Anatomy 101
Gastrointestinal Tract
presentation by f.k
,GIT Summary
Functions Regulation of satiety and hunger, mechanical digestion (mastication), swal
chemical digestion of food; absorption of necessary nutrients, elimination o
unnecessary matter and waste
Components Primary organs: mouth, pharynx, esophagus, stomach, small intestines (du
jejunum, ileum), large intestine (colon), rectum and anal canal
Accessory organs: salivary glands, liver, gall bladder, pancreas
Mouth Contains structures that start digestion: teeth (choping the food), salivary
glands (secrete saliva that contain enzymes that start chemical digestion o
fats), tongue (detects taste, pushes bolus towards the pharynx)
Pharynx Conducts the food to the esophagus
Esophagus Muscular tube that conduct the bolus to the stomach; It has upper sphincte
with swallow reflex and allows the bolus to enter the esophagus) and lower
sphincter (controls emptying of the esophagus content to the stomach)
Stomach Function - secretion of gastric acid (hydrochloric acid + sodium chloride +
that digests proteins and converts bolus to chyme
Parts - cardia (where content of the esophagus empties into stomach), fun
curved part), body (main, central region), pylorus (empties the chyme into
duodenum)
Spleen Breaks down spent erythrocytes -> production of bilirubin -> bilirubin sen
-> secreted in the bile
presentation by f.k
, Resources
Liver Main functions: detoxication of metabolytes, synthesis of proteins, produc
biochemicals needed for digestion -> regulation of body's metabolism and
Gallbladder Stores the bile and empties it into the duodenum from where it partially el
defecation
Pancreas Secretes insulin when sugar levels are high, secretes glucagon when sugar
secretes pancreatic juice (tripsinogen, chymotripsinogen, elastase, amilas
duodenum where it digests the chyme
Small intestines Duodenum - mixes chyme with bile, secretes bicarbonates to rise pH in ord
pancreatic enzymes which digest the chyme
Jejunum - absorbs small nutrients that have been previously digested in d
Ileum - absorbs vitamin B12, bile salts and all necessary materia that wer
in jejunum
Cecum - a pouch that marks division between small and large intestines ->
ileum with ascending colon
Large intestine Ascending colon - absorbs water from content and moves in to the transve
peristalsis
Transverse colon - extends from hepatic flexure to splenic flexure; absorb
Descending colon - extends from splenic flexure to the sigmoid colon; store
will be emptied into the sigmoid colon
Sigmoid colon - contracts to increase pressure inside the colon, causing th
into the rectum
presentation by f.k
