3. Urinary System & Nephron

Question 1

Vocab

What is Excretion?

Answer 1

• Process of sperating & removing wastes from bodily fluids

Question 2

What is the function of the Excretory System?

Answer 2

• Filters waste from blood and makes urine
• Maintains ion balance
• Secretes hormones

Question 3

Vocab

What is Urine?

Answer 3

• Filtrate of the nephron after collecting duct

Question 4

How is Urine Formed?

Answer 4

1. Filtration:
   blood enters the kidney and is filtered out (plasma, protein, blood and platelets stay in blood). Filtrate enters bowman’s capsule where contents (ie. ions, glucose) are absorbed or excreted.
2. Reabsorbtion:
   Filtrate and water gets reabsorbed into the blood, nephron’s concentration goes up. Water is further absorbed collecting duct
3. Secretion:
   Urine is produced and hormones are secreted.

Question 5

What is the Process of Blood In The Nephron?

Answer 5

1. Blood enters nephron through renal artery (kidney’s cortex)-afferent
2. Forced through glomerulus (filtering capillary bed). Surrounded by Bowman’s capsule.
3. Fluid enter proximal tubule
4. Blood leaves from glomerulus through capillary network-efferent
5. Fluid in proximal tubule travel from loop of Henle to distal tubule collecting duct.
6. Collects into ureter, then bladder
7. Solutes are reabsorbed back into blood in Medulla.
8. Blood leaves the capillary network as a venule (renal vein).