Principles of Anatomy and Physiology Thirteenth Edition Chapter 24 The Digestive System Copyright ©...

Principles of Anatomy and Physiology

Thirteenth Edition

Chapter 24The Digestive System

Copyright © 2012 by John Wiley & Sons, Inc.

Gerard J. Tortora • Bryan H. Derrickson

Mouth (oral cavity)contains teeth and tongue

Sublingual gland(salivary gland)

Pharynx

Stomach

Pancreas

Transverse colon

Descending colon

Sigmoid colon

Rectum

Anal canal

Anus

Parotid gland(salivary gland)

Submandibular gland(salivary gland)

Esophagus

Liver

Duodenum

Gallbladder

Jejunum

Ascending colon

Ileum

Cecum

Appendix

(a) Right lateral view of head and neck and anterior view of trunk

SUPERIOR

Diaphragm

Ileum

Cecum

Ascending colon

Gallbladder

Liver

Falciform ligament

Descending colon

Jejunum

Transverse colon

Stomach

(b) Anterior view

Muscularis mucosae

Duct of gland outside tract (such as pancreas)

Gland in mucosa

Glands in submucosa

Submucosal plexus (plexus of Meissner)

Vein

Artery

Mucosa-associated lymphatic tissue (MALT)

SUBMUCOSA

MUSCULARIS:Circular muscle

Longitudinal muscle

Myenteric plexus (plexus of Auerbach)

SEROSA:Areolar connective tissueEpithelium

Lumen

Mesentery

MUCOSA:Epithelium

Lamina propria

Nerve

Longitudinal and circular smooth muscle layers of the muscularis

ENTERIC NERVOUS SYSTEM

Myenteric plexus

To ANS and CNS neurons

Interneuron

Submucosal plexus

Motor neuron Motor neuron Sensory neuron

Mucosal epithelium

(a) Midsagittal section showing the peritoneal folds

LESSER OMENTUM

MESOCOLON

MESENTERY

GREATER OMENTUM

PARIETAL PERITONEUM

VISCERAL PERITONEUM

PERITONEAL CAVITY

Diaphragm

Liver

Pancreas

Stomach

Duodenum

Transverse colon

Jejunum

Ileum

Sigmoid colon

Uterus

Urinary bladder

Rectum

Pubic symphysis

ANTERIORPOSTERIOR

Midsagittal plane

(b) Anterior view

FALCIFORM LIGAMENT

GREATER OMENTUM

Stomach

Transverse colon

Urinary bladder

Liver

LESSER OMENTUM

Stomach

Duodenum

Descending colon

Sigmoid colonAscending colon

Transverse colon

Liver(reflected upward)

Gallbladder (reflected upward)

(c) Lesser omentum, anterior view(liver and gallbladder lifted)

(d) Anterior view (greater omentum lifted and small intestine reflected to right side)

GREATER OMENTUM (reflected upward)

Descending colon

Jejunum (pulled laterally)

MESENTERY

Urinary bladder

Transverse colon

Sigmoid colon

Ileum (pulled laterally)

(e) Anterior view

Lungs

FALCIFORM LIGAMENT

DiaphragmRight lobe of liver

Stomach

Heart

Left lobe of liver

GREATER OMENTUM

SUPERIOR

Superior lip (lifted upward)

Superior labial frenulum

Gingivae (gums)

Palatoglossal arch

Fauces

Palatopharyngeal arch

Palatine tonsil (between the arches)

Tongue (lifted upward)

Lingual frenulum

Opening of duct of submandibular gland

Inferior labial frenulum

Inferior lip (pulled down)

Gingivae (gums)

Hard palate

Soft palate

Uvula

Cheek

Molars

Premolars

Cuspid (canine)

IncisorsOral vestibule

Anterior view

Parotid duct

Opening of parotid duct (near second maxillary molar)

Second maxillary molar tooth

Tongue (raised in mouth)

Lingual frenulum

Sublingual ducts

Submandibular duct

Mylohyoid muscle

SUBMANDIBULAR GLAND

Zygomatic arch

PAROTID GLAND

Lesser sublingual duct

SUBLINGUAL GLAND

(a) Location of salivary glands

(b) Portion of submandibular gland

240x

Serous acini

Mucous acini

LM

Enamel

Dentin

Gingival sulcus

Gingiva (gum)

Pulp in pulp cavity

Cementum

Root canal

Alveolar bone

Periodontal ligament

Apical foramen

Nerve

Blood supplySagittal section of a mandibular (lower) molar

CROWN

NECK

ROOT

Sagittal plane

First molar (12–16 mo.)

Central incisor(8–12 mo.)

Lateral incisor(12–24 mo.)

Second molar (24–32 mo.)

Second molar (24–32 mo.)

First molar (12–16 mo.)

Cuspid or canine (16–24 mo.)

Lateral incisor(12–15 mo.)

Central incisor(6–8 mo.)

(a) Deciduous (primary) dentition; teeth are designated by letters (with times of eruption)

Lower Teeth

Upper Teeth

Cuspid or canine (16–24 mo.)

ABC

D E FGH

IJ

K

LM

NOPQR

S

T

First molar (6–7 yr.)

Central incisor (7–8 yr.)

Lateral incisor(8–9 yr.)

Second molar (12–13 yr.)

Third molar or wisdom tooth(17–21 yr.)

First molar (6–7 yr.)

Cuspid or canine (11–12 yr.)

Lateral incisor(7–8 yr.)

Central incisor(7–8 yr.)

(b) Permanent (secondary) dentition; teeth are designated by numbers (with times of eruption)

Lower Teeth

Upper Teeth

Cuspid or canine (9–10 yr.)

1

2

3

4

567 8 9 10

17

18

19

20

212223242526

Third molar or wisdom tooth(17–21 yr.)

First premolar or bicuspid (9–10 yr.)

Second premolar or bicuspid (10–12 yr.)

Second molar (11–13 yr.)

First premolar or bicuspid (9–10 yr.)

Second premolar or bicuspid(11–12 yr.)

1112

13

14

15

16

2728

29

30

31

32

Wall of the esophagus

Lumen of esophagus

Mucosa:

Submucosa

Muscularis (circular layer)

Muscularis (longitudinal layer)

Adventitia

Nonkeratinizedstratified squamousepithelium

Muscularis mucosae

Lamina propria

Transverse plane

20xLM

Nasopharynx

Bolus

(a) Position of structures before swallowing (b) During pharyngeal stage of swallowing

Hard palate

Soft palate

Uvula

Oropharynx

Epiglottis

Laryngopharynx

Larynx

Esophagus

Tongue

Longitudinal muscles contract

Esophagus

Lower esophageal sphincter

Bolus

Stomach

Relaxed muscularis

Relaxed muscularis

Circular muscles contract

(c) Anterior view of frontal sections of peristalsis in esophagus

PYLORIC ANTRUM

CARDIA

BODY

FUNDUS

Serosa

Muscularis:Longitudinal layer

Circular layer

Oblique layer

Greater curvature

Rugae of mucosa

PYLORIC CANAL

Pyloric sphincter

Duodenum

Esophagus

Lower esophagealsphincter

Lesser curvature

PYLORUS

(a) Anterior view of regions of stomach

PYLORIC CANAL

BODY

Rugae of mucosa

Lesser curvature

(b) Anterior view of internal anatomy

Pyloric sphincter

Duodenum

PYLORUS

PYLORIC ANTRUM

Esophagus

CARDIA

FUNDUS

Greater curvature

Longitudinal layer of muscle

Gastric pits

Surface mucous cellLamina propria

Mucous neck cellParietal cell

Chief cell

Gastric glandG cellLymphatic nodule

Muscularis mucosae

Lymphatic vessel

Venule

Arteriole

Oblique layer of muscle

Circular layer of muscle

Myenteric plexus

MUCOSA

SUBMUCOSA

MUSCULARIS

SEROSA

Lumen of stomach

(a) Three-dimensional view of layers of stomach

G cell (secretes the hormone gastrin)

Gastric glands

Lamina propria

Muscularis mucosae

Mucous neck cell (secretes mucus)

Parietal cell (secretes hydrochloric acid and intrinsic factor)

Chief cell (secretes pepsinogen and gastric lipase)

Surface mucous cell (secretes mucus)

(b) Sectional view of stomach mucosa showing gastric glands and cell types

Gastric pit

Submucosa

Surface mucous cells

Gastric pit

40x

Stomach mucosaSEM

Lumen of gastric gland

Gastric pitLamina propriaSurface mucous cell

Mucous neck cell

Parietal cell

Chief cells

Lumen of gastric gland

G cells

180xLM

(c) Fundic mucosa

Chyme in stomach lumen

Blood capillary in lamina propria

Basolateral membrane

Interstitial fluid

Alkaline tide

Parietal cellApical membrane

ATP ADP

H+

K+

Cl– H2O + CO2

CAH2CO3 H+ + HCO3

– HCO3– HCO3

–

Cl–

Key:

Proton pump(H+/K+ ATPase)

K+ (potassium ion) channel

Cl– (chloride ion) channel

Carbonic anhydrase

Diffusion

HCO3– /Cl– antiporter

HCO3–

Cl–

CA

Lumen of stomach

Parietal cell

Interstitial fluid

Acetylcholine (ACh)

ACh receptor

Gastrin

Gastrin receptor

Histamine

Histamine receptor

HCl secretion

Apical membrane

Basolateralmembrane

Uncinate process

Right lobe of liver

Left hepatic duct

Falciform ligament

Diaphragm

Right hepatic duct

Cystic duct

Gallbladder:

Neck

Body

Fundus

Duodenum

(a) Anterior view

Accessory duct (duct of Santorini)

Hepatopancreatic ampulla(ampulla of Vater)

Jejunum

Pancreatic duct (duct of Wirsung)

Common bile duct

Common hepatic duct

Round ligament

Pancreas

Coronary ligament

Left lobe of liver

Head

Body

Tail

Major duodenal papilla

Mucosa of duodenum

Common bile ductPancreatic duct (duct of Wirsung)

(b) Details of hepatopancreatic ampulla

Hepatopancreatic ampulla (ampulla of Vater)

Sphincter of the hepatopancreatic ampulla (sphincter of Oddi)

Common bile duct

Right hepatic duct

Common hepatic duct from liver

Cystic duct from gallbladder

Duodenum

SphincterLiver

Key:

Gallbladder

Pancreas

Left hepatic duct

(c) Ducts carrying bile from liver and gallbladder and pancreatic juice from pancreas to duodenum

Pancreatic duct from pancreas

(d) Anterior view

Falciform ligament

Diaphragm

Spleen

Tail of pancreas


Body of pancreas

Head of pancreas

Liver

Hepatic bile duct

Cystic bile duct

Gallbladder

Common bile duct

Major duodenal papilla

Duodenum

Common bile duct

MEDIAL

SUPERIOR

(e) Anterior view

Uncinate process

Body of pancreas

Tail of pancreas

Head of pancreas

Majorduodenal papilla

Duodenum

LATERAL


Hepatic sinusoids

Hepatic laminae

Bile duct

Connective tissue

Branch of hepatic portal vein

Central vein

(a) Overview of histological components of liver

Hepatocyte

Branch of hepatic artery

Inferior vena cava

Hepatic artery

Hepatic portal vein

Liver

Portal triad:

Hepatic sinusoid

To hepatic vein

Hepatic laminae

Branch of hepatic artery


Bile canaliculi

Hepatocyte

Stellatereticuloendothelial(Kupffer) cell

Connective tissue

(b) Details of histological components of liver

Hepatic sinusoids

Bile duct

Central vein

Portal triad:

(c) Photomicrographs

100x

50x

150x

Hepatocyte

Central vein

Sinusoid

Portal triad:Branch of hepatic artery


Bile duct

LM

LM

LM

Central vein

Hepatic lobule Portal lobule

Portal triad

(d) Comparison of three units of liver structure and function

Hepatic acinus

(e) Details of hepatic acinus

Central vein

Central vein

Portal triad

Zone 1

Zone 2

Zone 3

Oxygenated blood from hepatic artery

Right atrium of heart

Nutrient-rich, deoxygenated blood from hepatic portal vein

Inferior vena cava

Liver sinusoids

Hepatic vein

Central vein

2

3

4

5

6

1

DUODENUM

JEJUNUM

ILEUM

Stomach

Large intestine

(a) Anterior view of external anatomy

Circular folds (plicae circulares)

(b) Internal anatomy of jejunum

(a) Relationship of villi to circular folds

Submucosa

Villi



Serosa

Circular folds

Circular folds (plicae circulares)

MUSCULARIS

Muscularis mucosae

Absorptive cell

Goblet cell

Lacteal

Lamina propria

Enteroendocrine cell

Paneth cell

Lymphatic nodule

Lymphatic vessel

Arteriole

Venule


Myenteric plexus


(b) Three-dimensional view of layers of the small intestine showing villi

VilliBlood capillary

Lacteal Opening of intestinal gland

Lumen of small intestine

SUBMUCOSA

MUCOSA

SEROSA

Lacteal

Microvilli

Absorptive cell (absorbs nutrients)

Goblet cell (secretes mucus)

Enteroendocrine cell (secretes the hormones secretin, cholecystokinin, or GIP)

Paneth cell (secretes lysozyme and is capable of phagocytosis)

Blood capillary

Submucosa

Muscularis

Lymphatic vessel

Venule

Arteriol

Muscularis mucosae

Intestinal gland

Lamina propriaMucosa

(c) Enlarged villus showing lacteal, capillaries, intestinal glands, and cell type

(a) Wall of duodenum

Duodenal gland

Muscularis mucosae

Intestinal glands

Muscularis

Submucosa

Mucosa

Villi

Lumen of duodenum

45xLM

160xLM

(b) Several villi from duodenum

Duodenum

Intestinal glands

Lamina propria

Absorptive cell

Goblet cell

Simple columnar epithelium

Lumen of duodenum

Brush border

Villi

14xLM

Muscularis

(c) Lymphatic nodules in ileum

Lumen of ileum

Villus

Solitary lymphatic nodule

Submucosa

Brush border

46,800xTEM

(d) Several microvilli from duodenum

Simple columnar epithelial cell

Microvilli

Epithelial cells of villus

(a) Mechanisms for movement of nutrients through absorptive epithelial cells of villi

Glucose and galactose

Secondary active transport with Na+

Fructose Facilitated diffusion

Amino acids Active transport or secondary active transport with Na+

Dipeptides

TripeptidesSecondary active transport with H+

Small short-chain fatty acids

Simple diffusion

Monoglycerides

Large short-chain and long-chain fatty acids Simple

diffusion

Facilitated

diffusion

Triglyceride

Chylomicron

To blood capillary of a villus

To lacteal of a villus

Diffusion

Basolateral surface

Monosaccharides

Diffusion

Amino acids

Micelle

Lumen of small intestine

Microvilli (brush border) on apical surface

(b) Movement of absorbed nutrients into blood and lymph

Left subclavian vein

HeartSmall short-chain fatty acid

Villus (greatly enlarged)

Chylomicron

Blood capillary

Lacteal

Arteriole

Amino acid

Monosaccharide

Venule

Blood

LymphLymphatic vessel

Hepatic portal vein

Thoracic duct

Liver

Total absorbed = 9.2 liters

ABSORBED

Ingestion of liquids(2.3 liters)

Saliva (1 liter)

Gastric juice(2 liters)

Bile (1 liter)

Pancreatic juice(2 liters)

Intestinal juice (1 liter)

Total ingested and secreted= 9.3 liters

INGESTED AND SECRETED

Small intestine (8.3 liters)

Large intestine (0.9 liters)

Excreted in feces (0.1 liter)

Fluid balance in GI tract

RECTUM

Right colic (hepatic) flexure

ASCENDING COLON

Teniae coli

CECUM

Ileocecal sphincter (valve)

VERMIFORM APPENDIX

(a) Anterior view of large intestine showing major regions

IleumMesoappendix

TRANSVERSE COLON

Left colic (splenic) flexure

DESCENDING COLON

Teniae coli

SIGMOID COLON

Haustra

Omental appendices

ANAL CANAL

ANUS

Internal anal sphincter (involuntary)

Rectum

Anal canal

(b) Frontal section of anal canal

Anal columnAnus

External anal sphincter (voluntary)

(a) Three-dimensional view of layers of large intestine

Muscularis mucosae

Lymphatic vessel

Arteriole

Venule


Myenteric plexus


Absorptive cell

Goblet cell

Intestinal gland

Lamina propria

Openings of intestinal glands

Lymphatic nodule

Lumen of large intestine

SUBMUCOSA

MUCOSA

MUSCULARIS

SEROSA

(b) Sectional view of intestinal glands and cell types

Openings of intestinal glands

Intestinal gland

Muscularis mucosae

Submucosa

Absorptive cell (absorbs water)

Lymphatic nodule

Goblet cell (secretes mucus)

Lamina propria

Microvilli

(c) Portion of wall of large intestine


Intestinal gland

Lamina propria

Muscularis mucosae

Lymphatic nodule

Mucosa

Submucosa

Muscularis

Serosa315xLM

300xLM


(d) Details of mucosa of large intestine

Opening of intestinal gland

Lamina propria

Intestinal gland

Goblet cell

Absorptive cell

Increase in acidity of stomach chyme; mixing of stomach contents; emptying of stomach

Food entering stomach disrupts homeostasis by

pH of gastric juice Distention (stretching) of stomach walls

Control center

Input

Output

Nerve impulses

Nerve impulses (parasympathetic)

Effectors

Submucosal plexus

Parietal cells secrete HCI and smooth muscle in stomach wall contracts more vigorously

HCI

Return to homeostasis when response brings pH of gastric juice and distention of stomach walls back to normal (pre-eating status)

Receptors

Chemoreceptors and stretch receptors in stomach detect pH increase and distention

Chemoreceptors and stretch receptors in stomach detect pH increase and distention

Increasing

Principles of Anatomy and Physiology Thirteenth Edition Chapter 24 The Digestive System Copyright ©...

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