histological structure of upper alimentary system

Medical Faculty of Udayana University.

The Histologic Structure of Upper Alimentary Tract

Medical Faculty of Udayana University 2008

I Wayan Sugiritama


HISTOLOGY OF UPPER ALIMENTARY TRACT

Digestive system composed of :ORAL CAVITY

Histologic Structure of LipsHistologic Structure of PalateHistologic Structure of TeethHistologic Structure of Tongue

ALIMENTARY TRACKHistologic Structure of EsophagusHistologic Structure of StomachHistologic Structure of Small intestineHistologic Structure of Large IntestineHistologic Structure of Rectum and Anal Canal

ASSOCIATED GLANDSalivary Gland


ORAL CAVITY

• The first steps of digestion– Food moisten by saliva (Parotid,

Submandibular & Sublingual, & minor salivary glands)

– Ground by teeth smaller pieces– Initiation digestion of carbohydrate

Moistened the food + chewed BOLUS


HISTOLOGIC STRUCTURE OF THE ORAL CAVITY

The oral mucosa compose by epithelium and connective tissue:

• Masticatory mucosa: – covers the surfaces involved in

the processing of food (tongue, gingivae and hard palate).

– Strat. Sq. E. keratinized to different degrees

• Lining mucosa:– covers the remaining surfaces of

the oral cavity– non-keratinised strati. sq.

epithelium

• Specialized mucosa :– Taste buds


HISTOLOGIC STRUCTURE OF THE HARD AND SOFT PALATE

Separate the oral and nasal cavity• Hard Palate

– Keratinized St. Sq. Epith.

– Dense. Irreg. Coll. C.T– Rests on bony tissue

• Soft Palate– Non-keratinized St. Sq.

Epith– Irreg. Coll. C.T.– Minor Salivary Glands

• Uvula ~ Soft Palate


Histologic Structure of Lips

• The core: skeletal muscle fibers• External (skin) aspect:

– Thin skin, with sweat glands, hair follicles, & sebaceous gland

• Vermilion zone :– Thin skin, capillary loops close to the skin pink color

• Internal (mucous) aspect:– Strat. Sq. non-keratinized epith.


Pharynx

• Transition : oral cavity-respiratory-digestive system

• Lined by :– Strat. Sq. Epith.– Ciliated Pseudostrat. Colum. Epith.

(respiratory portion)

• Contains the tonsil


Histologic Structure of Teeth• Mineralized

– Enamel• Consist 96% calcium• Enamel rods coated with

organic matrix

– Dentin• Consist 70% calcium• Dentinal tubules

– Cementum• Consist 50% calcium• Cementocytes within

lacunae

• Pulp• Loose connective Tissue

with nerve and blood vessels


Structure Associated with Teeth

• Periodontal Ligament– Suspend the tooth in

its socket– Dense irregular

connective tissue

• Alveolus– Bony Socket

• Ginggiva (gums)– Keratinized St. Sq.

Epith.– Dense collagenous

connective tissue

Periodontal. L.

ALVEOLUS

CEMENTUM


Histologic Structure of Tongue

• Bulk of skeletal muscle fibers

• Dorsal surface :– Irregular

• Anterior (2/3)– Lingual papillae

• Sulcus terminalis• Posterior (1/3)

• Ventral Surface– Mucous membrane is

smooth


LINGUAL PAPILLAE

Filiform• Elongated conical shape• Keratinized. Strat. Sq. Ep.• (-) taste buds

Fungiform• Mushroom (slender stalk &

broad cup)• Nonkeratinized Strat. Sq.

Ept.• (+) taste buds


LINGUAL PAPILLAE

Circumvallate• V-shape (7-12)• Submerge into the

surface of tongue• Ducts of glands of

Von Ebner

• +Taste Buds Foliate• Appear as vertical

furrows• Poorly develope


TASTE BUDS

• Intraepithelial sensory organs perception of taste

• ± 3000 • Composed by :

– 60-80 spindle shape cells

• Basal cells• Dark Cells• Light Cells• Intermediate Cells

– The narrow end taste pore

• Nerve fibers


GENERAL STRUCTURE OF ALIMENTARY TRACT

• Mucosa– Epithelium– Lamina

Propia– Mucularis

mucosae

• Submucosa• Muscularis

externa• Adventitia


ESOPHAGUS

• Muscular tube• Transport foodstuffs (BOLUS) from

mouth to the stomach


Histologic Structure of Esophagus

• Mucosa– Strat. Sq. Non Keratinized E.– Lamina Propia (unremarkable)

• esophageal cardiac glands mucus coat

• Muscularis mucosae

• Submucosa– Dense fibroelastic C.T.– Esophageal glands proper

• Mucous • Serous Pepsinogen &

lysozyme

• Muscularis Externa– Skeletal & smooth muscle

• Adventitia


STOMACH

• Responsible for the formation & processing of ingested food CHYME

• Digestion – HCL– Pepsin– Rennin– Gastric lipase


Histologic Structure of StomachMucosa• Epithelium

– Simp. Colum. Epit. PROTECTIVE MUCUS

– InvaginateGastric pits

• Lamina propia– Loose C.T

– Branch Tubular Glands open

into gastric pits

• Muscularis mucosae– Smooth muscle

Submucosa– Dense irreg. coll. C.T.

Muscularis externa– Three layer of smooth M.


CARDIAC REGION OF STOMACH

• Simple tubular cardiac gland

• Shallow of gastric pits

• Base of glands is highly coiled

• Cells population mostly surface lining epith

• (-)chief cells• Mucus & lyzosyme


FUNDIC REGION OF STOMACH

• Branch Tubular gastric glands

• Type of cells :– Surface lining cells mucus– Regenerative cells regeneration– Mucous neck cells mucus– Parietal (oxyntic) cells HCL & intrinsic factor– Chief (zymogenic) cells pepsinogen & lipase– DNES cells


PYLORUS REGION OF STOMACH

• Deep of gastric pits• Short, higly

convulated, branch gland

• Predominant cells is mucous neck cells mucus & lysozyme

• Gastrin cells gastrin HCL production

• D cells somatostatin


Histologic Structure of Stomach


HISTOLOGIC STRUCTURE OF DUODENUM

Small intestine• Digest food

– Enzyme– bile

• absorb end product– Plicae circulares– Villi– microvilli

histological structure of upper alimentary system

Education

keratinized epith

sweat glands

coiled cells population

oral cavityrespiratory

t branch tubular glands

bony tissue soft palate

minor salivary glands

minor salivary glands