Quick Summary
Structural Organisation of Animals explains how cells form tissues, tissues form organs, and organs form systems. This chapter is diagram and comparison heavy.
Key Definitions
- Tissue: Group of similar cells performing a specific function.
- Organ: Structure made of different tissues working together.
- Organ system: Group of organs performing a major body function.
- Epithelial tissue: Covering and protective tissue.
- Connective tissue: Tissue that connects, supports, and binds body parts.
- Muscular tissue: Tissue responsible for movement.
- Nervous tissue: Tissue that conducts impulses.
Major Animal Tissues
| Tissue | Main function | Example |
|---|---|---|
| Epithelial | Protection, absorption, secretion | Skin lining |
| Connective | Support and transport | Blood, bone |
| Muscular | Movement | Skeletal muscle |
| Nervous | Coordination | Brain, spinal cord, nerves |
Epithelial Tissue
Epithelial tissue covers body surfaces and lines internal organs. It protects tissues, absorbs materials, and helps in secretion.
Connective Tissue
Connective tissue includes blood, bone, cartilage, tendons, ligaments, and adipose tissue. Blood transports substances, while bone and cartilage provide support.
Muscular Tissue
| Muscle type | Feature |
|---|---|
| Striated muscle | Voluntary, attached to bones |
| Smooth muscle | Involuntary, found in internal organs |
| Cardiac muscle | Involuntary, found in the heart |
Nervous Tissue
Nervous tissue is made of neurons. A neuron has a cell body, dendrites, and axon. It receives and transmits impulses.
Epithelial Tissue — types (deeper)
Tendon vs Ligament (common 2-mark)
| Feature | Tendon | Ligament |
|---|---|---|
| Connects | Muscle to bone | Bone to bone |
| Material | Strong, non-elastic (collagen) | Elastic |
| Function | Transmits muscle pull | Holds joints, allows movement |
Why Blood is a Connective Tissue
Blood has a fluid matrix (plasma) in which cells (RBC, WBC, platelets) are suspended, and it connects/transports materials between organs — meeting the definition of connective tissue even though it is liquid.
Levels of Organisation
Textbook Solution Strategy
1. Identify the tissue type asked in the question. 2. Write its location, structure, and function. 3. Use a comparison table for difference questions. 4. Draw neuron or muscle diagrams when asked. 5. Mention examples to complete the answer.
Important Questions
One Mark
- Name the four major animal tissues.
- What is the function of epithelial tissue?
- What is a neuron?
Two Marks
- Differentiate between tendon and ligament.
- Compare striated and smooth muscles.
- Why is blood called connective tissue?
Five Marks
- Explain the major animal tissues with functions.
- Describe the structure of a neuron.
- Compare the three types of muscular tissues.
Common Mistakes
- Confusing tendon with ligament.
- Writing cardiac muscle as voluntary.
- Forgetting blood is a connective tissue.
- Drawing neuron without direction or labels.
Revision Checklist
- Four animal tissues revised
- Muscle type comparison memorised
- Neuron diagram practised
- Blood, bone, cartilage examples revised
- Difference between tendon and ligament understood