Anatomy and Physiology: Nervous System and Glial Cells

Introduction

• Lecture by Professor Long on Anatomy and Physiology.
• Videos are unedited due to COVID-19 constraints.
• Focus on synaptic activity and the role of glial cells.

Synaptic Activity

• Importance of understanding synapses: once one is understood, others follow with changes only in neurotransmitter, enzyme, and receptor names.
• Need to differentiate between excitatory and inhibitory synapses.

Nervous System Cell Types

• Neurons: Primary nerve cells.
• Neuroglia (Glial Cells): Supportive cells, often referred to as the 'glue' of the nervous system.
  • Provide physical, biochemical, and nutritional support.

Glial Cells in the Central Nervous System (CNS)

1. Astrocytes

• Function: Provide physical support; form the framework for axons and dendrites.
• Blood-Brain Barrier: Astrocytes have extensions that form a filtration membrane (blood-brain barrier) for cerebrospinal fluid (CSF) formation.
• Role in Choroid Plexus: Involved in nutrient transfer and waste removal between blood and brain cells.

2. Ependymal Cells

• Function: Line ventricles and central canal; monitor and adjust CSF composition.
• Location: Found in the ventricular system and spinal cord.

3. Microglia

• Function: Act as immune cells in the brain; phagocytic, consume debris and pathogens.

4. Oligodendrocytes

• Function: Myelinate axons in the CNS; aid in action potential conduction.
• Difference from Schwann Cells: One oligodendrocyte can myelinate several axons.

Glial Cells in the Peripheral Nervous System (PNS)

1. Schwann Cells

• Function: Myelinate axons in the PNS; aid in action potential velocity.
• Myelination: Involves wrapping axons with a fatty substance (myelin).

2. Satellite Cells

• Function: Provide nutritional and biochemical support similar to ependymal cells.

Clinical Relevance

• Multiple Sclerosis (MS): Affects myelination; Schwann cells may "unwrap" and "rewrap," leading to progressive deterioration.

Conclusion

• Covered the role of various glial cells in the nervous system.
• Understanding these cells is crucial for grasping nervous system functionality.
• Final video on the nervous system will follow.

Note

• These notes were compiled from the unedited and impromptu lecture by Professor Long.