CS: Blood Vessels Flashcards
Elastic Arteries
Structure- located closest to the heart, has large diameters, thick tunica media w/ tons of elastin
Function- conduct blood away from the pressure reservoirs
Muscular Arteries
Structure- further away from the heart, thick tunica media with/ tons of smooth muscle layers
Function- distribute blood to the organs, perform vasoconstriction
Arterioles
Structure- small diameter, has a few smooth muscle layers
Function- constrict and dilate to control blood flow entering capillary beds
Capillaries
Structure- continuous capillaries, simple squamous endothelium with intercellular clefts
Function- site for exchange
Venules
Structure- form when capillaries merge, look like small veins, little bit of smooth muscle
Function- merge to form veins
Veins
Structure- formed when venules merge, valves to prevent backflow
Function- blood reservoirs that require external pumps to send blood back to heart
Blood Pressure
The force blood exerts within blood vessel walls
Pressure Gradient
Blood will flow from areas of high pressure to low pressure. Arterial systems start high while venous has low pressure.
Arterial Pressure
High pressure and pulsatile
Systolic pressure- high (~120 mm Hg)
Diastolic pressure- low (~80 mm Hg)
Capillary Pressure
Low pressure but not 0 mm Hg
Venous Pressure
Very low, all the way down to 0 mm Hg at vena cava
Mean Arterial Pressure (MAP)
Average BBP in arterial system
Systolic Pressure
during ventricular contraction
Diastolic Pressure
during ventricular relaxation
Perfusion
blood flow to organs and tissues (deliver 02 and nutrients)
Intrinsic Autoregulation
Goal- maintain constant perfusion into tissues and organs
Metabolic vasodilation occurs when : hypercapnia, acidosis, hypoxia, and elevated lactate.
Starlings Law
Osmotic pressure and hydrostatic pressure drive the movement of fluids. Net filtration pressure depends on these forces
Arteriole end of capillaries
- osmotic pressure will want to push fluids into capillaries
- hydrostatic pressure within capillaries, however, is: higher than OP
- therefore fluids are pushed out of capillaries (AKA filtration)
On the venule end of capillaries
- hydrostatic pressure will want to send fluids out of the vessel
- osmotic pressure within capillaries, however, is stronger than HP
- fluids are pushed into capillaries (AKA reabsorption)
Varicose Veins
dilated and twisted veins due to incompetent valves (blood pools)
Atherosclerosis
plaque build up in blood vessels
