Anatomy Introduction to the cardiovascular system Flashcards
How many layers do all arteries and veins have
3 layers
what are the 3 layers of arteries and veins
- tunica intima
- tunica media
- tunica adventitia
How many layers do capillaries have
1 - tunica intima
describe the structure of the tunica Intima
- Basement membrane
- Endothelium – simple squamous
- Endothelial function – vasoactive/minimizes friction – smooth surface for the blood to flow across
describe the structure of the tunica media
- Circular smooth muscle – mostly made up of smooth muscle
- Collagen and elastic fibres
- Vaso-constriction/dilation
Describe the structure of the tunica adventitia
- Connective tissue elastin and collagen
- Protects, strengthens, anchors
- Vaso vasorum – most blood vessels are thin so can get oxygen by diffusion but in the thick blood vessels the walls are too thick so the vaso vasorum are blood vessels in the blood vessels that take the oxygen to the blood vessel
- This is where autonomic nerve fibres are present here this controls vasco constriction and vaso dilation
what are the 2 types of arteries
elastic/conducting artery
muscular distributing artery
where do the elastic conducting artery originate from
they come out of the heart
where does the muscular distributing artery come from
they are the main named arteries
describe the structure of the elastic conducting arteries
- Large tunica media – made predominantly of smooth muscle not elastic fibres due to volume of blood that they are receiving
- Large amount of elastin
- Own blood supply vasa vasorum
- Aorta – arteries that leave the heart
describe the structure of the muscular distributing artery
- Large tunic media with IEL and EEL – made up of predominantly smooth muscle
- Elastic tissue condensed into two bands there is the internal elastic lamina and external elastic lamina
- Large amount of smooth muscle
- Renal artery
describe the arteriole structure
- Narrow lumen
- Large number of smooth muscle
- Direct blood into capillary beds
Describe the structure of the capillary
- Do not have three layers
- Only have one layer – tunica intima
- Simple endothelial tubes
- Specialised for exchange of nutrients
- Lumen; 7microns or less
- No adventitia or media layers
describe the structure of the veins
- Venules and veins have a larger lumen and thinner walls than corresponding arteries
- Valves – helps blood flow in one direction
- Developed tunica adventitia
- Has a lower pressure than arteries
describe how the musculovenus pump works
- Venous return to the legs is aided by muscular contraction
- Valves keep it flowing in one direction and prevents backflow
- Veins in the lower limb are placed in between muscles so when the skeletal muscles contract is squeezes the vein and helps contract the vein and pushes the blood up towards the heart
How do you differentiate between arteries and veins
- Artieres = away from the heart (most carry oxygenated, except in pulmonary)
- Veins = towards the heart (most carry deoxygenated)
describe the blood flow through the heart
- Deoxygenated blood enters the heart through the superior and inferior vena cava
- Superior – head neck upper limbs
- Inferior – lower limbs abdomen
- Bring it to the right atria
- Right atria goes to the right ventricle, passes through tricuspid valve (3 parts to it)
- From the right ventricle travels through pulmonary valves and goes into the pulmonary trunk
- The pulmonary trunk splits into 2 vessels the left and the right pulmonary arteries – carry deoxygenated blood towards the lungs
- The blood back form the lungs are oxygenated
- Travels into the pulmonary vein (4 of these) they drain in the left atria
- Goes into the left ventricle through the mitral valve
- Passes through the aortic valve into the ascending aorta and then into the arch of the aorta
- Aorta on picture to the right side (your left), pulmonary trunk to the left side (your right)
what are the 3 vessels that lead of the arch of the aorta
1 = brachiocephalic artery - right subclavian artery and right common carotid artery 2 = left common carotid artery 3 = left subclavian artery
what does the brachiocephalic artery split into to
right subclavian artery
right common carotid artery
what does the brachiocephalic artery supply
head, neck, arm on the right hand side
what does the left common carotid artery supply
- head and neck on the left hand side