Human Digestive System Parts Quiz

Study Notes

Human Body Systems and Nutrients - Digestive System Parts

The human digestive system is responsible for breaking down the food we consume into smaller molecules that can be absorbed by our cells. It's made up of several organs and structures that work together to carry out this process. Here are the main parts of the digestive system:

Mouth

Your mouth is where your journey towards digestion begins. Teeth help you chew food into smaller pieces, while salivary glands release enzymes like amylase which starts breaking down starches. The tongue helps mix the food with saliva.

Esophagus

After swallowing, food travels from the back of the throat through the esophagus. This muscular tube carries the food from the mouth to the stomach. You might sometimes feel it contract during mealtimes.

Stomach

The stomach continues the mechanical breakdown of food initiated in the mouth. Its lining secretes hydrochloric acid and digestive enzymes that break down proteins into peptides and amino acids. After about two hours, most of the food has been turned into chyme—partially digested food that moves on to the small intestine.

Small Intestine

Chyme enters the small intestine and mixes with more digestive juices released by the liver (bile) and pancreas. These fluids further break down complex carbohydrates into simple sugars and fatty acids into monoglycerides. Nutrients from these breakdown products are then pulled into the bloodstream via tiny finger-like projections called villi, located along the walls of the small intestine.

Large Intestine

Undigested food particles move from the small intestine into the large intestine. The primary function of the large intestine is to remove water from solid waste (stool). Bacteria living here also aid in fermentation processes that produce vitamin K and some other B vitamins. Once all the water has been removed, the remaining matter becomes feces, which is passed out of the body through the anus.

Liver

While not part of the digestive tract itself, the liver plays a crucial role in processing the nutrients absorbed from the small intestine. A major component of its job is removing toxic substances from the bloodstream before they can harm the rest of the body. It metabolizes nutrients such as glucose, breaks down drugs, synthesizes proteins required for blood clotting, and produces bile, which emulsifies fats so that they can be broken down in the small intestine.

Pancreatic Duct

A short duct connects the pancreas to the small intestine. It releases pancreatic juice containing enzymes that break down protein, fat, and carbohydrate molecules into simpler forms that can be absorbed into the bloodstream.

In summary, the digestive system is composed of various organs working together to convert food into nutrient molecules that the body can use for energy, growth, and repair.

Description

Test your knowledge about the main parts of the human digestive system, from the mouth to the liver. Learn about the functions of key organs like the stomach, small intestine, and large intestine in breaking down food and absorbing nutrients.