DIGESTIVE SYSTEM

Two Types of Digestion Mechanical Digestion- food is physically broken down into smaller pieces by the chewing action of the teeth and the tongue within in the mouth Chemical Digestion- chemicals/enzymes produced by the body break the food down into its simpler building blocks (happens in mouth, stomach, intestine) ex) proteins → __________________________ Carbohydrates → __________________________________________ Lipids → ___________________________________

Mouth The place where digestion begins → food is chewed and softened to be swallowed Saliva, that comes from the salivary glands around the face, iis mixed with the chewed food. An enzyme called salivary amylase begins the digestion of STARCHES ONLY in the mouth

Epiglottis and Esophagus Epiglottis - flap of cartilage located behind the tongue that closes off the trachea (windpipe that brings air to the lungs) so food and water does not enter lungs Esophagus- Connects the throat (pharynx) to the stomach for the passage of chewed food

Peristalsis The involuntary muscle contractions that push the food through the esophagus towards the stomach

Stomach Made of ridges, folds, and muscles that keep food moving Blood vessels and glands line the stomach wall → gastric juices are produced which contain enzymes and hydrochloric acid Partially digested food, called chyme, moves from stomach to the small intestine

Small Intestine Where the most digestive action and absorption of nutrients happens The nutrients are broken down small enough to pass through the lining of the small intestine and into the bloodstream by diffusion

Villi Covers the inner wall of the small intestine. • Microscopic finger like projections • Capillaries of villi absorb glucose, amino acids, fats and minerals into the circulatory system

Small Intestine The small intestine is also the place where the bile from the gallbladder and digestive juice from the pancreas mixes -Pancreases makes digestive enzymes and the liver makes bile (digests fats)

Bile The liver produces bile (a yellow-greenish substance) that helps break down large fat molecules Excess bile is stored in the gallbladder

Large Intestine -Main function is to remove water from undigested matter that will eventually become the feces -End of the large intestine & the next part of the track, the rectum, stores feces Feces are finally squeezed through a ring of muscle, the anus, and out of the body