Fewell - Microcirculation, Lymphatic System & Starling Forces 2021.pdf

Question 1

why are right anf left coronary blood flows different?

Answer 1

The left pump has to work harder than the right pump
>because metabolic demand is higher for the left pump
>left heart has to generate higher pressure transmural pressure drops to almost zero and have to generate more pressure to componsent???

Question 2

Myocardial Oxygen Supply & Demand

Answer 2

In the normal heart, the oxygen requirements of the myocardium
are continuously matched by the coronary arterial supply

Question 3

Major Determinants of Myocardial

Oxygen Consumption

Answer 3

• Heart Rate
• Wall Stress (Systolic Pressure)
• Cardiac Contractility

Question 4

coronary blood flow and myocardical oxygen consumption have a ___ relationship

Answer 4

linear relationship

Question 5

components of myocardial oxygen supply

Answer 5

• O2 content

- coronary blood flow

Question 6

determinants of coronary blood flow

Answer 6

-coronary perfusion pressure
-coronary vascular resistance
>external compression
>intrinsic regulation

Question 7

regulating coronary microvascular tone (resistance)

Answer 7

balance between vasodilator and vasoconstrictor signals

>exerted by: neurohumoral, metabolic, exxtravascular, endocrine, paracrine and endothelial influences

Question 8

Macrocirculation

Answer 8

circulation of

blood to and from organs

Question 9

Microcirculation

Answer 9

vasculature
embedded within organ tissues
and composed of arterioles,
capillaries and venules

Question 10

slide 3 figure

Answer 10

**8 maybe a question???

Question 11

circulatory system has blood vessels that are all lined with ____

Answer 11

all blood vessels are lined with endothelial cells

that are continuous with the endothelial lining of the heart

Question 12

arterioles

Answer 12

(aka resistance vessels in
the circulation) are highly muscular and
their diameters can change many fold

Question 13

metarterioles

Answer 13

(i.e., the terminal
arterioles) do not have a continuous
muscular coat but smooth muscle fibers
encircle the vessel at intermittent points

Question 14

precapillary sphincter

Answer 14

At the point where a capillary originates
from a metarteriole, a smooth muscle
fiber usually encircles the capillary

Question 15

vasomotion

Answer 15

intermittent
contraction of metarterioles and precapillary
sphincters (likely regulated by O2 in tissue)

Question 16

Capillaries walls

Answer 16

thin and constructed of a single layer
of endothelial cells surrounded by a thin basement membrane
(exchange vessels)

Question 17

Diffusion definition

Answer 17

most important method of capillary exchange
• Lipid soluble [nonpolar] substances such as oxygen, carbon dioxide, steroid hormones) – across lipid bilayer wall

(water!!)

Question 18

clefts/fenestrations allows entry of substance via

Answer 18

Small water soluble substances [ions & polar] such as glucose &
amino acids) – clefts or fenestrations (water!!)

Question 19

Transcytosis

Answer 19

allows transport of large molecules across capillary

walls (large lipid insoluble molecules & protein hormones)

Question 20

Bulk Flow

Answer 20

> transfer of fluids across capillary walls
regulates the relative volumes of blood and interstitial
fluid (regulated by Starling Forces)

Question 21

Continuous Capillary

Answer 21

Lipid-soluble substances
diffuse directly through the
cell membranes of the
capillary endothelium
e.g., oxygen & carbon
dioxide, H2O, ions
>found in the heart

Question 22

Fenestrated Capillary

Answer 22

Water-soluble, non-lipidsoluble substances diffuse
through intercellular clefts
and fenestrations in the
capillary membrane
e.g., H20, Na+, Cl-, glucose
>pinocytic vessicles can transport larger substances

Question 23

Discontinuous Capillary

Answer 23

Plasma proteins pass through
these walls almost as easily
as water and other
substances. Note large
intercellular clefts and pores
and incomplete basement
membranes

Question 24

what determine filtration across capillaries

Answer 24

by Capillary and Interstitial

Fluid Pressure & Colloid Osmotic Pressure (thanks to Ernest Starling)

Question 25

Lymphatic System functions

Answer 25

maintenance of fluid balance in the internal environment
and immunity
> to provide an accessory return route to the blood for the surplus 3L

Question 26

capillary filtration

Answer 26

removes plasma while leaving blood cells from circulatory system

Question 27

where does filtered plasma go?

Answer 27

reabsorbed directly into the blood vessels,
while the remaining 3L remain in the
interstitial fluid

Question 28

pinocytic vessicles

Answer 28

> can transport larger substances

> found in fenestrated capillaries

Question 29

aterial end has _ starling forces

Answer 29

-greater capillary hydrostatic pressure than colloidal osmotic pressure
>filtration
>(+10 mm Hg)

Question 30

mid capillary end has _ starling forces

Answer 30

-capillary hydrostatic pressure is the same as collodial osmotic pressure
>no net movement
> (0 mm Hg)

Question 31

venous end has _ starling forces

Answer 31

-blood colloidal osmotic pressure is greater than capillary hydrostatic pressure
>reabsorption
> (-7mm Hg)

Question 32

without lymphatic system there would be an

Answer 32

accumulation of fluid in interstitial space

Question 33

does the lymphatic system include the heart

Answer 33

yes