The Bio Brief

What are Animal Tissues?

Animal tissues are groups of similar cells that work together to perform specific functions like:

 Protection
 Movement
 Transport
 Coordination

 Types of Animal Tissues

Animal Tissues

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Epithelial  Connective  Muscular  Nervous

 1. EPITHELIAL TISSUE (Protective Tissue)

 Covers body surfaces and organs

Examples:

• Skin
• Mouth lining
• Blood vessels
• Lung alveoli
• Kidney tubules

Features:

 Cells tightly packed

Very little space between cells

 Forms continuous sheet

 Protects body

 Helps in absorption & secretion

Types of Epithelial Tissue

 Simple Squamous

• Thin & flat cells
• Found in lungs & blood vessels
• Helps in diffusion

 Stratified Squamous

• Many layers
• Found in skin
• Protects from wear & tear

 Columnar Epithelium

• Tall pillar-like cells
• Found in intestine
• Helps in absorption

 Ciliated Columnar

• Has hair-like cilia
• Found in respiratory tract
• Moves mucus

 Cuboidal Epithelium

• Cube-shaped cells
• Found in kidney tubules
• Provides support

Glandular Epithelium

• Secretes substances (sweat, saliva)

2. CONNECTIVE TISSUE (Connecting Tissue)

 Connects, supports and transports

Cells are loosely arranged in a matrix.

Types of Connective Tissue

 Blood

• Liquid tissue
• Transports oxygen, food, wastes

Contains:

• RBC → oxygen
• WBC → immunity
• Platelets → clotting

Bone

• Hard & strong
• Supports body
• Stores calcium

 Cartilage

• Flexible
• Found in nose, ear
• Reduces friction

 Ligament

• Connects bone to bone
• Elastic

Tendon

• Connects muscle to bone
• Very strong

 Areolar Tissue

• Fills spaces
• Supports organs
• Helps repair

 Adipose Tissue

• Stores fat
• Acts as insulation
• Found below skin

3. MUSCULAR TISSUE (Movement Tissue)

Made of muscle fibres.

Special proteins help muscles contract & relax.

Types of Muscles

Muscular Tissue

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Striated  Smooth    Cardiac

Striated (Skeletal / Voluntary)

• Attached to bones
• Under our control
• Long, cylindrical cells
• Many nuclei

Example: arm muscles

 Smooth (Involuntary)

• Not under our control
• Found in stomach, intestine
• Spindle-shaped cells
• One nucleus

 Cardiac (Heart Muscle)

• Found only in heart
• Rhythmic movement
• Branched cells
• One nucleus

 4. NERVOUS TISSUE (Control Tissue)

Controls body activities.

Found in:

• Brain
• Spinal cord
• Nerves

Nerve Cell (Neuron Diagram)

Dendrites → Cell body → Axon

Parts:
 Dendrites – receive message

Cell body – control centre

Axon – carries message

Function:

Carries nerve impulses very fast → helps in quick response.

Very Short Revision Chart

Tissue	Function
Epithelial	Protection
Connective	Support & transport
Muscular	Movement
Nervous	Control & coordination

  Points

 Blood is connective tissue

Muscles cause movement

Neurons carry impulses

Heart has cardiac muscles

Skin is stratified epithelium