Chapter 26: Urinary System

Question 1

Filtrate→Urine

Answer 1

Working part of the kidney are the nephrons (Action part “does the job”)

Filtrate from nephrons (turns to urine) drains into calyces (Calyx) (Tube that nephrons leak into)

Into Renal pelvis (Middle kidney)→Ureters→Urinary bladder

Question 2

Nephron:

Answer 2

Consists of renal corpuscle and renal tubule
Nephrons cannot regenerate
At rest, kidneys receive 20-25% of total cardiac output

Question 3

Renal Corpuscle:

Answer 3

Glomerulus (Bunch of blood capillaries)
Glomerular capsule (2 layers)

Coming out of those glomerular capsule is water and solutes in between both layers

Question 4

Blood supply to the nephron:

Answer 4

Renal artery→Afferent arteriole→Glomerulus→efferent arteriole→

Question 5

Renal Tubule:

Answer 5

Proximal Tubule→ Nephron loop with descending and ascending limbs→ Distal Tubule→ Empties into collecting duct

Question 6

Juxtaglomerular Apparatus:

Answer 6

Responsible for BP and Filtration rate
Macula Densa: Part of ascending loop + afferent arteriole

Question 7

Basic Functions of the Nephron:

Answer 7

Glomerular Filtration (Water and solutes from Glomerular blood move into glomerular capsule)
Tubular Reabsorption (Returns substances from filtrate to blood)
Tubular secretion (Removes additional substances from blood into filtrate)

Question 8

Basic Functions of the Nephron: Renal Corpuscle

Answer 8

Filtration (Blood→Filtrate)
Tubule: → Reabsorption (Filtrate→Blood)
Tubule: → Secretion(Blood→Filtrate)

Question 9

Glomerular Filtrate:

Answer 9

All the fluid entering the glomerular capsule space (150-180 Liters/Day)
99% reabsorbed; 1-2 Liters of urine/day produced

Filtration Rate is adjusted by the diameter of the afferent arterioles

Question 10

Reabsorption and Secretion: Proximal Convoluted tubule:

Answer 10

*Reabsorbs 100% of amino acids and Glucose *

Permeable to Water (65%)
Obligatory reabsorption of Water (by osmosis– Not adjustable)
Majority happens here

Question 11

Reabsorption: Nephron Loop

Answer 11

Reabsorbs 15% of Water
Reasorbs 20-30% of Na+, K+

Question 12

Reabsorption: Distal Convoluted Tubule

Answer 12

Reabsorption of 10-15% Water
Reabsorption of Na+, K+

Question 13

Reabsorption and Secretion: Collecting Duct

Answer 13

Reabsorption of Na+, K+, Urea, HCO3
Facultative reabsorption of water (adjustable)
Secretes H+ and recovers HCO3 for Ph balance
Aldosterone: Increases sodium and water reabsorption in collecting duct

Question 14

Renin - Aldosterone - Angiotensin

Answer 14

Decreased BP or BV gets detected by JGA which secretes Renin
Renin activates angiotensinogen→angiotensinogen I→angiotensinogen II = Strong Vasoconstrictor

Question 15

Effects of Angiotensinogen II

Answer 15

Vasoconstriction of afferent arterioles
Increased Reabsorption of sodium and water
Secrete aldosterone
Stimulates Antidiuretic Hormone (ADH) from posterior pituitary (In brain)

Question 16

ADH (Antidiuretic Hormone)

Answer 16

Increases water permeability of cells of collecting duct (Facultative aka Adjustable)
Increases reabsorption of water
Anti/Durectic
Opposed to/ Loss of water in urine

Question 17

Water Follows Sodium!

Answer 17

Water Follows Sodium!