NATS 1675 Lecture Notes - Lecture 9: Growth Factor, Carcinoembryonic Antigen, Antigen
18 Apr 2015
School
Department
Course
Professor
Document Summary
The digestive system consists of the digestive tract (tube) and associated digestive organs such as salivary glands, liver, pancreas, etc. The digestive tract in humans and other mammals is complete; it is a long tube beginning with the mouth and ending with the anus. The cavity of the digestive tract is called the lumen. The walls of the digestive tract consist of 4 layers: the lumen is lined with the mucosa (a mucus membrane). The salivary glands, liver/gall bladder and pancreas are accessory organs found outside the digestive tract that empty their products into the digestive tract. Mouth--initial processing of food which includes both mechanical and chemical digestion. Teeth: children have 20 milk or deciduous teeth; adults have 32 teeth, 16 in each jaw: Teeth, with the aid of the tongue, reduce the food into particles small enough to be swallowed. Chewing also aids in mixing the food with saliva that begins the digestive process of starch.
