The Alimentary Canal - the one way passageway for food / nutrients / waste

Human Alimentary Canal Mouth Pharynx Esophagus Stomach Small intestine Large intestine

Mouth True digestive organ physical & chemical digestion Salivary Amylase breaks carbohydrates into disaccharides/maltose contains teeth, tongue, soft & hard palate to help with physical digestion food is ingested

Salivary Glands Accessory Organs produce salivary amylase –sublingual –submandibular –parotids

Pharynx aka. The throat True digestive organ no physical or chemical digestion occurs here hooks in with the respiratory system

Esophagus True digestive organ no physical or chemical digestion occurs here food considered a BOLUS - wet ball of chewed food PERISTALSIS starts here - wavelike contractions of the tube that moves the foodstuff along the alimentary canal

Stomach Very muscular organ that participates in both physical & chemical digestion true digestive organ lined with thick protective mucous the enzyme pepsinogen activates in the acid conditions in the stomach and becomes pepsin

pepsin digests the proteins into groups of 2 amino acids cardiac sphincter valve is at the top and the pyloric valve is between the stomach & small intestine the bolus is now considered chyme

Small Intestine True digestive organ chemical digestion is completed here contains 3 main portions –duodenum first 10 cm of small intestine –jejunum next 2 ½ meters –ileum last 4 meters

the role of the small intestine is threefold 1. Finish digestion 2. Absorb nutrients 3. Storage contains villi for absorption of nutrients

Small Intestine Enzyme Action Common bile duct hooks into duodenum this hooks up to the pancreas and gallbladder pancreatic juice & bile is secreted is secreted through this BILE & bile salts- emulsifies the fat - breaks into smaller droplets

Pancreatic Juice contains: –sodium bicarbonate / to neutralize the acid from the stomach –lipase / breaks fats into fatty acids & glycerol –trypsinogen in changed into trypsin in the si. Environment and digests the dipeptides into single amino acids –pancreatic amylase finishes carbohydrate digestion by breaking disaccharides into monosacharides

Villi Increases the surface area in the small intestine for the maximum nutrient absorption monosaccharides & amino acids are diffused into the capillaries  bloodstream fatty acids & glycerol are absorbed by the lacteal which hooks into the lymphatic system

Pancreas Accessory digestive organ produces pancreatic juice which contains pancreatic amylase, sodium bicarbonate, trypsinogen and lipase located under the stomach

LIVER –produces bile which breaks up the larger fats GALLBLADDER –stores the bile until needed

Large Intestine True digestive organ, but digestion is all done by now!!! The function is to absorb water & minerals at the junction of the small & large intestine is the appendix

there are 5 portions of the large intestine –ascending colon –transverse colon –descending colon –sigmoid colon –rectum which ends in the anal sphincter

methane in is a normal bi-product and in combination with e. coli bacteria produce flatulence

At this point the waste products are referred to as feces CONSTIPATION - waste sits in large intestine too long and the stool becomes too hard and is difficult to evacuate DIARRHEA - waste does not sit in the large intestine long enough and not enough water is absorbed  producing a watery stool

Hormones of the Digestive System GASTRIN - –cells of the stomach secrete into bloodstream –triggers cells of stomach to secrete hydrochloric acid so pepsinogen converts to pepsin SECRETIN - –when food enters the small intestine –secreted by the cells of si. Into the bloodstream –triggers pancreas to make pancreatic juice