Histology various type of epithelium

1. Simple SquamousEpithelium
Composed of a single layer of flattened cells lying on a
basement membrane. In section only their flattened nuclei are
often visible. Function:Provides a selective barrier which
allows for filtration, passive diffusion and pinocytosis.

2. A single layer of cuboidalcells with rounded nuclei, lying on a
basement membrane. They are often found lining ducts and may possess
basal infoldings. Function: They transport fluids and may modify the
contents of the lumen by selective absorption.

3. Function:
Absorption, lubrication or movement of luminal contents.

4. Uterian tube

5. PseudostratifiedEpith. Treachea

6. PseudostratifiedEpididymis

7. Stratified columnar/cuboidalepith
Multiple layers of cells in which the surface layer is cuboidalor
columnar.
Function: Protection or secretion.
Location examples: Male Urethra, Large GlanduclarDucts, Sweat
Glands

8. Transitional

9. Simple CuboidalEpith

10. Simple CuboidalSalivary gland

15. Fig. 20.7

17. to protect

18. where diffusion is important
where tissues are
involved in secretion
and absorption: larger
cells because of the
machinery of
production, packaging,
and energy
requirements

21. “ciliated” literally = eyelashes
(see next page)

23. Stratified: regenerate from below

24. Rare…

25. Rare…

27. Endothelium
A simple squamous
epithelium that lines the
interior of the
circulatory vessels and
heart
Mesothelium
Simple squamous epithelium that lines the
peritoneal, pleural and pericardial cavities and covers
the viscera

28. Glands
•Epithelial cells form them
•Production & secretion of needed substances
•Are aqueous (water-based) products
•The protein product is made in rough ER, packed
into secretory granules by Golgi apparatus,
released from the cell by exocytosis

29. Classification of glands
•By where they release their product
–Exocrine: external secretion onto body surfaces
(skin) or into body cavities
–Endocrine: secrete messenger molecules
(hormones) which are carried by blood to target
organs; “ductless” glands
•By whether they are unicellular or
multicellular

30. Exocrine glands
unicellular or multicellular
Unicellular: goblet cell
scattered within epithelial lining
of intestines and
respiratory tubes
Product: mucin
mucus is mucin & water

31. Multicellular exocrine glands
Epithelium-walled
ductand a
secretory unit

32. •Cilia
–Whiplike motile
extentions of the
apical surface
membranes
•Flagellum
–Long isolated cilium
–Only found as sperm
in human

34. Classes of Connective Tissue: note the cell types
and great variety of subclasses

38. *
Classes of Connective Tissue

41. *
Classes of Connective Tissue

45. Classes of Connective Tissue
*

47. Classes of Connective Tissue
*

49. Membranesthat combine epithelial sheets
plus underlying connective tissue proper (see
next slide)
•Cutaneous membranes
–Skin: epidermis and dermis
•Mucous membranes, or mucosa
–Lines every hollow internal organ that opens to the outside
of the body
•Serous membranes, or serosa
–Slippery membranes lining the pleural, pericardial and
peritoneal cavities
–The fluid formed on the surfaces is called a transudate
•Synovial membranes
–Line joints

50. (a)Cutaneous membrane
(b)Mucous membrane
(c)Serous membrane

51. •Four basic types of tissue
–Epithelium
–Connective tissue
–Muscle tissue
•Skeletal
•Cardiac
•Smooth
–Nervous tissue

55. •Four basic types of tissue
–Epithelium
–Connective tissue
–Muscle tissue
–Nervous tissue
•Neurons
•Supporting cells

57. Tissue response to injury
•Immune: takes longer and is highly specific
•Inflammation
–Nonspecific, local, rapid
–Inflammatory chemicals
–Signs: heat, swelling, redness, pain
•Repair –two ways
–Regeneration
–Fibrosis and scarring
•Severe injuries
•Cardiac and nervous tissue

59. Tumors (neoplasms): abnormal growth of
cells
•Adenoma –neoplasm of glandular epithelium,
benign or malignant
•Carcinoma –cancer arising in an epithelium
(90% of all human cancers)
•Sarcoma –cancer arising in mesenchyme-
derived tissue (connective tissues and muscle)

60. STEM CELLS….
STEM CELLS
______
Inner cell mass becomes the baby