Components of the Nervous System

This page delves deeper into the structure and function of the nervous system, defining key terms and concepts.

The nervous system is composed of various specialized cells and structures:

1. Central Nervous System (CNS): Consists of the brain and spinal cord.
2. Peripheral Nervous System (PNS): Controls motor output, such as running and walking.

Definition: Neurons are nerve cells that transmit electrical impulses throughout the body.

Types of neurons include:

• Sensory neurons: Transmit impulses to the CNS
• Motor neurons: Transmit impulses away from the CNS
• Relay neurons: Make up the CNS

Vocabulary: Neurotransmitters are chemicals that carry messages across synapses.

The process of responding to environmental changes involves:

1. Stimulus: A change in the external environment
2. Receptor: The cell that detects the change
3. Coordinator: The brain cell that decides the appropriate response
4. Effector: The muscle or gland that reacts to the change
5. Response: The body's reaction to the stimulus

Highlight: The nervous system's ability to rapidly process stimuli and generate responses is crucial for an organism's survival and adaptation to its environment.

The Nervous System and Synapses

This page introduces the nervous system and its key components, focusing on the process of neural transmission through synapses.

The nervous system is an organ system that allows organisms to react to their environment and coordinate behavior. It consists of two main parts:

1. The central nervous system (CNS): Comprises the brain and spinal cord, acting as coordinators.
2. The peripheral nervous system: Connects the CNS to the rest of the body.

The process of neural transmission follows a specific pathway:

Stimulus → Receptor → Coordinator → Effector → Response

Definition: A synapse is a junction between two neurons where chemical transmission occurs.

The synaptic transmission process involves three main steps:

1. An electrical impulse reaches the end of the nerve cell at the synapse.
2. A chemical (neurotransmitter) diffuses across the synaptic cleft.
3. The chemical initiates a new electrical impulse in the next nerve cell, propagating the signal.

Highlight: Understanding synapses and nerve impulse transmission is crucial for comprehending how information flows through the nervous system.

Vocabulary: Synaptic cleft - The small gap between two neurons at a synapse where neurotransmitters are released.