Circulatory System Flashcards
What is the function of capillary beds?
Are a network of capillaries that extend between the arterioles and the venules (small veins) between tissues.
Venules collect deoxygenated blood from the capillary beds in the tissues and return it to the heart in veins.
What is the function of capillaries?
Small, thin walled, permeable vessels.
- Exchange of gases take place here
- Uptake of nutrients
- Removal of metabolic waste products
- Small diameter, blood flows slowly through them.
What is the function of veins?
Thin walls, carry deoxygenated blood under low pressure, smooth muscle.
- Veins carry blood towards the heart.
- Carry deoxygenated blood under low pressure
- Collapsible blood vessels
- Contain valves to prevent back flow
Exception is pulmonary vein which carries oxygenated blood from lungs to the heart.
What is then function of the arteries?
Thick walls, muscular, capable of withstanding blood under pressure.
- carry blood away from the heart under pressure
- oxygenated blood
Exception is pulmonary artery which carries deoxygenated blood to the lungs
What is the function of blood?
1- carries food materials from digestive tract to tissues
2-removes waste products and transports them to the organ or excretion
3- transports O2 from lungs to tissues
4-transports co2 from tissues to lungs
5-distributes heat around body
6-combats infection
Name the vessel that carries oxygenated blood to the heart muscle.
Coronary arteries
Name the vessel that carries deoxygenated blood to the lungs.
Pulmonary artery
Name the vessel that supplies the brain with oxygenated blood.
Aorta or carotid artery
What vessel carries oxygenated blood to the liver? And which vessel carries deoxygenated blood away from it?
To the liver- Hepatic artery
Away from liver- Hepatic Vein
What vessels carry blood to and away from the gut?
To the gut- Mesenteric artery
Away from gut- Hepatic portal bein
What vessels carry blood to and away from the kidneys?
To kidneys- Renal artery
Away from kidney- Renal vein
What vessels carry blood to and away from the hind limbs?
To hind limbs- Femoral artery
Away from hind limbs- iliac vein
What vessels carry blood to and away from the fore limbs?
To fore limbs- subclavian artery
Away from fore limbs- subclavian vein
What vessels carry blood to and away from the brain?
To the brain- carotid artery
Away from brain- jugular vein
What is the order blood would flow through vessels in?
Heart Aorta Other arteries Arterioles Capillaries Venules Other veins Vena cava Back to heart
Why would blood flow backwards in a vein of there were no valves?
As there is no pulse and blood is at a low pressure so there is a tendency for blood to pull backwards
How is the movement in veins brought about?
By the contraction of surrounding muscles and also gravity.
How thick is the wall of the capillary?
Very thin, one cell thick
What substances pass out of the capillary walls to surround the tissues?
Water, oxygen, salts, amino acids, glucose ect
What is tissue fluid?
It is the clear fluid that surrounds the cells of tissues. Formed by blood plasma
How do lymphatic vessels differ from capillaries?
Similar in structure having only one cell thick.
Main difference: capillaries carry blood, lymph vessels carry lymph
What is capillary refill time?
The time taken for colour to return to external capillary bed after pressure is applied
What is the possible cause of a pale or white mucous membrane?
Low blood circulation
What is the possible cause of a blue-grey mucous membrane?
Respiratory problems
