Structure and Function II Exam 3

veins 64%, capillaries 5%, arteries 15% (systemic circuit 84%), pulmonary circuit 9%, heart 7%

What is the percentage of blood in the veins, capillaries, arteries, systemic circuit, heart, pulmonary circuit

oxygenated, deoxygenated

in systemic circuit all arteries carry ______ blood and all veins carry ______ blood

deoxygenated, oxygenated

in pulmonary circuit all arteries carry _____ blood and all veins carry ______

elastic artery, muscular artery, arteriole (controls blood flow into tissues)

what are the 3 types of arteries? from closest to the heart to farthest

large vein, medium-sized vein, venule

what are the 3 types of veins? closest to the heart to farthest

tunica externa, tunica media, endothelium, tunica intima

label 1-4

lumen

what is the "hole" in the middle of the blood vessel called

artery: thicker walls, stays open when empty, high pressure, average pressure is 90-100 mmHg (max is 120 mmHg),greater resistance, smaller lumen, pulsatile flow

veins: thinner walls, will collapse when empty, lower pressure and resistance, average pressure is 90-100 mmHg (max is 120 mmHg), veins have valves that prevent blood from flowing backwards, bigger lumen, steady flow

describe differences in an artery and vein (wall size, pressure, resistance, lumen size, valves, type of flow)

these arteries are closest to the heart, and it allows for expansion when full of blood and to absorb pressure. the walls will expand and pop back which pushes the blood forward. elasticity declines with age

distributing elastic arteries: why is elasticity important

to help raise or lower BP throughout the body, controls blood flow into an area or reroutes blood

what physiological purposes do vasoconstriction and vasodilation serve?

angiotensin II (raises BP)

what is the most powerful vasoconstrictor in the body

true

t/f in general vasoconstriction raises BP, vasodilation lowers BP

the SNS vasoontricts most blood vessels, but will dilate coronary arteries (heart), skeletal muscles arteries, and arteries of the brain

what is the SNS effect on vasoconstriction/ dilation

it is routing of blood, for example during exercise more blood will go to muscles and less blood will go to digestive organs

what is selective perfusion in an organ

5800; 17,500

average total blood flow at rest is ____ ml/min, whereas average blood flow during strenuous exercise is ______ ml/min

3/4

at any given time ____ of capillaries are shut off

continuous, fenestrated, discontinuous

what are the 3 types of capillaries

there are no gaps between endothelial cells, less permeable, these are in most tissues/ organs (ex. fat, skeletal muscles, lungs, brain)

describe a continuous capillary

have pores in endothelial cells, highly permeable, these are in kidneys, choroid plexus (in brain for csf), small intestine, endocrine organs

describe a fenestrated capillary

have big gaps in the endothelial cells, are very permeable especially to blood cells and proteins, the rarest type, are found in liver, spleen, bone marrow

describe a discontinuous capillary

filtrations is when fluid moves out of capillaries, reabsorption is when fluid moved back into capillaries

what is filtration? reabsorption?

hydrostatic pressure (HP) and colloid oncotic pressure (COP)

what are filtration and reabsorption determined by?

pressure of a fluid (blood) on a surface (capillary wall)

what is hydrostatic pressure

attractive force due to proteins (albumin)

what is colloid oncotic pressure

COP: 20 mmHg (in), HP: 33mmHg (out), net filtration (13 mmHg out)

on the arterial end of a capillary, what is the net colloid oncotic pressure (COP), net hydrostatic pressure? is it net filtration or net reabsorption

COP: 20mmHg (in), HP: 13mmHg (out), net reabsorption (7mmHg in)

on the venous end of a capillary, what is the net colloid oncotic pressure (COP), net hydrostatic pressure? is it net filtration or net reabsorption

there should be little/ no filtration to keep fluid out of the lungs

what is filtration and reabsorption like in the lungs?

85%

in reality, we only reabsorb about ___ of the water that was filtered out

high

if someone has a high blood pressure, what will hydrostatic pressure be

drop

if someone has a bad liver, albumin will decrease, what will happen to colloid oncotic pressure

the 15% of fluid that was not reabsorbed is taken by the lymphatic capillaries and that fluid is called lymph

describe lymph

they have WBC where the lymph fluid is cleaned and returned to the heart

describe lymph nodes

due to a damaged lymph system where lymphatic fluid cannot return to the heart and it accumulated and causes edema (swelling)

describe lymphedema

respiratory pump, muscular pump, valves, pressure gradient

what things drive venous return to the heart?

As muscle contracts it puts pressure on veins pushing blood to the heart

describe the skeletal muscle pump

Pressure changes occurring in the ventral body cavity during breathing create the respiratory pump that moves blood up towards heart

describe the respiratory pump

valves

why does blood only flow in the direction of the heart

faulty valves in veins cause blood to pool in the veins and they protrude out of the skin

describe varicose veins

pressure gradient (blood flows from high pressure to low pressure)

blood flows due to a ______

120; 110; 40; 30; 18; 16; 12; 7; 4.6

The flow of blood is aorta, large arteries, arterioles, arterial end of capillaries, venous end of capillaries, venules, muscular veins, central veins (IVC/SVC) and right atrium. what is the pressure in each of those blood vessels

pressure of blood against the walls of the arteries

what is the definition of blood pressure

systolic (top number) is the pressure in the arteries when the heart is in systole (contraction), diastolic (bottom number) is the pressure in the arteries when the heart is in diastole (rest/ filling)

what is systolic blood pressure? diatolic bp?

elastic

____ arteries keep systolic pressure from getting too high, and from diastolic pressure from getting to 0

mean arterial pressure, it is the estimate of the average BP in the body during 1 cardiac cycle

what is MAP and what does is stand for?

[systolic pressure + 2 diastolic pressure]/3

remember systole is 1/3 of the cardiac cycle, diastole is 2/3 of the cardiac cycle

what is the MAP equation

greater than 96mmHg; less than 65mmHg, 24 hr MAP under 90mmHg

what MAP score is a risk for adverse cardiac events and stroke? what score poses an increased risk of mortality in critically ill patients and causes hypofusion? what is the optimal range

BP= Q x SVR

Q: cardiac output (HR x SV)

HR: SNS (increases), PSNS (decreases)

SV: blood volume, venous return, EDV, preload

SVR: systemic vascular resistance

- length of blood vessels (shouldn't change in adulthood)

- viscosity of blood (if viscosity is high, SVR is high vice versa)

- diameter of blood vessels (changed throughout the day), vasoconstriction decreases diameter, so SVR increases vice versa

what is the blood pressure equation? what factors determine bp?

true

ex is a blood vessel has a radius of 1cm, another had 2cm, and another 3cm. the 1cm has a blood flow of 1 cm/sec, the 2cm 16 cm/sec, and the 2cm 81 cm/sec

t/f blood flow in our vessels increases by r^4 (radius)

normal: systolic less than 120 and diastolic less than 80

elevated: systolic 120-129 and diastolic less than 80

stage 1: systolic 130-139 or diastolic 80-80

stage 2: systolic 140 or higher or diastolic 90 or higher

crisis: systolic higher than 180 and/or diastolic higher than 120 (risk for stroke)

hypotension: systolic less than 90 or diastolic less than 60

what is normal blood pressure? elevated? hypertension stage 1? hypertension stage 2? hypertensive crisis? hypotension?

increase bp means a very high afterload, so the heart has to work extra hard to pump blood, there is a risk of stroke, and low BP means blood cannot get to all the body (hypoperfusion)

why is BP regulation necessary in the body?

tissues can control their own blood flow

metabolic: vasodialation can occur to wash away chemicals (CO2, H, K, LA, adenosine)

angiogenesis: technically means forming new blood vessels, but this can occur during the thickening of uterine lining (during a woman's cycle), athlete's skeletal muscles, cancer

what is auto regulation of blood supply

SNS always has the blood vessels a little vasoconstricted to maintain a blood pressure

what is sympathetic tone

corrects sudden changes in BP (only BP not HR)

what is the baroreflex

low BP is detected by baroreceptors in the walls of the elastic arteries near the heart and the glossophangeal nerve (9) sends that info the cardiac regulatory center (medulla) and the vasomotor center (medulla). the cardiac regulatory center stimulates SNS and turns of PSNS to increase HR, force, and SV, thus elevating Q. the vasomotor center stimulates SNS to vasoconstrict, thus elevating SVR. Since Q and SVR are raised, BP is also raised

describe the baroreflex for low blood pressure

high BP is detected by baroreceptors in the walls of the elastic arteries near the heart and the glossophangeal nerve (9) sends that info the cardiac regulatory center (medulla) and the vasomotor center (medulla). the cardiac regulatory center turns off SNS and turns on PSNS to decrease HR, force, and SV, thus lowering Q. the vasomotor center turns off SNS to vasodialate, thus decreasing SVR. Since Q and SVR are lowered, BP is also lowered

describe the baroreflex for high blood pressure

increase BP (most powerful vasoconstricter)

increase BP

decrease BP

increase BP

increase BP (maintains sympathetic tone)

what are these hormones effect on blood pressure? angiotensin II, aldosterone, ANP, ADH, EPI/NE

true

t/f in the brain total blood flow fluctuates less than other organs as consistency is important because even a few seconds of o2 deprivations can cause a loss of consciousness and 4-5 mins can cause permanent brain damage, however, blood can shift to different parts of the brain

yes

does the brain regulate its own blood flow in response to changes in blood pressure and blood chemistry

dilate, constrict

cerebral arteries ___ when BP is low and ____ when BP is high so that blood flow can remain stable even at high blood pressures

true

t/f high co2 lowers pH and triggers local vasodilation in the brain

brief episodes of cerebral ischemia (lack of blood flow) characterized by temporary dizziness, loss of vision, weakness, paralysis, headache, aphasia. this can be an early warning sign of a stroke and immediate treatment is needed

what is transient ischemic attacks

sudden death (infarction) of brain tissue caused by ischemia caused by atherosclerosis, thrombosis or ruptured aneurysm

what is cerebrovascular accident (CVA or stroke)

true

t/f skeletal muscles have high variable blood flow which is dependent on the state of exertion

constricted; shut down; dilated; 20x

in the skeletal muscles: at rest arterioles are ______ and most capillaries are _______, during exercise arterioles are _________ and blood flow can increase _____

true

t/f in the lungs blood flows slower through pulmonary capillaries so there is more time for gas exchange

true

t/f in the lungs oncotic pressure overrides hydrostatic pressure, so capillaries are engaged almost entirely in absorption. also, pulmonary arteries constrict in response to hypoxia and redirects blood flow to better ventilated regions

beta blockers, diuretics

ACE-inhibitors, antiogentension receptor blocker (ARBs), vasodilators

what are the 2 types of BP medications used to effect Q? the 3 used to effect SVR?

blocks the SNS effects, decreases HR, ctx force, cardiac output, blood pressure

describe beta blockers

increases urinary output, decreases blood volume, stroke volume, cardiac output, blood pressure

describe diuretics

inhibit ACE, thus there is no antiogenosein II, so no vasoconstriction and less aldosterone (thus urinary output increases). this causes vasodilation, increased UO, decreased Q, SVR and BP

describe ace inhibitors

same effects as ACE inhibitors but a different approach by inhibiting antiogentension II from binding to its receptors

describe antiogentension receptor blockers (ARBs)

will be used is BP is very very high and immediately needs to be dropped. used in ERs because it causes fainting as the blood vessels dilate quickly

describe vasodilators

-regulation of BP via BV

- regulation of osmolarity (water/salt balance)

- regulation of pH

- hormone production (EPO + renin)

- filter blood

what are the functions of the kidney's

T12-L2

what spinal cord level is the kindey at

true; behind the peritoneum (sack around the abdominal organs)

t/f the kidney is retroperitoneal. what does that mean

a by-product of blood; it varies in concentration and urine should not have blood cells or protein

what is urine? how does it differ from blood?

nephron; Arthur Grollman 1957

"plasma undergoes modification to urine in the _____" (who said this)

no (it's a kidney tubule)

is a nephron a blood vessel

1) filtration

2) reabsorption

3) secretion

what are the 3 processes to form urine in the nephron

hyperglycemia means there in an increase in filtered glucose, which exceeds the ability of transporters to reabsorb it, so it stays in the urine

why can glucose show up in the urine of someone with diabetes mellitus

1) bowman's capsule

2) proximal convoluted tubule (PCT)

3) loop of henle (descending limb & ascending limb)

4) distal convoluted tubule (DCT)

5) collecting duct (CD)

what are the 5 parts of a nephron

true

t/f several nephrons can share a collecting duct

afferent; efferent; pertitubular capillary

blood goes into the glomerulus (the fenestrated capillary of the urinary system) in the _____ arteriole and exits in the ______ arteriole and that branches into what vessel

glomerulus in the bowman's capsule

where is blood filtered in the urinary system

everything in blood gets filtered out if it can fit through the holes of the capillaries and is not highly charged (ex. proteins); filtrate

what gets filtered in the glomerulus? what is that filtered stuff called

blood hydrostatic pressure: 60 mmHg (out)

colloid oncotic pressure: 32 mmHg (in)

bowman's capsule hydrostatic pressure: 18 mmHg (in)

net pressure: 10mmHg out (filtration)

what are the pressures of the glomerulus that causes the net filtration

glomerular filtration rate, the volume of filtrate formed by both kidneys per minute; 125 mL/min

what is GFR, what is the set point

high, thus urinary output would be high and that can lead to dehydration

low, thus uo would be low as there is too much reasborption, that can lead to toxicity

if there was no regulation: if MAP was high, what would GFR be and what would be the opposite

PCT (proximal convoluted tubule) 65-75%; due to the Na gradient and low hydrostatic pressure and high oncotic pressure

where does most reabsorption occur in the nephron and why

6%

___% of the bodies ATP is used in the PCT to drive the Na/K pump

water; high (1200); salts; low (100)

on the descending limb of the loop of henle, ______ is reabsorbed making the osmolarity _______, on the ascendingn limb _____ is reabsorbed making the osmolarity______

hypertonic (that draws water out of the collecting duct via aquaproins to produce concentrated urine and conserve water)

the loop of henle creates and maintains a _____ ISF via the countercurrent multiplier which allows the collecting duct to concentrate the urine if necessary

the top part of the ascending limb, the distal convoluted tubule (DCT) and collecting duct (CD)

where in the nephron do hormones go to work

papilla, minor then major calyx, renal pelvis, ureter, bladder

out of the collecting duct, what is the path of urine

high; ADH; aquaporins; water; lowers; increases (plasma osmolarity can get as high as 1200)

If someone is dehydrated, their plasma osmolarity will be (HIGH OR LOW) and ___ will be released which causes the _____ in the wall of the collecting duct to open and reabsorb _____, this (RAISES OR LOWERS) urinary output and (INCREASES OR DECREASES) urine concentration.

low; will not; raises; decreases (plasma osmolarity can get as low as 50)

If someone very hydrated, their plasma osmolarity will be (HIGH OR LOW) and ADH (WILL OR WILL NOT) be released, this (RAISES OR LOWERS) urinary output and (INCREASES OR DECREASES) urine concentration.

renal blood flow and blood pressure

what drives the process of filtration?

1) vasoconstriction of afferent arteriole (when BP is high, this decreases blood flow into the glomerulus, and decreases GFR)

2) vasodilation of afferent arteriole (when BP is low, this increases BF and GFR)

3) vasoconstriction of efferent arteriole (when BP is low to build pressure)

How do the kidney's maintain a relatively constant GFR

the kidney's ability to regulate its own blood flow and GFR

what is renal autoregulation

smooth muscles response to stretch

- If BP is high, there will be an increased stretch on the wall of the afferent arteriole and it responds by contracting, and lowering blood flow into glomerulus

- If BP is low, wall of afferent arteriole relaxes, which increases blood flow into glomerulus

what is the myogenic mechanism of renal autoregulation