Week 1 - Introduction to the Urinary System

Question 1

How many litres of water does the average 70kg adult contain, and how is this water distributed?

Answer 1

40 litres:

• 25 L in cytosol/intracellular fluid
• 15 L in ECF - 12L of interstitial fluid and 3L of plasma (plus very small amounts in other places e.g. lymph)

Question 2

Describe the pathway of fluid through the microscopic structures of the kidney

Answer 2

Glomerulus - PCT - Loop of Henle - DCT - CD - Renal pelvis

Question 3

What is the role of the glomerulus?

Answer 3

Filtration

Question 4

Does filtration occur in the cortex, medulla, or both?

Why?

Answer 4

Cortex - occurs in glomeruli, all of which are found in the cortex

Question 5

What is the role of the proximal convoluted tubule?

Answer 5

Reabsorption

Question 6

What is the major function of the Loop of Henle?

What else does it do?

Answer 6

Major function = create gradient of increasing osmolarity within the medulla
Also involved in further reabsorption

Question 7

What is the role of the DCT?

Answer 7

Fine-tuning the urine to make it more or less concentrated, depending on the body’s need for water conservation

Question 8

What are the 4 major roles of the kidney?

Answer 8

Regulation
Excretion
Endocrine functions
Metabolic functions