Kidney Function

Question 1

What are the functions of the kidneys ?

Answer 1

• maintain homeostasis
• excretion
• hormonal
• metabolic

Question 2

What does the kidneys excrete ?

Answer 2

• nitrogenous urea

- creatine

Question 3

What are the hormonal functions of the kidney ?

Answer 3

• synthesises renin
• controlls BP
• synthesises erythropoietin

Question 4

What does the synthesis of erythropoietin stimulate ?

Answer 4

Stimulates erythrocytes production in bone marrow

Regulates 02 carrying capacity of blood

Question 5

What does the kidneys metabolise ?

Answer 5

Vitamin D

Question 6

What do the kidneys filter

Answer 6

Small molecules from blood plasma

Question 7

What do the kidneys selectivly reabsorb ?

Answer 7

• water

- some molecules from ultrafiltrate

Question 8

What do the kidneys ?

Answer 8

Renin
Erythropoietin
H+ ions

Question 9

Describe the kidneys structure :

Answer 9

• has outer cortex

- inner medulla

Question 10

What are the medullary pyramids ?

Answer 10

Cone shaped masses of medullary substance

Project into subdivisions of the renal pelvis

Question 11

What is the hilum ?

Answer 11

• site of entry and exit of the renal blood vessels and ureter

Question 12

What is the renal corpsucle ?

Answer 12

Made up of Bowmans capsule

Glomerulus

Question 13

What is the renal tubule ? What does it consist of ?

Answer 13

• proximal convoluted tubule
• loop of henle
• distal convoluted tubule
• collecting tubule

Question 14

What are the 3 layers the plasma filtrate passes through before entering the renal tubule ?

Answer 14

• capillary endothelium
• glomerular basement membrane
• podocytes

Question 15

What is the juxtaglomerular apparatus ?

Answer 15

Specialisation of the afferent arteriole and distal convoluted tubule
Regulates blood pressue via renin-angiotensin-aldosterone system

Question 16

What is the macula densa ?

Answer 16

An area of large closely packed tall epithelial lining cells adjacent to the juxtaglomerular apparatus

Question 17

What are juxtaglomerular cells ?

Answer 17

Specialised smooth muscle cells of the afferent arteriole wall that contain and secrete renin

Question 18

What are lacis cells ?

Answer 18

• derived from mesangial cells

- responsible for erythropoietin synthesis and secretion

Question 19

What do principal cells do ?

Answer 19

• actively reabsorp Na

- secrete K

Question 20

What do intercalated cells do ?

Answer 20

• important for acid-base homestasis
• secrete H+
• reabsorb HCO3 and K+

Question 21

What is the ureter ?

Answer 21

• muscular tube that conducts urine from the kidney to the bladder

Question 22

What moves the urine down the ureter ?

Answer 22

Moves via peristaltic action of ureteric wall

Question 23

What 2 layers make up the ureter ?

Answer 23

• longitudinal

- circular

Question 24

Describe the longitudinal layer of smooth muscle :

Answer 24

• inner layer and elongated spiral

Question 25

Describe the circular layer of smooth muscle :

Answer 25

• outer layer

- tight sprial

Question 26

What lines the ureter ?

Answer 26

• transitional epithelium

- deep lamina propria rich in collagen

Question 27

Describe the structure of the bladder :

Answer 27

• has 3 smooth muscle layers :
  Inner longitudinal
  Outer circular
  Outermost longitudinal
• lots of elastic fibre