1. Epithelial Tissue (Covering & Lining)

General Features

• Cells are tightly packed with little extracellular matrix.

• Forms coverings and linings of organs, surfaces, and glands.

Types of Epithelial Tissue

• Simple Squamous

  • Single layer of flat cells.

  • Function: Diffusion and filtration.

  • Location: Alveoli (lungs), capillaries, lining of heart.

• Simple Cuboidal

  • Single layer of cube-shaped cells.

  • Function: Secretion and absorption.

  • Location: Kidney tubules, glands.

• Simple Columnar

  • Single layer of tall, column-like cells.

  • Function: Absorption and secretion (often mucus).

  • Location: Digestive tract, uterine tubes.

• Stratified Squamous

  • Multiple layers; surface cells are flat.

  • Function: Protection against abrasion.

  • Location: Skin, mouth, esophagus.

• Pseudostratified Columnar (Ciliated)

  • Appears layered but is not; often ciliated.

  • Function: Secretion and movement of mucus.

  • Location: Trachea, upper respiratory tract.

• Transitional

  • Multiple layers; shape changes with stretching.

  • Function: Allows stretching.

  • Location: Bladder, ureters, urethra.

2. Connective Tissue (Support & Binding)

General Features

• Cells are scattered in an abundant extracellular matrix.

• Matrix contains fibers (collagen, elastic, reticular).

• Supports, binds, and connects other tissues.

Types of Connective Tissue

• Bone (Osseous Tissue)

  • Function: Support, protection, blood cell formation.

  • Location: Skeleton.

• Cartilage (Hyaline, Elastic, Fibrocartilage)

  • Function: Support, flexibility.

  • Location: Joints, ear, discs.

• Adipose

  • Function: Stores energy, insulates, cushions organs.

  • Location: Under skin, around organs.

• Blood

  • Function: Transports gases, nutrients, wastes.

  • Location: Blood vessels.

• Dense Connective Tissue

  • Function: Attaches muscles to bones (tendons), bones to bones (ligaments).

3. Muscle Tissue (Movement)

General Features

• Specialized for contraction and movement.

Types of Muscle Tissue

• Skeletal Muscle

  • Striated, voluntary, multinucleated.

  • Function: Moves skeleton.

• Cardiac Muscle

  • Striated, involuntary, intercalated discs present.

  • Function: Pumps blood.

• Smooth Muscle

  • Non-striated, involuntary.

  • Function: Moves substances via peristalsis.

  • Location: Walls of hollow organs (stomach, intestines, bladder, blood vessels).

4. Nervous Tissue (Communication)

General Features

• Specialized for communication via electrical and chemical signals.

Types of Nervous Tissue Cells

• Neurons

  • Function: Transmit electrical impulses.

  • Location: Brain, spinal cord, nerves.

• Neuroglia (Support Cells)

  • Function: Support, protect, and nourish neurons.