Lecture 3 - Blood Distribution

Question 1

What gets alot of blood?

Answer 1

liver digestive tract and kidneys and skeletal muscles and brain - kidneys get the greatest in respect to mass

Question 2

Can the amount of blood blow an organ receive be modulated based on demand?

Answer 2

yes via vasoconstriction and vasodilation

Question 3

What is velocity or flow inversely proportional to?

Answer 3

cross sectional area

Question 4

Why do capillaries have slowest flow rate?

Answer 4

have greast summed cross sectional area allowing for diffusion of materials

Question 5

What are the three types of capillaries?

Answer 5

continuous, fenestrated, sinusoidal

Question 6

What is a continuous capillary?

Answer 6

ther are haps in between adjacent cells and this si just a prore or gap which fluid cna leak throughn and the ion and organis mcolecules come out but not proteins

Question 7

What are continous cpailalris like in the CNS?

Answer 7

they are sealed by tight junctions and they prevent the diffusion of materials and the astrocyte layers and form the BBB so stuff in plasma cannot get into the brain

Question 8

What is a fenastrated capillary?

Answer 8

endothelial cells are perforated by many pores and are found in kideny and glomerulus and liver and allows for moevment of plasma proteins via transcytosis - pick up fluid via endocytosis and dump it via exocytosis on other side

Question 9

What is a sinusoidal?

Answer 9

endothelum not continuous and is where cells need to cross so red bone marrow and spleen need to move rbcs

Question 10

What do immine cells do to rbs in the spleen?

Answer 10

test them to make sure they are okay but when they are old they can enter the spleen be nabbed by immune cells and be replaced by new ones from red bone marrow

Question 11

What drives inward fluid movement into the capillary?

Answer 11

colloid gradient is highe rin cpailalry so fluid goes in

Question 12

What drives outward fluid into capillary?

Answer 12

blood pressure highwr in arteriole side so filtration and lower in venous side so absorption

Question 13

What are the four causes of edema?

Answer 13

1. decreased osmotic gradient due to low plasma protein from malnutirtion or increased interstital osmoalrity (inflammation)
2. increased filtration pressure heart failue or incompetent valves or gravity
   ‘3. increased caoillary permeability from histamine
3. poor lymph drainage parasute tumors or surigically removed

Question 14

In preeclampsia what does the liver damage do?

Answer 14

cause low plasma proteins

Question 15

How does right side heart fasilure cause edema?

Answer 15

fluid back up in the veins cause heart cnat pump all so this causes less absoprtion on venule side of capillaries

Question 16

How does an incompetent valve cause edema?

Answer 16

left ventrcile if left AV vakve no work cannot make enough pressure to release everything so flkuid backs up into the pulmpnary veins causing less absorption more filrtration

Question 17

How does histamine cause edema?

Answer 17

mast cells release histamine making the capillaries more leaky

Question 18

What is the baroreceptor reflex?

Answer 18

-it is used to regulate bp

Question 19

What is a baroreceptor?

Answer 19

pressure receptor in aorta and cartopid and if there is high pressure there is strecth sensootve nerve whjich trigger a sodium channel and cause an AP which goes to the medulla CV control center which then talks to auotnomic parasympthetic and sympathetic neurons

Question 20

In the barorecpeot reflex what do sympthetic neurons do?

Answer 20

psoitive chronotropic and ionotropic effect and talk to SA node and ventrciles and artioles and veins

Question 21

In the baroreceptor reflex what does the parasympatheti neuorns do?

Answer 21

negatuve chronotropic effect by working in SA node

Question 22

Question 23

What is the vasalva maneuver?

Answer 23

forced expiration against a closed glottis

Question 24

What happens to intrathoracic pressure in the esophagus is 0 when you try to exhale against closed glottis?

Answer 24

the pressure increases the pressure in the aorta increases because you also squeeze on the aorta increasing blood pressure

Question 25

What happens when the baroreceptor reflex in the valsalva manuever senses the high bp?

Answer 25

since the intrathroacic pressure is high and the veins are compressed there is less venous return which is sensed by the baroreceptors and causes tachycardia and increases the peripheral reisistance

Question 26

What happens when the glottis opens?

Answer 26

IP ois normal and CO resumes but peripheralp reisstance is high so eleveated jump in blood pressure

Question 27

What does the barorecptor do after the glottis opens and the bp is high due to ihgh peripheral reisiatnce?

Answer 27

causes bradycardia and decreases the epripheral reistsance so it is or the bp is normal again