Anatomy and Physiology: Tissues (copy)

Tissue Definition

A tissue is a group of cells working together to perform a specific function.

Histology

The microscopic study of tissues.

Epithelial Tissue Characteristics

Composed predominantly of cells, with minimal extracellular matrix; avascular and has a high regeneration capacity.

Functions of Epithelial Tissue

Protection, barrier role, selective permeability, secretion, and absorption.

Types of Epithelial Tissues based on Layers

Simple, stratified, pseudostratified, and transitional.

Simple Squamous Epithelium

Single layer of flat, hexagonal cells, found in blood vessels and alveoli of lungs.

Stratified Squamous Epithelium

Several layers, cuboidal in basal layer, flattened at the surface; found in skin and mucous membranes.

Cell Connections in Epithelial Tissue

Types include desmosomes, hemidesmosomes, tight junctions, adhesion belts, and gap junctions.

Connective Tissue Characteristics

Abundant and composed of cells dispersed within an extracellular matrix.

Functions of Connective Tissue

Structural support, tissue connection, support and movement, storage, cushioning, transportation, and protection.

Types of Muscle Tissue

Skeletal muscle (striated and voluntary), cardiac muscle (striated and involuntary), smooth muscle (non-striated and involuntary).

Neurons

Cells capable of generating electrical signals known as action potentials.

Glial Cells

Support cells of the nervous system that nourish, protect, and insulate neurons.

Extracellular Matrix

Composed of protein fibers (collagen, reticular, elastic) and ground substance (hyaluronic acid, proteoglycans, adhesive molecules).