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Category:

biology

Tissue as a system of cells and their derivatives. Epithelial tissue

2.

is a complex assemblage of cells and
cell derivatives, that have a common
origin, structure and functions.

- Cells
- Extracellular matrix
- Postcellular structures
- Symplastos: there is a common cytoplasm
and many nuclei (myosymplast,
syncytiotrophoblast)
- Sincytium: there are cytoplasmic bridges
between neighboring cells(developing male sex
cells).

4.

Myosymplast (skeletal muscle
fiber)
Syncytium (developing
male sex cells)

5.

Laws of evolutionary development of
tissues are extended in the theory of
divergent development of
tissues(N.G.Khlopin) and the theory of
collateral series, or parallel development
of tissues (A.A.Zavarzin)

6.

considers evolutionary transformations of
tissues and organisms as a divergent
process, during which each embryonic
rudiment gives rise to tissues that
gradually acquire more and more
pronounced differences in structural and
functional characteristics.

7.

is based on the similarity of the structure
of tissues that perform the same
functions in unrelated groups of animals
that are far from each other in
phylogenetic terms.

8.

Similar structures in various branches of
phylogenetic tree arose parallel during
divergent development.
Tissues development (histogenesis)
occurs with processes of determination
and differentiation of their cells.

9.

Determination is the process of
“programming” of the direction of their
development.
Differentiation is a process during which
of the definite tissue incomplement
potencies anchored with determination.

10.

- Is the complex of all cells of definite
line of differentiation from the least
differentiated (stem cell) up to the
most mature differentiated.

11.

There are origin of other cells
development in all types of tissues.
Properties of SC :
form self-maintained population
divides seldom
stable for damage
pluripotetial in some tissues.

12.

13.

Physiologic regenaration -is process of
renovation during normal development of
tissue.
Reparative regenaration - is process of
tissue reconstruction after injury.
Levels of regenaration:
intracellular, cellular, tissue and organic.

14.

Epithelial
Muscle
Tissues of internal medium
(connective tissue, blood and lymph)
Nervous

15.

muscular
epithelial
blood
connective
nervous

16.

Еpithelial
tissue
is the whole complex of differons
of differentiated cells close as a layer
on a basal membrane on border with
external or internal environment, and
also forming a majority of body
glands.

17.

18.

Еpithelial
tissue:
1) covers body surface and lines
mucous and serous layers of
internal organs
(covering and lining superficial
epithelium);
2) forms parenchyma of
numerous glands
(glandular epithelium).

19.

Superficial
epithelium
Glandular
epithelium

20.

Superficial
epithelium
Glandular
epithelium

21.

1. Form barriers and divide the body
into functional compartments.
2.Protection from mechanical, physical
and chemical influences.
3. Transport of substances through
epithelium.
4.Absorbtion of substances.
5.Secretory function (in glands).
6.Sensory function (in organs of touch
taste, hearing and equilibrium).

22.

I.Simple epithelium:
1. Squamous
2. Cuboidal
3. Columnar
4. Pseudostratified columnar

23.

II. Stratified epithelium :
1. Stratified squamous
а) keratinized
б) nonkeratinized
2. Stratified cuboidal
3. Stratified columnar
4. Transitional

24.

1. Epidermal type (from ectoderm: skin
epidermis, E of cornea, oral cavity and etc).
2. Endodermal type (from endoderm: E of
stomach, intesting and etc).
3. Coelonephrodermal (from mesoderm: E of
kidney, gonads and serous layers)
4. Ependymoglial (from neural tube: ependymal
glial cells in CNS).
5. Angiodermal (from mesenchyme: E of inner
layer of heart and vessels).

25.

Disposed
on basement membrane
Form layers
Minimum of extracellular matrix or
absence of it
Epithelial cells united with junctional
complexes (lateral specializations)

26.

Polarity of epithelial cells:
in columnar cells: nuclei in basal
portion, apical specializations
(microvilli, cilia, stereocilia) – in
apical portion.
Nucleus
Lack of blood and lymph vessels
High ability for regeneration
Maintenance of numerous nervous
receptors

27.

28.

All cells are on a basal membrane
According to a shape of cells it was
distinquished:
squamous, cuboidal and columnar
epithelium.

29.

А) mesothelium –
lines serous layers

30.

31.

32.

In kidney tubules
and thyroid follicles

33.

III. Simple columnar
epithrlium
Cells have polarity
Epithelium lines :
- stomach,
- intestine,
- large ducts of glands.
In intestine this epithelium
has brush border.

34.

In
epithelium of
small intestine:
- Goblet cells
- surface
absorbtive cells

35.

36.

37.

38.

Pseudotratified columnar ciliated
epithelium lines mucosa of :
- respiratory tract
- some portions of male
reproductive tract

39.

Consists of several layers of epithelial cells
Only proximal layer of cells is on a basal
lamina, others lose junctions with it.
There are different shapes of cells in
distinctive layers.
Type of epithelium estimated according
to shapes of a superficial cells layer.

40.

Stratified epithelia subdivides into:
I.
Keratinized
II.
Nonkeratinized
I. Stratified squamous keratinized
epithelium is found in the skin
epidermis, mucosa of gingiva, hard
palate, filiform papilla of tonque and
skin zone of anal canal.
It forms a specialized barrier against
physical, chemical and antigens
influences.