04 - Vasculature Flashcards
What are the types of blood vessels and what do they do
arteries - blood away from heart
arterioles - distribute blood within tissues
capillaries - exchange of substnaces between blood and tissues
venules - drain capillary beds
veins - blood towards the heart
What are the layers of the blood vessel
1) tunica intima: lines the bv anad is in contact with the blood
- has single layer of endothelium that is glued to a basement membrane
- outermost layer is the internal elastic lamina
2) tunica media: smooth muscle and connective tissue – regulates bv diameter (vasoconstriction and vasodilation) and in small arteries can limit loss of blood (vasospasm) from a damaged vessel
3) tunica externa: tunica adventitia - anchors blood vessel to surrounding tissue
- may contain vaso vasorum
What is the difference between arteries and veins
arteries: thicker muscular layer and elastic lamina
- arterial wall tick comapred to size of lumen
- pressure vgessels –> regulate blood flow and blood pressure
veins: thin tunica intima and tunica media
- less elastic tissue, lots of collagen
- wall thickness thin compared to sie of lumen
- volume resevoirs (contain 2/3 of blood volume)
What are the two types of arteries
Elastic (conducting) arteries: largest arteries of the body
- contain an abundance of elastic fibers
- propel blood forward while ventricles are relaxing
- stretch during ventricular systole –> store energy
- elastic fiberes recoil and propel blood forward to maintain flow
Muscular (distributing) arteries: medium sized arteries
- tunica media contain more smooth muscle and less elastic tissue than elastic arteries
- greater vasoconstriction and vasodilation
- branch extensively
- range in size
Describe blood flow through the microscopic vessels
- arterioles (resistance) - fenestrated internal elastic membrane and two layers of smooth muscle cells in the intima
- metaarterioles
- pre capillary sphincter
- capillaires: smalles bv
- lack tunica media and tunica externa - capillary beds
- throughfare channels: divert blood from capillary beds
venules: drain blood from capillaries
6. postcapillary venule –> muscular venule
What are the types of capillaries
- continuous: most abundance, endothelial cells in continuous lining
- fenestrated capillary: plasma membrane of endothelial cells have small pores
- sinusoid: endothelial cells have large fenestrations and intercellular clefts (gaps)
Where are continuous capillaries found
What is the function
CNS
lungs
muscle
skin
when you dont want fluid to leak
Where are fenestrated capillaries found
What is the function
kidney
ciliary process
endocrine glands
for filtration of waste
Where are sinusoid capillaries found
What is the function
red bone marrow
liver
spleen
allow proteins and blood to pass
What are the types of pumps regulating venous return
why do we needs pumps
skeletal muscle pump: contraction of skeletal muscle
respiratory pump: diaphram moving up –> more pressure –> abdominal vein compression
very low pressures in venous circuit
What are the types of capillary exchange
diffusion: through endothelial cells or through intercellular clefts
- O2, CO2, glucose
transcytosis: substances endocytosed from blood by endothelial cells (lipid soluble mol)
bulk flow: passive process by pressure –> large # of ions, mols, particles dissolve in fluid and move
- filtration (out of capillary)
- reabsorption (into capillary)
What are the divisons of the aorta
arch of aorta
ascending aorta
thoracic aorta
abdominal aorta
what are the unpaired branches of the abdominal aorta
celliac trunk: liver, stomach, spleen, duodenum, pancreas
superior mesenteric artery: small intestine, 2/3 of large intestine
inferior mesenteric artery: distal 1/3 of large intestine
what are the paired branches of the abdominal aorta
suprarenal arteries: adrenal glands
renal arteries: kidneys
gondal arteries: ovaries/testes
lumbar artery: vertebrae, body wall
what are the systemic veins returning blood to the heart
superior vena cava: head, neck, chest, upper limbs
coronary sinus: myocardium - coronary circulation
inferior vena cava: abdomen, pelvis, lower limb
