digestive system: obtains nutrients cells need to survive, grow, and function ingestion propulsion =...

Digestive system: obtains nutrients cells need to survive, grow, and function

• Ingestion• Propulsion = movement

– Muscle tissue

• Digestion = breakdown of ingested materials– Mechanical – Chemical w/ enzymes

• Absorption = transport of nutrients from digestive tract into circulation

• Elimination = pooping (defecation)

Figure 26.1

Digestive Tract (primary organs)

Figure 26.3

Figure 26.3

Figure 26.4

Figure 26.12

Figure 26.14

Anterior view

Stomach

Jejunum

Ileum

Appendix

Duodenum

Mesentery

Ileocecaljunction

Cecum

Ascending colon

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Figure 26.7

Figure 26.8

Figure 26.16

Figure 26.16

Figure 26.9

Figure 26.15

Figure 26.10

Mucosa Submucosa Muscularis Serosa(mucousmembrane)

Epithelium

Laminapropria

Muscularismucosae

Circularmusclelayer

Longitudinalmusclelayer

(serous membrane;visceral peritoneum)

Connectivetissuelayer

Peritoneum

Intestinalgland

Lymphaticnodule

Ducts fromglands

Gland in submucosa

Entericplexus

Myentericplexus

Submucosalplexus

Blood vessels

Nerve

Mesentery

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20,000x

(c)

Villus

Epithelialcell

Lacteal (lymph)

Capillary(blood)

Epithelial cell

Microvilli

Microvilli ofepithelial cellsurface

Villi

Blood capillarynetwork

Lacteal

Epithelium

Intestinalgland

Duodenalgland

Top ofcircular fold

(b)

(d)

Figure 26.16

Figure 26.18

Figure 26.20

Figure 26.21

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Liver

Left and right hepatic ductsCommonhepatic duct

Gallbladder

Cystic duct

Hepatic portal vein

Common bile ductAccessory pancreaticduct

Minor duodenalpapilla

Major duodenalpapilla

Hepatopancreatic ampulla

Duodenum(cutaway view)

Anterior view

Pancreas

Pancreaticduct

Spleen

1

2

3

4

5

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(a)

Circular folds

EpitheliumSubmucosa

Circular muscle

Longitudinal muscle

Serosa

Jejunum

Duodenum

PancreaticductsHead of

pancreas

Major duodenal papilla

Minor duodenalpapilla

Common bileduct from liver

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Transverse colon

Right colic flexure(hepatic flexure)

Ascendingcolon

Ileum

Ileocecalvalve

Cecum

Vermiformappendix

Left colic flexure(splenic flexure)

Descending colon

Haustra

Teniae coli

Epiploicappendages

Sigmoid colon

Internal anal sphincter

External anal sphincter

(b) Anterior view

Anal canal

Rectum

(a) Anterior view

Figure 26.5

Figure 26.6

s.m.

s.l.