Chapter 21: Capillaries Flashcards

Vocabulary flashcards based on the capillaries lecture notes.

Capillaries

Site of nutrient, waste, and gas exchange within the cardiovascular system.

Tunica interna (intima)

Epithelial tissue and basement membrane; the basic layer or tunic of a vessel wall.

Metarteriole

Branch from arteriole to venule; its precapillary sphincter controls flow to the capillary bed.

Continuous capillaries

Most common type of capillary; features a continuous tube with small intercellular clefts.

Fenestrated capillaries

Capillaries found in kidneys, villi of small intestines, and endocrine glands; characterized by pores through endothelial cells.

Sinusoids

Capillaries found in the liver and spleen; feature large pores through which blood can percolate.

Starling Forces

Hydrostatic and osmotic forces at the capillaries that determine filtration and reabsorption.

Filtration

Movement of fluid through the walls of the capillary into the interstitial fluid.

Reabsorption

Movement of fluid from the interstitial fluid back into the capillary.

Blood hydrostatic pressure (BHP)

Decreases from 35 to 16 mmHg from the arterial to the venous end of the capillary during filtration.

Interstitial fluid osmotic pressure (IFOP)

Constant at about 1 mmHg during filtration.

Blood colloid osmotic pressure (BCOP)

Averages 26 mmHg on both ends of the capillary during reabsorption; due to plasma proteins too large to exit the capillary.

Interstitial fluid hydrostatic pressure (IFHP)

Close to zero except in states of edema; related to reabsorption.

NFP

Net filtration pressure