the kidney Flashcards
What is the nephron and its role in the kidney? (2)
Filtering unit of the kidney
Responsible for filtering blood and producing urine
What is the Bowman’s capsule in the nephron? (3)
Structure in nephron
That contains a knot of blood vessels - glomerulus
Involved in the filtration of blood
What are podocytes in the nephron? (2)
Specialised cells that make up the inner layer of the Bowman’s capsule
Wrap around the capillaries of the glomerulus
What are the main structures of the nephron in sequence? (5)
- Bowman’s capsule
- Proximal convoluted tubule (PCT)
- Loop of Henle
- Distal convoluted tubule (DCT)
- Collecting duct
What are the two main functions of the kidney? (2)
To excrete waste products, such as urea
To regulate water potential in the body
What is ultrafiltration, and where does it occur in the kidney? (2)
Process by which substances are filtered out of the blood under high pressure in the glomerulus
Into the Bowman’s capsule
Why is the blood in the glomerulus under high pressure? (2)
The afferent arteriole (bringing blood into the glomerulus) is wider than the efferent arteriole (carrying blood away)
Creating high pressure
What are the three layers that substances must pass through during ultrafiltration? (3)
The capillary wall
The basement membrane
The epithelium of the Bowman’s capsule
Why can’t proteins and blood cells pass through the basement membrane during ultrafiltration? (2)
Proteins and blood cells are too large to pass through the basement membrane
So they remain in the blood
What happens to the liquid and small molecules that pass through the Bowman’s capsule? (3)
The liquid and small molecules, now called filtrate
Pass along the nephron, and useful substances are reabsorbed along the way
The remaining filtrate flows through the collecting duct and exits the kidney through the ureter
