Maintains high blood pressure-increase oxygen supply to tissues, lower pressure- reduces build up of tissue fluid in lungs, systemic system-
1 of 10
What are the features of an artery?
Thick layer of smooth muscle to withstand high pressure and elastic tissue to maintain pressure - narrow lumen - smooth endothelium lining to reduce friction - collagen, connective tissue to resist over stretching
2 of 10
What are the features of a vein?
valves to prevent back flow - large lumen to reduce resistance flow - thin layer of smooth muscle and elastic tissue as blood is at a lower pressure - smooth endothelium lining to reduce friction
3 of 10
What are the important features of a endothelium? (inner most layer)
Once cell thick providing a short diffusion pathway, reduces friction and provides minimal resistance to blood flow
4 of 10
What is the important feature of elastic fibres and smooth muscle? (middle layer)
The smooth muscle with stands high blood pressure and the elastic fibres means elastic recoil maintains the blood pressure and aids pumping
5 of 10
how do valves work?
Blood above the valve tries to flow back - blood fills the pockets - this forces the valve to shut
6 of 10
give the function of the tendinous chords in the heart
Prevents the valves inverting by keeping tension on them
7 of 10
What is the first step of the cardiac cycle?
1. Atrial systole- Both atria contract at the same time, blood flows from the atria to the ventricle. Back flow is prevented by closure of valves in veins.
8 of 10
What is the second step of the cardiac cycle?
2. Ventricular systole- Both ventricles contract. The atrio-ventricular valves are pushed shut by pressurised blood in the ventricles. The semi lunar valves in the aorta and pulmonary artery are pushed open. Blood flows from the ventricles->arteries
9 of 10
What is the third step of cardiac cycle?
3. Ventricular diastole- Atria and ventricles relax. The semilunar valves in the aorta and pulmonary artery are pushed shut. Blood flows from the veins through the atria and into the ventricles
10 of 10
Other cards in this set
Card 2
Front
What are the features of an artery?
Back
Thick layer of smooth muscle to withstand high pressure and elastic tissue to maintain pressure - narrow lumen - smooth endothelium lining to reduce friction - collagen, connective tissue to resist over stretching
Card 3
Front
What are the features of a vein?
Back
Card 4
Front
What are the important features of a endothelium? (inner most layer)
Back
Card 5
Front
What is the important feature of elastic fibres and smooth muscle? (middle layer)
Comments
No comments have yet been made