BYMAYUR CHAKRABORTY
ASSISTANT PROFESSOR, BENGAL SCHOOL OF TECHNOLOGY,
HOOGHLY
a group of cells specialized to perform a a group of cells specialized to perform a particular functionparticular function
tissue = cells + extracellular matrixtissue = cells + extracellular matrix– nonliving portion of a tissue that supports cellsnonliving portion of a tissue that supports cells
There are 5 types of tissuesThere are 5 types of tissues– Epithelial tissues give protection, allow secretion Epithelial tissues give protection, allow secretion
and absorptionand absorption– Connective tissues support soft body parts and bind Connective tissues support soft body parts and bind
structures togetherstructures together– Muscle allow movementMuscle allow movement– nervous tissues conducts impulses used to help nervous tissues conducts impulses used to help
control and coordinate body activitiescontrol and coordinate body activities– Bone tissues forms structural unit of the bodyBone tissues forms structural unit of the body
Simple = one layer
Stratified = more than one layer
Pseudostratified = false layered (appears to be more than one
layer, but only one); ciliated = with cilia
Terms referring to the cell shapes Squamous = flat
Cuboidal = cube
Columnar = rectangular (column)
Transitional = ability to change shape
Stratified
Simple
Apical surface
Basal surface
Apical surface
Basal surface
Classification based on number of cell layers.
Squamous
Cuboidal
ColumnarClassification based on cell shape.
The following types of epithelial tissues are covered in this activity:
1. Simple squamous epithelial tissue (lungs)
2. Simple cuboidal epithelial tissue (kidneys)
3. Simple columnar epithelial tissue (small intestine)
4. Pseudostratified (ciliated) columnar epithelial tissue (trachea lining)
5. Stratified squamous epithelial tissue (mouth lining)
6. Stratified cuboidal epithelial tissue (salivary glands, sweat glands)
7. Stratified columnar epithelial tissue (male reproductive tract)
8 Transitional epithelial tissue (bladder)
a. The tissue may show a full bladder
b. The tissue may show an empty bladder
a single layer of a single layer of thin, flattened cellsthin, flattened cells– look like a fried egglook like a fried egg
easily damagedeasily damaged common at sites of common at sites of
filtration, diffusion, filtration, diffusion, osmosis; cover osmosis; cover surfacessurfaces
air sacs of the air sacs of the lungs, walls of lungs, walls of capillaries, linings capillaries, linings of blood and lymph of blood and lymph vesselsvessels
• Description: Single layer of
cubelike cells with large,
spherical central nuclei
Function: Secretion and
Absorption
single layer of cells single layer of cells that are longer than that are longer than they are widethey are wide– nucleus located near nucleus located near
basement mem.basement mem. ciliated or nonciliatedciliated or nonciliated some have microvillisome have microvilli goblet cells = goblet cells =
secrete mucussecrete mucus absorption, absorption,
secretion, protectionsecretion, protection linings of the uterus, linings of the uterus,
stomach, and stomach, and intestineintestine
• Description: Single layer of cells of differing heights, some not reaching the free surface; nuclei seen at different levels; may contain mucus-secreting cells and bear cilia.
• Function: Secretion, particularly of mucus; propulsion of mucus by ciliary action
Description: Thick membranecomposed of several cell layers;basal cells are cuboidal or
columnarand metabolically active; surfacecells are flattened (squamous);
in the keratinized type, the surface cells are full of keratin and dead; basal cells are active in mitosis and produce the cells of the more superficial layers
Function: Protects underlying
tissues in areas subjected to abrasion
Stratified Stratified cuboidal cuboidal
epitheliumepithelium 2 or 3 layers of 2 or 3 layers of
cuboidal cellscuboidal cells protectionprotection linings of larger linings of larger
ducts of ducts of mammary glands, mammary glands, sweat glands, sweat glands, salivary glands, salivary glands, and pancreasand pancreas
Stratified Stratified columnar columnar
epitheliumepithelium protection and protection and
secretionsecretion vas deferens, vas deferens,
part of the male part of the male urethra, parts of urethra, parts of the pharynx the pharynx (throat)(throat)
Description: Resembles both stratified squamous and stratified cuboidal; basal cells cuboidal or columnar; surface cells dome shaped or squamous like, depending on degree of organ stretch.
Function: Stretches readily and permits distension of urinary organ by contained urine
cells that are specialized to produce cells that are specialized to produce and secrete substances into ducts or and secrete substances into ducts or into body fluidsinto body fluids
gland = 1 or more cuboidal or gland = 1 or more cuboidal or columnar cellcolumnar cell
secretionsecretion salivary glands, sweat glands, salivary glands, sweat glands,
endocrine glandsendocrine glands
THANK YOU
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