question_answer 108)

    Describe the alimentary canal of man.

Answer:

                  Alimentary canal of man it measures about 8 to 10 metres in length and extends from mouth to anus. It has following parts Mouth It consists of the oral cavity, through which food is ingested. It contains teeth, tongue and three pairs of salivary glands, Pharynx The oral cavity opens into the pharynx. The swallowing mechanism guides the masticated food through the pharynx into a tube, called esophagus, Oesophagus It is a muscular, tubular part of the alimentary canal. The muscular movement called peristalsis carries the food down to the stomach. Stomach It is a J-shaped sac-like muscular structure that serves as a storehouse of food. It a large organ which expands when food enters it. The muscular walls helps in mixing food thoroughly with more digestive juices. Small intestine It is about 6 metres in length and has three divisions, i.e., duodenum(first part as C-shaped, begins from the pyloric stomach), jejunum and ileum. Large intestine The ileum passes into large intestine, which can be divided into two parts as anterior colon and posterior rectum. The terminal part of rectum is called anal canal. It opens through the anus, guarded by sphincter muscles. It allows the faucal matter to be egested out.