Blood Flow Flashcards
Methods of capillary exchange
Diffusion
Transcytosis (vesicles)
Filtration
Fluids move out of capillaries to interstitial fluid
-Arterial end
Absorption
Fluids move from interstitial into capillaries
-Venous end
Hydrostatic Pressure
Forces fluid out of the capillary
Colloid osmotic pressure
Proteins inside the capillary pull fluid inside
Arterial End
Net filtration
Hydrostatic pressure b/c of blood pressure
Venous end
Net absorption
-Osmosis causes high colloid osmotic pressure
Korotkoff Sounds
- Snapping sound first heard at systolic pressure
- Murmurs heard for most of area b/w systolic and diastolic
3-4. Pressures w/in 10mmhg above diastolic bp (thumping and muting) - Silence as cuff drops below diastolic pressure
Pulse Pressure
Difference felt b/w diastolic (feel nothing) and systolic (feel a thump as artery expands)
-systolic-diastolic
Mean Arterial Pressure (MAP)
average arterial pressure during cardiac cycle
-diastolic + 1/3 pulse pressure
Regulates blood pressure
CVCC
regulates heart rate, force of contraction, and arteriole diameter
Baroreceptors
Mechanoreceptors in aorta and carotid arteries that detect stretch
- continuous action po. at normal bp
- Stretching sends action po. to brain at higher freq
- causes decrease in hr, decrease in force of contraction, and vasodilation of arterioles
Orthostatic Hypertension
Drop in bp upon standing
- venous return and cardiac output decline
- sensory info from baroreceptiors travel in nerves IX and X to medulla
- Increase sympathetic
Hypertension
Chronic high blood pressure
- common causes: obesity, Na sensitivity, insulin resistance, sleep apnea, genetics, age
- Risk factor for strokes, heart attacks, aneurysm, renal failure
- Liquorice
Essential Hypertension
no medical cause found
Secondary Hypertension
high bp caused by another condition
-kidney disease, tumors
Liver Mortis/Lividity
Settling of blood in body after death
-purple/red color in 1-3 hrs
Max in 6-12 hrs
Aneurysm
Ballooning of artery
-can compression nearby structures, get infected, rupture
Edema
Accumulation of fluid in interstitial spaces
- Increase in hydrostatic pressure
- decrease bp
- decrease oncotic pressure
- Na retention and inflammation
Hypovolemic Shock
Shock due to low blood volue
-Sympathoadrenal activation leads to tachycardia, vasoconstriction to non vital organs, drop in hr, cold clammy skin
Atherosclerosis
Inflammatory disease of arterial walls
-loss of elasticity of arteries
Embolism
Blockage of blood vessel by embolus
-often blood clot but can be air embolism
Ischemic Stroke
blood flow cut off by clot
Hemorrhagic stroke
bleeding into brain
