Structure and function of the kidney

Question 1

Where are the kidneys located?

Answer 1

Posteriorly on the right lower part of the body.

Question 2

Where is the blood supply for the kidney from?

Answer 2

The renal arteries from the aorta.

Question 3

What is the protective tissue that surrounds the kidney?

Answer 3

The renal capsule.

Question 4

What is the hilum?

Answer 4

The opening for attachment of the renal artery and vein, nerves and ureter.

Question 5

What is the central cavity called of the kidney?

Answer 5

The renal sinus.

Question 6

What direction is the afferent arteriole to?

Answer 6

Towards the nephron.

Question 7

What direction is the efferent arteriole to?

Answer 7

Leaves the nephron.

Question 8

What is the name of the network of capillaries that surrounds the kidney?

Answer 8

Peritubular capillaries.

Question 9

What is the functional unit of the kidney?

Answer 9

The nephrons.

Question 10

What is the Bowman’s capsule?

Answer 10

It is where filtration occurs.

Question 11

What are the different types of nephron?

Answer 11

Cortical nephrons (close to the the cortex) and ones closer to the medulla - juxtamedullary.

Question 12

How many nephrons are there per kidney?

Answer 12

1.3 x 10^6.

Question 13

What percentage of the blood is filtered?

Answer 13

20%.

Question 14

Why is the glomerulus tangled?

Answer 14

It creates a large surface area for filtration.

Question 15

What is the renal corpuscle?

Answer 15

It contains the functional units of the kidneys such as the glomerulus and Bowman’s capsule.

Question 16

What is the brush border.

Answer 16

A microvilli-covered surface that provides a large surface area for processes to occur.

Question 17

What is the limb of Henle made up of?

Answer 17

Flattened squamous epithelial cells with few organelles.

Question 18

What are the two layers of the Bowman’s capsule?

Answer 18

The visceral layer and the parietal layer. The visceral layer is in contact with the organs and the parietal is the outer layer.

Question 19

What is the visceral surface made up of?

Answer 19

It is covered with podocytes.

Question 20

Where is the juxta glomerular?

Answer 20

It is next to the glomerulus. It secretes hormones into the glomerulus. They are important for regulation.

Question 21

What are fenestrations in the capillaries?

Answer 21

Large gaps between endothelial cells.

Question 22

What is the basal lamina?

Answer 22

The thin layer of extracellular matrix that separates the endothelial cells from the podocytes.

Question 23

What are podocytes?

Answer 23

Narrow filtration slits that are the finest level of filtration.

Question 24

What are the three filtration barriers?

Answer 24

Fenestrations of the glomerular endothelial cells, the basal lamina of glomerulus and the slit membrane between pedicels

Question 25

What drives filtration?

Answer 25

The hydrostatic pressure of the glomerular capillaries.

Question 26

How does the relaxation of the arterioles drive filtration?

Answer 26

The afferent arteriole is more relaxed than the efferent arteriole leaving which forces filtration to occur.

Question 27

What is oncotic pressure?

Answer 27

Pressure due to osmotic forces.

Question 28

What is glomerular filtration rate?

Answer 28

The volume of filtrate produced by the kidneys per minute.

Question 29

What is the average healthy GFR for adults?

Answer 29

125ml/minute.

Question 30

Despite a relatively low filtration pressure, why is the volume of filtrate large?

Answer 30

The surface area of the glomerular capillaries is large, the glomerular capillary endothelium is fenestrated and the glomerular capillary blood pressure is high.

Question 31

What are some of the ways that GFR can be altered?

Answer 31

Changes in diameter of the afferent and efferent arterioles, The efferent arteriole usually has a smaller diameter than the afferent arteriole to help drive the GFR.

Question 32

What does the urinary excretion of a substance depend on?

Answer 32

FIltration, reabsorption and secretion.

Question 33

Where are most of the fluid and solutes reabsorbed?

Answer 33

In the proximal convoluted tubule.

Question 34

Where is most of the water reabsorbed in the loop of Henle?

Answer 34

At the end.

Question 35

What primarily controls the regulation of the loop of Henle and glomerulus?

Answer 35

Autoregulation - tubuloglomerular feedback.

Question 36

What primarily controls the regulation of collecting duct and DCT?

Answer 36

Hormones.