epithelial tissue

Where is epithelial tissue found?

Lining:

• Cavities

• Hollow Organs

• Ducts

• Glands (glandular tissue)

Epithelial Cell tissue Features

• Closely packed cells

• Cell layers (single or multiple)

• Adjacent cells

• Thin fibrous sheet (base)

• Great capacity for renewal

Functional Units

The basic working parts of epithelial tissue, made of tightly packed cells linked by junctions.

4 main functions of epithelial tissue

• Secretion

• Excretion

• Absorption

• Protection

• (SEAP)

4 basic types of cell tissue

• Connective tissue

• Muscle Tissue

• Epithelial Tissue

• Nervous Tissue

Simple epithelial tissue

Single layer of cells

Stratified epithelial tissue

Multiple layers of cells

Pseudostratified

(False Layers)

Single layered, appears double layered.

Not all cells reach surface

Squamous epithelial tissue

Flat cells

(Like fish scales)

Cuboidal epithelial tissue

Cube shaped cells with central neuclei

Columnar epithelial tissue

long column like cells

How is epithelial tissue named?

Using the top layer of cells (shape and formation)

E.g Stratified columnar epithelium

Structures found in pseudostratified epithelial tissue

Goblet cells

Cilia

Goblet cells

Specialised unicellular glands that secrete mucus to protect surfaces

Cilia

Small hair like structures used to move substances across the epithelial tissue

Where is stratified cuboidal epithelium commonly found

• Mammary Glands

• Sweat Glands

• Salivary Glands

Where is stratified columnar epithelium commonly found

Urethra

Conjunctiva

Excretory ducts of some gland

Pharynx

Anus

Where is stratified squamous epithelium commonly found

Oral Cavity

Skin surface

Oesophagus

Vagina

Anal canal

Where is pseudostratified epithelium commonly found

Respiratory Tract

Male reproductive system

Exocrine gland function

secrets products that are found outside the body

Exocrine gland examples

Sweat glands

Mammary glands

Pancreatic glands

Sebaceous glands (oil)

• Examples of exocrine secretions

• Sweat

• Milk

• Tears

• Saliva

• Digestive enzymes

• Mucus

• Oil

Endocrine gland function

Secretes products found inside the body directly into the bloodstream (no ducts)

Example of endocrine secretions

• Horomones

Endocrine gland examples

• Pituitary gland

• Adrenal gland

• Thyroid gland

• Gonads