Question at position 9 Which type of capillary is characterized by having pores in the endothelial lining, making it permeable to larger molecules?Arteriole capillariesSinusoid capillariesContinuous capillariesMuscular capillariesFenestrated capillaries单项选择题
A
Arteriole capillaries
B
Sinusoid capillaries
C
Continuous capillaries
D
Muscular capillaries
E
Fenestrated capillaries

Question

Question at position 9 Which type of capillary is characterized by having pores in the endothelial lining, making it permeable to larger molecules?Arteriole capillariesSinusoid capillariesContinuous capillariesMuscular capillariesFenestrated capillaries单项选择题

A

Arteriole capillaries

B

Sinusoid capillaries

C

Continuous capillaries

D

Muscular capillaries

E

Fenestrated capillaries

BlackTom AI · Accepted Answer

The question asks which capillary type has pores in the endothelial lining, allowing larger molecules to pass through.
Option 1: Arteriole capillaries — This term is not a standard distinct capillary type based on permeability; arterioles are small arteries, and their endothelium resembles continuous capillaries, but the characteristic pores are not their defining feature.
Option 2: Sinusoid capillaries — These have highly permeable, discontinuous endothelium with large gaps and a discontinuous basement membrane, which permits extensive exchange of even large proteins and cells. However, their hallmark is large gaps rather than discrete pores or fenestrae, so the description about pores is more characteristic of another type.
Option 3: Continuous capillaries — The most common type, with uninterrupted endothelium and tight junctions, allowing only small molecules to pass; they lack numerous pores, making them less permeable to larger molecules.
Option 4: Muscular capillaries — This is not a standard term used to describe a capillary-type classification; it does not emphasize pore structure or permeability features.
Option 5: Fenestrated capillaries — This type features pores (fenestrae) in the endothelial lining that increase permeability to larger molecules such as hormones and nutrients. The presence of these fenestrae is the defining feature that matches the description in the question.
Therefore, the option that aligns with pores in the endothelium facilitating passage of larger molecules is the fenestrated capillary type.