The document summarizes the structure and function of the digestive tract. It describes the four layers that make up the wall of the digestive tract - mucosa, submucosa, muscularis externa, and serosa/adventitia. It then discusses the tissues and glands associated with specific parts of the digestive tract including the mouth, tongue, teeth, and salivary glands.

2. - composed of the alimentary canal and the
associated glands
- the alimentary canal is a long, tortuous
tube, which begins with the lips and
terminates with the anus

3. Common properties of the wall of the
digestive tract
The wall is composed of the following layers
as follows from the lumen:
1. Tunica mucosa ( mucous membrane)
2. Tunica submucosa
3. Tunica muscularis
4. Tunica serosa ( serous membrane) or
adventitia

4. the most inportant layer with various tissue
components
has diverse functions:
- protection
- secretion
- absorption

5. - sublayers of the submucosa:
1./ a. lamina epithelialis - epithelium
1./ b. lamina propria connective tissue
proper
1./ c. lamina muscularis mucosae smooth
muscle

6. adluminal, covering epithelium
functions:
physicochemical barrier between the lumen
and the connective tissue
selective absorption of the digested
substances
secretion of digestive enzymes and lubricating
mucins

7. the types of the epithelium reflects the
special demands of the appropriate
segments of the alimentary canal
examples:
oral cavity, esophagus stratified,
nonkeratinized squamous epithelium
stomach simple columnar epithelium
small intestine simple columnar epithelium
with cuticle

8. loose connective tissue, which contains blood -
and lymphatic vessels, nerve fibers and different
kinds of connective tissue cells
in the lamina propria of most segments of the
G.I.T., there are tubular glands, such as the
gastric - and intestinal glands
elements of the immune system is present
throughout the G.I.T. to defend the body
against possible bacterial attacks

9. thin layer of smooth muscle, which is
often composed of an inner circular and
outer longitudinal sublayers
contributes to the motility of the mucous
membrane; this movement is independent
of the peristaltic movement of the tract

10. connective tissue layer with various thickness;
here blood vessels run
contains plexus of lymphatics
contains vegetative ganglion cells and peripheral
nerves, which together make the submucous
plexus of Meisner
may contain glands in the submucosa of certain
segments ( esophagus and duodenum)

11. relatively thick layer with two sublayers of
smooth muscle in the vast majority of cases
inner circular sublayer ( str. circulare)
outer longitudinal sublayer ( str. longitudinale)
the sublayers are separated by thin connective
tissue containing the myenteric plexus of
Auerbach as well as blood and lymphatic vessels

12. there are striated muscles in the proximal
segments of the esophagus, and also in the
anal canal
there is a third muscular sublayer in the wall of
the stomach: inner oblique fibers
in the large intestine, the external sublayer
forms longitudinal bands of smooth muscle
taeniae coli

13. tunica serosa ( serous membrane) is the
outermost layer of those segments of the
alimentary canal that are enveloped by
peritoneum
has simple squamous epithelium ( lamina
epithelialis; mesothelium) and a thin connective
tissue sublayer ( lamina propria serosae)
the serous membrane is attached to the
muscularis through a subserous connective
tissue

14. Tunica advenitia
certain segments of the G.I.T. are not
enveloped by peritoneum
in these segments, the outermost layer is
loose connective tissue ( adventitia) , which
connects the tract to the its surroundings

15. salivary glands in the lamina propria mucosae
submucous glands in the tela submucosa
extramural glands ( large digestive glands) are
located outside the wall of the tract ; they
discharge their products into G.I.T. lumen
through excretory ducts

16. characteristic anatomical items:
lips
teeth
tounge
salivary glands

17. border the mouth opening ( oral fissure)
there scaffoldings are striated muscle
fibers of the orbicularis oris m.
have cutaneous and mucous surfaces
( pars cutanea and pars mucosa)

18. Pars cutanea - outer surface, which is composed of skin ( epidermis,
dermis and hypodermis, which is also called subcutaneous tissue).
In this surface, there various derivatives of the skin: hair follicles,
sebaceous and sweat glands.
Pars mucosa inner surface, which lines the oral cavity. This
surface is covered by a mucous membrane, containing stratified,
nonkeratinized, squamous epithelium and connective tissue. In the
later layer there are small salivary glands: labial glands.
Rubor labii - vermilion zone between the ordinary skin and the
mucous membrane. The vermilion zone is covered by stratified,
keratinized, squamous epithelium. This zone is devoid of skin
appendages. However, the zone has capillary- rich connective tissue
papillae, the red color of which may be well visible through the
relatively thin skin.

22. The tongue is a muscular organ, covered by
mucous membrane. Its main mass is striated
muscle, fibers of which run in all directions of
space. This sort of organization is highly typical
of the tongue.
The mucous membrane on the superior and
inferior surfaces are very much different .
On the superior surface ( dorsum of tongue) ,
there are lingual papillae.

23. Behind the sulcus terminalis, there are
lymphatic follicles of the lingual tonsil.
The mucose membrane of the inferior
surface is smooth, lacks connective
tissue papillae.

24. serosus glands of Ebner, which open at the
base of vallate - and foliate papillae
mucinous glands in the root of tongue
posterior lingual glands
mixed glands in the apex of tongue
anterior lingual glands ( gland of Blandin and
Nuhn)

25. filiform papillae
fungiform papillae
foliata papillae
vallatae papillae

28. they are located in front of the sulcus terminalis
large, roundish lingual papillae with a diameter
of 2-3 mm; thus, they can be readily seen with
naked eyes
one man has 8-12 vallate papillae
have taste buds in their walls
each papilla is encircled by a moat - like trench
the Ebner s serous glands empty into the moats
of the papillae

30. are lightly stained oval bodies, located in the
stratified, nonkeratinized, squamous epithelium
of the mucous membrane
cell types:
supporting cells
secondary neuroepithelial cells
undifferentiated stem cells

32. Parts
crown of tooth
neck of tooth
root of tooth
inside the crown and neck, there is a tooth
pulp, inside the root , there is a root canal,
which opens in the apical foramen

33. Dentin ( substantia eburnea)
Enamel ( substantia adamantina,
enamelum)
Cementum ( substantia ossea, cementum)

34. inorganic substances: 80%
hydroxy- apatite crystals
organic substances: 20%
its 9/ 10: type I collagen
its 1/ 10: proteoglycans

35. Enamel
inorganic substances: 98%
hydroxy- apatite crystals
organic substances: 2%
insoluble proteins
There are NO cells within the enamel!

36. Cementum
covers the roots of teeth
cementoblasts produce; the resting cells are
cementocytes
inorganic substances: 50%
organic content is mainly made up of collagen fibers
the cementum is tethered to the periodontium by
Sharpey s fibers

37. PARODONTIUM
Cementum
Periodontium connecting tissue
membrane, which is rich in fibers; contains
blood vessels and nerves. Its cells are
fibroblasts, which can be converted either
cementoblasts or osteoblasts of alveolar
bone.
Alveolar bone

38. loose connecting tissue, which is rich in
capillaries and nerves
cells:
fibroblasts, mast cells, macrophages,
lymphocytes
odontoblasts, which produce the dentin

41. Small salivary glands labial, buccal, palatine, linguales,
etc. glands
Large salivary glands parotid, submandibular, sublingual
glands
All of them are exocrine glands.

42. secretory portion can be serous, mucous
or mixed / Gianuzzi s demilune/
excretory portion
intralobular ducts intercalated tubules, striated
ducts
interlobular ducts excretory ducts

43. purely serous gland
there are many fat cells among the acini
well-developed intercalated tubules and salivary
ducts
in the interlobular septa, run the larger excretory
ducts, blood vessels and peripheral nerves
there may be many cross- sections of the
branches of the facial nerve, which pass the
parotid

46. mixed gland, but the mucous secretory
cells predominate over the serous ones.
the serous cells are located as small
clusters around the mucous acini: these
are Gianuzzi demilumes
both the intercalated tubules and the
striated ducts are usually absent

49. mixed gland, in which the serous secretory
cells predominate
the scattered mucous acini are partly
covered by serous cap / Gianuzzi s
demilune/
there are somewhat smaller number
intercalated tubules and striated ducts
than in the parotid