basic cell type

1. Tissues and Basic Cell Types
Dr. Catthareeya Sukwan (D.V.M., PhD.)
Veterinary Technology, NRRU

2. Basic Tissue Classes
• Tissues are groups of cells with a common structure
(form) and function (job).
• 4 Basic Tissue Classes
– Epithelium
– Connective tissue
– Muscle
– Nervous tissue

3. Classes/Definition/Location
Type Definition and Function Location
Epithelial
(lines and covers
surfaces )
Tissue composed of layers of closely
spaced cells that cover organ surfaces,
form glands, and serve for protection,
secretion, and absorption
Epidermis
Inner lining of digestive
tract
Liver and other glands
Connective
(protect, support,
and bind
together)
Tissue with more matrix than cell
volume, often specialized to support,
bind together, and protect organs
Tendons and Ligaments
Cartilage and Bones
Bloods, collagen fiber,
fibroblast/fibrocyte
Nervous
(produces
movement )
Tissue containing excitable cells
specialized for rapid transmission of
coded information to other cells
Brain
Spinal cord
Nerves
Muscular
(receive stimuli
and conduct
impulses)
Tissue composed of elongated,
excitable cells specialized for
contraction
Skeletal muscles
Heart (cardiac muscle)
Walls of viscera (smooth
muscle)

4. 1. Epithelium
• forms the coverings of surfaces of the body
– covers the body surface,
– Lines body cavities,
– forms the external and internal linings of many organs
– constitutes most gland tissue
• Squamous Epithelium
• Cuboidal Epithelium
• Columnar Epithelium

5. Epithelium
• Structural Characterisation of Epithelia
– absence of nerves (except for a few axons in the
deeper layers)
– absence of blood vessels — nutrition is by diffusion
from the highly vascular connective tissue (known as
the lamina propria) underlying all epithelia
– close packing of the constituent cells with minimal
intercellular substance.

6. • Morphological Classification of Epithelia
– number of layers of cells
• Simple: an epithelium with only one layer
• Stratified : an epithelium with more than one layer
• Pseudostratified : appears to be more than one cell thick
since the nuclei lie at different heights, but in fact all cells
are in contact with the basement membrane
– shape of cells at free surface :
• squamous (flattened)
• cuboidal
• columnar.
– surface specialisation (if any)
• Keratinised
• ciliated.
Epithelium

7. Epithelium
• Shape of epithelial cell
1. Squamous Epithelium : flat and
scale-like
2. Cuboidal Epithelium: Cubic
shaped, as tall as they are wide
3. Columnar Epithelium : tall,
column-shaped
Basement membrane

8. •
Basement membrane = Basal Layer

9. Arrangements of Epithelial Tissue
• Simple
– Cells are found in a single
layer attached to the
basement membrane
• Stratified
– Cells are found in 2 or more
layers stacked atop each
other
• Pseudostratified
– a single layer of cells that
appears to be multiple layers
due to variance in height and
location of the nuclei in the
cells.
• Transitional
– cells are rounded and can
slide across one another to
allow stretching

10. Arrangements of
Epithelial Tissue
Simple Epithelium (1bm)
Stratified Epithelium (stacked)
Transitional Epithelium (1bm)
Basement membrane (bm)
(stacked)
(stacked)

11. Special Features of Epithelium:
• Cilia
– (singular= cilium, Latin= eyelash)- hair-like appendages attached to the apical
surface of cells that act as sensory structures or to produce movement.
• Goblet cells
– specialized cells that produce mucus to lubricate and protect the surface of an
organ
• Villi
– (singular= villus, Latin= shaggy hair)- finger-like projections that arise from the
epithelial layer in some organs. They help to increase surface area allowing for
faster and more efficient adsorption.
• Microvilli
– smaller projections that arise from the cell's surface that also increase surface
area. Due to the bushy appearance that they sometimes produce, they are
sometimes referred to as the brush border of an organ.

12. Simple squamous epithelium
a single layer of flattened cells
Function:
The thinness provides minimal barrier to the
movement of materials.
Examples:
Alveolar lining of the lung, renal corpuscle.

14. Simple cuboidal epithelium
a single layer of box-shaped (cuboidal) cells
Function:
Usually have a role in active transport or
synthesis.
Examples:
Lining of ducts, thyroid follicles.

16. Simple columnar epithelium
a single layer of tall cells.
Function:
Metabolically active cells — absorption,
synthesis.
Example:
Lining of intestine.

18. Pseudostratified columnar ciliated
epithelium
although nuclei lie at different levels, all the cells
are attached to the basement membrane and so
there is only one layer
Function.
Complex — several different functions.
Example.
Lining of trachea.

20. Stratified squamous epithelium
Many layers of cells; those at the free surface
are flattened
Function:
To withstand mechanical wear and tear;
resist desiccation
Example:
Lining of mouth, vagina and rectum

21. Stratified squamous epithelium
(keratinized)
the surface cells are dead and filled with an
inert protein, keratin, forming flakes or
squamus.
Function:
To withstand mechanical wear and tear;
resist desiccation
Example:
Skin

23. Transitional epithelium
there are several layers of cells; those at the free
or luminal surface are irregularly polyhedral (like
squashed bubbles) and it is called transitional
Function:
To allow large changes in the volume of
the lumen
Examples
Bladder, ureter