Net filtration pressure and lymph formation, edema & blood velocity

1723

0

HWC

Bulk flow -net filtration pressure and lymph formation • The net filtration pressure (NFP) is the force promoting filtration minus the force promoting reabsorption. • At the arterial end of an ideal capillary, the filtration pressures are stronger. The result: net filtration. • At the venous end of an ideal capillary, the reabsorption pressures an stronger. The result: net reabsorption. • About 90% of the fluid that is filtered at the arterial end is reabsorbed at the venous end. • The remaining fluid drains. into lymphatic capillaries to form lymph. • An abnormal buildup of interstitial fluid results in swelling known as edema. • Major causes of edema include: • Increased capillary hydrostatic pressure • Increased capillary permeability • Decreased blood colloidal osmotic pressure • Blockage of lymphatic drainage • Blood velocity is inversely related to total cross-sectional area; the greater the area, the slower the velocity. • Capillaries have a higher total cross-sectional area; therefore blood flows more slowly. • Slower blood flow allows greater time for exchange of materials. • Arteries and veins have lower total cross-sectional areas; blood flows more quickly. • Blood velocity slows as blood travels away from heart, increases as it returns to heart.

Share

Embed

Copy and paste this code into your website or blog.

Add To

You must login to add videos to your playlists.

Comments

0 Comments total

to post comments.

No comments have been posted for this video yet.