This document discusses the four basic tissues - epithelium, connective tissue, muscular tissue, and nervous tissue. It focuses on epithelium, describing its main characteristics and classifications. The major classifications of epithelium are based on number of cell layers (simple vs stratified) and cell morphology (squamous, cuboidal, columnar). Specific types of simple epithelia are described such as simple squamous, simple cuboidal, and simple columnar epithelia. Simple columnar epithelium can contain cilia or microvilli, with details provided on cilia, microvilli, goblet cells, and other cell types.

1. TISSUE
AGGREGATE OR GRROUPS OF
CELLS ORGANIZED TO PERFORM
SPECIFIC FUNCTIONS

2. FOUR BASIC TISSUES
• EPITHELIUM
COVERING & LINNING MEMBRANES
• CONNECTIVE TISSUE
SUPPORTIVE TISSUE
• MUSCULAR TISSUE
CONTRACTILE TISSUE
• NERVOUS TISSUE
EXCITABILITY

3. EPITHELIUM
• LAYER/LAYERS OF CLOSELY
APPOSED CELLS WITH LITTLE INTER
CELLULAR MATERIAL RESTING ON A
BASEMENT MEMBRANE

4. CHARACTERISTICS
• POLARITY APICAL LATERAL & BASAL
DOMAINS
• BASEMENT MEMBRANE
• SPECIALIZED CELL JUNCTIONS
• AVASCULARITY
• INNERVATION
• RENEWAL OF CELLS
• METAPLASIA

6. CLASSIFICATION
• NUMBER OF CELL LAYERS
SIMPLE EPITHLIUM
STRATIFIED EPITHLIUM
• MORPHOLOGY OF SURFACE CELLS
SQUAMOUS, CUBOIDAL
COLUMNAR

9. SIMPLE SQUAMOUS
EPITHLIUM
• Thin flat scale like cells
• Width > height
• Central bulging nucleus surrounded by attenuated
cytoplasm (few organelles)
• Specific names in specific locations
endothelium, mesothlium
• Transverse section mosaic like with irregular or straight
boundries
• Functions
passive exchange ( endothelium, lungs)
reducing friction( mesothelium)
barrier( junctions)

13. SIMPLE CUBOIDAL
EPITHELIUM
• HEIGHT =WIDTH
• CENTRAL ROUND NUCLEUS
• EQUAL AMOUNT OF CYTOPLASM
• LINNING OF PASSAGES
• ABSORPTIVE & SECRETORY
FUNCTION

15. SIMPLE COLUMNAR
EPITHELIUM
• HEIGHT > WIDTH
• OVAL BASAL NUCLEUS
• SECRETORY & ABSORPTIVE
EPITHLIEM
• WITHOUT SURFACE SPECIALIZATION
– ( STOMACH)
• SURFACE SPECIALIZATION
MICROVILLI, CILIA, GOBLET CELLS

16. SIMPLE COLUMNAR CILIATED
EPITHLIUM
• COLUMNAR CELLS WITH CILIA ON THE
APICAL SURFACE
• CAPABLE OF MOVING FLUID & PARTICLES
ALONG EPITHELIAL SURFACE
• CREWCUT APPEARANCE
short fine hair on the free surface & a dark
staining band extending across the cell at the
base of cilia due to presence of basal body
BRONCHI OVIDUCT

19. CILIA
 Motile extension of cytoplasm covered by cell membrane
 Light microscopic
 Microtubules
 central pair & 9 doublet
 Central pair (central sheath, radial spokes)
 doublet (2 tubules)
A complete, B incomplete 13+10
Dyenin ( motor protein)
nexin ( passive elastic componet permanet)
 Basal body modified centriole
 Cilia develop from procentrioles
 Regular synchronous movement effective & recovery strokes
 Kartegnar syndrome

21. CENTRIOLES
• Paired short rod like cylinders
• Nine triplet microtubules surrounding an
internal lumen
• Perpendicular to each other`
• Centrosome
• Function
Basal body formation, Mitotic spindle,
microtubule formation

22. COLUMNAR EPITHELIUM WITH
MICROVILLI
• FINGER LIKE E/M PROJECTIONS OF
THE CYTOPLASM COVERED BY CELL
MEMBRANE
• Striated & Brush border
• Number variable
• L/M faint line
• Absorptive
• Intestine ,Kidney

25. MICROVILLI
• E/M
• ACTIN CORE
• ANCHORED
APEX VILLIN
BASE TERMINAL WEB
SIDES FASCIN & FIMBRIN
TERMINAL WEB actin filament stabilized
spectrin also contains myosin II & tropomyosin

26. STEROCILIA
• MISNOMER
• LONG MICROVILLI
• EPIDIDYMIS VAS DEFERENCE INNER EAR
• THICK STEM CONNECTED BY CYTOPLASMIC
BRIDGES
• VILLIN ABSENT
• ERZIN REPLACES MYOSIN I
• ALPHA ACTININ

27. GOBLET CELL
• UNICELLULAR GLAND
• Mucous producing (viscous suspension of
complex glycoproteins)
• Dilated upper part vacuolated
• stem like base( organelles)
• Intestinal & respiratory epithelium

29. SENSORY EPITHELIUM
• Neuro epithelial cells
• Epithelial in otigin with specialized sensory
functions
• Taste bud , olfactory epithelium

30. MYOEPITHELIAL CELLS
• Epithelial in origin
• Contractile apparatus
• Between secretory cells and basement
membrane