digestive system anatomy & physiology. digestive processes
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Digestive System
Anatomy & PhysiologyAnatomy & Physiology
Alimentary CanalOne-way digestive tract through the body
Lumen of digestive tract
is externalenvironment
1-way flow ishighly effi cient
Body
Alimentarycanal
Digestive Processes
Digestive Organs
Mesentary
Peritonitis
Oral Anatomy Lateral View
Cadaver Midsaggital Section of Oral Structures
Oral Anatomy Anterior View
Tongue Anatomy
Taste Bud Anatomy
Salivary Glands
Cadaver ___ Gland
Tooth Anatomy
Tooth Eruption
Impacted Molar
Gingiva
Universal Tooth Numbering System
Tooth Faces• Lingual (Nearest Tongue)Lingual (Nearest Tongue)
• Facial (Farthest from tongue)Facial (Farthest from tongue)
• Mesial (Closest to the Mesial (Closest to the incisors)incisors)
• Distal (Farthest from the Distal (Farthest from the incisorsincisors
• Occlusal (Grinding surfaceOcclusal (Grinding surface
Splanchnic Circulation
25% of Cardiac Output
Endoscope
Larynx
Esophageal Reflux
G.E.R.D. (GastroEsophageal Reflux
Disease)
Gastric Fundus
Gastritis due to Helicobacter Pylori
Gastric Diverticulum
Gastric Polyps
Gastric Carcinoma
Duodenal Mucosa
Duodenal Ulcer
Proctologist
Testing for Occult Blood
Colonoscopy
Colonoscopy Administration
Caecal Diverticula
Descending Colon
Tapeworms
Ulcerative Colitis (Sigmoid Colon & Rectum)
Rectum
Anal Hemorrhoids (Piles) Caused by Inflammation of
the Superior & Inferior Hemorrhoid Veins
Scope Comparison
Barium Enema
Colostomy& Stoma
Colostomy Bag
Peristalsis
27 Year Old Male
81 Year Old Male
Swallowing
Gastric Regions
Gastric Anatomy
Gastric Cells
Gastric Cell FXN’s
• Goblet cells – produce alkaline mucusGoblet cells – produce alkaline mucus• Mucus Neck cells – produce acidic Mucus Neck cells – produce acidic
mucusmucus• Parietal cells – produce HCl & Intrinsic Parietal cells – produce HCl & Intrinsic
FactorFactor• Chief cells – produce pepsinogenChief cells – produce pepsinogen• Enteroendocrine cells – produce gastrin, Enteroendocrine cells – produce gastrin,
pepsin, cholecystokinin, & somatostatinpepsin, cholecystokinin, & somatostatin
Gall Bladder & Pancreas Empty Contents into
Duodenum
Liver & Pancreas Secretions
Liver FXN’s
• Synthesizes bile (bile salts, Synthesizes bile (bile salts, biliruben, & cholesterol)biliruben, & cholesterol)
• Stores glucose as glycogenStores glucose as glycogen
• Stores fat soluble vitamins ADEKStores fat soluble vitamins ADEK
Gall BladderFXNFXN• Stores bileStores bile• CCK contracts gall bladder secretion of pancreatic CCK contracts gall bladder secretion of pancreatic
juice & relaxation of the sphincter of Oddijuice & relaxation of the sphincter of Oddi
PathophysiologyPathophysiology• Gall stones – too much cholesterol or too few bile Gall stones – too much cholesterol or too few bile
salts resulting in cholesterol crystal accumulationsalts resulting in cholesterol crystal accumulation
• Obstructional jaundice – bile duct becomes Obstructional jaundice – bile duct becomes obstructed & bilirubin increases in bloodobstructed & bilirubin increases in blood
Gallstones
Bile Salt
PancreasFXNFXN• Secretes basic pancreatic juice (pH 7.5-8.0)Secretes basic pancreatic juice (pH 7.5-8.0)
Pancreatic Juice (p.j.)Pancreatic Juice (p.j.)• Bicarbonate rich p.j. neutralizes HCl in the duodenum Bicarbonate rich p.j. neutralizes HCl in the duodenum
(Stimulated by secretin when HCl enters the duodenum)(Stimulated by secretin when HCl enters the duodenum)
• Enzyme rich p.j. stimulated by CCK when fatty or protein Enzyme rich p.j. stimulated by CCK when fatty or protein rich foods enter the duodenumrich foods enter the duodenum
NoteNote• Hormones released in inactive form so they don’t digest Hormones released in inactive form so they don’t digest
the pancreasthe pancreas
Accessory Organ Ducts & Sphincter
H2O
CO2
H2CO3
H+
Na+
HCO3-
Na+
Blood capillary
Pancreaticacinar
cell
Pancreatic duct
Pancreatic secretion ofNaHCO3 (sodium bicarbonate)
[simplified]
Water & minerals• No need f or digestion• Water absorbed by osmosis
8.5 liters/ day• Minerals absorbed by
– Active transport– Facilitated diff usion
Water & Mineral Digestion
Absorption of…
Vitamins – Vitamins – • A,D,E,K fat soluble (diffuse into blood)A,D,E,K fat soluble (diffuse into blood)• B & C water soluble (diffuse into blood)B & C water soluble (diffuse into blood)• B12 requires intrinsic factor for diffusion…leads to B12 requires intrinsic factor for diffusion…leads to
pernicious anemiapernicious anemia
• Electrolytes (NaElectrolytes (Na++, K, K++, HCO, HCO33--, Cl, Cl--))
• Iron – binds to ferratin in mucosal cells & transferrin in Iron – binds to ferratin in mucosal cells & transferrin in the blood for transportthe blood for transport
• Calcium – PTH increases ionic calcium & vitamin D aids in Calcium – PTH increases ionic calcium & vitamin D aids in absorptionabsorption
Lipid Emulsification
Lipid Digestion
Carbohydrate Digestion
Na/K Symport
Protein Digestion
Brush Border
Villi
Small Intestine
Large Intestine with Mesentery
Cecum
Anal Sphincter
Control
Hormonal Control of Digestion
(Produced in stomach)• Gastrin - HCl secretion & gastric emptyingGastrin - HCl secretion & gastric emptying• Serotonin – Contracts gastric muscleSerotonin – Contracts gastric muscle• Histamine – HCl release from parietal cellsHistamine – HCl release from parietal cells• Pepsinogen – Pepsinogen – inactive form of pepsin (HCl activated) inactive form of pepsin (HCl activated)
catabolyzes proteincatabolyzes protein
• Somatostatin – Inhibits:Somatostatin – Inhibits: gastric secretionsgastric secretions gastric emptyinggastric emptying pancreatic secretionspancreatic secretions intestinal absorptionintestinal absorption gall bladder contraction (bile release)gall bladder contraction (bile release)
Hormonal Control of Digestion (Produced in
Duodenum)• Secretin - pancreatic juice secretion & bile outputSecretin - pancreatic juice secretion & bile output
• Cholecystokinin - pancreatic juice output, contracts gall Cholecystokinin - pancreatic juice output, contracts gall bladder, & relaxes sphincter of Oddibladder, & relaxes sphincter of Oddi
• Gastric inhibitory peptide – inhibits gastric secretion & Gastric inhibitory peptide – inhibits gastric secretion & motilitymotility
• Vasoactive intestinal peptide – dilates intestinal Vasoactive intestinal peptide – dilates intestinal capillaries & inhibits HCl productioncapillaries & inhibits HCl production
Hormonal Control of Digestion
(Produced by pancreas)• Trypsinogen – Inactive form of trypsin (activated by Trypsinogen – Inactive form of trypsin (activated by
enterokinase) catabolyzes protein to peptidesenterokinase) catabolyzes protein to peptides
• Amylase – catabolyzes polysaccharidesAmylase – catabolyzes polysaccharides
• Lipase – catabolyzes lipidsLipase – catabolyzes lipids
• Carboxypeptidase – catabolyzes protein to amino acidsCarboxypeptidase – catabolyzes protein to amino acids
• Chymotrypsin – catabolyzes protein to peptidesChymotrypsin – catabolyzes protein to peptides
Metabolic statesThe absorptive state•During & for several hours after a meal•Insulin
glucose uptake by cells (from blood)
glycogenesis in liver cells lipogenesis in fat cells lipolysis in fat cells
Continues until . . .
Metabolic statesThe postabsorptive state•Begins several hours after a meal•Glucagon
glycogenolysis gluconeogenesis lipolysis in fat cells lipogenesis in fat cells
Feces may indicate health issues
•Motility / timing•Diarrhea•Constipation
•Color / consistency•Gray = lack of bile•Black/tarry = bleeding (upper)
•Black = PeptoBismol•Red = bleeding (lower)
Digestion of Alcohol