The lecture covered information about the upcoming exam. It will be online and cover the material from the slides and lectures. The professor also discussed the homework, saying it was just part of the academic process and no extra credit would be given.

1. Dr. Qasem started the lecture by saying that
the exam is going to be online and the
questions are going to be regarding the slides
which you have seen in the lab and what you
covered during lectures .
Also he discussed the homework .. And he
said that it is just related to the academic
process so .. No there will be no bonus, no
extra marks for those who did it .

2. Osteoblasts – Bone Formation
An osteocyte, is the most commonly found cell in mature bone . some of which
differentiate into active osteoblasts . In mature bone, osteocytes and their processes
reside inside spaces called lacunae and canaliculi. When osteoblasts become trapped
in the matrix they secrete, they become osteocytes. Osteocytes are networked to
each other via long cytoplasmic extensions that occupy tiny canals called canaliculi,
which are used for exchange of nutrients and waste through gap junctions. The space
that an osteocyte occupies is called a lacuna (Latin for a pit).

3. Osteoclasts
Now this is a picture of Osteoclasts which can be identified as very
large and multinucleated cells and it has an attachment process
creating the Ruffled border .

4. Osteoclasts – Ruffled Border
Here is a picture showing the Ruffled border .
In active Osteoclasts, the surface against the bone matrix is folded
into irregular projections which form this border .

5. Trabecular Bone – Periosteum
Notice the Periosteum , Bone matrix and Osteocytes in lacunae.
- The periosteum. A thin layer of cell-rich connective tissue.
- The Endosteum, lines the surface of the bone facing the marrow
cavity .

6. Compact Bone – Haversian System
Now this is a picture of a compact bone showing Central Canal of
Haversian System .

7. Haversian System
Again we have the same picture over her and you have to notice
the Osteocytes, the Canaliculi , the Central Harvesian Canal and the
Proximal canal .

8. Harvesian System – Proximal Canal
Here you can see the Proximal Canal , which connects the
adjacent Osteons ( Harvesian Systems ) .

9. Zones Of Bone Ossificatin
- Identify the zones of bone
conformation :
(1) Resting Zone
(2) Zone of proliferation
(3) Zone of hypertrophy
(4) Zone of calcification
(5) Zone of ossification

10. Cartilage
Here we can see the cartilage and of course other structures like
Pseudostratifed Ciliated Epithelum .
On top we can see the cilia .

11. Hyaline Cartilage
This is a typical structure Hyaline Cartilage where we have
chondrocytes in lacunae , in between the extra cellular matrix and
down there we have perichondrium .

12. Elastic Cartilage

13. Fibrocartilage
This is a picture of Fibrocartilage and you can see the
chondrocytes which are arranged in rows surrounded by
thick bundles of collagen cartilage and the extra cellular
matrix .

14. Connective Tissue
This is a picture of connective tissue and the main cells you can see
here are Fibroblasts so all of the nuclei you can see are fibroblasts
and there are the extracellular matrix and collagen bundles .
As we said before, Collagen present in tissues as bundles .

15. Reticular Fiber

16. This is a picture you can see in the
cardiovascular system and here when you stain
the elastin component it takes a black color you
can see over here also you can see the Tunica
Intima Media of the artery and another layers
of elastin fibers .

17. Loose connective tissue
This is a very typical picture of loose connective tissue.
The Fibroblasts, the elastic fibers and the extra cellular
matrix are shown .

18. Again this is the same picture, but this is a caillary as
you can see .

19. This is about the Dense connective tissue
you can see the Fibrocytes and collagen
bundles present there .

20. This is the dense irregular connective tissue .
It’s taken from the breast , you can see the
collagen bundles running in different directions ,
we see blood vessels so these are like arterioles
or capillaries because all you can see here are

21. The simple endothelium , but in the blood vessels
we don’t see any wall like tunica media , tunica
external .
So what we are talking about here is a capillary
because in the level of capillaries most of these
layers which are in the tunica media
and tunica externa will not be present
over there at the level of capillary we have
exchange .
So we just need to have the
structure that
make up the wall of the capillary
which are simple endothelium cells ,
so this is a capillary .

22. Renal system
1 2

23. Now that was a picture taken from the renal
system which you have covered , showing the
different structures , the different views .
And you have to differentiate between them .
For example looking at pic.1 ( large lumen ) the
nuclei is almost tall cuboidal or low columnar
so this is something like Collecting Duct .
Now looking at pic.2 it’s much likely a proximal
convoluted tubule .
-And you have to differentiate between
collecting ducts , proximal tubules (PT) and
distal tubules (DT) .

24. - Collecting Ducts : Columnar epithelium , larger than
the rest with wide lumen

25. - Distal Convoluted
Tubules : lined by
Cuboidal epithelium , no
microvilli and smaller
cells so more cells in
cross section .
- Proximal Convoluted
Tubules : lined by
cuboidal to low
columnar epithelium ,
acidophilic cytoplasm ,
have microvilli and 3-5
cells in cross section .

26. Simple cuboidal / squamous epithelium

27. Now the first picture is from the small intestine
from the duodenum , you can see the simple
columnar epithelium and the goblet cells .
In the second picture you can see the simple
squamous epithelium from a blood vessel .
- To differentiate between an artery and a vein
we can say that the arterys’ outline is circular .
But the outline of the vein as you can see is
collapsed .

28. Here are different types of epithelium and I put them together so
you can differentiate between them , for example in pic.1 you can
see the stratified squamous epithelium .
We see the basal layer and as we go up the cells try to become
flatter and eventually when we reach the top most layer they
become completely squamous .

29. Now pic.2 it could be stratified cuboidal or
even stratified columnar .
So all you have to do is to look at the wall over
there and you can see 2 layers ( 2 nucleus )
and the shape of the nuclei is rounded so it’s
Stratified cuboidal .
It could be columnar , but the nuclei don’t
look elongated in the picture they look more
oval and rounded so it’s stratified cuboidal .

30. Now here we have the stratified epithelium and next to it you can
see the transitional epithelium to differentiate between them .
In the stratified type usually we have 2 layers ( 2 nuclei ), but in
the Transitional you can see more .
The second thing , look at the top most layer (in pic.2) its dome
shaped , and that’s a typical feature of transitional epithelium .

31. We’ve talked about cuboidal and columnar .
And here pic.1 is the Pseudostratified ciliated columnar
epithelium and pic.2 is about cuboidal epithelium .
To differentiate you can see that the nuclei in pic.1 are
columnar in addition to that we have two more features
here you can see goblet cells and on top you can see cillia .

32. It’s a bronchiole taken from a section of lung tissue of course
the structure over her we are talking about is alveoli .
The features of bronchiole that we’ve talked about are : the
type of epithelium , the presence of cartilage within the wall ,
the transition and we said that the last level where you expect
to see cartilage is the tertiary bronchi , after that we don’t
need cartilage . Also cillia and goblet cells decrease as you can
see and so we end up having rounded nucleus . This has to be
Terminal Bronchiole .

33. lungs
Here is another section
from the lung .
We can see the alveolar
duct surrounded by
alveoli .

34. In GIT system we have different layers like mucosa , submucosa …
and you must know that the top most layer is always the
epithelium and here it’s the stratified squamous epithelium
which I find in the pharynx and esophagus or down there in the
anorectal junction .
Now in the other structure I see mucosa and submucosal glands
and in the muscularis layer I can see different layers of muscles …

35. … In the Esophagus you can see that the
mucosa is thrown into villi (projections ) .
Now looking at the villi I see submucosal
glands .. Which are structurally the same as
those in the esophagus , but I can tell the
difference by knowing that there in the
esophagus we have stratified squamous
epithelium , but here in the duodenum we
have villi + large accumulation of submucosal
glands .

36. Now in pic.1 I can see a very long and numerous villi so this is the
Jejunum which is almost obstructing the lumen , the submucosa has
got no glands so it has to be the main sight of absorption ( the
jejunum – Small intestine ) .
In pic.2 I can see the mucosa doing invasion downward . Also I can
see that the majority of the lining cells are goblet cells .
So this is a part of the large intestine (Colon) .

37. here we can see the Plicae ciculares ( folds ) of the Jejunum . The
mucosa and submucosa of the small intestine form distinct
projecting folds called plicae which encircle around the inner
circumference developed in the jejunum .

38. Again I have different layers and the top most layer is the mucosa
also I have submucosa and the muscularis layer …
the features I can see here , the mucosa is thrown into pits like so
it’s the stomach , In addition to the presence of gastric cells that
present along these pits ( parietal cells and chief cells ) .
Now the second picture with a higher magnification to show the
differences between the parietal cells, which take a lighter stain
and present at higher levels.. and chief cells, which takes more
stain and present downward the bottom .

39. Here we have villi like projections ( villus ) and I have
aggregates of lymphoid tissue ( lymphoid follicles ) and this is
taken from the ileum .

40. Here is the appendix , you can see the crypts of lieberkuhn and
invasionations in large intestine also you can see the aggregations of
lymphoid tissue .
In the cross section notice the crypts of lieberkuhn , the
invasionations and the lymphoid follicles .

41. This is the anorectal junction , above here we can see
invasionation crypts of lieberkuhn so this is a part of large
itestine , down there you can see stratified squamous
epithelium and no crypts .
Also notice the stratified squamous epithelium and the central
columnar so it’s a junction .

42. Here is another junction
between the stomach and
esophagus .
Here you will never see abrupt
changes .. There are gradual
changes .
As you can see here in the upper
part of the stomach we still have
some stratified squamous epithelium . Which means that we never
go immediately from the stratified squamous epithelium to the
simple columnar .

43. Blood – WBC’s
Neutrophils :
multinucleated (3-5 lobes),
Neutral (not stained nucleus) .
Eosinophils :
nucleus made of 2 lobes,
eosinophilic red granules .

44. Basophils : nucleus made of 2-3
lobes,
basophilic dark blue granules .
Monocytes : kidney shaped nucleus,
slightly larger than graulocytes , sky
clear blue color .
Lymphocytes : large oval nucleus
fills the entire cell , vary in size fom
small as RBC’s to large .