small intestine

The transport of food in plants is called translocation. It takes place with the help of a conducting tissue called phloem. Phloem transports glucose, amino acids and other substances from leaves to root, shoot, fruits and seeds.

Peristalsis

The digestive system is made up of the alimentary canal (also called the digestive tract) and other organs, such as the liver and pancreas. The alimentary canal is the long tube of organs — including the esophagus, stomach, and intestines — that runs from the mouth to the anus.

The alimentary tract of the digestive system is composed of the mouth, pharynx, esophagus, stomach, small and large intestines, rectum and anus. Associated with the alimentary tract are the following accessory organs: salivary glands, liver, gallbladder, and pancreas.

The wall of the digestive tract has four layers or tunics:

• Mucosa.
• Submucosa.
• Muscular layer.
• Serous layer or serosa.

mucosa

The vagus nerve helps manage the complex processes in your digestive tract, including signaling the muscles in your stomach to contract and push food into the small intestine.

The stomach secretes water, electrolytes, hydrochloric acid, and glycoproteins, including mucin, intrinsic factor, and enzymes (Figure 25-3). Gastric motility and secretion are regulated by neural and humoral mechanisms.

Since it controls vital functions such as breathing, swallowing, digestion, eye movement and heartbeat, there can be no life without it. But the rest of the brain is obviously capable of some remarkable feats, with one part able to compensate for deficiencies in another.