is folded into several vertical folds and contains arteries and veins called anal columns. Anal column may get enlarged and causes piles or haemorrhoids . involved in the process of absorption and the cells lining the villi produce numerous microscopic projections called microvilli giving a brush border appearance that increase the surface area enormously. Along with villi, the ileal mucosa also contain mucus secreting goblet cells and lymphoid tissue known as Peyer’s patches which produce lymphocytes.
The wall of the small intestine bears crypts between the base of villi called crypts of Leiberkuhn (Figure. . ). 7HHWK +DUGSDODWH 6RIWSDODWH 7RQJXH IURQW WZRWKLUGV )ORRURIPRXWK %XFFDO PXFRVD OLS DQGFKHHN OLQLQJ 7RQVLO 8YXOD Figure .
Buccal Cavity 0XVFOH OD\HUV 9LOOL 9LOOL 9HLQFDUU\LQJ EORRGWR KHSDWLFSRUWDO YHLQ %ORRG FDSLOODULHV (SLWKHOLDO FHOOV /DUJHFLUFXODUIROGV YDOYHRINHUNLQJ &U\SWVRI OHLEHUNXKQ /\PSK YHVVHO /DFWHDO %DVDO VXUIDFH (SLWKHOLDOFHOOV /XPHQ 0LFURYLOOL EUXVK ERUGHU DWDSLFDO OXPHQDO VXUIDFH Figure . Small Intestine with Villi XI Std Biology-Zoology Chapter- Salivary Glands There are three pairs of salivary glands in the mouth. They are the largest parotids gland in the cheeks, the sub-maxillary/ sub-mandibular in the lower jaw and the sublingual beneath the tongue. These glands have ducts such as Stenson’s duct, Wharton’s duct and Bartholin’s duct or duct of Rivinis respectively (Figure.
. ) . The salivary juice secreted by the salivary glands reaches the mouth through these ducts. The daily secretion of saliva from salivary glands ranges from to 1500mL.
Gastric Glands The wall of the stomach is lined by gastric glands. Chief cells or peptic cells or zymogen cells in the gastric glands secrete gastric enzymes and Goblet cells secrete mucus. The Parietal or oxyntic cells secrete HCl and an intrinsic factor responsible for the absorption of Vitamin B called Castle’s intrinsic factor . Liver The liver, the largest gland in our body is situated in the upper right side of the abdominal cavity, just below the diaphragm.
The liver consists of two major left and right lobes and two minor lobes. These lobes are connected with diaphragm. Each lobe has many hepatic lobules (functional unit of liver) and is