Lec 21- Urinary system

Question 1

Ureter

Answer 1

Tube that goes from kidneys to bladder.

Question 2

Urethtra

Answer 2

Tube that goes from bladder to external environment.

Question 3

Nephron

Answer 3

Functional unit of the kidney responsible for forming urine.
Each kidney has 1 million of these.
Functional units that are bound together by connective tissue.

Question 4

Bowman’s capsule

Answer 4

Collects the glomerular filtrate.

Question 5

Proximal convoluted tubule

Answer 5

uncontrolled reabsorption and secretion of selected substances occur here.

Question 6

Loop of henle

Answer 6

Establishes osmotic gradient in the renal medulla that is important in the kidney’s ability to produce urine of varying concentrations

Question 7

Distal convoluted tubule

Answer 7

variable, controlled reabsorption of Na+ and H2O and secretion of K+ and H+ occur here; fluid leaving the collecting duct is urine, which enters the renal pelvis

Question 8

Collecting duct

Answer 8

Duct that drains fluid from up to 8 different nephrons to renal pelvis.

Question 9

Renal corpuscle

Answer 9

Includes the glomerulus and the glomerular capsule

Question 10

Glomerular filtration rate AKA glomerular ultrafiltration

Answer 10

180 L a day; 125 mL/min in males.

160 L a day; 115 mL/min in females.

Question 11

Afferent arteriole

Answer 11

carries blood to the glomerulus.

Question 12

Efferent arteriole

Answer 12

Carries blood from the glomerulus.

Question 13

Obligatory water loss

Answer 13

400 mL

But we normally produce about 1-2L of urine per day.

Question 14

Reabsorption

Answer 14

filtrate returning (most in proximal convoluted tubule) -> 85% occurs before distal convoluted tubules.

Question 15

Descending Loop of Henle

Answer 15

Permeable to H2O.

Does not actively extrude Na+ (does not reabsorb Na)

Question 16

Ascending Loop of Henle

Answer 16

Actively transport NaCl out.

Always impermeable to H2O (due to cholesterol).

Question 17

Countercurrent Multiplier System

Answer 17

Produced by nephrons, due to flow of ultrafiltrate in counter direction and differential movement of molecules and permeabilities, allows got the creation of hyperosmotic interstitial fluid environment.

Question 18

Urea

Answer 18

Waste product from the breakdown of protein.

Passive reabsorption.

Question 19

Vasa recta

Answer 19

peritubular capillaires in the medulla.