Kidney 2 - Structure & Tubular Filtration

Question 1

What are the components of the renal tubule?

Answer 1

• Proximal convoluted tubule (PCT)
• Loop of Henle
• Distal convoluted tubule (DCT)

Question 2

What are some of the things reabsorbed in the renal tubule?

Answer 2

• Water
• Glucose
• Amino Acids
• Urea
• Sodium, Chloride, Calcium, Phosphate, Potassium, Bicarbonate

(CREATININE is NOT reabsorbed) by product of creatine

Question 3

The majority of the filtrate is reabsorbed where in the renal tubule?

Answer 3

Proximal convoluted tubule reabsorbs 2/3 of filtrate (Most reabsorbed ‘things’ follow Na+ movement)

Question 4

How does the loop of henle reabsorb water and concentrate urine?

Answer 4

Using counter current multiplication

Question 5

What is the role of the distal convoluted tubule?

Answer 5

To fine-tune fluid volume and regulate electrolytes

Question 6

How are Sodium and Water hormonally regulated in the DCT?

Answer 6

• ADH increases water reabsorption
• Aldosterone increases Na+ reabsorption
• Atrial natriuretic hormone (ANH) promotes Na+ secretion

Question 7

How does ADH function to increase water reabsorption?

Answer 7

Acts on DCT and collecting tubules by promoting insertion of aquaporins allowing water to be reabsorbed by filtrate

Question 8

How does Aldosterone increase Na+ reabsorption?

Answer 8

Acts on DCT and collecting tubules. Upregulates activity and insertion of Na+K+ pumps and channels

Question 9

How does Atrial natriuretic hormone (ANH) promote Na+ secretion?

Answer 9

Inhibits action of ADH and aldosterone resulting in LARGE VOLUME of DILUTE urine being produced