Neuron Structure and Function

Neuron Structure

• A neuron consists of:
  • Cell Body (Soma): contains nucleus and organelles
  • Dendrites: branching extensions that receive signals
  • Axon: long, slender extension that carries signals away from the cell body
  • Terminal Buttons: ends of the axon where neurotransmitters are released
• Neuron structure allows for:
  • Reception of signals through dendrites
  • Integration of signals in the cell body
  • Transmission of signals through the axon
  • Release of neurotransmitters at terminal buttons

Myelin Sheath Composition

• The myelin sheath is composed of:
  • Lipids (70-80%): fatty substances that provide insulation
  • Proteins (20-30%): help maintain structure and function
• Myelin sheath composition allows for:
  • Rapid transmission of signals through saltatory conduction
  • Reduced energy consumption due to increased conduction velocity
  • Protection of the axon from damage

Synapse Formation

• Synapse formation involves:
  • Terminal Buttons: release neurotransmitters into the synapse
  • Postsynaptic Density: area on the dendrite where neurotransmitters bind
  • Synaptic Cleft: small gap between the terminal button and postsynaptic density
• Synapse formation allows for:
  • Chemical transmission of signals between neurons
  • Integration of signals from multiple neurons
  • Modulation of signal strength and duration

Glial Cells Function

• Glial cells provide:
  • Support: physical support and maintenance of neurons
  • Protection: insulation and protection of neurons from damage
  • Nutrition: supply of oxygen and nutrients to neurons
  • Waste Removal: removal of waste products from neurons
• Glial cells include:
  • Astrocytes: provide support and nutrition to neurons
  • Oligodendrocytes: produce myelin for axons in the CNS
  • Schwann Cells: produce myelin for axons in the PNS
  • Microglia: act as immune cells in the CNS

Axon Morphology

• Axon morphology includes:
  • Length: varies from a few millimeters to over a meter
  • Diameter: ranges from 0.1-20 micrometers
  • ** Branching**: axons can branch to form collaterals
  • Terminal Arbors: branching at the end of the axon to form terminal buttons
• Axon morphology affects:
  • Signal transmission speed and distance
  • Branching patterns influence signal distribution
  • Terminal arbors influence synaptic strength and plasticity

Neuron Structure

• A neuron consists of: Cell Body (Soma) containing nucleus and organelles, Dendrites branching extensions receiving signals, Axon carrying signals away from the cell body, and Terminal Buttons releasing neurotransmitters
• Neuron structure enables: Reception of signals through dendrites, Integration of signals in the cell body, Transmission of signals through the axon, and Release of neurotransmitters at terminal buttons

Myelin Sheath Composition

• Myelin sheath composed of: 70-80% Lipids providing insulation and 20-30% Proteins maintaining structure and function
• Myelin sheath composition enables: Rapid transmission of signals through saltatory conduction, Reduced energy consumption due to increased conduction velocity, and Protection of the axon from damage

Synapse Formation

• Synapse formation involves: Terminal Buttons releasing neurotransmitters, Postsynaptic Density binding neurotransmitters, and Synaptic Cleft separating the terminal button and postsynaptic density
• Synapse formation allows for: Chemical transmission of signals between neurons, Integration of signals from multiple neurons, and Modulation of signal strength and duration

Glial Cells Function

• Glial cells provide: Support, Protection, Nutrition, and Waste Removal for neurons
• Glial cells include: Astrocytes providing support and nutrition, Oligodendrocytes producing myelin for axons in the CNS, Schwann Cells producing myelin for axons in the PNS, and Microglia acting as immune cells in the CNS

Axon Morphology

• Axon morphology features: Length varying from a few millimeters to over a meter, Diameter ranging from 0.1-20 micrometers, Branching forming collaterals, and Terminal Arbors branching to form terminal buttons
• Axon morphology affects: Signal transmission speed and distance, Branching patterns influencing signal distribution, and Terminal arbors influencing synaptic strength and plasticity

Neuron Structure

• A neuron consists of cell body, dendrites, axon, and terminal buttons
• Cell body contains the nucleus and organelles responsible for protein synthesis and cell maintenance
• Dendrites are branching extensions that receive signals from other neurons
• Axon is a long, thin extension that carries signals away from the cell body
• Terminal buttons are the end of the axon, where neurotransmitters are released

Myelin Sheath Composition

• Myelin sheath is composed of myelin, lipids, and proteins
• Myelin is a fatty, insulating substance produced by Schwann cells in the PNS and Oligodendrocytes in the CNS
• Lipids in the myelin sheath are primarily cholesterol and phospholipids
• Proteins in the myelin sheath include myelin basic protein (MBP) and proteolipid protein (PLP)

Synapse Formation

• Synapse formation involves neurotransmitter release, binding, and signal transmission
• Neurotransmitters are released from the terminal buttons of the presynaptic neuron
• Neurotransmitters bind to receptors on the postsynaptic neuron
• Binding of neurotransmitters to receptors triggers a response in the postsynaptic neuron
• Synaptic plasticity allows synapses to change strength based on experience and activity

Glial Cells Function

• Glial cells perform various functions, including support and protection, nutrient and waste management, immune response, and synaptic maintenance
• Glial cells provide structural support and protection to neurons
• Glial cells regulate the exchange of nutrients and waste between neurons and the bloodstream
• Glial cells can respond to injury or infection by activating the immune system
• Glial cells help to maintain and regulate synaptic function

Axon Morphology

• Axon morphology includes length and diameter, myelination, and branching
• Axon length and diameter influence signal transmission speed and efficiency
• Presence or absence of myelin sheaths affects signal transmission speed and saltatory conduction
• Axons can branch to form collaterals, allowing signals to diverge and reach multiple targets

Understand the components of a neuron, including the cell body, dendrites, axon, and terminal buttons, and how they work together to receive, integrate, and transmit signals. Learn about the structure and function of neurons in the nervous system.