L7/L8 Flashcards
Endothelium of Vasculature definition
epithelial cells that make up inner layer of blood vessels
the endothelium is surrounded by ___ which does _
basement membrane which supports cells
basement membrane is surrouned by ___ which does _
smooth muscle which is responsible for vasoconstriction and dilation
smooth muscle cells are surrounded by __ which does _
connective tissue
>elastic: stretches with incoming blood
>fibrous: fights the pressure from blood flow
vascular tone
partial contrcation of blood vessles in smooth muscles
Types of Arteries
- elastic
- muscular
elastic vs muscular arteries
-elastic
>have more elastic connective tissue
>large diameter
-muscular
>have more smooth muscles
>medium diameter
elastic arteries function
pressure reservoirs
>stretch to store pressure & recoil to release
muscular arteries function
vasocontriction/dilation and distributing blood to organs
large vs small arterioles
-large: have less fibrous connective tissue
-small: smaller diamter making it a resistance vessel
>increased blood flow resistance b/c increased friction
capillaires function
exchange vessels
>because exchange nutrients and waste between blood and tissue cells
capillaries structure
thin walls with pores in endothelial to basement membrane
capillary bed
10-100 capillaries
metarteriole
in capillary bed can bypass it
at capillary junction with arterioles or metarterioles there are
precapillary sphincters
>they open and close to impact blood flow
>usualy 5-10 times per minute (vasomotion)
capillary types
- continuous
- fenestrated
- sinusoids
continuous capiilaries function
PM is continous with intercellular clefts
>ion/water permeable
continuous capiilaries location
muscle, connective tissue and lungs
fenestrated capillaires function
have fenestrations (cyclindrical pores that increase permeability)
fenestrated capillaires location
kidneys, small intestine and endocrine glands
sinusoids capillaires function
wide/winding with large fenestrations
>very permeable
sinusoid capillaries location
bone marrow, spleen and liver
venules post capillary vs larger
- post capillary: samller, endothelium & basement membrane with pores
- larger: thick walls, smooth muscle and fibrous connective tissue
veins layers
-less elastic connective tissue and less smooth muscle than other vasculature
veins structure
valves prevent back flow
>malfunction leads to varicose veins
what is the relationship between veins and skeletal musclels
skeletal muscles contract to help move blood back to the heart (skeletal muscle pimp)
what is milking your veins
>valves?
stand on your tippy toes then on your heel
> distal valve -(blood)-> poximal valve
blood reservoirs
mostly systemic veins and venules (64% of blood)
>increased activity -> venoconstriction -> reduced blood reserves -> increased blood flow to skeletal muscles
Diffusion in capillaries purpose
diffuse nutrients, gases and wastes between blood and interstital fluid
what kind of capillaries allow diffusion of plasma proteins and blood cells
sinusoids
>via intercellualr clefts
transcytosis (rarer) in capillaries
blood -(substances)-> vesicle -(endocytosis) -> endothelial cells -> (exocytosis)
>ex: hormones and antibodies
bulk flow in capillaries definition
greater movement rates than diffuse BUT passive transport
>blood capillaries -(filtration)-> interstitial fluid
>blood capillaires interstital fluid
Starling forces
-pressures that determine bulkflow >capillary hydrostatic >interstitial fluid hydrostatic >plasma colloid osmotic >interstital fluid colloid osmotic
net filtration pressure in capillaries definition
indicates direciton of fluid movement
> + means outward
> - means inward
net filtration pressure in capillaries formula
NFP = (capillary hydrostatic + interstitial fluid colloid osmotic) - (plasma colloid osmotic + interestital fluid hydrostatic)
Lymphatic system components
lymph, lympathic vessels, lymphoid organs/tissues
lymphatic system functions
> drains excess interestitial fluid: via lymapthatic vessels
returns filtered plasma proteins to blood: via lymphatic capillaires (increases permeability)
carries out immune response (microbes & adnormal cells)
transports dietary lipids: GI tract to blood (via lymphatic vessels)
lymphatic capillaries vs blood capillaries
> more permeable (endothelial cells do not attached end to end)
larger
lymphatic vessels vs veins
> thinner walls
>both have valves
lymph fluid flow
> blood capillaires -(blood)-> interstital spaces -(interstitual fluid)-> lymphatic capillaries -(lymph)-> larger lymphatic vessels -(lymph)-> venous circulation
lymph fluid mechanisms of flow
> smooth miscle contractions
skeletal muscle pump
respiratory pump
capillary hydrostatic
filtration or reabsorption?
filtration
capillary hydrostatic what is it?
pressure from water on outter capillaries
interstitial fluid hydrostatic filtration or reabsorption?
reabsorption
interstitial fluid hydrostatic what is it?
pressure from water on outer capillaries
capillary plasma colloid osmotic filtration or reabsorption?
reabsorption
plasma colloid osmotic what is it?
plasma in blood
interstital fluid colloid osmotic filtration or reabsorption?
filtration
interstital fluid colloid osmotic what is it?
plasma in interstitial fluid
