Anatomy & Anatomy & Physiology IIPhysiology IIUnit Three Unit Three

DigestionDigestion

The digestive tract is a tubular The digestive tract is a tubular passage that extends from the passage that extends from the lips of the mouth, through the lips of the mouth, through the body, and terminates with an body, and terminates with an anusanusThis system can be divided into This system can be divided into three regions:three regions: + oral cavity+ oral cavity + pharynx+ pharynx + alimentary canal+ alimentary canal

DigestionDigestion

The alimentary canal can be The alimentary canal can be further divided into four further divided into four segments:segments: + esophagus+ esophagus + stomach+ stomach + small intestine+ small intestine + large intestine+ large intestine

DigestionDigestion

Associated with the system are Associated with the system are four glands/organs that are four glands/organs that are located outside the tube, but located outside the tube, but secrete fluids into the system to secrete fluids into the system to aid in digestion:aid in digestion: + salivary glands+ salivary glands + liver+ liver + gall bladder+ gall bladder + pancreas+ pancreas

Digestive Digestive SystemSystem

DigestionDigestion

The function of the digestive The function of the digestive system is to mechanically & system is to mechanically & chemically breakdown food so chemically breakdown food so that nutrients can be obtained that nutrients can be obtained through absorption and energy through absorption and energy can be released can be released

DigestionDigestion

Mechanical digestion breaks the Mechanical digestion breaks the food into physically smaller food into physically smaller particles, while chemical digestion particles, while chemical digestion breaks macromolecules into breaks macromolecules into monomersmonomers

DigestionDigestion

The monomers and other The monomers and other nutrients are now small enough to nutrients are now small enough to be absorbed through the wall of be absorbed through the wall of the digestive tract and into the the digestive tract and into the bloodstream where they will be bloodstream where they will be distributed to body cells for distributed to body cells for energy needs and building energy needs and building materialsmaterials

Oral DigestionOral Digestion

TeethTeeth

TongueTongue

TonsilTonsil

UvulaUvulaHard Hard palatepalate

Soft Soft palatepalateOral structures Oral structures

involved in involved in mechanical mechanical digestion:digestion: * teeth* teeth * tongue* tongue * hard palate* hard palate * cheeks* cheeks

PulpPulp

GingivaGingiva

DentinDentin

EnamelEnamel

Oral DigestionOral Digestion

IncisorsIncisors

MolarsMolars

CaninesCanines

PremolarsPremolars

Oral DigestionOral Digestion

Sublingual Sublingual salivary glandsalivary gland

Submandibular Submandibular salivary glandsalivary gland

Parotid Parotid salivary salivary glandgland

Oral structures Oral structures involved in involved in chemical chemical digestion:digestion: * parotid * parotid salivary salivary glandsglands * * submandibular submandibular salivary salivary glandsglands * sublingual * sublingual salivary salivary glandsglands

Oral DigestionOral DigestionSoft Soft

palatepalate UvulaUvulaHard Hard palatepalate

PharynxPharynx

EpiglottisEpiglottis

GlottisGlottis

EsophagusEsophagus

TonsilsTonsils

Structures Structures involved in involved in swallowing:swallowing: * soft palate & * soft palate & uvulauvula * pharynx* pharynx * epiglottis* epiglottis * esophagus* esophagus

Oral DigestionOral Digestion

Deglutition Deglutition (swallowing)(swallowing)

Alimentary Canal HistologyAlimentary Canal Histology

SerosaSerosa

Muscularis Muscularis externa externa

(longitudinal (longitudinal muscle)muscle) Muscularis Muscularis

interna interna (circular (circular muscle)muscle)

SubmucosaSubmucosa

MucosaMucosa

Alimentary Canal Alimentary Canal MovementsMovements

PeristalPeristalsissis

SegmentaSegmentationtion

Alimentary Alimentary Canal Canal

MovementsMovements

Alimentary Alimentary CanalCanal

EsophagusEsophagus

DiaphragmDiaphragm

StomachStomach

StomachStomach

A aa

EsophagusEsophagusDiaphragmDiaphragmFundic Fundic regionregionCardiac Cardiac

regionregionBodyBody

Lesser Lesser curvaturecurvature

Greater Greater curvaturecurvature

RugaeRugaePyloric Pyloric antrumantrum

Pyloric Pyloric sphinctersphincter

Muscle Muscle layerslayers

Stomach WallStomach WallRugaeRugae

MucosaMucosaGastric Gastric

pitpit

SubmucosaSubmucosaGastric Gastric glandgland

SerosaSerosa

MuscularisMuscularislayerslayers

Stomach Stomach WallWall

Mucous Mucous cellcell

Parietal Parietal cellcell

Chief Chief cellcell

Cardiac or Cardiac or Pyloric GlandPyloric Gland

Gastric Gastric GlandGland

G cellG cell

Activation of PepsinActivation of Pepsin

Control of Gastric Control of Gastric SecretionSecretion

Control of Gastric Control of Gastric SecretionSecretion

Stomach DisordersStomach Disorders

Emesis - the forceful ejection Emesis - the forceful ejection of stomach or duodenal of stomach or duodenal contentscontentsBulimia – eating disorder in Bulimia – eating disorder in which emesis is induced so as which emesis is induced so as to rid the body of the food to rid the body of the food recently eatenrecently eaten

Stomach DisordersStomach Disorders

Peptic ulcers – erosion of the Peptic ulcers – erosion of the stomach lining caused by stomach lining caused by bacteria, aspirin, HCl or bacteria, aspirin, HCl or pepsinpepsin

Anorexia – eating disorder in Anorexia – eating disorder in which a person loses their which a person loses their appetite because they believe appetite because they believe they are fatthey are fat

Accessory Organ AnatomyAccessory Organ Anatomy

LiverLiver

AnteriorAnterior PosteriorPosterior

Gall Gall bladderbladder

Common Common hepatic hepatic

ductduct

Liver FunctionLiver Function

The liver carries out a number The liver carries out a number of functions:of functions: > degradation of toxins, > degradation of toxins, drugs, drugs, etc.etc. > cleaning bacteria and > cleaning bacteria and debris debris from the bloodfrom the blood > produces and secretes > produces and secretes plasma plasma proteinsproteins

Liver FunctionLiver Function

The liver carries out a number The liver carries out a number of functions that concern of functions that concern digestion:digestion: > process the monomers of > process the monomers of digestiondigestion > processes vitamins and > processes vitamins and ironiron > produces bile> produces bile

Accessory Organ AnatomyAccessory Organ Anatomy

Liver FunctionLiver Function

Cirrhosis of the liver is the Cirrhosis of the liver is the replacing of liver tissue with replacing of liver tissue with connective tissue, reducing the connective tissue, reducing the function of the liverfunction of the liver

Liver FunctionLiver Function

Cirrhosis can have several Cirrhosis can have several causes:causes: > viral (hepatitis)> viral (hepatitis) > drug abuse> drug abuse > trauma> trauma

Accessory Organ AnatomyAccessory Organ Anatomy

Hepatic ductsHepatic ductsCommon Common

hepatic ducthepatic duct

Gall bladderGall bladder

Cystic Cystic ductduct

Common bile Common bile ductduct

Pancreatic Pancreatic ductduct

PancreasPancreas

Hepatopancreatic Hepatopancreatic ductduct

Hepatopancreatic Hepatopancreatic sphinctersphincter

DuodenumDuodenum

Small Intestine AnatomySmall Intestine Anatomy

Small Intestine PhysiologySmall Intestine Physiology

Small Small Intestine Intestine

PhysiologyPhysiologyVillusVillus

MicrovilliMicrovilli(brush border)(brush border)

CapillariesCapillaries

LactealLacteal

Small Small Intestine Intestine

PhysiologyPhysiology

Large Intestine AnatomyLarge Intestine Anatomy

Large Intestine DisordersLarge Intestine Disorders

DiverticulitisDiverticulitis

DiarrheaDiarrhea

ConstipationConstipation

FlatulenceFlatulence