Nutri Sci 332: Digestion And Absorption

Front 1

Mouth

Back 1

-swallowing: reflex initiated by the voluntary movement of food from the mouth to the pharynx.
-this reflex causes the epiglottis to close over the larynx, thereby closing the trachea and allowing the movement of food into the esophagus.
-saliva moistens food
-mucus lubricates
-release amylase

Front 2

Esophagus

Back 2

-lubricate food with mucus
-peristaltic waves move food down

Front 3

Gastroesophageal Reflux Disease (GERD)

Back 3

acid reflux
-heartburn, regurgitation, trouble swallowing

Front 4

Stomach

Back 4

-gastric secretions (HCL) cause acidification of the meal
-muscle contractions grind and mix food to produce chyme
-proteins are denatured
-pepsin is secreted
-Gastric Lipase is secreted
-intrinsic factor is secreted for vitamin B12 absorption
-the pyloric sphincter regulates entry of the chyme into the small intestine
-gastric emptying takes about 2-3 hours and is dependent on food make up
-mucus lubricates and protects stomach surface

Front 5

Small Intestine

Back 5

-site of most digestion and absorption of nutrients
-receives digestive enzymes and bicarbonate from the exocrine pancreas
-receives bile from the liver via the gallbladder
-epithelial cells lining the small intestine also contain digestive enzymes and nutrient transport proteins on their outer membranes that are necessary for digestion and absorption
-3-10 hours transit time

Front 6

Large Intestine

Back 6

-receives food residue from small intestine
-site of water and some mineral absorption
-contains a rich micoflora (bacteria)
-microflora digest dietary fiber and produce short chain fatty acids that are absorbed into the blood stream
-produces feces
-absorb sodium and potassium
-synthesize some vitamins
-can take up to 3 days

Front 7

Rectum

Back 7

-stores and expels feces via the anus

Front 8

Lower esophageal sphincter (LES)

Back 8

closes the distal end of the esophagus and blocks the reflux of stomach contents into the esophagus.

Front 9

Gall Bladder

Back 9

store, concentrate, and release bile into the small intestine for fat digestion and absorption.

Front 10

Pancreas

Back 10

secrete sodium bicarbonate and enzymes to digest carbohydrates, fat, and protein

Front 11

Liver

Back 11

produce bile to be stored in gall bladder and sent to the small intestine

Front 12

Autonomic Nervous System

Back 12

branch of the central nervous system that regulates the function of visceral organs (GI tract)

Front 13

GI Hormones

Back 13

-small polypeptides released from the GI tract into the blood in response to a meal
-travel to different regions of the digestive system to regulate GI function
-secretion of various chemicals, regulation of GI motility, epithelial cell growth
-cholecystokinin, secretin, gastrin, gastric inhibitory peptide

Front 14

Peristalsis

Back 14

coordinated muscle contractions that propel food through the GI tract
-swallowing
-stomach
-small intestine

Front 15

Segmentation

Back 15

-in small intestine
-closely spaced contractions in discrete areas of the intestine that act to mix the chyme with the digestive secretions and increase contact with the mucosal surface.

Front 16

Mass movements

Back 16

-large intestine
-contractions that occur over a large area of intestine that act to move the waste towards the rectum