APII Notes Home Page

Digestive Anatomy

Alimentary Canal

http://www.argosymedical.com/flash/digestion/landing.html

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I). Layers of the Digestive Tract

A. Peritoneum:

B). Mesentery

C). Mucosa

D). Submocousa

E). Muscularis

F). Serosa:

II). Smooth Muscle

http://www.lab.anhb.uwa.edu.au/mb140/CorePages/Muscle/Muscle.htm

Innervated: autonomic nervous system.

Longitudinal and circular muscle layer orient at right angles to each other.

• contracts longitudinal muscles it shortens and dilates.
• contract circular muscles the lumen constricts and the organ lengthens.

                    rhythmic contraction called peristalsis.

III). Alimentary Canal:

Breaks down food and absorbs nutrients

 

A). Mouth or Oral Cavity or Buccal Cavity

1). Lips and cheeks

2). Palate:

a). Hard Palate:

b). Soft Palate

Accessory Digestive Organ

(tongue, teeth, salivary glands)

3). Tongue

Manipulates food forming bolus

Interlacing bundles of skeletal muscles

Sense organs

4). Salivary glands

a). Buccal glands

b). Parotid gland

c). Submandibular gland

d). Sublingual gland

5). Teeth

 

a). 2 sets

 primary teeth

secondary set consists of 32 teeth

Incisors:

Central Incisor

Lateral Incisor

Cuspid (canine):

Bicuspid premolar;

First Molar

Second Molar

Third (wisdom teeth)

b). Tooth Structure

Crown

Gum (gingival)

Enamel

Cells that develop the enamel degenerate when the tooth erupts thus there are none available for repair.

Root

Dentin

B). Pharynx

C). Esophagus

Collapses when not needed and mucosa folds.

Passes the diaphragm at the esophageal hiatus

 

D). Stomach

1). Cardiac Region

with the cardiac sphincter

2). Fundus

3). Body

• Lesser curve
• Greater curve

4). Pylorus

connected to the small intestine by the pyloric sphincter

5). Rugae of mucosa

6).  Blood Vessels

Left and Right Gastric Arteries

(come from the celiac artery)

Also serves the esophagus

 

Left and Right Gastric Veins

(drain into the inferior vena cava)

 

7). Histolgoy

Gastric pits

http://webanatomy.net/histology/digestive/digestive_index.htm

 

E). Small Intestine

Extends from pyloric sphincter to the ileocecal valve of large intestine.

1). Regions

i). Duodenum (25 cm) ii). Jejunum (2.5 m) iii). Ileum (3.6 m)
Mnemonic: Dow Jones Industrial Duodenum Jejunum Ileum	http://www.uclan.ac.uk/facs/health/nursing/sonic/scenarios/scenario1GITlecture.htm

2). Histology

i). Villi and microvilli  

ii).  Peyer’s patches

http://www.mhhe.com/biosci/ap/histology_mh/simpleep.html	http://www.lab.anhb.uwa.edu.au/mb140/CorePages/Lymphoid2/lymph2.htm

F). Large Intestine

  ileocecal valve to the anus.

1). Gross anatomy

i). Teniae coli: 

ii). Haustra: 

iii) Epiploic appendages: 

2). Subdivisions

i). Cecum

ii). Appendix

iii). Colon

a). Ascending Colon

b). Transverse Colon

c). Descending Colon

d). Sigmoid Colon

iv). Rectum

v). Anal Canal

Anal Sphincters

internal  external

3. Histology

Goblet cells   Mucosa layer   Submucosa layer Smooth muscle layer
	http://biodidac.bio.uottawa.ca/thumbnails/histocatquery.htm

4.  Vessels of the small & large intestine

Arteries

i.   Common hepatic artery ii.   Superior mesenteric artery iii.  Inferior mesenteric artery

Veins

i.  Superior mesenteric vein ii. Inferior mesenteric vein iii.  Splenic vein from the spleen iv.  Hepatic portal system