Structure & Function | AQA GCSE Biology Revision Notes 2016
Nervous System: Basics
- Components:
- Central Nervous System (CNS): Comprises the brain and spinal cord.
- Peripheral Nervous System (PNS): Consists of all other nerves in the body.
- Functions:
- Enables humans to react to surroundings and coordinate behavior.
- Transmits information as electrical impulses through nerve cells known as neurones.
- A bundle of neurones is referred to as a nerve.
Adaptations of the Nervous System
- Neurones:
- Comprise a cell body with a nucleus and main organelles.
- Have cytoplasmic extensions called axons and dendrites.
- Some neurones have axons over a meter in length, enhancing efficiency.
- Axons are insulated by a fatty myelin sheath with nodes that facilitate impulse jumping.
Structure of the Nervous System
- Information Pathway:
- Stimulus → Receptor → Coordinator (CNS) → Effector → Response.
- Receptors detect stimuli in the environment and pass information as electrical impulses.
- Coordinator (CNS): Coordinates responses by effectors such as muscle contractions or hormone secretion.
Additional Resources
Note: This summary is based on the AQA GCSE Biology course, focusing on the human nervous system's structure and function. It outlines key components and functionality relevant for exams and understanding of biological processes.