Urinary System

Question 1

The components of the urinary system

Answer 1

Kidneys - left is slightly superior to the right. Filters the blood to remove waste, retains water and essential substances.
Ureters - transport urine from the kidneys to the bladder
Bladder - temporarily stores the urine
Urethra - expels the urine.

Question 2

Renal Terminology

1. Glycosuria
2. Haematria
3. Pyuria
4. Dysuria
5. Polyuria
6. Oligouria
7. Anuria
8. Ketonuria
9. Albuminuria
10. Nepthrotoxin
11. Nocturnal enuresis

Answer 2

1. Glucose in the urine
2. Blood in the urine
3. Pus in the urine
4. Difficulties with urination
5. Excessive amounts of urine
6. Small amounts of urine
7. No urine
8. Ketones in the urine (caused by diabetes mellitus or starvation)
9. Albumin in the urine
10. Substance toxic to the kidneys
11. Inability to control bladder while sleeping (bedwetting)

Question 3

Major functions of the kidneys

Answer 3

• Remove metabolic waste products from the body.
• Regulate loss of water ad salt from the body.
• Produce renin to help regulate blood pressure.
• Maintain pH of blood by selectively secreting or retaining H+ and HCO3- ions
• Produces erythropoietin to stimulate RBC production

Question 4

Structural components of the kidney

Answer 4

• Ruggae. Folds in the bladder lining that allow the bladder to stretch when full and shrink when empty.
• Uretric orifices, where the ureters enter.
• Bladder neck.
• Trigone of bladder, marked by the uretric orifices and bladder neck.
• The bladder is funnel-shaped.

Question 5

Gross structural components of the kidney

Answer 5

• Adrenal gland - sits atop the kidney.
• Renal cortex - the outer section of the kidney.
• Medulla - the inner section of the kidney.
• Renal pelvis - connects to the ureter.
• Minor and major calyxes - indents between the pyramids.

Question 6

Structural components of the nephron

Answer 6

Afferent arteriole - Blood flows into the glomerulus
Efferent arteriole - Blood flows away from the glomerulus
Glomerulus - Glomerular capillaries experience high blood pressure to push the filtrate into the Bowman’s capsule.
Bowman’s capsule - Where the filtrate is collected from the glomerulus.
Renal corpuscle - Encompasses both the glomerulus and the Bowman’s capsule.
Proximal convoluted tubule - the majority of re-absorption occurs here.
Ascending and descending loops of Henle - salt is drawn out at the ascending loop, water follows from the ascending loop.
Distal convoluted tubule - aldosterone impacts the dct to increase salt re-absorption
Collecting duct - ADH impacts the collecting duct to increase the reabsorption of water. Carries urine to the ureters.

Question 7

Glomerular filtration

Answer 7

• Separates solids from liquids.
• Blood cells and proteins are too big to be filtered. They remain in the capillaries.
• The product is called filtrate, and it is comprised of water, urea, uric acid, NaCl, H+, K+, NH4-, HCO3-, glucose, amino acids, vitamins and possibly some drugs.
• Occurs in the glomerulus of the nephron.

Question 8

Renin-angiotensin-aldosterone mechanism

Answer 8

Following a drop in blood pressure or volume:

• Cells in the juxtaglomerular complex release renin, which converts angiotensinogen to angiotensin I, then II.
• Angiotensin II stimulates the adrenal cortex to release aldosterone.
• Aldosterone increases reabsorption of NaCl, and therefore water, which raises BP.

Question 9

Anti-diuretic hormone (ADH)

Answer 9

• Decreases urine output by increasing reabsorption of water by the collecting duct.
• Released by the posterior pituitary.
• Sufficient hydration ad alcohol both inhibit it’s release, therefore increasing urine output.

Question 10

Micturition

Answer 10

• Emptying the bladder
• When the bladder fills, the parasympathetic nervous system triggers the micturition reflex.
• This can be temporarily voluntarily delayed.
• Incontinence by weakened pelvic floor.
• Some drugs and an enlarged prostate can cause urine retention, which may require a catheter.