9Hur2 Science work

Here is my science work around the digestive system. This describes what each part of the digestive system does.

Ingestion is the consumption of a substance by an organism. In animals, it normally is accomplished by taking in a substance through the mouth into the gastrointestinal tract; such as through eating or drinking. In single-celled organisms ingestion takes place by absorbing a substance through the cell membrane.

Egestion- Egestion is the act or process of voiding or discharging undigested food as faeces. To egest means to discharge undigested material or food.

Digestion-Digestion is the breakdown of large insoluble food molecules into small water-soluble food molecules so that they can be absorbed into the watery blood plasma. In certain organisms, these smaller substances are absorbed through the small intestine into the bloodstream.

Absorption- Digestion is the chemical breakdown of the ingested food into absorbable molecules. Absorption refers to the movement of nutrients, water and electrolytes from the lumen of the small intestine into the cell, then into the blood.

Teeth- Food is broken down into smaller pieces in the mouth by chewing. This is an example of mechanical digestion. The teeth cut and crush food, and the pieces are mixed with saliva to form a ball of food called a bolus.

Large intestine The large intestine (colon or large bowel) is about 5 feet long and about 3 inches in diameter. The colon absorbs water from wastes

Esophagus Anatomically and functionally, the esophagus is the least complex section of the digestive tube. Its role in digestion is simple: to convey boluses of food from the pharynx to the stomach. The esophagus begins as an extension of the pharynx in the back of the oral cavity.

Stomach The stomach secretes acid and enzymes that digest food. Ridges of muscle tissue called rugae line the stomach. The stomach muscles contract periodically, churning food to enhance digestion. The pyloric sphincter is a muscular valve that opens to allow food to pass from the stomach to the small intestine

Anus The anus is the opening at the far end of the digestive tract through which stool leaves the body. The anus is formed partly from the surface layers of the body, including the skin, and partly from the intestine. The anus is lined with a continuation of the external skin.

Liver The liver is an organ about the size of a football. It sits just under your rib cage on the right side of your abdomen. The liver is essential for digesting food and ridding your body of toxic substances. Liver disease can be inherited (genetic).

Rectum The rectum is the concluding part of the large intestine that terminates in the anus. The average length of the human rectum may range between 10 and 15 cm. Its diameter can be compared to that of the sigmoid colon (the part of the large intestine nearest the rectum)

Small intestine The small intestine or small bowel is an organ in the gastrointestinal tract where most of the end absorption of nutrients and minerals from food takes place. It lies between the stomach and large intestine, and receives bile and pancreatic juice through the pancreatic duct to aid in digestion.