neurons

Overview of Neurons

  • Neurons are specialized cells that transmit electrical signals in the nervous system.

  • This video focuses on the structure and function of neurons to understand their role in the nervous system's activity.

Learning Objectives

  • Distinguish between glial cells and neurons.

  • Identify the parts of a neuron and describe their functions.

  • Refer to Saladin's 8th edition, pages 433 to 437 for relevant content.

Structure of a Generic Neuron

  • Type of Neuron: Focus on multipolar neurons, which typically have multiple projections.

Key Parts of a Neuron

  1. Cell Body:

    • Contains the nucleus, which is typically large and easily identifiable.

    • Serves as the metabolic center of the neuron.

  2. Dendrites:

    • Small projections extending from the cell body.

    • Responsible for receiving electrical signals or impulses from other neurons.

  3. Axon:

    • A long projection emerging from the cell body, usually singular in a typical neuron.

    • Can vary in length; for example, axons from spinal cord to feet can reach lengths of 2.5 to 3 feet.

    • Emerges from the cell body at the axon hillock, which is funnel-shaped and marks the beginning of the axon.

    • Terminates at synaptic terminals (or bulbs) where neurotransmitters are released.

Functionality of Neurons

  • The flow of information begins at the dendrites where electrical signals are generated, leading to an action potential.

  • The action potential travels down the axon to the synaptic terminals to trigger neurotransmitter release.

Supporting Cells: Glial Cells

  • Glial cells (specifically Schwann cells) are non-neuronal cells that support neuron function.

  • They wrap around the axon, forming myelin sheaths, which are crucial for efficient signal conduction.

Conclusion

  • Understanding the structure and function of neurons sets the stage for further discussion on glial cells and their role in the nervous system.