Renal Anatomy and Blood Supply

Question 1

What are the 3 functions in which the kidneys work?

Answer 1

• as excretory organs
• as regulatory organs
• endocrine organs

Question 2

How do the kidneys function as excretory organs?

Answer 2

They ensure that those substances in excess or that are harmful are excreted in urine in appropriate amounts

Question 3

How do the kidneys function as regulatory organs?

Answer 3

They maintain a constant volume and composition of the body fluids by varying the excretion of solutes and water

Question 4

How do the kidneys function as endocrine organs?

Answer 4

They synthesize and secrete 3 hormones: renin, erythropoietin, and 1,25-dihydroxycholecalciferol

Question 5

What are the 3 main regions of the kidneys in the sagittal section?

Answer 5

• the cortex is the outer region
• the medulla is the central region
• the papilla is the innermost tip of the inner medulla

Question 6

What do the papillae empty into?

Answer 6

pouches called minor and major calyces

Question 7

The minor and major calyces are extensions of what?

Answer 7

The ureter

Question 8

What is the functional unit of the kidney?

Answer 8

The nephron

Question 9

Each kidney contains approximately how many nephrons?

Answer 9

1 million

Question 10

What does a nephron consist of?

Answer 10

A glomerulus and a renal tubule

Question 11

What surround the glomerular capillaries?

Answer 11

the Bowman’s capsule

Question 12

What are the 5 segments that comprise the renal tubule?

Answer 12

• the proximal convoluted tubule
• the proximal straight tubule
• the loop of Henle
• the distal convoluted tubule
• the collecting ducts

Question 13

What is unique about the cells of the proximal convoluted tubule?

Answer 13

They have an extensive development of microvilli, called a brush border, on their luminal side

Question 14

What is the function of the brush border?

Answer 14

It provides a large surface area for the major reabsorptive function of the proximal convoluted tubule

Question 15

What are the 2 types of nephrons?

Answer 15

• superficial cortical nephrons

- juxtamedullary nephrons

Question 16

Where do superficial cortical nephrons have their glomeruli?

Answer 16

In the outer cortex

Question 17

Where do juxtamedullary nephrons have their glomeruli?

Answer 17

near the corticomedullary border

Question 18

Which type of nephrons have higher filtration rates? Explain why

Answer 18

The juxtamedullary nephrons because their glomeruli are larger than those of the superficial cortical nephrons

Question 19

Superficial cortical nephrons have ____ loops of Henle. Juxtamedullary nephrons have ____ loops of Henle.

Answer 19

short

long

Question 20

Describe the path blood takes as it enters the kidneys

Answer 20

Blood enters via the renal artery, which branches into interlobar arteries, arcuate arteries, and then cortical radial arteries

Question 21

What do the smallest arteries (cortical radial arteries) subdivide into?

Answer 21

The first set of arterioles, the afferent arterioles

Question 22

Where do the afferent arterioles deliver blood to?

Answer 22

The first capillary network, the glomerular capillaries

Question 23

What occurs across the glomerular capillaries?

Answer 23

ultrafiltration

Question 24

Blood leaves the capillaries via what?

Answer 24

a second set of arterioles, the efferent arterioles

Question 25

Where do the efferent arterioles deliver blood to?

Answer 25

To the secondary capillary network, the peritubular capillaries

Question 26

What occurs across the peritubular arteries?

Answer 26

Solutes and water are reabsorbed into the from the nephron

Question 27

Where does blood flow after exiting the peritubular arteries?

Answer 27

Into small veins and then into the renal vein

Question 28

How does juxtamedullary nephron blood flood differ?

Answer 28

The peritubular capillaries have a specialization called the vasa recta, which are long, hairpin-shaped blood vessels that follow the same course as the loop of Henle

Question 29

What do the vasa recta serve as?

Answer 29

Osmotic exchangers for the production of concentrated urine