries
Thicker wall than veins to help prevent the vessels bursting due to the high pressure
What is the wall thickness like in veins
Thin as the pressure is much lower so there is less risk of bursting. The thinness means the vessels are easily flattened which helps the flow of blood up to the heart
What is the pulmonary artery
Carrying deoxygenated blood from the heart to the lungs
Why does the artery contain alot of elastic fibres
so they can stretch to accommodate the greater volume if blood without being damaged
What does the capillary network link
the arterioles and the venules
What is the positive of the capillary diameter being small
blood travels slowly through them giving more opportunity for diffusion to occur
What is the muscle layer like in capilaries
No muscle layer
What is the elastic layer like in capillaries
No elastic layer
What is wall thickness like in capilaires
one cell thick consisting of only a lining layer. This provides a short diffusion distance for exchanging materials between the blood and cell
Does capilaries have valves
No
What is the muscle layer like in arterioles
Thicker than in arteries to help restrict blood flow into the capillaries
What is the elastic layer like in arterioles
Thinner than in arteries as the pressure is lower
What is the wall thickness like in arterioles
relatively thick muscular walls because blood pressure in them is high
Does the arterioles have valves
No
What is the role of veins
Carry blood back towards the heart
What is the role of the inferior vena cava
large vein that carries the returning blood from the lower parts of the body to the hearts
What is the role of the superior vena cava
large vein that carries the retutning blood form the upper part of the body to the heart
What is the semi lunar valves
valves found at frequent intervals throughout the venous system to prevent the back flow of blood
What are peripheral arteries
arteries further away from the heart but before the arterioles
What do the atrioventricular valves do
control the flow of blood between the chambers of the heart
What is the role of the pulmonary aterey
The pulmonary arteries carry blood from the right side of the heart to the lungs.
How does fibre low blood chlosteral levels
Lower BMI which reduces BP
Fibre helps to lower absorption of cholesterol and increase excretion of cholesterol
Low cholesterol level reduces the chance of atherocloris
