Digestive System Anatomy & Physiology

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) • Facial (Farthest from tongue) • Mesial (Closest to the incisors) • Distal (Farthest from the incisors • Occlusal (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 mucus Mucus Neck cells – produce acidic mucus Parietal cells – produce HCl & Intrinsic Factor Chief cells – produce pepsinogen Enteroendocrine cells – produce gastrin, pepsin, cholecystokinin, & somatostatin

Gall Bladder & Pancreas Empty Contents into Duodenum

Liver & Pancreas Secretions

Liver FXN’s • Synthesizes bile (bile salts, biliruben, & cholesterol) • Stores glucose as glycogen • Stores fat soluble vitamins ADEK

Gall Bladder FXN • Stores bile • CCK contracts gall bladder secretion of pancreatic juice & relaxation of the sphincter of Oddi Pathophysiology • Gall stones – too much cholesterol or too few bile salts resulting in cholesterol crystal accumulation • Obstructional jaundice – bile duct becomes obstructed & bilirubin increases in blood

Gallstones

Bile Salt

Pancreas • FXN Secretes basic pancreatic juice (pH 7.5-8.0) Pancreatic Juice (p.j.) • Bicarbonate rich p.j. neutralizes HCl in the duodenum (Stimulated by secretin when HCl enters the duodenum) • Enzyme rich p.j. stimulated by CCK when fatty or protein rich foods enter the duodenum Note • Hormones released in inactive form so they don’t digest the pancreas

Accessory Organ Ducts & Sphincter

HCO 3 Na + Pancreatic duct H 2 O H 2 CO 3 CO 2 Na + Pancreatic acinar cell H + Pancreatic secretion of NaHCO 3 (sodium bicarbonate) [simplified] Blood capillary

Water & Mineral Digestion

Absorption of… Vitamins – • A,D,E,K fat soluble (diffuse into blood) • • B & C water soluble (diffuse into blood) B12 requires intrinsic factor for diffusion…leads to pernicious anemia • Electrolytes (Na + , K + , HCO 3 , Cl ) • Iron – binds to ferratin in mucosal cells & transferrin in the blood for transport • Calcium – PTH increases ionic calcium & vitamin D aids in absorption

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 emptying Serotonin – Contracts gastric muscle Histamine – HCl release from parietal cells Pepsinogen – inactive form of pepsin (HCl activated) catabolyzes protein Somatostatin – Inhibits: gastric secretions gastric emptying pancreatic secretions intestinal absorption gall bladder contraction (bile release)

• Hormonal Control of Digestion (Produced in Duodenum) Secretin - pancreatic juice secretion & bile output • Cholecystokinin - pancreatic juice output, contracts gall bladder, & relaxes sphincter of Oddi • Gastric inhibitory peptide – inhibits gastric secretion & motility • Vasoactive intestinal peptide – dilates intestinal capillaries & inhibits HCl production

• Hormonal Control of Digestion (Produced by pancreas) Trypsinogen – Inactive form of trypsin (activated by enterokinase) catabolyzes protein to peptides • Amylase – catabolyzes polysaccharides • Lipase – catabolyzes lipids • Carboxypeptidase – catabolyzes protein to amino acids • Chymotrypsin – catabolyzes protein to peptides

Metabolic states

The 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 states

The 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