Renal System

Question 1

Function of the kidneys

Answer 1

Regulation of fluid and electrolyte balance
Excretion of metabolic wastes and foreign substances
Regulation of pH
Maintenance of blood pressure
Regulation of erythropoiesis
Metabolic functions

Question 2

Gross anatomy

Answer 2

Renal cortex outer region
Renal medulla hollow part
Renal pelvis funnel shape

Question 3

nephron

Answer 3

The renal corpuscle Specialised for filtration
The renal tubule Reabsorption secretion
Cortical nephrons renal cortex has a lot of nephrons
Juxtamedullary nephrons descends to renal medulla

Question 4

glomerular filtration membrane

Answer 4

glomerular capillaries, Basement membrane and Podocytes
allows free passage of water and
most solutes, including ions, glucose, amino acids, small proteins, vitamins and nitrogenous wastes

Question 5

Glomerular filtration

Answer 5

non-selective process in which hydrostatic (blood pressure) forces fluid through the glomerular filtration membrane into the glomerular capsule

Question 6

forces determining the filtration pressure

Answer 6

Glomerular hydrostatic pressure
Glomerular Colloid Osmotic Pressure
Capsular hydrostatic pressure

Question 7

GFR

Answer 7

Total volume of filtrate formed each minute
how quickly the blood is cleansed of metabolic waste

Question 8

Factors determining GFR

Answer 8

NFP x SA x PERM

Question 9

tubular reabsorption

Answer 9

A selective process that reclaims most of the filtrate formed during glomerular filtration, occurs when it enters proximal tubule
Proximal tubule site of most reabsorption
Nephron loop reabsorption of water and solutes. Not coupled.
Distal tubule and collecting duct reabsorption regulated by hormones

Question 10

tubular secretion

Answer 10

Selective process moving substances from the blood into the filtrate
removal of unwanted substance
Elimination of excess K+

Question 11

renal regulation of GFR

Answer 11

Maintains production of filtrate and therefore adequate reabsorption
and secretion
Maintains extracellular fluid homeostasis

Question 12

Intrinsic regulation of GFR

Answer 12

myogenic mechanism= Increased blood pressure stretches vascular smooth muscle afferent arteriole constricts in
response=decrease GHP GFR

Question 13

continued

Answer 13

TUBULOGLOMERULAR FEEDBACK MECHANISM-
GFR increases less time for reabsorption concentration of NaCl in filtrate remains high macula densa cells respond to cause constriction
of afferent arteriole GHP GFR slows
down flow of filtrate

Question 14

Extrinsic controls

Answer 14

Neural control
blood pressure falls noradrenaline is
released from sympathetic nerve fibres constricting afferent arterioles GFR

Question 15

RAAS

Answer 15

JG release renin in kidney
enzyme angiotensin released
vasoconstriction in efferent arterioles
ADH release
aldosterone release
thirst centre in hypothalamus
increase in blood pressure

Question 16

properties of urine

Answer 16

Physical characteristics: be clear and pale to deep yellow
slightly aromatic
slighty acidic usually around pH 6
Chemical composition: 95% H2O and 5% solutes
Urea
nitrogenous waste

Question 17

Pathway of urine

Answer 17

Filtrate enters CD
reabsorbed ADH
Secretion of H+ ions and reabsorption
of HCO3 to maintain blood pH
Filtrate passes through papillae
then enters minor then major calyces
renal pelvis (URINE)
Drains into ureter, bladder, urethra

Question 18

Urine output modified

Answer 18

aldosterone ◦ ↑ Na+ reabsorption
◦ ↑ water reabsorption
◦ ↑ K+ secretion
◦↑ ECF volume
◦ ↓ urine output
ADH DT and CD ↑permeable to water (↑ aquaporins)
Results in ↑ water reabsorption
↓ urine output, which ↑
BV & BP