Learning Objectives Describe how the digestive system breaks down food either chemically or physically List and describe the function of the parts of the digestive system List and describe the function of the accessory organs of the digestive system Describe how bulimia, anorexia, and alcohol consumption affect the body

Digestive system

Digestion: chemical and mechanical breakdown of food so it can be absorbed Begins in mouth

Label Organs Mouth pharynx (throat) esophagus stomach small intestines large intestines rectum

Other organs involved Salivary glands Liver Gall bladder pancreas

Parts of digestive system Pharynx: aka throat, connects mouth w/ larynx & esophagus Epiglottis: flap of tissue covers windpipe when you swallow

Esophagus: straight tube from mouth to stomach Peristalsis: wave-like motion of muscle movement that sends the food down

Stomach: food is broken down into chyme (mix of food and digestive juices) Juices: hydrochloric acid, mucus, enzymes (chemicals that speed up the breaking down of food)

Stomach absorbs a small amount of nutrients Liquids pass fast Solids: a few hours –Carbs (potatoes) faster than protein (meat) –Get hungry faster if eat mostly carbs –Fatty food: 3-6 hours

Small intestines: absorbs most of the nutrients from food Intestinal villi: line S.I. and increase surface area= more absorption Area= size of tennis court

Movement of SI: mixing and peristalis Chyme moves slowly thru SI (3-10 hrs) If SI becomes stretched  peristalitic rush (diarrhea)

Large intestines: diameter is bigger than SI 1.5 meters long

Function of LI Absorbs water and salts from chyme Forms and stores feces (“dookey”) No digestive function Secretes only mucus (sliiiiide)

Feces Undigested material  75% water, mucus, bacteria Color comes from bile Odor: comes from bacteria Defecation reflex: vasalva maneuver (sqeeeeze & poo) peristaltic waves produced and muscles relax

The end