how is a lymph capillary like a blood capillary?

Question

Biology

Answer 1

Like blood capillaries, lymphatic capillaries are made of a single layer of squamous epithelial cells. Lymphatic capillaries are slightly larger in diameter than blood capillaries and have a unique structure that allows interstitial fluid to flow into, but not out of, lymphatic capillaries. The ends of the endothelial cells that make up the wall of the lymphatic capillaries overlap and act like valves. Whe the pressure increases in the interstitial fluid, it pushes the flaps open, and fluid enters the capillary. When the pressure of the fluid is greater inside the capillary, it forces the overlapping cells closer together, trapping the fluid inside the lymph capillary. At right angles to the lymphatic capillaries are structures calles anchoring filaments which attach lymphatic endothelial cells to the surrounding tissue. When edema causes swelling of the tissue, these filaments pull on the endothelial cells, opening the spaces wider so that more fluid can enter the lymphatic capillary. Lymphatic capillaries are found everywhere in the body except: 1) avascular tissues, 2) the central nervous system, 3) the splenic pulp, and 4) bone marrow. They also tend to run in paths similar to blood capillaries.

Answer 2

Capillaries - are blood vessels that connect the arteries and veins. (1) They are thin walled, (one endothelial cell layer thick) which permits rapid diffusion of substances through the capillary membrane. (2)They are extensively branched, which increases the cross sectional area of the capillary system, which causes the blood to slow down allowing more time for the exchange process to occur. (3) They have a very small diameter which provides friction which increases the resistance of flow. This causes the blood pressure to drop in the capillaries which allows easier passage of materials between the tissues and the blood.