#29

Question 1

Capillaries

Answer 1

Smallest blood vessels that delivery nutrients and oxygen to cells throughout your body

Question 2

Capillary beds

Answer 2

organized branching networks of capillaries

Question 3

How is the flow of blood regulated through a capillary bed?

Answer 3

regulated by arterioles and anastomoses

Question 4

Pre-capillary sphincters

Answer 4

smooth muscle rings that open and close to regulate perfusion

Question 5

Atriovenous anastomoses

Answer 5

direct shunt vessels that bypass the capillary bed allowing rapid diversion of blood

Question 6

Metarteriole

Answer 6

vessel that acts as a bridge between an arteriole and a venule

Question 7

True Capillaries

Answer 7

10-100 exchange vessels branching off the metarteriole to supply tissue

Question 8

Thoroughfare channel

Answer 8

continuation of the metarteriole that connects directly to the post capillary venule

Question 9

Venule

Answer 9

The vessel receiving blood from the capillary bed to return it to the veins

Question 10

What do arteriovenous anastomoses do?

Answer 10

bypass the capillary network to regulate temperature or redirect blood to other organs

Question 11

What do pre-capillary sphincters do?

Answer 11

muslces that contract to shut off blood flow to inactive tissues or relax to allow flow when oxygen is needed

Question 12

How is blood flow through the capillaries?

Answer 12

Slow, allowing for large amounts of time to exchange between contents of blood and tissue

Question 13

What are capillary walls made of

Answer 13

endothelial cells, simple squamous epithelium that line the inner surface forming a tube

Question 14

Pericytes

Answer 14

connective tissue cells scattered aling the outer surface that provides structural support and repair

Question 15

Basement membrane [basal lamina]

Answer 15

thing extracellular layer that supports the endothelial cells

Question 16

Continuous capillaries

Answer 16

endothelial cells will form an uninterrupted lining here, connected by tight junctions with only small intercellular clefts
- have a complete basement membrane

Question 17

Fenestrated capillaries

Answer 17

ednothelial cells contain small pores, fenestrae, covered by a diaphragm allowing for increased permeability while maintaining a complete basement membrane

Question 18

Sinusoidal [discontinuous] capillaries

Answer 18

the have large gaps in endothelial cells and an incomplete or absen basement membrane making them most permeable

Question 19

Where are continuous capillaries found?

Answer 19

skin, skeletal muscles, lungs

Question 20

Where are fenestrated capillaries found?

Answer 20

kidneys. small intenstine and endocrine glands (areas involved in filtration, absorption or secretion)

Question 21

Where are sinusoidal capillaries found?

Answer 21

liver, bone marrow and spleen. organs that produce or recycle large plasma proteins and blood cells

Question 22

Paracellular transport

Answer 22

passive movement of water, ions and small molecules between adjacent epithelial or endothelial cells

Question 23

Transcullular transport

Answer 23

fluids, ions or macromolecules move directly through cell membrane and cytoplasm. can be active or passive

Question 24

Transcytosis

Answer 24

specialized energy-dependant process in which cells transport macromolecules across the cytoplasm within vessels. from one membrane surface to another

Question 25

Barrier capillary

Answer 25

does not allow paracellilar transport or transcytosis. primarily found in the brain forming the BBB

Question 26

Hydrostatic Pressure

Answer 26

pressure exerted by a fluid at rest due to the force of gravity (same as blood pressure)

Question 27

What does hydrostatic pressure do for capillary exchange?

Answer 27

Blood puts pressure against the capillary wall Drives luid, water and small solutes, out of the vessel and into the surrounding interstitial space

Question 28

Hydrostatic force on the arteriole end

Answer 28

30mmHg

Question 29

What happens to proteins like albumin that are too big to move out?

Answer 29

They stay within the blood and have a negative charge that attracts water inwards

Question 30

What is too big to be moved out due to hydrostatic pressure?

Answer 30

wbcs, rbcs, platelets, proteins

Question 31

Osmotic pressure

Answer 31

Force that is pushing water to to flow by osmosis

Question 32

Osmosis

Answer 32

diffusion of water molecules across a selectively permeable membrane due to osmotic pressure

Question 33

Diffusion

Answer 33

passive movement of substances due to concentration differences

Question 34

Filtration

Answer 34

bulk movement of fluid through small pores in response to pressure differences

Question 35

What exerts osmotic pressure?

Answer 35

proteins like albumin. They draw fluid from the interstitial space back into capillaries opposing hydrostatic pressure

Question 36

What is the attractive inward force at the arteriole end?

Answer 36

20mmHg

Question 37

Net Filtration pressure

Answer 37

the total force promoting fluid movement across capillary walls. calculated as the difference between hydrostatic and colloidal osmotpic pressure

Question 38

What is NFP on the arteriole end?

Answer 38

10mmHg

Question 39

What happens to hydrostatic pressure as it moves to the venous end?

Answer 39

Drops

Question 41

What is the outward pushing force at the venous end?

Answer 41

15mmHg

Question 42

What is the inward pushing foce at the venous end?

Answer 42

20 mmHg

Question 43

What is the NFP at the venous end?

Answer 43

5mmHg

Question 44

What happens at the venous end?

Answer 44

CO2 and wastes get pulled back

Question 45

Oedema

Answer 45

swelling caused by excess fluid trapped in the body's tissue

Question 46

Inflammation

Answer 46

caused by damage to vascularized tissue

Question 47

What happens then vascularized tissue is damaged?

Answer 47

prostaglandins, histamune, bradykinin

Question 48

What do the chemicals released at inflammation do?

Answer 48

Vasodilate the incoming blood to more comes in, the gaps become bigger in capillaries

Question 49

Why do the gaps need to be bigger when chemicals get released due to inflammation?

Answer 49

For white blood cells to leave between the gaps so they can ingest damaged cells or bacteria

Question 50

What happens as a consequence of gaps becoming larger due to inflammation?

Answer 50

WBCs can leave, but proteins that have negative charge attracting water also leave so the fluid stays out in the interstition

Question 51

Interstition

Answer 51

area between cells and blood

Question 52

Why does oedema tend to affect ankles/wrists worst?

Answer 52

Due to gravity pulling bodily fluids downward