Lecture 27- Nephrons

Question 1

Bowman’s capsule (glomerular capsule)

Answer 1

Has parietal layer and visceral layer surrounding capillaries, consisting g of pod of cytes that allow filtrate to pass into space within bowman’s capsule

Question 2

Proximal convoluted tubule

Answer 2

Wall has dense microvilli to increase SA for absorption and secretion to urine

Question 3

Loop of henle

Answer 3

Has thin descending limb and an ascending limb that has both thin and think segments

Question 4

Distal convoluted tubule

Answer 4

Similar to proximal convoluted tubule but cells lack microvilli

Question 5

Collecting duct

Answer 5

Contains principal cells with sodium and potassium ion channels and auquaporins to reabsorb water and intercalated cells that control pH

Question 6

Cortical nephrons

Answer 6

85%
Located almost entirely within cortex and halve SHORT nephron loop (loop of henle)

Question 7

Juxtamedullary nephrons

Answer 7

15%
Located near cortex- medulla junction and have LONG nephron loop

Question 8

Peritubular capillaries

Answer 8

In Cortical nephrons

Low pressure, porous absorb solutes and water from tubule cells

Around nephron loop

Question 9

Vasa recta

Answer 9

In Juxtamedulalry nephron

Arise from efferent arterioles run parallel to longest nephron loops

Question 10

Juxtaglomerular apparatus

Answer 10

Structural arrangement between afferent arteriole and distal convoluted tubule

Question 11

Macula dense cells

Answer 11

In distal convoluted tubule , uses chemoreceptors to monitor NaCl content of filtrate

Question 12

Granular cells

Answer 12

Derived from wall of arterioles, act as mechanoreceptors that monitor blood pressure and house secretory vesicles that contain the enzyme renin

Question 13

What a re the three processes involved in urine formation and adjustment of blood composition?

Answer 13

Glomerular filtration- produces cell and protein free filtrate

Tubular reabsorption selectively returns 99% of substances from filtrate to blood in renal tubules and collecting ducts

Tubular secretion- selectively moves substances from blood to filtrate in renal tubules and collecting ducts

Question 14

Glomerular filtration

Answer 14

Passive, non selective process i which hydrostatic pressure forces fluid through glomerular membrane

Question 15

Filtration membrane

Answer 15

Porous membrane that allows free passage of water and olives smaller that plasma proteins

Question 16

What are the three layers of the filtration membrane?

Answer 16

Fenestrated endothelium

Basement membrane- consist of negatively charged glycoproteins that inhibit filtration large or negatively charged molecules

Foot processes (pedicels)

Question 17

Hydrostatic pressure in glomerular capillaries

Answer 17

Primary face pushing water and solutes out of blood across filtration membrane

Question 18

Net filtration pressure calculation

Answer 18

= GBHP (glomerular blood hydrostatic pressure) - CHP (capsular hydrostatic pressure) - BCOP (blood colloid osmotic pressure