the digestive system. 15.1 functions: mechanical and chemical breakdown of food *absorption of...
TRANSCRIPT
The Digestive System
15.1
Functions: mechanical and
chemical breakdown of food
*absorption of nutrients
Consists of alimentary canal
and accessory organs
Wall of the Alimentary Canal
Mixing Movements
Contractions mix food
with digestive juices
Peristalsis - pushes food
down the tube
Anatomy of the Mouth
Salivary Glands Parotid - ear, cheekSubmandibular - below jawSublingual - under tongue
Esophagus
esophageal hiatus is where it penetrates the diaphragm cardiac sphincter at entrance to stomach
STOMACH MUSCLES: Longitudinal, Circular, Oblique
Stomach
Regions
●Cardiac●Fundic●Body (greater and
lesser curvature)●Pyloric
Stomach Lining
Gastric Juices contain acids that break down food - secreted by gastric glands
PEPSIN - most important digestive enzyme for breaking down food
Mucus prevents stomach from digesting itself
Chyme - paste, after food has been broken down, released then into the duodenum via the pyloric sphincter valve
Rugae - folds within stomach
Gastric Pits contain glands to make juices
PANCREAS - secretes insulin which breaks down sugars
Pancreatic Juice also breaks down fat
Liver
1 large right lobe | 1 smaller left lobe
Liver - ducts and vessels
Hepatic duct --> to common bile duct
Hepatic portal vein - circulates blood through liver
Liver Functions1. blood glucose levels2. breakdown of lipids and fats3. protein metabolism4. stores vitamins5. destroys damaged RBCs6. removes toxins7. secretes bile
Remember Bili Lights?
Using bili lights is a therapeutic procedure performed on newborn or premature infants to reduce elevated levels of bilirubin. If blood levels of bilirubin become too high, the bilirubin begins to dissolve in the body tissues, producing the characteristic yellow eyes and skin of jaundice.
Gall Bladder - under liver cystic duct --> common bile duct stores bile, digests fat *gallstones may form
Small Intestine
Starts at the pyloric
sphincter
1. Duodenum
2. Jejunum
3. Ileum
*Mesentery
Membrane holds it
together, contains
blood vessels
Greater Omentum
a "curtain-like" membrane that covers the intestines, stores fat and lays like a drape
The main function of the small intestine is to secrete chemicals that break down food and carry the nutrients away in the blood stream. In one word:
ABSORPTION
Large Intestine
Cecum
Appendix
Colon (4 parts)
Cecum
Ascending
Transverse
Descending
Sigmoid
Rectum
Anus
Function of Large IntestineSecretes mucus, reabsorbs water, contains bacteria to aid in digestion (intestinal flora)
Mass Movements (defecation) - removes undigested food
The main job is WATER REABSORPTION...
stomach
cecum
appendix
ascending colon
transverse colon
descending colon
sigmoid colonrectum
1. esophagus2. liver3. stomach4. pyloric sphincter5. duodenum6. pancreas7. jejunum8. ileum9. cecum10. appendix11. ascending colon12. descending colon13. sigmoid colong14. anus
Disorders of the Digestive System
GERD
Gastroesophageal
reflux disease
STOMACH ULCERS
Lactose Intolerance Inability to digest milk, can cause stomach upset
Appendicitis
Hernia
intestines poke through abdominal muscles
Gallstones (Cholelithiasis)
Gallstones are made from cholesterol and other things found in the bile. They can be smaller than a grain of sand or as large as a golf ball.
Gallstones within the gall bladder
Gastric Bypass Surgery