chapter 20

what are the three factors that determine resistance to blood flow?

1) blood viscosity- thickness, RBC count. 2) blood vessel length- the farther the blood travels down a tube it decreases the flow and pressure. 3) blood vessel radius- most powerful.

what are the 3 types of arteries?

1) conducting/elastic(biggest, stretch and recoil and regulates BP). 2) distributing/muscular (they go to specific major organs). 3) resistance/small (not elastic, thick, major in controlling blood flow

what are the 3 types of capillaries?

1) continuous (with or without intercellular clefts). 2) fenestrated (rapid, absorption/filtration). 3) sinusiods (discontinued, spaces filled with blood and allows proteins.

what are the different types of veins?

1) postcapillary venules (porus, thin, smallest). 2) muscular venules (smooth muscle). 3) median veins (intermediate, they have one way venous valves. 4) large vein (thickest ex. SVC). 5) venous sinuses (thin walls, collect b lood from brain).

anaphlactic shock

allergic reaction

what are precapillary sphincters?

allows blood to bypass capillary bed

low venous return (LVR)

anytime blood is not enough in heart

what are the arteries, capillaries, and veins?

arteries-resisting vessels. capilaries- exchange. veins- capacitance

what is mean atrial pressure and how do you find it?

average pressure throughout cardiac cycle. (diastolic+diastolic+systolic)/3

septic shock

bacterial toxins

what is the portal system?

blood flows through 2 capillary networks

hypovolemic shock

common, decrease blood volume

what are the responses to shock?

compensated shock- recovery. decompensated shock- life-threatening and positive feedback loop

what is pulse pressure and how do you find it?

difference between systolic and diastolic pressure. (systolic-diastolic)

what are the mechanism of movement across capillaries?

diffusion, transcyosis, filtration and reabsorption

neurogenic shock

disruption of sympathetic nervous system ex: emotional shock

colloid osomtic pressure

draw fluids into cappilary

blood pressure

force that blood exerts against vessel wall

filtration and reabosption

happens at capillary beds, fluid will squeeze out and come back in.

what is the general route usually taken by the blood from the heart and back again?

heart-arteries-arterioles-cappilaries-vanules-veins

what is a sphygmomanometer and what is it measured in

how they measure BP and mmHg

what is hypercapnia and hypocapnia

hypercapnia- increase in CO2 and triggers vasodilation. hypocapnia- decrease in CO2 and triggers vasocontriction

what is cardiogenic shock

inadequate pumping of the heart

3 primary cuases of edema

increase cappilary filteration, reduce cappilary absorption and obstructed hymphatic drainage

what is the importance of physical activity in venous return?

increases HR, increases blood flow and increases respiratory pumps

what are the three ways of controlling vasomotion?

local control, neural control and hormonal control

describe the structure of a blood vessel

lumen (empty space). 3 layers: tunica interna (endothelial cell layer), tunica media (smooth muscle layer), tunica externa (connective tissue layer)

diffusion

most important, glucose and oxygen go out and cardon dixoside and waste go in. down concentration gradient.

what are the factors of venous return?

pressure gradient (BP), gravity((drains blood from neck and head) , skeletal muscle pump (in limbs, squeezes blood through veins), respiratory pump (forces blood through inferior vena cava) , and cardiac suction (atria creates suction to pull blood from vena cava and pulmary veins)

hydrostalic pressure

pressure when fluid is being pushed against surface

interstitial hydrostatic pressure

pulls fluid out, suction

blood hydrostatic pressure

pushes fluid out. postive number

what are metarterioles?

short vessels that link arterioles to venues and have capillary beds

venous pooling shock

sitting/standing for long periods of time

obstructed venous return

something is blocking the vein

systolic and diastolic

systolic- peak arterial pressure. diastolic- minimum arterial pressure

what is venous return

the flow of blood back to the heart

what are anastomoses and the three different types?

they are points where two blood vessels merge. 1) ateriovenous (no cappliary, goes artery to vein). 2) venous (common, vein drains into another vein). 3) arterial (arteries merge).

what are the three routes chemicals cross the capillary wall?

through endothelial cells, between cells, and through filtration pores

4 primary effects of edema

tissue death, pulmonary edema, cerebral edema, and circulatory shock

transcytosis

transporting across the cell, particles are too big and bulky to fit through. Ex. albumin, fatty acids

difference between vasomotion, vasconstriction and wasodialiation?

vasomotion: change in vessel radius. Vasocontriction- narrow, contraction. vasodialation: relaxing