Urinary System

Question 1

The functional unit of kidney. Note that Bowman’s capsule is not part of it.

Answer 1

Nephron

Question 2

permeable to H2O but not sodium. Therefore H2Ois reabsorbed and the filtrate becomes more concentrated (hypertonic).

Answer 2

Descending Loop of Henle

Question 3

permeable to sodium but not H2O. Therefore salt is reabsorbed and the filtrate becomes less concentrated (hypotonic).

Answer 3

Ascending Loop of Henle

Question 4

The vasa recta of the nephron runs counter to the loop of Henle.
This acts to multiply the resorption of H2O.

Answer 4

Countercurrent multiplier system

Question 5

The hormone aldosterone will act on the — to increase sodium reabsorption.

Answer 5

distal convoluted tubule

Question 6

The hormone ADH will increase water permeability through aquaporin increase.
Also responsive to aldosterone similar to the distal convoluted tubule.

Answer 6

Collecting duct

Question 7

Renal hormones

Released from juxtaglomerular cells in response to low blood pressure.
Responds to sensors from the macula densa of low sodium concentration or baroreceptor stretch reflex of low renal perfusion pressure.
Triggers angiotensinogen, a cleavage enzyme that result in production of angiotensin II.

Answer 7

Renin

Question 8

Renal hormones

Triggered by renin and results in release of aldosterone.

Answer 8

Angiotensin II

Question 9

Renal hormones

Synthesized in adrenal cortex.
Main function: regulates sodium and potassium ion balance by increasing Na+ re-absorption and K+ excretion in the distal convoluted tubule.
This will also lead to increase in blood pressure due to Na+ and water reabsorption.

Answer 9

Aldosterone

Question 10

Renal hormones

Also called vasopressin.
Synthesized in hypothalamus and released by posterior pituitary.
Regulates blood osmolarity and blood pressure by acting on the collecting duct of the kidney to increase water reabsorption.

Answer 10

ADH

Question 11

Function of renin-angiotensin-aldosterone system

Answer 11

Regulates blood pressure and fluid volume.

Question 12

A hormone produced by kidneys that triggers production of RBCs in the bone marrow.

Answer 12

Erythropoietin

Question 13

pH and electrolyte regulation of the kidneys

Answer 13

Through the nephron, the kidneys regulate the balance of reabsorption and excretion of water and electrolytes.
They also regulate blood pH through reabsorption of bicarbonate and H+ ions affecting the bicarbonate buffer system.

Question 14

Kidney excretes nitrogenous wastes like

Answer 14

ammonia and urea.

Question 15

Urine is produced by

Answer 15

the kidney, stored in the bladder, and exits through the urethra.

Question 16

Made of smooth muscle, it contracts during urination.

Answer 16

Detrusor muscle

Question 17

Made of smooth muscle and under involuntary (parasympathetic) control.

Answer 17

Internal urinary sphincter

Question 18

Made of skeletal muscle and under voluntary control.

Answer 18

External urinary sphincter

Question 19

Cortex vs medulla

Answer 19

Cortex contains Bowman’s capsule, proximal and distal convoluted tubules.
Medulla contains the Loop of Henle and collecting duct.

Question 20

Responsible for moving solutes from blood to the filtrate fluid.
Movement is regulated by hydrostatic pressure.

Answer 20

Bowman’s capsule

Question 21

Network of capillaries at the start of a kidney through which filtrate enters.
Helps filter out large molecules like proteins.

Answer 21

Glomerulus

Question 22

Renal pathway

Answer 22

Glomerulus → Bowman’s capsule → proximal convoluted tubule → Loop of Henle → distal convoluted tubule → collecting duct

Question 23

A measure of the volume of fluid being filtered through the kidney.

Answer 23

Glomerular filtration rate

Question 24

The pressure in the blood vessels that “pushes” filtrate into the kidney through the glomerulus.
Higher hydrostatic pressure leads to increased GFR.

Answer 24

Hydrostatic pressure

Question 25

Afferent and efferent arterioles in renal physiology

Answer 25

Blood flow goes into the kidney through the afferent arteriole and exits through the efferent arteriole.
Vasoconstriction of the afferent arteriole decreases GFR whereas vasoconstriction of the efferent arteriole increases GFR.

Question 26

Osmotic pressure in renal physiology

Answer 26

The osmotic pressure in the tubule “sucks” filtrate into the kidney.
Higher solute concentration in the tubule increases osmotic pressure and increases GFR.