Lecture 27. Fundamentals of Cardiovascular and Renal Physiology

Question 1

What type of capillaries do lymph vessels have ?

Answer 1

Blind ending

Question 2

Where do large lymph vessels empty into ?

Answer 2

The subclavian vein

Question 3

What do valves prevent ?

Answer 3

Backflow

Question 4

What are the major functions of lymph vessels ?

Answer 4

1. Tissue drainage
2. Return leaked plasma proteins
3. Absorption of digested fat
4. Defence

Question 5

How is leaked fluid returned to cardiovascular system /

Answer 5

Via the lymphatic system

Question 6

What is an oedema ?

Answer 6

Build up of fluid in the interstitium/tissue

Question 7

What are some ways oedema may occur ?

Answer 7

1. Reduced plasma proteins
2. Increased capillary permeability
3. Increased venous pressure
4. Lymph blockage

Question 8

How may plasma proteins be reduced ?

Answer 8

1. Loss in urine - kidney disease
2. Reduced synthesis - liver disease
3. Dietary

Question 9

How may capillary permeability be increased ?

Answer 9

Inflammation and allergic responses

Question 10

How may venous pressure be increased ?

Answer 10

1. Uterine compression during pregnancy

2. Aeroplane flight - decompression and immobility

Question 11

How may lymph blockage occur ?

Answer 11

1. Damage during surgery

2. Parasitic infection

Question 12

What does osmoregulation do ?

Answer 12

Balances the uptake and loss of water and solutes

Question 13

What is plasma composition regulated by ?

Answer 13

Kidneys

Question 14

What is urine ?

Answer 14

Filtered plasma

Question 15

How does the renal system produce urine ?

Answer 15

By refining a filtrate derived from plasma

Question 16

What are the steps of osmoregulation ?

Answer 16

1. Filtration
2. Reabsorption
3. Secretion
4. Excretion

Question 17

In osmoregulation, what is filtration ?

Answer 17

Filtering of plasma

Question 18

In osmoregulation, what is reabsorption ?

Answer 18

Reclaiming of valuable solutes

Question 19

In osmoregulation, what is secretion ?

Answer 19

Adding nonessential solutes and wastes to the filtrate

Question 20

In osmoregulation, what is excretion ?

Answer 20

Processed filtrate containing nitrogenous wastes is released from the body

Question 21

What does filtrate produced in Bowman’s capsule contain ?

Answer 21

Salts, glucose, amino acids, vitamins, nitrogenous wastes

Question 22

What happens in the proximal tubule ?

Answer 22

1. Reabsorption of ions, water and nutrients takes place

2. Materials to be excreted become concentrated and some toxic materials are secreted into the filtrate

Question 23

How are molecules transported from the filtrate into the interstitial fluid and then capillaries ?

Answer 23

Actively and passively

Question 24

What happens in the descending limb loop of henle ?

Answer 24

Water is reabsorbed through channels and the filtrate becomes more concentrated

Question 25

What are the channels with which water is reabsorbed from formed by ?

Answer 25

Aquaporins

Question 26

What is the reabsorption of water in the descending limb of the loop of henle driven by ?

Answer 26

The high osmolarity of the interstitial fluid which is hyperosmotic to the filtrate

Question 27

What happens in the ascending limb of the loop of henle ?

Answer 27

Salt but not water is able to diffuse from the tubule into the interstitial fluid, causing the filtrate to become increasingly dilute

Question 28

What is the function of the distal tubule ?

Answer 28

Regulates the potassium ions and sodium chloride concentrations of body fluids

Question 29

What is the function of the collecting duct ?

Answer 29

1. Carries filtrate through the medulla to the renal pelvis. 2. Reabsorption of solutes and water

Question 30

What is urine hyperosmotic to ?

Answer 30

Body fluids

Question 31

What manages the osmoregulatory functions of the mammalian kidney ?

Answer 31

A combination of nervous and hormonal controls

Question 32

What is another name for anti-diuretic hormone ?

Answer 32

Vasopressin

Question 33

What do ADH bind to ?

Answer 33

Membrane receptors on collecting duct cells

Question 34

What does the binding of ADH to receptors initiate ?

Answer 34

A signal cascade leading to insertion of aquaporin proteins into the membrane lining the collecting duct

Question 35

What does the increase in water recapture reduce ?

Answer 35

Urine volume

Question 36

What do osmoreceptor cells in the hypothalamus monitor ?

Answer 36

Blood osmolarity and regulate release of ADH from the posterior pituitary

Question 37

What happens when osmolarity rises above its set point ?

Answer 37

ADH release into the bloodstream increases

Question 38

What happens when ADH drops below a set point ?

Answer 38

Causes a reduction in ADH secretion

Question 39

What generates thirst ?

Answer 39

Specific neurons of hypothalamus

Question 40

What is normal blood osmolarity ?

Answer 40

285-295 mOsm/L

Question 41

What is a major contributor to blood pressure ?

Answer 41

Blood volume

Question 42

What regulates blood pressure via neuronal and hormonal control ?

Answer 42

Cardiovascular and renal systems