Digestive Organs and their Functions

Rectum

Connects the colon to the anus. It receives stool from the colon and sends signals to the brain to let it known that there are contents to be released.

Pharynx

Connects the mouth to the esophagus

Large Intestine

Connects the small intestine to the rectum. The large intestine is made up of the cecum, the ascending (right) colon, the transverse (across) colon, the descending (left colon) and the sigmoid colon, which connects to the rectum. The large intestine is the site of vitamin synthesis and some water absorption. When the descending stool becomes full of faeces, it empties its contents into the rectum.

Esophagus

Located in your throat near the trachea, the esophagus receives food from your mouth when you swallow. By peristalsis, the esophagus moves the food from the pharynx into the stomach

Small Intestine

Made up of three segments - the duodenum, the jejunum and the ileum. The small intestine is the main site of digestion and absorption of food due to its large surface area. Peristalsis is at work in this organ, moving food through and mixing it with digestive secretions from the pancreas and the liver. The duodenum is largely responsible for the breaking down process, while the jejunum and ileum are mostly responsible for the absorption of nutrients into the blood stream. Once the nutrients have been absorbed, the leftover-food liquid residue moves onto the large intestine

Liver

Main function is to process nutrients absorbed from the small intestine. Bile secreted from the liver into the small intestine plays an important role in digesting fat - emulsifies it by breaking it into smaller globules. The liver takes raw materials absorbed by the small intestine and makes all the various chemicals the body needs to function. The liver also detoxifies potentially harmful chemicals - breaks down and secretes many drugs.

Salivary glands

Secrete saliva containing enzymes (amylase) to mix with the food and begin breaking it down into a form the body can absorb and use

Mouth (Oral Cavity)

The beginning of the digestive tract - chewing breaks the food down into smaller pieces so they are easy to digest. Mastication occurs here which increases surface area of food - therefore increases efficiency of enzymes therefore increasing efficiency of digestion

Pancreas

The pancreas secretes digestive enzymes into the duodenum (i.e. amylase, lipase and peptidases). These enzymes break down proteins, fats and carbohydrates.

Stomach

The stomach functions primarily as a storage and mixing chamber for ingested food. As food enters the stomach, it is mixed with stomach secretions (e.g. hydrochloric acid, pepsin and mucus) to become a semifluid mixture called chyme. Mucus lines the stomach to protect it from the actions of the pepsin and hydrochloric acid.