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Digestive System of A shark. Esophagus. Tube that leads to stomach Its walls are characterized by numerous projections called ESOPHAGEAL PAPPILAE. S TOMACH. J-shaped 3 portions: Cardiac: anterior portion Body: central portion Pyloric: posterior
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Esophagus • Tube that leads to stomach • Its walls are characterized by numerous projections called ESOPHAGEAL PAPPILAE
STOMACH • J-shaped • 3 portions: • Cardiac: anterior portion • Body: central portion • Pyloric: posterior • The distinguishing internal feature is the rugae
RUGAE • Longitudinal folds on the internal surface of the cardiac stomach • Function- Increase surface area during digestion
Pyloric Sphincter • Surrounds the pylorus • Caudal opening of the stomach • Keeps food from backing up into the stomach once passed into the intestines
Small Intestines • 2 parts • DUODENUM: short segment immediately following the pylorus • ILEUM: longer, thicker segment; characterized internally by the spiral valve
SPIRAL VALVE • Interconnected sheets of tissue on inner wall of ileum • Provides extra surface area for the absorption of nutrients
COLON • Segment of the digestive system immediately following the ileum • Ends where the rectal gland enters the gut
RECTAL GLAND • Removes excess salt from the blood and passes them into the rectum for excretion • Helps the shark maintain osmotic equilibrium with the salt water • Helps with the kidney function
Rectum • Continuation of the colon • From the rectal gland to the cloaca
CLOACA • Common exit for intestinal, rectal gland, and urinary wastes leave the body • In males, sperm also passes here • In females, serves as the birth canal