The document summarizes the anatomy of several organs in the oral cavity and alimentary canal. It describes the histological structure of the lips, palate, tongue, esophagus, stomach, small intestine, large intestine, and associated glands. Key details provided on each organ include the epithelial lining, layers of tissue, presence of glands or muscle, and histological cell types. Functions of some structures are also mentioned.

1. Zulham, Radita, AlyaDepartment of Histology
Faculty of Medicine USU

2.  Oral Cavity
• Lip
• Palate
• Tongue
 Alimentary Canal
• Esophagus
• Stomach (Cardia, Fundus and Corpus, Pylorus)
• Small intestine (Duodenum, Jejunum, Ileum)
• Large Intestine (Appendix, Colon, Rectum, Anal Canal)
 Glands
• Salivary Gland
• Liver
• Gall bladder
• Pancreas

3.  3 regions:
• External aspects
 Is covered by stratified squamous keratinized epithelium
 Like the rest of the skin
 Has hairs and eccrine sweat glands
• Vermillion Zone
 The pink region of the lip
 is covered with thin skin, devoid sweat gland and hair follicles
• Mucous aspect
 is covered by stratified squamous non keratinized epithelium
 Contains numerous small mucous glands
 Sub mucosa is composed of dense and loose connective
tissue.They have dense vascularization
 Muscle: skeletal muscle, called orbicularis oris

5.  Crown, cervix, root
 Crown covered by enamel ( a
secretion product of ameloblast)
 Crown rest in dentin ( a
secretion product of
odontoblasts)
 Mineralized: Enamel, Dentin,
Cementum
 Periodonsium: Gingiva,
Alveolus, Periodontal ligament
 Pulp chamber: Connective
tissue, vascular, lymph, nerve

6.  Composed of hard palate, soft palatae, and
uvula
 Hard palate is composed of str squamous
keratinized/parakeratinized ep, irregular
collagenous CT, and bony shelf
 Soft palate is composed of str squamous
nonkeratinized ep, dense irregular CT,
minor salivary glands, and bony shelf
 Uvula is composed of str squamous
nonkeratinized ep, areolar CT, muscle

7.  Layers
• Is composed of three orthogonally arranged layers
of skeletal muscle fibers
 Dorsal surface
• Lingual papillae
 Filiform papillae
 The most abundant type, flame like structures, do not contain
taste bud
 Fungiform papillae
 Scattered among the filiform papillae, mushroom-shape
structure, contain a few tasted bud
 Foliate papillae (degenerate at 3 y old)
 Circumvalate papillae
 Exist only in the V-shape boundary between the anterior
posterior section, many of tasted bud,Von Ebner glands
produces lipase
 Intrinsic and extrinsic skeletal muscle

8. Papila filiformis
Papila foliate
Papila
fungiformis
Papila
circumvallate

9.  Sensory organs, perception of
taste. (In fungiform and
circumvalate papillae)
 Taste pore
 Oval structure, composed of 60
– 80 spindle-shaped cells, pale.
Microvili protrudes from taste
pore
• Basal cells (type IV cells)
• Dark cells (type I cells)
• Light cells (type II cells)
• Intermediate cells (type III cells)
 Nerve fibers form synaptic
junctions w/ type I, II, III cells

11.  Mucosa
• Epithelium
• Lamina proria (loose CT): glands, lymph vessel and nodules, richly
vascularized
• Muscularis mucosae
 Submucosa
• Dense, irregular fibroelastic CT: glands (+) in oesophagus n duodenum
• Meissner’s submucosal plexus
 Muscularis Externa
• Smooth muscle
• Auerbach’s myenteric plexus
 Serosa/adventitia
• Thin CT
 Serosa, if it is invested by peritoneum
 Adventitia, if it is retroperitoneal

12. Mucosa Submucosa
Muscularis
externa
Serosa/
Adventitisa

13.  Enteric Nervous System
• Meissner’s submucosal plexus
 Controlling secretory, mucosal movement, blood flow
regulation
• Auerbach’s myenteric plexus
 Peristaltic Motility functions
 Parasympathetic and Sympathetic Nerve
• Parasympathetic
 Stimulates peristalsis; inhibits sphincter muscle;
triggers secretion
• Sympathetic
 Inhibit peristalsis; activate sphincter muscles

15.  Mucosa
• Epithelium: Str squamous nonkeratinized ep,
• Lamina propria: esophageal cardiac glands
• Musc. Mucosa: single layer of longitudinally oriented smooth
muscle
 Submucosa
• Esophageal glands
 Mucous cells
 Serous cells: pepsinogen + lysozyme
 Abundant blood supply
 Muscularis externa
• 2 layers: inner circular; outer longitudinal
• 1/3 upper skeletal; 1/3 mid skeletal and smooth; 1/3 lower smooth
 Adventitia/Serosa
• Thin layer of collagenous and elastic fibers
 F: conveys the bolus from oropharynx to stomach

16. Epithelium
Lamina Propria
Muscularis mucosae
Submucosa
Muscularis Externa
Mucosa
Esophageal glands
Inner circular layer
Outer longitudinal layer

20.  Mucosa
 Submucosa
 Muscularis Externa
 Serosa

21.  Epithelium: simple columnar ep
• Mucus layer/visible mucus; bicarbonate ion
• Gastric pit/Foveola gastrica
 Surface lining cells
 Regenerative/stem cells
 Lamina propria
• Loose CT, vascular >>>
• Houses gastric/fundic/oxyntic glands
 Surface lining cells
 Mucous neck cells
 Regenerative (Stem) cells
 Parietal (Oxyntic) cells
 Chief (Zymogenic) Cells
 Diffuse NeuroEndocrine System
Cells/APUD/Enteroendocrine/Argentaffin Cells
 Muscularis mucosae
• 3 layers: inner circular; outer longitudinal; outermost circular
(occasionally)

22. Submucosa of gaster
• Many collagen and elastic fibers
• Dense, irregular CT
• Richly vascularized n lymphoid tissue
• Submucosal plexus
Muscularis externa of gaster
• Inner most oblique layer, middle circular layer,
outer longitudinal muscle layer
• Auerbach’s myenteric plexus
Serosa of gaster
• Thin, loose CT covered by simple squamous ep

23. REGION CELL TYPES
ISTHMUS Surface-lining cells and few DNES cells
NECK Mucous neck cells, Stem cells, parietal
cells, and few DNES cells
BASE Chief cells, occasional parietal cells,
and few DNES cells

24.  Cardiac
• Gastric pit depth is shallower
• Highly coiled glands
• Cell population: mostly
surface-lining cell, some
mucous neck cells, a few
DNES and Parietal cell, but
no chief cells
 Pylorus
• Gastric pit deeper
• Highly convoluted and tend
to branch
• Same as cardiac; but mostly
mucous neck cells

25.  The most superficial cells in the glands
 Form a simple columnar epithelium that
covers the gastric mucosa
 Produced thick mucus layer
 Contain numerous apical mucous droplets,
a well-development apical Golgi
apparatusnand a basal nucleus and RER
 Stain intensively with PAS reaction
 Secrete a continuous mucous film that
prevents the acidified proteinase solutions
in the stomach from ulcerating the gastric
mucosa

27.  Columnar, resemble surface-lining cells
 Produce soluble mucus and lysozyme to
lubricate gastric contents
 Predominat in pyloric

28.  In the base of pits but more numeous in the
neck
 Columnar
 Have little heterochromatin and display large
nucleolus

29.  Large, round to pyramid-
shaped
 Mainly in upper half of
fundic glands
 Produce HCl and gastric
intrinsic factor
 Eosinophilic cytoplasm
 Invaginations apical
plasmalemma to form
intracellular canaliculi
 Tubulovesicular system

30.  Columnar with basophilic
cytoplasm, basally
located nuclei, apical
secretory granules
(pepsinogen)
 Rich RER, Golgi
apparatus, but a few
lysosomes
 Microvilli
 Secretion of pepsinogen
is induced by both neural
and hormonal, triggered
by secretin binding to
the receptor (in basal
cell)

32. Modifications of the Luminal Surface
 Plicae circulares (valves of Kerckring)
• Transverse folds of submucosa and mucosa that form
semicircular to helical elevations
 Vili
• Epithelially covered, finger-like or oak leaf-like protrusions of
lamina propria
 Microvili
• Modifications of apical of intestinal epithelium cell membrane

33.  Intestinal Mucosa
• Epithelium: surface absorptive cells, Goblet Cells, DNES cells,
M (microfold) cells
• Lamina propria
 Forms the core of villi
 Tubular glands (Crypts of Lieberkuhn): + Regenerative cells , Paneth
cells
• Muscularis mucosae
 Inner circular layer; outer longitudinal layer
 Inner layer enter the villus and extend through its core
 Submucosa
• Dense, irregular fibroelastic CT; rich in lymph and vascular
 Muscularis Externa
• Inner circular, outer longitudinal smooth muscle
 Serosa

34.  Duodenum
• Brunner’s (duodenal) glands in submucosa
 Jejunum
• Plicae circulares (Valves of Kerckring)
 Ileum
• Peyer’s patch

35. Jejunum
Ileum

37.  The most numerous
 Tall cell with basally located nucleus,
brush border (microvili), and cell junction
 For terminal digestion and absorptions of
water and nutrients

38.  Unicellular glands
 Produced
mucinogen

39.  Squamous like cell above the lymphoid
nodule
 Important for defense mechanism

40.  Large, eosinophilic,
apical secretory
granules lysozyme→
 Pyramid-shape cell
in bottom of crypts
Lieberkuhn

41.  Appendix
 Caecum and Colon
 Rectum and Anal Canal

42.  Mucosa
• Epithelium: simple columnar
 Surface absorptive cells, goblet cells, M cells
• Lamina propria
 Loose CT
 Lymphoid nodules
 Shallow crypts of Lieberkuhn
 Surface absorptive, goblet , regenerative, DNES, and Paneth Cells
 Submucosa, Muscularis externa, Serosa
 Stellate lumen that is filled by debris

44.  Mucosa
• Epithelium: simple columnar
• Lamina propria
 Richly endowed crypths of Lieberkuhn
 No Paneth cells; surface absorptive cells >>>>> Goblet cells
>>>, DNES >
 Submucosa
 Muscularis externa
• 2 layers: inner circular; outer longitudinal
• Outer longitudinal layer is not continous but is gathered into
3 fascicles: taenia coli
 Serosa
• Appendices epiploicae: fat-filled pouches

45. Taenia Coli

46.  Rectum resembles colon but the crypts of
Lieberkuhn are deeper and number
fewer per unit area

47.  Mucosa
• Epithelium:
 simple cuboidal from rectum to pectinate line
 Str squamous nonkeratinized: from pectinate line to external anal
orifice
 Str squamous keratinized: epidermis at anus
• Lamina propria houses anal glands (at rectoanal junction) and
circumanal glands (distal end of anal canal)
 Submucosa
• Fibroelastic tissue houses 2 venous plexus: internal and
external hemorrhoidal plexus
 Muscularis externa
• Inner circular layer becomes thickened at pectinate line to
form internal anal sphincter muscle
• External anal sphicter muscle comes from pelvis

49. ThankYou