The Digestive System

Bile

produced in liver, stored in gallbladder, secreted into the small intestine -changes larger fat molecules into smaller fat droplets

Rectum

short tube at the end of the large intestine

liver

-upper right side of abdomen -largest organ in the body -does a variety of things like break down meds -PRODUCES BILE -bile comes from the liver and is stored in the gallbladder -bile passes by a tube from the gallbladder to the small intestine -bile is not an enzyme but it breaks large fat molecules into smaller fat droplets.

What are the two important things that take place in the large intestine

1-absorbs water and electrolytes from digestive materials 2-remaining material is readied for elimination by formation of feces Plus*- bacteria ferments indigestible food matter recovering certain vitamins.

Stomach

A J-shaped muscular pouch in the abdomen that expands to hold the food that you swallow. Both mechanical and chemical digestion occur in the stomach.

Chemical Digestion

In chemical digestion, chemicals called enzymes produced by the body, break the particles down into their smaller chemical molecules.

Mechanical Digestion

In mechanical digestion, foods are are physically broken down into smaller pieces via biting and chewing.

Esophagus

Muscular tubuluar structure that connects the mouth to the stomach. It is lined with mucus to help the food slide down. It is a smooth muscle that contracts to push the food towards the stomach.

Enzymes

Proteins created by your body that speed up chemical reactions. Enzymes have a specific shape that allow them to act on a substance called a substrate. It then changes that substrate chemically.

Digestion in The Mouth

Mechanical digestion in the mouth begins with your teeth. It occurs when your incisors cut the food into bite sized pieces, and your canines slash and tear it into smaller pieces. The premolars crush and grind the food and the saliva moistens the food into a slippery mass ready for the esophagus. Chemical digestion in the mouth begins with the saliva. The saliva has enzymes in it that chemically break down the food. In the mouth it breaks up starch into smaller sugar molecules. BREAKS DOWN FOOD INTO SMALL PARTICLES AND BREAKS DOWN STARCHES INTO SUGARS

Digestion in The Stomach

Mechanical digestion in the stomach occurs when the 3 strong layers of stomach muscle contract causing a churning motion. This motion mixes the food with chemicals like a washing machine mixes the clothes with soap. This allows the chemicals of the stomach to coat the food particles. Chemical digestion occurs when the stomach digestive juices contact the food. Stomach digestive juice has: pepsin - which breaks protein into short chain amino acids hydrochloric acid - creates the best environment for pepsin to work and kills bacteria food remains in the stomach until all of the solid material has been turned into liquid form. The stomach has mucus to protect it form the acid. CHURNS SMALL PARTICLES AND COATS THEM WITH PEPSIN AND ACID. PEPSIN BREAKS PROTEINS INTO AMINO ACIDS TURNS FOOD INTO LIQUID FORM

Large Intestine

The last part of the digestive system includes cecum, ascending colon, transverse colon and descending colon, ends in the rectum and the anus. The 2 major functions are absorbing water and preparing the waste for elimination.

Villi

finger like structures in the small intestine that absorb nutrient molecules. Tiny blood vessels are in the center of the villi and the small digested molecule can be absorbed via the villi.

Peristalsis

peristalsis is the involuntary wave of contractions that moves the food down the esophagus in one direction. Peristalsis continues throughout the GI tract.

Describe how smooth muscle works in the digestive system

smooth involuntary muscle contracts in a coordinated fashion that propels food forward in one direction through the digestive tract. This movement is called peristalsis and starrs at the level of the esophagus but continues to propel the food through the stomach, small intestine, and large intestine. Smooth muscles in the stomach also churn the food.

Gallbladder

the organ that stores bile then secretes it into the small intestine

Absorption

the process by which the nutrient products that have been digested pass through the wall of your digestive tract and into your bloodstream. Materials that are not absorbed ( like fiber) pass through the digestive system and are eliminated as waste.

Pancreas

triangular organ that does a bunch of things but for digestion it produces enzymes that pass it secretes into the small intestine that breakdown starches, protiens, and fats.

Epiglottis

a flap of tissue that seals off your windpipe preventing the food from entering your windpipe.

Anus

a muscular opening at the end of the rectum

Saliva

Saliva is a fluid with enzymes in it that is released in the mouth from the salivary glands. It plays a role in both mechanical and chemical digestion

Digestion

The process by which your body breaks down food into small nutrient molecules. There are two kinds of digestion: mechanical and chemical.

small intestine

The small intestine is a 20 foot long tube located between the stomach and the large intestine. ALMOST ALL CHEMICAL DIGESTION AND ABSORPTION OF NUTRIENTS TAKES PLACE IN THE SMALL INTESTINE. The intestine is connected to the liver, gallbladder and pancreas which secrete liquids into the SI to help its chemical digestion.

How do villi work

The small intestine is lined with villi which are small finger like projections that increase its surface area. If the villi were made flat, the surface area of the small intestine would be as large as a tennis court. This large surface area creates an efficient means of absorbing all of the dissolved nutrients in the small intestine, through a thin layer of cells on the villi. There are small blood vessels at the center of each villi so the villi allow digested food to be absorbed very efficiently and rapidly.

Mucus

Thick slippery substance produced by the body. In the digestive system it helps food go down the esophagus.