Special tissues: Transitional for urinary systems, pseudostratified for respiratory with cilia.

Stratified tissues: Multiple layers, apical layer's shape significant.

Simple tissues: Single layer, different shapes (squamous, cuboidal, columnar).

Presence of cilia and goblet cells, looks stratified but is not.

Epithelial cells close together, showing domed apical layer.

Basal cells are cuboidal, apical cells are squamous.

Subtypes: Keratinized (no nuclei in top layer) and non-keratinized (nuclei present).

Cilia can be present to move fluid.

Long, narrow nuclei, often with apical microvilli (brush border).

Nuclei are round/oval, cytoplasm is pink.

Hematoxylin and Eosin (H&E) stain: Nuclei stain dark purple, cytoplasm pink.

Summary:

Analogy: Like the bristles of a brush.

Increases surface area for absorption.

Located on the apical surface.

Analogy: Like arms in a crowd surf.

Moves liquid over the cell surface (e.g., respiratory tract).

Located on the apical surface.

Histological Features:

Locations: Trachea, proximal bronchi.

Functions: Secretion (mainly mucus), propulsion (cilia).

Definition: Appears stratified but all cells touch the basement membrane.

Histological Features:

Locations: Urinary bladder, ureter.

Functions: Permits stretching and distension.

Definition: Multiple layers, apical layer cells are dome-shaped.

Histological Features:

Locations: Epidermis, esophagus, vagina.

Functions: Protection against abrasion.

Definition: Multiple layers of cells, topmost being flat.

Histological Features:

Modification: Can have cilia.

Locations: GI tract, glands, airways, uterus.

Functions: Absorption, secretion.

Definition: Single layer of tall, column-shaped cells.

Histological Features:

Locations: Nephron tubules, glands (e.g., sweat glands).

Functions: Absorption, secretion.

Definition: Single layer of cube-shaped cells.

Histological Features:

Locations: Alveolus, glomerulus, blood vessels.

Functions: Diffusion, filtration, lubrication.

Definition: Single layer of flat cells.

Avascular (no blood vessels) – relies on nutrients from nearby loose connective tissue.

No extracellular matrix (cells packed closely like bricks).

Consists of epithelial cells anchored to a basement membrane.

Example: Lines stomach, tubular organs, thoracic cavity, and skin (epidermis).

Lines the inside and outside of the body.

Forms glands (e.g., liver, pancreas, etc.).

Nervous tissue

Muscle

Connective tissue

What are cilia and microvilli?

What are the different classifications, functions, and locations of epithelium?

What is epithelium?

Special structures like cilia and microvilli enhance function.

Classifications aid in understanding functions and locations.

Epithelium is vital for forming glands and lining organs.

Match-the-tissue:

Microvilli:

Cilia:

Pseudostratified Ciliated Columnar Epithelium

Transitional (Urinary) Epithelium

Stratified Squamous Epithelium

Simple Columnar Epithelium

Simple Cuboidal Epithelium

Simple Squamous Epithelium

Structure:

Functions:

One of the four basic tissue types (

Overview Questions:

Topic: Epithelium, one of the four basic tissue types in the body.

Lecturer: Dr. Morton, a noted anatomist.

Conclusion

Practice Session

Cilia and Microvilli

Classifications of Epithelium

What is Epithelium?

Introduction

Epithelium in Histology