Kaplan Prep - Renal System (Kidneys) - problem set 2

Question 1

What are the 3 major processes by which the nephron is able to carry out its functions?

Answer 1

The kidney filters the blood, reabsorbs needed materials, and excretes the rest as urine.

Question 2

What are the six main functions of the kidney?

Answer 2

The six main functions of the kidney are to:

control the concentration of water and soluble materials
eliminate wastes from the body
regulate blood volume
regulate pH 
regulate blood pressure 
and control levels of electrolytes

Question 3

What are the main two parts of the kidney nephron?

Answer 3

A nephron is made up of:

the renal corpuscle
and
the renal tubule.

Question 4

What is the function of the renal corpuscle?

Answer 4

The renal corpuscle filters the blood

Question 5

What is the function of the renal tubule?

Answer 5

the renal tubule REABSORBS needed materials

Question 6

What tube carries urine away from the nephron?

Answer 6

collecting ducts

carry urine away from the nephron to be excreted.

Question 7

What are the two parts of the renal corpuscle?

Answer 7

the Glomerulus
and
the Bowman’s capsule

Question 8

Describe the glomerulus

Answer 8

a network of tiny blood capillaries

Question 9

What type of cells make up the Bowman’s capsule?

Answer 9

double-walled simple squamous epithelial

Question 10

What is unique about the glomerular capillaries?

Answer 10

The glomerular capillaries are the only capillaries in the body which lie between two arterioles rather than between an artery and a vein.

Question 11

What causes the very high pressure in the glomerular capillaries ?

Answer 11

The afferent arteriole which runs into the glomerular capillaries is much larger in diameter than the efferent arteriole which drains the glomerular capillaries causing an extremely high blood pressure in the glomerular capillaries.

Question 12

What is the result of the very high pressure in the glomerular capillaries?

Answer 12

This high pressure forces water and solutes out of the blood and into the glomerular capsule causing the glomerulus to act as a filter.

Question 13

Name the sections of tubes/ducts beyond the nephron (beyond the renal capsule)

Answer 13

The first section of the renal tubule is the proximal convoluted tubule. The second section is the loop of Henle. The last part of the tubule is the distal convoluted tubule. The urine then drains into collecting ducts, which join to form papillary ducts, which drain into the calyces and subsequently into the renal pelvis and out of the kidney by way of the ureter.

Question 14

What is the function of the proximal convoluted tubule?

Answer 14

It is specialized to reabsorb water and many solutes from the glomerular filtrate and secrete certain unwanted substances.

Question 15

What is the function of the loop of Henle?

Answer 15

Re-absorption of water and salt (NaCl).

Question 16

What is the function of the distal convoluted tubule?

Answer 16

It allows hormonally controlled reabsorption of water and solutes but mostly secretion of unwanted substances.

Question 17

Name the 2 types of nephrons

Answer 17

cortical nephrons
and
juxtamedullary nephrons

Question 18

What are the differences between the cortical and juxtamedullary nephrons?

Answer 18

Most kidney nephrons are located mainly in the cortex with a small portion of their loop of Henle extending into the medulla. The juxtamedullary nephrons have longer loops of Henle that pass deeply into the medulla.

Question 19

Name the 3 types of capillaries associated with nephrons

Answer 19

glomerular capillaries

peritubular capillaries

vasa recta

Question 20

Are the glomerular capillaries porous?

Answer 20

Yes

Question 21

Besides the porous capillaries, what other factor contributes to the filtering that occurs in the glomerular capillaries?

Answer 21

The high pressure

Question 22

When fluid and solutes are filtered out of the glomerulus, where do they go?

Answer 22

into the glomerular capsule.

Question 23

What happens to most of the blomerular filtrate?

Answer 23

It gets reabsorbed through the renal tubule and returned to the blood in the peritubular capillary bed

Question 24

Describe the peritubular capillaries

Answer 24

Most of the glomerular filtrate is reabsorbed through the renal tubule and returned to the blood in the peritubular capillary bed which arises from the efferent arterioles and closely follow the renal tubules and drain into the interlobular vein. Because of their porosity and low pressure, the peritubular capillaries are adapted for absorption reclaiming water and solutes from the filtrate.

Question 25

Describe the vasa recta

Answer 25

The vasa recta follows the loops of Henle of the juxtamedullary nephrons in the medulla.