Question

List and briefly describe 4 defenses of the human gastrointestinal tract, and 4 microbial-caused diseases of the human GI tract.

Answer 1

Answer) Human body has a number of physical or chemical defenses which act as barrier to a number of infectious agents including microbes. Many barriers provide defense against microbial entry in to the body such as mucus membrane present in eye or mucus and hairs in the nostrils. However, if somehow microbes enter in to the body through food that we consume or by any other sources, another defense mechanisms try to get rid of harmful effects of microbes in various ways. Human gastrointestinal tract also has many defenses which are as follow:

Acid is present in our stomach. Acid act as a powerful barrier to microbial growth due to maintaining very low pH in the stomach. Most bacteria can not survive in extremely low pH.

Enzymes of the intestine. Various enzymes functioning in intestine as well as enzymes produced by intestinal microflora of good bacteria act as defense against infectious microbial growth.

Human GI tract is very rich in mucus secreting cells. Mucus act as one of the most important barrier for microbial growth. Mucus helps in immobilizing the bacteria, thereby preventing their movement to epithelium.

The smooth muscle cells surrounding the human GI tract is another good defense against microbial growth. These muscles are known to perform peristalsis movement by which they can excrete harmful agents by diarrhea.

The four diseses of GI tract caused by microbes are:

Cholera- The disease is caused by bacteria Vibrio cholerae. It is infection of small intestine The disease is characterized by watery diarrhea,

Giardiasis- It s caused by parasite Giardia duodenalis. The disease is characterized by vomiting, weight loss and bloody stool.

Intestinal Gastritis- The disease is caused by Helicobacter pylori. burning pain in abdomen, bloating, nausea. bloody vomiting etc,

Yellow fever- It is a viral disease. The disease is characterized by fever. The disease is transmitted by mosquitoes (Aedes aegypti).