Question

The glomerular capillaries differ from other capillary networks in the body because they?

1) have a larger surface area for anastamosis
2) are derived from and drain into arterioles
3) are not composed endothelial cells
4) are the primary sites of final filtrate formation in the collecting ducts

Answer 1

Glomerular capillaries are unique in that they originate from and drain into arterioles, and feature fenestrations aiding in filtration to form urine. The Correct Answer is Option.4.

Step-by-step explanation:

The glomerular capillaries differ from other capillary networks in the body because they are derived from and drain into arterioles. In particular, the glomerular capillaries are a high-pressure capillary bed that is fed by an afferent arteriole and drained by an efferent arteriole. This unique arrangement forms part of a specialised portal system, which is critical for the filtration process that occurs in the kidneys. Unlike typical capillary beds that are sandwiched between an arteriole and a venule, the glomerular capillaries are interposed between two arterioles.

Furthermore, glomerular capillaries have unique structures known as fenestrations which allow them to filter blood effectively. Filtrate formation occurs as blood plasma minus large proteins and cells moves from the capillaries into Bowman's capsule, starting the process of urine formation.