1. Name the parts of a tooth.
2. List the organs of the digestive system.
3. What is the function of the stomach in the digestive system?
4. What are germs? Give an example.
5. What are the different shapes of bacteria?
Answers
Explanation:
The human digestive system consists of the gastrointestinal tract plus the accessory organs of digestion (the tongue, salivary glands, pancreas, liver, and gallbladder). Digestion involves the breakdown of food into smaller and smaller components, until they can be absorbed and assimilated into the body. The process of digestion has three stages. The first stage is the cephalic phase of digestion which begins with gastric secretions in response to the sight and smell of food. This stage includes the mechanical breakdown of food by chewing, and the chemical breakdown by digestive enzymes, that takes place in the mouth.
Human digestive system
Human digestive system
DetailsIdentifiersLatinSystema digestoriumTA98A05.0.00.000TA22773FMA7152Anatomical terminology
[edit on Wikidata]
Saliva contains digestive enzymes called amylase, and lingual lipase, secreted by the salivary glands and serous glands on the tongue. The enzymes start to break down the food in the mouth. Chewing, in which the food is mixed with saliva, begins the mechanical process of digestion. This produces a bolus which can be swallowed down the esophagus to enter the stomach. In the stomach the gastric phase of digestion takes place. The food is further broken down by mixing with gastric acid until it passes into the duodenum, in the third intestinal phase of digestion, where it is mixed with a number of enzymes produced by the pancreas. Digestion is helped by the chewing of food carried out by the muscles of mastication, the tongue, and the teeth, and also by the contractions of peristalsis, and segmentation. Gastric acid, and the production of mucus in the stomach, are essential for the continuation of digestion.
Peristalsis is the rhythmic contraction of muscles that begins in the esophagus and continues along the wall of the stomach and the rest of the gastrointestinal tract. This initially results in the production of chyme which when fully broken down in the small intestine is absorbed as chyle into the lymphatic system. Most of the digestion of food takes place in the small intestine. Water and some minerals are reabsorbed back into the blood in the colon of the large intestine. The waste products of digestion (feces) are defecated from the anus via the rectum.
Answer:
1. Each tooth is made up of two basic parts: the crown and the root. Within each, you find the enamel, dentin, pulp (or nerve) and the bone.
2. 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.
3. Stomach. The stomach is a hollow organ, or "container," that holds food while it is being mixed with stomach enzymes. These enzymes continue the process of breaking down food into a usable form. Cells in the lining of the stomach secrete a strong acid and powerful enzymes that are responsible for the breakdown process.
4. The four major types of germs are bacteria, viruses, fungi, and protozoa. They can invade plants, animals, and people, and sometimes they can make us sick. Bacteria are tiny, one-celled creatures that get nutrients from their environments in order to live.
5. There are three basic shapes of bacteria: coccus, bacillus, and spiral. Based on planes of division, the coccus shape can appear in several distinct arrangements: diplococcus, streptococcus, tetrad, sarcina, and staphylococcus.