Love your kidneys

Question 1

What is included in the urinary system

Answer 1

kidneys, ureters, bladder, urethra

Question 2

Summary of renal functions

Answer 2

• Regulation of ECF volume and composition
• Elimination of endogenous waste products
• Kidneys eliminate foreign substances
• Kidneys have endocrine functions

Question 3

What is the most important function of the kidney

Answer 3

homeostatic maintenance of ECF volume and composition

Question 4

Why is water balance crucial

Answer 4

It is the solvent of ICF and ECF

Question 5

What else does the kidney regulate

Answer 5

The electrolyte composition of the ECF

Question 6

Failure to eliminate waste products

Answer 6

Can cause serious disease and even death if no interventions are made

Question 7

kidneys eliminate foreign substances

Answer 7

Such as:

• drugs
• food additives
• pesticides

Question 8

Erythropoietin (EPO)

Answer 8

Acts on bone marrow to enhance the synthesis of red blood cells

Question 9

Renin

Answer 9

substance involved in the autoregulation of the kidney

Question 10

What is the superiour surface of the kidney capped by

Answer 10

adrenal gland

Question 11

What is the basic unit of the kidney

Answer 11

nephron

Question 12

How many nephrons are in 2 kidneys

Answer 12

2.5 million

Question 13

What % of total cardiac output do they kidneys receive

Answer 13

20-25%

Question 14

Roughly how much blood flows through kidneys each minute

Answer 14

1200ml

Question 15

How do they kidneys receive blood

Answer 15

renal artery

Question 16

basic renal processes

Answer 16

• Filtration
• reabsorption
• secretion

Question 17

Filtration

Answer 17

The formation of glomerular capillaries of an essentially protein-free filtrate of plasma

Question 18

What allows pressure for filtration

Answer 18

blood pressure

Question 19

Glomerular filtration rate (GFR)

Answer 19

very high (180L/day)

Question 20

Reabsorption

Answer 20

Substances that the body wants are reabsorbed

- those that it doesnt, stay in the tubule and are excreted

Question 21

Secretion

Answer 21

Substances may be specifically removed from the body in this way

Question 22

Which substance is actually being regulated

Answer 22

The ECF is being regulated and not the urine

Question 23

What maintains pressure to allow filtration

Answer 23

Capsule

Question 24

What level of Mbp does filtration completely halt

Answer 24

40mmHg

Question 25

Autoregulation

Answer 25

Independent of nerves or hormones | - occurs in denervated and in isolated perfused kidneys

Question 26

Autoregulation range

Answer 26

60-130mmHg

Question 27

What can override autoregulation

Answer 27

Activation of sympathetic nerves and Angiotensin II

Question 28

Peritubular capillaries

Answer 28

Responsible for reabsorption

Question 29

What is a major site of reabsorption

Answer 29

proximal tubule

Question 30

how is the proximal tubule left after reabsorption

Answer 30

isosmotic with plasma

Question 31

What do all nephrons have in the cortex

Answer 31

proximal and distal tubules

Question 32

system essential for water balance

Answer 32

the loops of Henle of juxtamedullary nephrons

Question 33

the loops of Henle of juxtamedullary nephrons

Answer 33

Allows the kidney to make urine in times of water defecit q

Question 34

Maximum concentration of urine that can be produced by the kidney

Answer 34

1200-1400 Osmoles/L

Question 35

Minimum obligitary loss of water

Answer 35

0.5L/day

Question 36

Kidneys producing urine of varying concentration

Answer 36

Becuase loops of henle of juxtamedullary nephrons act as concurrent multipliers

Question 37

Ascending limb of the loop and Henle

Answer 37

- impermeable to water | - Actively co-transports Na+ and Cl- ions out of tubule lumen into the interstitium

Question 38

Descending limb of the loop of Henle

Answer 38

frrly permeable to water, but relatively impermeable to NaCl

Question 39

Significance of the concurrent multiplier

Answer 39

creates a hypertonic gradient in the medullary interstitium and delivers hypotonic fluid to the distal tubule

Question 40

Site of water regulation

Answer 40

collecting duct

Question 41

Collecting duct permeabiity

Answer 41

controlled by ADH

Question 42

How does ADH affect collecting duct permebility

Answer 42

If ADH is present then water can leave the collecting duct

Question 43

If maximum ADH is present

Answer 43

contents equilibrate with that of the medullary interstitium via osmotic efflux of water - becomes highly concentrated at the tip of the medulla

Question 44

absence of ADH

Answer 44

Collecting ducts are impermeable to water - large volume of dilute urine is excreted