normal histology course ppt

1. Systemic Histology

2. The digestive system

3. Digestive system includes:
1-The mouth cavity:
(lip, tongue, teeth and salivary gland).
2-The alimentary canal:
(esophagus, stomach and intestine).
3-The large glands:
(liver and pancreas).

4. The mouth cavity:
It is lined by oral mucosal membrane which is formed
of:
1-Non keratinizing stratified squamous epithelium
2-Lamina propria: (areolar CT, minor salivary glands,
blood and lymphatic vessels and capillaries)
The gum is a mucous membrane which adherent to
periosteum of alveolar bone of teeth
It is covered by stratified squamous epithelium

5. The lips:
It is junction between skin and mucous membrane. In
between there is striated (skeletal) muscles.
1-The outer surface (skin):
Thin skin formed of:
a- Epidermis: dry rough opaque keratinizing stratified
squamous epithelium
b- Dermis of the skin: areolar connective tissues, hair
follicles, sebaceous and sweat glands

6. 2- The inner surface:
It is covered by mucous membrane which is contains:
a- Thick transparent non keratinizing stratified
squamous epithelium.
b- Corium or lamina propria:
It is formed of connective tissues, blood and lymphatic
vessels and labial glands.

7. The tongue:
It is a muscular organ covered by mucous membrane.
Has dorsal rough surface (due to presence of papillae),
and ventral smooth surface.
Both sides are covered by mucous membranes
(stratified squamous epithelium + areolar connective
tissues).
In between there is striated (skeletal) muscles arranged
longitudinal, transverse and vertical.

8. The tongue papillae:
It is a little projection of mucous membrane, formed of
central core of connective tissues covered by stratified
squamous epithelium.
Types of tongue papillae:
1- Conical or filliform:
It is slender projection 2-3 mm long, consist of a
central core covered by partially keratinizing stratified
squamous epithelium.

9. Present in the anterior 2/3 of the dorsum
Numerous in number.
Conical in shape (broad base and pointed top).
No taste buds.
2- Fungiform:
Fewer in number.
Scattered between filliform
More numerous at the tip.
Short, broad and very vascular (red).

10. May contain some taste buds similar to fungi, narrow
base and broad top)
The covering epithelium is stratified squamous
epithelium.
3- Circumvallate:
8__12 in number.
Long with broad tops and constricted bas
Surrounded by deep grooves.
Do not project on the surface.

11. 4- Papillae foliata:
It is well developed in posterior.
It is formed of parallel ridges and grooves of
connective tissue.
Covered with stratified squamous epithelium.
Contain many taste buds.

12. The teeth:
It is formed of:
1- Crown: it is projection above the gum.
2- Aroot: it is the embedded part of the tooth in the
tooth socket of the bone.
3- A neck: it is the junction zone between crown and
root.
The dental calcified tissues of the tooth are:
1- Enamel: It is the hardest substance in the body,

13. 2- Dentine:
Surround the pulp cavity, formed of calcified matrix.
3- Cement:
Cover the dentine of the root, formed of bone
lamellae,
surrounded by periosteum.
Salivary glands: There are two types:
The main salivary glands and accessory salivary
glands.

14. a- Two parotid glands: front of the both ear.
b- Two submandibular glands: or sub maxillary, inner
mandible.
c- Two sublingual glands: under the tongue.
2- The accessory salivary glands:
Are branched tubulo- alveolar, scattered singly under
the
epithelium of the lips, tongue, tonsil and buccal cavity.
Each gland is formed of CT stroma or frame work and

15. The connective tissue stroma which formed of
covering
capsule, trabeculae and reticular connective tissues.
The parenchyma is the epithelial component of the
gland which is formed of:
1- Secretory acini: secrete saliva.
2-Different ducts: carry saliva to mouth cavity.
The secretory acini of three types:
a- Serous acini b- Mucous acini

16. The lingual tonsils:
They are accumulation of lymph follicles and diffuse
lymphatic tissues in the connective tissue under the
epithelium of the tongue.
The esophagus:
It is muscular tube 10 inches, connect pharynx and
stomach.
It is wall consists of four layers:
1- Mucosa: which is formed of:

17. b- Corium or layer of connective tissue: blood vessels,
nerve, mucous glands, and lymphatics.
c- Muscularis mucosa:
It is formed of smooth muscles arranged inner circular
and outer longitudinal.
2- Submucosa:
It is formed of areolar connective tissue, blood vessels,
and lymphatics, mucous glands are present.

18. 3- Musculosa:
It is formed of muscles, in the upper third the muscles
are skeletal (voluntary), in the middle third there are
mixture of skeletal and smooth muscles, in the lower
third are smooth (involuntary) arranged inner circular
and outer longitudinal.
4- Fibrosa:
It is formed of connective tissues, containing blood
vessels, nerve and lymphatics.

19. Changes at the gastro - esophageal junction:
1- The stratified squamous epithelium of the
esophagus changes to simple columnar.
2-The connective tissue corium of mucosa shows
branched-
tubular glands.
3- The mucous gland in the submucosa stop or
continue for
short distance in the submucosa of the stomach.

20. The stomach:
The mucosa is smooth (no villi).
Mucosa contain gastric pits (mucous glands secrete
via).
The surface epithelium is formed of tall columnar
cells.
The cells are present in surface and extend down to the
line
of the pits.

21. Fundus of the stomach:
1- Mucosa:
It is thick mucosa.
Surface epithelium: it is formed of simple columnar
with basal oval nuclei.
Lamina propria: it is formed of blood vessels, lymph
and nerve.
Muscularis mucosa: smooth muscles arranged inner
circular and outer longitudinal.

22. Character:
1- Occupy most thickness of the mucosa.
2- Crowded over each other.
3-Branched tubular glands.
4- The ratio between the length of the pit to the length
of the gland =1/3.
Each secretory gland is formed of 5 kinds of secretory
cells:
1- Surface epithelial cells.

23. 3- Parietal or oxyntic cells: HCL and IF.
4- Peptic cell, chief, zymogen, central cell: pepsin,
renin
5- Endocrine cells (hormones).
Submucosa:
It is formed of connective tissues, blood vessels and
lymphatics.
Musculosa:
Smooth muscles arranged inner oblique, middle

24. Serosa:
It is covered by the peritoneum.
Containing Simple squamous mesothelium.
Pylorus of the stomach:
Mucosa: Pyloric glands, corium and muscularis
mucosa.
Character:
It is widely separated (not crowded).
Shorted than fundic region.

25. They are branched glands.
The corium of connective tissue between pyloric
glands contain solitary lymph nodules.
Muscularis mucosa, smooth muscles arranged inner
circular and outer longitudinal.
Submucosa:
It is formed of CT rich in blood vessels and
lymphatics.
Musculosa: it is formed of thick smooth muscles

26. Serosa:
It is formed of connective tissues and simple
squamous epithelium.
Changes at the pyloro - duodenum:
1- appearance of intestinal villi.
2-intestinal crypts replace the pyloric glands.
3- appearance of goblet cells.
4-appearance of Brunner’s glands in submucosa.
5- the musculosa in thinner.

27. Small intestine:
It is 6 meters in long, digestion and absorption
Divided into three parts, duodenum, jejunum and
ileum.
Mucosa of small intestine (all parts):
Consist of villi and crypts, corium, muscularis
mucosa.
Villi are finger like projection (extending to lumen).
Crypts of Leiberkohn are simple tubular glands

28. Muscularis mucosa: It is formed of smooth muscles
arranged inner circular and outer longitudinal.
Intestinal villi:
They are finger like projection above the mucosa of
small intestine
In duodenum: broad, long, leaf like.
In jejunum: finger shape slightly short
In ileum: short absent over payer patches.

29. Each villi is formed of central layer of connective
tissue contain central lymphatic capillaries, covered by
simple columnar epithelium, goblet cells and
sometimes argentaffin cells (no paneth cell).
Crypts of Leiberkohn:
Are invagination of the mucosa from the surface
epithelium between the bases of villi.
Are simple tubular glands present in corium, lined by
simple columnar, goblet cells, argentaffin cell and

30. Cells:
Simple columnar, goblet cells, paneth cells (enzyme
lysis bacteria), argentaffin and coveolate cells.
Submucosa of small intestine:
It is formed of areolar connective tissues, blood
vessels, lymphatics and nerves.
In the first part of the duodenum there is Brunner’s
glands (compound tubulo alveolar glands open on
Leiberkohn).

31. Musculosa:
It is formed of smooth muscles arranged inner circular
and outer longitudinal.
Serosa:
It is formed of connective tissues with simple
squamous epithelium.
Differences between duodenum, jejunum an ileum:
Duodenum:
Villi are broad and leaf like.

32. Submucosa is thick containing Brunner gland
Goblet cells are not so numerous.
Jejunum:
Villi are long and slender.
Goblet cells are more numerous than duodenum.
Neither Brunner glands nor Payer Patches.
Ileum:
Villi are short and slender( absent or short over payer
Patch's).Presence of payer Patches (in corium).

33. The large intestine:
It is consist of:
Caecum, appendix, ascending, transverse and
descending colons and rectum.
Mucosa:
No villi
Much thicker than small intestine (crypts are deep).
Crypts are numerous (separated by reduce corium).
Muscularis mucosa (inner circular and outer

34. Submucosa:
It is formed of connective tissues, nerves, lymphatics,
no glands.
Musculosa:
It is formed of smooth muscles arranged inner circular
and outer longitudinal.
Serosa:
It is formed of connective tissues, fat cells simple
squamous epithelium.

35. Appendix:
It is the blind prolongation from the caecum.
The lumen is narrow and may become obliterated in
old age.
It is mucosa is similar to large intestine but have the
following character:
Crypts are shorter, fewer, may branch.
Muscularis mucosa may be absent.
Submucosa and mucosa are infiltrated by lymphocytes

36. Musculosa is thin arranged inner circular and outer
longitudinal.
Rectum:
Similar to large intestine but with the following
character:
Crypts are long.
Corium is rich in solitary lymph nodes.
Serosa is partially replaced by fibrosa.

37. Anal canal:
It is short communication between rectum and
exterior.
Mucosa shows longitudinal folds (columns of
morgagni) (artery, vein and smooth muscles).
Termination is connected to transverse fold (anal
valve).
Muscularis mucosa is broken in the region of
morgagni and disappear.

38. Recto-anal junction:
Simple columnar epithelium of rectum changed into
stratified columnar at the columns of morgagni.
At the anal valve changed to stratified squamous.
The liver:
It is the largest gland, compound tubular. Consist of
stroma of connective tissues and parenchyma of cells.
Stroma: It is consist of capsule, trabeculae and
reticular connective tissues.

39. Capsule:
It is known as Gilson's capsule. It is thin, formed of
C.T. cells (mainly fibroblast), and C.T. fibers (mainly
collagenous).
Covered partially by peritoneum
Trabeculae: It is formed of connective tissues
It descend from the capsule dividing the liver into
hepatic lobules.
It very thin (normal), or very thick (cirrhosis, fibrosis).

40. Reticular CT:
It is a net work formed of fibers and cells.
Portal canal:
It is a connective tissue septa of hepatic lobules and
condensed at the corners of lobules to form portal tract
or canal (cornered between three hepatic lobules).
It contains:
- Branch of hepatic artery - Branch of portal vein
- Branch of bile duct - Lymph vessels

41. Parenchyma of liver:
Liver cells are hepatocytes arranged in plates branched
and anatomose in hepatic lobules

42. Liver

43. Pancreas:
It is large mixed glands, present in abdomen in the
concavity of duodenum. It is formed of stroma and
parenchyma.
Stroma: It is formed of capsule, trabeculae, and
reticular connective tissue.
Capsule: It is formed of connective tissue cells and
fibers.
Very thin and soft, covered partially by peritoneum.

44. Trabeculae:
It is formed of connective tissue cells and fibers.
It is soft and thin. It carry ducts, blood vessels, and
lymph vessels.
Reticular connective tissue: It contains capillaries,
nerves. It is formed C.T cells and fibers (reticular)
The parenchyma:
It is formed of pancreatic acini which is formed of
pyramidal cells with basal rounded nuclei and

45. The end