Week 5 – The Urinary System

Question 1

What are the organs of the urinary system?

Answer 1

1. Kidneys
2. Ureters
3. Urinary Bladder
4. Urethra

Question 2

List the gross anatomy of the kidneys from superficial to deep

Answer 2

Renal capsule
Renal cortex
Renal medulla
* Renal pyramids
* Renal papillae
* Renal columns
Major and minor calcyes
Renal pelvis

Question 3

What do the organs of the urinary system do?

Answer 3

1. Ureters - transport urine from renal pelvis to urinary bladder - peristalsis
2. Urinary bladder - stores urine b4 micturition
3. Urethra - discharge urine from the body, and in males sprem

Question 3

What do the organs of the urinary system do?

Answer 3

1. Ureters - transport urine from renal pelvis to urinary bladder - peristalsis
2. Urinary bladder - stores urine b4 micturition
3. Urethra - discharge urine from the body, and in males sprem

Question 4

What are the main functions of the kidneys?

Answer 4

1. Filter water materials from the blood
2. Regulate blood pressure
3. Create hormones that help produce RBC’s

Question 5

What are the functional units of the nephron?

Answer 5

Renal corpuscle
* glomerulus
* and glomerular capsule
Renal Tubule
* Proximal convoluted tubule
* Descending limb of the nephron loop
* Ascending limb of the nephron loop
* Distal convoluted tubule (which drains into the collecting duct)

Question 6

What does the renal corpuscle/ glomerular capsule do?

Answer 6

Filters blood plasma

Question 7

What makes up the juxtaglomerular apparatus (JGA)?

Answer 7

juxtaglomerular apparatus (JGA) consists of
1. the juxtaglomerular cells of an afferent arteriole
1. and the macula densa of the final portion of the ascending limb of the nephorn loop.

Question 8

What do the renal tubules do (DCL< PCL & nephron loop)?

Answer 8

Tubular reabsorption - as filtered fluid flows through the tubules, paracellular (bw tubule cells) and transcellular (through tubule cells), tubule cells reabsorb 99% of water/ useful solutes returning them to the blood via peritubular capillaries
Tubular Secretion - as the filtered fluid flows through the renal tubles and collecting ducts, cells secrete (remove) waster materials from it

Question 9

What do the juxtamedullary nephrons do?

Answer 9

Involved in concentrating or diluting urea (versus cortcal nephrons (85%) which perform excretory and regulatory fns of kidney)

Question 10

What forces (pressures) that promote or counteract glomerular filtration?

Answer 10

• Glomerular blood hydrostatic pressure (GBHP) promotes filtration
• Capsular hydrostatic pressure (CHP) and blood colloid osmotic pressure (BCOP) oppose it
• Net filtration pressure (NFP) = GBHP - CHP - BCOP and is about 10mm Hg

Question 11

What is Transport Maximum?

Answer 11

Max amount of substance that can be reabsorbed per unit of time

Question 12

How much water reabsorption is obligatory?

Answer 12

• 90% - occurs via osmosis with reabsorption of solutes
• 10% is facultative which varies according to the body’s needs and is regulated by anti diuretic hormone (ADH)

Question 13

What are intrinsic controls of glomerular filtartion rate?

Answer 13

renal autoregulation - the kidney itself can adjust the dilation or constriction of the afferent arterioles

Question 14

What are intrinsic controls of glomerular filtartion rate?

Answer 14

renal autoregulation - the kidney itself can adjust the dilation or constriction of the afferent arterioles

Question 15

What is renal regulation and what does it do?

Answer 15

renal regulation or nervous system control and hormonal control - can extrinisically control / override renal autoregulation and decrease the glomerular filtration rate when necessary.
For example if you have a large drop in blood pressure, which can happen if you lose a lot of blood, your nervous system will stimulate contraction of the afferent arteriole, reducing urine production.

Question 16

Apart from nerous system control, how else gen the glomerular filtration rate be extrinsically controlled?

Answer 16

Hormonal regulation via atrial natriuretic peptide - a hormone that can increase the glomerular filtration rate and therefore urine production