Textbook of normal histology: including an account of the development of the tissues and of the organs . ll as a richnervous plexus. The muscular coat con-sists of two well-developedlayers—the thicker inner cir-cular and the less robustouter longitudinal are separated by a thinlayer of connective tissue,which externally becomescontinuous with the envel-oping areolar tissue and passesinto the outer fibrous tunic ofthe serosa. In parts of the large intes-tine—as the caecum and thecolon—the circular muscularcoat is relatively thin, whilethe longitudinal layer is in-complete, the fib
Textbook of normal histology: including an account of the development of the tissues and of the organs . ll as a richnervous plexus. The muscular coat con-sists of two well-developedlayers—the thicker inner cir-cular and the less robustouter longitudinal are separated by a thinlayer of connective tissue,which externally becomescontinuous with the envel-oping areolar tissue and passesinto the outer fibrous tunic ofthe serosa. In parts of the large intes-tine—as the caecum and thecolon—the circular muscularcoat is relatively thin, whilethe longitudinal layer is in-complete, the fibres of the lat-ter being collected into threefiat bands, 10-15 mm- wide ;these longitudinal bands aremuch shorter than the otherlayers of the intestinal wall,which arrangement results sacculationof the large intestine. In thelower part of the rectum the circular muscular layer becomes thick-ened to form the internal anal sphincter, composed of involuntarymuscle; the bands of longitudinal fibres spread out, and towards thelower end of the rectum form a thick, uniform B /Mm S Section of injected small intestine of cat: a, b, mu-cosa : g, villi; /, their absorbent vessels; h, simplefollicles; c, muscularis mucosas ; d, submucosa ; e, e,circular and longitudinal layers of muscle ; f, fibrouscoat. All the dark lines represent blood-vessels filledwith the injection mass. THE DIGESTIVE TRACT. ljc The blood-vessels supplying the intestines follow the generalarrangement of those of the stomach. The larger vessels pierce theserous and muscular coats, giving off slender twigs to supply thetissues of these tunics; upon reaching the submucosa the vesselsform a wide-meshed net-work. Numerous branches then passthrough the muscularis mucosae to be distributed to the deeper aswell as to the more superficial parts of the mucosa; narrow capil-laries form net-works which surround the tubular glands, while be-neath the epithelium wider capillaries encircle the mou
Size: 1203px × 2078px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorpiersolgeorgeageorgea, bookcentury1800, bookdecade1890
