Human Anatomy Epi tissue

1. Lecture 3. Epithelial tissues. Tissue.
HumanAnatomy
Learning outcomes:
1) Be able to define the term “tissue”.
2) List the four main tissue types and the major functions of each.
3) Be able to describe 5 types of epithelial tissue, presented in the lecture,
including functions and examples of location.
4) Name special characteristics of all epithelial tissues.

2. A tissue is an ensemble of similar cells from the same embryonic origin
that together carry out a specific function.
Be able to define the term “tissue”.
Histology (‘histo’ meaning ‘fabric’) is the study of the microscopic structure of tissues.
Marie François Xavier Bichat (14 November 1771 – 22 July
1802) was a French anatomist and pathologist;
he is known as the father of histology.
Although working without the microscope,
Bichat distinguished 21 types of elementary tissues from
which the organs of human body are composed.

3. List the four main tissue types and the major functions of each.
Typical functions of
Connective
tissue: protects,
supports, connects or
separates different
types of tissues and
organs.
Functions of Muscle
tissue provides posture
and body support,
locomotion and heat
production.
Functions of
the nervous system:
sensory input,
integration, control and
regulation of muscles
and glands, homeostasis,
and mental activity.
Functions of
epithelial tissues:
secretion, absorption,
filtration and protection.

4. • Blood

5. Diversity of tissue types

6. Based on
number of
layers.
Based on
cell’s
shape.
Epithelial tissues (epithet means covering) line body surface, the
cavities and surfaces of blood vessels and organs throughout the body;
including glands.
Epithelial tissues lies on basement membrane – “glue”-like substances
produced by fibroblasts of connective tissue to hold cells together.
Be able to describe 5 types of epithelial tissue, including functions and examples of location.

7. 5 types of epithelial tissue

8. Simple
involved in
absorption,
secretion and
filtration.
Microvilli are
projections of
cell body,
function:
increase
surface area.
Stratified involved in protection.
Microvilli
Cilia
skin, mouth, esophagus,
nose, vagina
alveolar, capillaries
kidney tubules, glands Psedo means false
trachea
small and large intestine
ducts of large glands
ducts of large glands
Ciliated moves mucus or
reproductive cells.

9. Simple squamous
• Lines blood vessels
and air sacs of lungs.
• Permits exchange
of nutrients, wastes,
and gases
Simple cuboidal
• Lines kidney
tubules and glands.
• Secretes and reabsorbs water
and small molecules.
Simple columnar
• Lines most
Digestive organs.
• Absorbs nutrients,
produces mucus.
Secretory (Goblet) cell
Stratified cuboidal
Stratified columnar
• Outer layer of skin,
mouth, vagina.
• Protects against
abrasion, drying out,
infection.
• Lines ducts of sweat glands.
• Secretes water and ions.
• Lines epididymis,
mammary glands, larynx.
• Secretes mucus.
Basement membrane
Stratified squamous
keratinized or
nonkeratinized
Most epithelial tissues line or cover surfaces or body cavities.

10. Alveoli

11. Capillary

12. Blood
vessels

13. Kidney

15. Secrete oil Secrete sweat

16. Gland
Epithelium of thyroid gland

17. intestine

18. intestine

19. skin
keratinized

20. tongue
nonkeratinized

21. Vaginal epithelium
nonkeratinized

22. Stratified Cuboidal Epithelium
Description: 2 to 3 layers of cube-shaped cells
Function: Protection
Location: Linings of ducts of mammary glands, sweat
glands, salivary glands, and pancreas

23. Pseudostratified Columnar Epithelium
Description: Single layer, nuclei are uneven which gives it a layered appearance.
Have ciliated cells and secretory goblet cells which secrete mucus.
Location: trachea, tubes of reproductive system.
Ciliated cells
Goblet cells
Connective tissue

24. trachea
Ciliated cells

25. Bulbar conjunctiva; the epithelial cells become cylindrical when they reach the surface. Note the
abundant goblet cells.
Stratified
columnar
epithelium

26. The conjunctiva is a thin,
semitransparent mucous
membrane that covers the
posterior surface of the eyelids
and is then reflected onto the
eyeball.

27. Transitional Epithelium is a highly modified, stratified
squamous epithelium that forms the lining of only a few
organs: urinary bladder, ureters and part of urethra.
All of these organs have ability to stretch. When these
organs filled with urine, appearance of epithelium change to
thin and with squamous-shape cells.

28. transition
Empty Full
Epithelial tissue of Urinary bladder
stretched

32. Sweat and Salivary glands
Oil glands

33. Mammary gland
Sweat and Salivary glands Oil glands

35. Goblet cells – mucus secreting unicellular glands. Microvilli – extension of the
cell,
function increase surface area
of absorption epithelial cells in
intestine.

37. Can be keratinized and nonkeratinized.

39. Special characteristics of all epithelial tissues:
1)Epithelial cells are tightly packed, closely
connected to each other.
2)Epithelial cells lies on the basement membrane.
3)Epithelial tissue – avascular, lack blood vessels.

40. 1) Be able to define the term “tissue”.
2) List the four main tissue types and the major functions of each.
3)Be able to describe structure of 5 types of epithelial tissue,
including functions and examples of location.
Active Learning

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