Question 3.1.1 [4 marks]
- A: Afferent arteriole
- B: Efferent arteriole
- C: Glomerulus
- E: Bowman's capsule
Question 3.1.2 [1 mark]
The physiological process of excretion that takes place in the above diagram is filtration.
Question 3.1.3 [4 marks]
The difference in diameter between the afferent arteriole (A) and the efferent arteriole (B) plays a critical role in the process of filtration in the Malpighian body (also known as the renal corpuscle). The afferent arteriole has a larger diameter compared to the efferent arteriole. This difference in diameter creates a higher pressure within the glomerulus (the network of capillaries within the Malpighian body).
As blood enters through the larger afferent arteriole, it flows into the narrow space of the glomerulus, where the increased pressure forces water, ions, and small molecules out of the blood and into the Bowman's capsule. This process of filtration is essential for the initial formation of urine. The narrower diameter of the efferent arteriole helps to maintain this high pressure by restricting the outflow of blood, thus ensuring efficient filtration occurs.
Question 3.1.4 [1 mark]
The specialised cells found at D are podocytes.
1 answer