Capillaries

Question 1

Continuous capillaries

Fenestrated capillaries

Sinusoidal capillaries

Answer 1

• Majority
• uninterrupted lining, and they only allow smaller molecules, such as water and ions to pass through
• in the kidney and endocrine glands for absorption.
• pores in endothelial lining = rapid exchange.
• spaces between endothelial cells in the liver.
• Incomplete/absent basement membrane for exchange of large solutes e.g. plasma proteins.
• Slow blood flow.

Question 2

Capillary beds
-Metarterioles

• Precapillary sphincters
• Arteriovenous anastomosis

Answer 2

thoroughfare channel from arteriole straight to venule with many capillaries leading of of it. Constriction can reduce flow to the whole bed.

guard entrances to each capillary that can dilate/constrict to alter blood flow.

direct between arteriole and venule, bypasses capillaries.