Types of Neurons and Neural Pathways

The pathway of nerve impulses in sensory and motor neurons demonstrates how information flows through the nervous system. This chapter explores the various types of neurons and their specific roles in neural communication.

Definition: Receptor cells are specialized cells in sensory organs that detect environmental changes and initiate neural responses.

Example: When a student hears a question and raises their hand, the signal follows this pathway:

1. Receptor cells in the ear
2. Sensory neurons
3. Interneurons in the brain
4. Motor neurons
5. Arm muscles (effectors)

Highlight: The synapse, a gap between neurons, is crucial for signal transmission through neurotransmitters.

Vocabulary:

• Presynaptic neuron: The sending neuron
• Postsynaptic neuron: The receiving neuron
• Neurotransmitters: Chemical messengers that cross the synapse

Neurotransmitters and Their Functions

This section details the various neurotransmitters and their specific roles in neural communication and behavior regulation.

Definition: Acetylcholine (ACh) is a versatile neurotransmitter that can be either excitatory or inhibitory, functioning as a neuromodulator.

Highlight: Dopamine plays a crucial role in both motor control and reward pathways, while endorphins are natural pain relievers.

Example: The dopamine reward pathway activates when we experience pleasure, explaining why certain substances can be addictive.

Vocabulary:

• Neuromodulator: A neurotransmitter that regulates large groups of neurons
• Endorphins: Endogenous morphine produced by the body
• Reuptake: Process of recycling unused neurotransmitters