Types and examples of capillaries

              CAPILLARY :(hair like) It has two meanings: 1-pertaining to hair or resembling a hair. 2-any one of minute vessels that connect the arterioles and venules, forming a network in nearly all parts of the body. Walls of capillaries: The walls of the capillary act as semipermeable membranes for interchange of fluids, gases, nutrients, hormones, vitamins, minerals antibodies, etc., between the blood and tissue fluids. Their diameter varies from 7-9 m. Types of capillaries ; a) Continuous capillaries:  In these capillaries, no pores are seen. They are present at following sites: *Skin. *Connective tissue *Skeletal and smooth muscle. * Lungs. *Brain. b) Fenestrated capillaries : These are those capillaries, the lining endothelial cells of which show characteristic pore system. They are seen at following sites: *Renal glomeruli. * Intestinal villi. * Endocrine glands. *Pancreas Sinusoids of sinusoidal capillaries  : These are dilated capillaries and are lined by reticulo-endotheli