Topic 16: Urinary System - Nephrons

Question 1

What are nephrons composed of? (2)

Answer 1

• renal corpuscle
  -renal tubules

Question 2

Where is the renal corpuscle located?

Answer 2

• in cortex

Question 3

What is the function of the renal corpuscle?

Answer 3

• site of blood filtration (first step in urine formation)

Question 4

What are the three parts of a renal corpuscle?

Answer 4

• glomerulus
• Bowman’s Capsule
• Filtration membrane

Question 5

What is the glomerulus?

Answer 5

capillary bed

Question 6

What is a bowman’s capsule? (2)

Answer 6

• surrounds glomerulus
• collects filtrate from glomerulus

Question 7

What are the two layers of a bowman’s capsule? aka outer and inner

Answer 7

outer - simple squamous
inner - podocytes wrapped around glomerular capillaries

Question 8

What is the filtration membrane of a nephron composed of? (3)

Answer 8

1. Glomerular endothelium (capillaries)
2. Basement membranes
3. Podocytes (of Bowman’s Capsule)

Question 9

What is the structure of the filtration membrane of glomerular endothelium?

Answer 9

• simple squamous with pores called fenestrations

Question 10

what is the structure of the filtration membrane of podocytes of Bowman’s capsule? (2)

Answer 10

• simple epithelium
• projections cling to glomerulus

Question 11

What are the 4 parts of the renal tubules?

Answer 11

1. Proximal convoluted tubule (PCT)
2. Loop of Henle
3. Distal Convoluted Tubule (DCT)
4. Collecting ducts

Question 12

Where is the proximal convoluted tubule located?

Answer 12

• in cortex

Question 13

What is the loop of henle, and where is it located?

Answer 13

• descending and ascending limbs
• in medulla

Question 14

Where is the distal convoluted tubule located?

Answer 14

in cortex

Question 15

What are the collecting ducts in renal tubules? (2)

Answer 15

• connect nephron to ureter
• via calyces and renal pelvis

Question 16

Where are collecting ducts located?

Answer 16

• in cortex and medulla

Question 17

What are the 2 types of nephrons called?

Answer 17

• Cortical (85%)
• Juxtamedullary (15%)

Question 18

What are cortical nephrons? (2)

Answer 18

• renal corpuscles near kidney surface in cortex
• short Loop of Henle in outer medulla

Question 19

What are juxtamedullary nephrons? (2)

Answer 19

• renal corpuscles in cortex near medulla
• long loops of Henle that penetrate deep into medulla

Question 20

Why do juxtamedullary nephrons have long loops of Henle?

Answer 20

• allows concentration of urine, depending on need

Question 21

Please know this diagram of kidney and nephron blood supply

Answer 21