Intro to the Kidney

Question 1

What are the different types of human tissue?

(recap card)

Answer 1

Epithelia

Connective Tissue

Blood

Muscle

Nervous Tissue

Question 2

What are the roles of simple squamous epithelium?

Answer 2

Filtration

Exchange of substances

Question 3

What are the roles of simple cuboidal cells?

Answer 3

Absorption and production of substances

Contain mitochondria and protein producing organelles.

Larger intracellular volume= larger amount of contents

Question 4

What are the functions of simple columnar cells?

Answer 4

Motility, absorption and processing

Question 5

What are the functions of the kidney?

Answer 5

• Regulation of body fluid volume
• Regulation of body fluid composition
• Excretion of metabolic waste and toxins
• Endocrine functions

Question 6

What are the main processes the kidney carries out?

Answer 6

Filtration

Reabsorption

Secretion

= forms urine

Question 7

What does the uriniferous tubule consist of?

Answer 7

Nephron and collecting duct

Question 8

What is the nephron made up of?

Answer 8

Renal corpuscle

Proximal convoluted tubule

Loop of Henle

Distal convoluted tubule

Question 9

What is the renal corpuscle made up of?

Answer 9

Glomerulus

Bowman’s capsule

Question 10

Describe the arterial supply to the kidneys

Answer 10

Renal artery→Segmental arteries→Interlobar arteries→Arcuate arteries→Interlobular arteries→Afferent arterioles to the renal corpuscle→Glomerular capillaries→Efferent arterioles→Peritubular capillaries

Question 11

What is the role of the glomerular capillaries?

Answer 11

Filtration

Question 12

What is the role of the peritubular capillaries?

Answer 12

Reabsorption and secretion

Question 13

What 2 layers make up the Bowman’s capsule?

What type of epithelium are they covered in?

What is their role?

Answer 13

Parietal layer:

• Outer
• Simple squamous
• Containment

Visceral layer:

• Inner
• Modified simple squamous (podocytes)
• Filtration

Question 14

What cells are between the loops of the glomerular capillary for support?

Answer 14

Mesangial cells

Question 15

Which structures form the filtration barrier?

What is its role?

Answer 15

1. Glomerular capillary endothelium (fenestrated)
2. Basement membrane (-ve charge)
3. Epithelium (podocytes)

Limits the passage of substances based on their size, shape and charge.

Question 16

What happens in the proximal convoluted tubule?

What is its epithelium?

Answer 16

Unmodified filtrate leaves the bowman’s capsule into the PCT.

• Majority of water, Na⁺, amino acid, glucose and Cl^- reabsorption takes place here.
• Secretion of some drugs and waste products
• Simple cuboidal epithelium with microvilli (brush border- increases surface area)

Question 17

What happens in the loop of Henle?

What are the different parts and their epithelia?

Answer 17

Thin descending limb:

• Permeable to water
• No active reabsorption or secretion of solutes
• Simple squamous epithelium

Thin ascending limb:

• Impermeable to water
• No active reabsorption of Na⁺ and other solutes
• Simple squamous epithelium

Thick ascending limb:

• Impermeable to water
• Active reabsorption of Na⁺ and other solutes
• Simple cuboidal cells

Question 18

What happens in the distal convoluted tubule?

What are the different parts and their epithelia?

Answer 18

Early part and late parts

• Active reabsorption of Na⁺ and other solutes
• Secretion of K⁺ and H⁺
• Simple cuboidal cells
• Early part passes back to the vascualar pole of its own renal corpuscle to form the juxtaglomerular apparatus

Question 19

What are the 3 components of the juxtaglomerular apparatus?

Answer 19

• Macula Densa: specialised cells that sense levels of Na⁺ and Cl^- in the tubule
• Extraglomerular mesangial cells (Lacis cells): supporting cells
• Granular/juxtoglomerular cells: cells in afferent arterioles that alter BP and filtration.

Question 20

What occurs in the collecting duct?

What is its epithelium?

Answer 20

• Final site for urine processing
• Water permeability is under the control of anti-diuretic hormone (ADH)
• Surrounded by medullary interstitium with a high concentration of solutes.
• Simple columnar cells