Digestive System

Gastrointestinal System

physical and chemical breakdown of food for use by the body

alimentary canal and the accessory organs

Alimentary Canal

long muscular tube

begins @ mouth and ends @ anus

Buccal Cavity

receives food as it enters the body

food is tastes, broken down physically by teeth, lubricated and partially digested by saliva, and swallowed

Teeth

structures in the mouth that physically break down food by chewing/grinding

tongue: muscular organ that contains special receptors; taste buds

Pharynx/Throat

carrier for both air and food

carries bolus to esophagus, and when food is swallowed, epiglottis closes to prevent food from entering respiratory tract

Esophagus

muscular tube dorsal to trachea

carries bolus to stomach

peristalsis moves food towards stomach

Stomach

receives food from esophagus

mucus membrane lining contain rugae

cardiac sphincter and pyloric sphincter

Gastric Juices

hydrochloric acid - kills bacteria, helps absorb iron and activates pepsin

pepsin - starts protein digestion

lipase - starts chemical breakdown of fats

rennin - aids in digestion of milk, but is only present in infants

Small Intestine

20 feet long, 1 inch diameter

receives food from the stomach in the form of chyme

duodenum, jejunum and ileum

walls lined with villi

Large Intestine

final section of alimentary canal

5 feet long, 2 inch diameter

absorbs water and remaining nutrients

stores indigestible material before elimination

synthesis and absorption of some B complex vitamins and vitamin K

Liver

largest gland in the body

secretes bile

stores sugar in the form of glucose

produces heparin and cholesterol, and detoxifies substances

Gallbladder

small muscular sac that stores concentrates bile

Pancreas

fish shaped organ behind the stomach

produces pancreatic juices and secretes insulin

Appendicitis

acute inflammation of the appendix, usually refers from an obstruction and infection

Cholecystitis

inflammation of the gallbladder

if blocks bile ducts, gallbladder can rupture and cause peritonitis

Cirrhosis

chronic destruction of liver cells accompanied by formation of fibrous connective and scar tissue

Constipation

fecal matter remaining in colon too long causing excessive reabsorption of water

feces becomes dry and hard / difficult to eliminate

Diarrhea

frequent watery stools

can be VERY dangerous in infants

Diverticulitis

inflammation of the diverticula (pouches or sacs) that form in the intestine and mucosal lining pushes through surrounding muscle

Gastroenteritis

inflammation of the musosal membrane that lines the stomach

Hemorrhoids

painful dilated veins of the rectum / anus

Hepatitis

A: most benign form

B: serum / transmitted by body fluids

C: contact w/ blood / body fluids

viral inflammation of the liver

Hernia

internal organ pushes through weakened area or natural opening

Pancreatitis

inflammation of the pancreas

treatment depends on the cause

Peritonitis

inflammation of the peritoneal cavity, usually when a rupture of the intestines allows the contents to leak into the abdominal cavity

Ulcer

open sore on the lining of the digestive tract

major cause: H. Pylori (Helicobacter Pylori)