Human Digestive System

The kidneys perform the essential function of removing waste products from the blood and regulating the water fluid levels. It does not produce digestive juices.

Saliva is a clear liquid .It is made up mostly of water, with a few other chemicals. It is produced by the salivary glands. Saliva wets food and makes it easier to swallow. It also helps the tongue to taste. It helps begin the process of digestion Saliva also cleans the inside mouth and rinses the teeth to keep them clean.

Amylase is an enzyme that breaks down starch, converting it into sugar. There are two major types of amylase, alpha and beta. Alpha-amylase is found in human saliva, where it begins a chemical process in digestion with the hydrolysis of starch. It is also found in the pancreas. Beta-amylase is found in the seeds of some plants, as well as bacteria, yeast, and molds. Amylase is also found in other animals that use it to aid the digestive process.

The pancreas secretes digestive enzymes into the duodenum, the first segment of the small intestine. These enzymes break down protein, fats, and carbohydrates. The pancreas also makes insulin, secreting it directly into the bloodstream. Insulin is the chief hormone for metabolizing sugar.

It is made up of three segments — the duodenum, jejunum, and ileum .It is a 22-foot long muscular tube that breaks down food using enzymes released by the pancreas and bile from the liver. Peristalsis also is at work in this organ, moving food through and mixing it with digestive secretions from the pancreas and liver. The duodenum is largely responsible for the continuous breaking-down process , with the jejunum and ileum mainly responsible for absorption of nutrients into the bloodstream.

All the above three are enzymes.

Pepsinogen is the inactive version or precursor of pepsin, a protease (protein-digesting enzyme), secreted in the stomach. The active site of the pepsin enzyme is obscured by a section of polypeptide (propeptide) chain - 44 amino acid residues long - and this is removed by the action of hydrochloric acid and pepsin already in the stomach. This means that the enzyme is inactive when first secreted from chief cells in the stomach wall, which prevents damage to the cells of the stomach wall itself. Pepsinogen is converted by autocatalysis into the active form of the enzyme pepsin.

The anus is the last part of the digestive tract. It is a 2-inch long canal consisting of the pelvic floor muscles and the two anal sphincters (internal and external). The anus is surrounded by sphincter muscles that are important in allowing control of stool. The pelvic floor muscle creates an angle between the rectum and the anus that stops stool from coming out when it is not supposed to. The internal sphincter is always tight, except when stool enters the rectum.

The enzyme splits starch and is important for digestion, but not for protection.

Urine contains bile pigments in jaundice. Due to this, urine appears dark brownish in colour.

Renin is a proteolytic enzyme secreted by the kidney.

Bacteria can enter the body through various routes and target different organs, including the digestive system (gut) and the liver. Many foodborne or waterborne pathogens affect these specific areas.

The enzyme present in tears is lysozyme. It has antimicrobial action.

Seminal vesicle contains seminal fluid which has fructose, citric acid, coagulating enzyme, vesiculose enzyme and other nutrient substance which provide nutrient to sperm. So, this answer is right.

Digestion is cutting things down to a size in which they can be absorbed into the body. Digestion occurs in the gastrointestinal tract-the ,extending from mouth to anus. Whatever food is eaten it flows through this system,until it is absorbed through the intestinal tract. This is because the gastrointestinal tract functions like an internal skin and provides a barrier between whatever is ingested from the outside and internal bloodstream and cells. Part of the digestion process, then, is the selective transport of nutrients through the cell wall that lines your intestinal tract.