Circulation Flashcards
Vasodilation is caused by
Parasympathetic
Vasoconstriction is caused from
Sympathetic
Increase resistance =
Increase BP
Elasticity
⬆️elasticity = ⬇️BP ⬇️elasticity = ⬆️BP
Hydrostatic BP
Arteriole end of capillary bed
Colloid osmoid pressure
Venule end of capillary bed
Blood vessel walls
Tunica interna-smooth endothelial lining
Tunica media-contains smooth muscle for dilation & constriction
Tunica Externa-collagen fibers
Arteries
Elastic
Muscular
Arterioles
Capillaries
Site of gas and nutrient/waste exchange between blood & tissues
3 types of capillaries
Continuous-skin muscles & BBB
Fenestrated-more permeable, absorption, filtration
Sinusoids-very permeable, large fenestrations, let in bacteria, found in liver bone marrow, lymph
Veins
Have lower BP than artery. Thin walls.
Low oxygen causes
Precapillary sphinxters to open
MAP
Mean arterial pressure
MAP=diastolic + 1/3 pulse pressure
Pulse pressure
Difference between systolic-diastolic
After load
⬇️BP=⬇️SV=⬆️HR
Chemicals that increase BP
NE/Epinephrine
ADH-⬆️blood volume
Angiotensin II -potent vasodilator
Chemicals that decrease BP
ANP- produced by heart
Nitric oxide-vasodilator
Inflammatory chemicals
Alcohol-inhibits adh
Short term BP regulation
Responding to ⬆️BP- baroreceptors in carotid & aorta stretched
Sympathetic is inhibited & parasympathetic increased
⬇️BP-baroreceptors are inhibited. Sympathetic increased
Long term BP regulation
If BP falls renin is released
Renin➡️Angiogensin II(vasoconst)
Angiotensin II releases aldosterone from adrenals
Aldosterone stimulates kidneys to absorb Na+ water follows
The water ⬆️BV & BP
Net filtration pressure
Movement of fluid and nutrients at capillary beds. Controlled by hydrostatic & colloid osmotic pressure
