Bio 4C

Cells of the Nervous System

Refers to the different types of cells that make up the nervous system, including neurons and neuroglial cells.

Structure of Neurons

Describes the specialized shape and components of a neuron, including dendrites, cell body, and axon.

Nerve Impulses (Action potentials)

Refers to the electrochemical signals that neurons use to transmit information, involving the movement of sodium and potassium ions across the cell membrane.

Synaptic Transmission

Describes the process by which nerve impulses are transmitted from one neuron to another at the synapse.

Central Nervous System (CNS)

Refers to the division of the nervous system that includes the brain and spinal cord.

Peripheral Nervous System (PNS)

Refers to the division of the nervous system that includes all the nervous tissue outside the CNS.

Neurons

Refers to the excitable cells that generate and transmit messages in the nervous system.

Neuroglial Cells

Refers to the glial cells that outnumber neurons and provide support, growth factors, and insulating sheaths around axons.

Sensory Neurons

Refers to the neurons that carry information from sensory receptors to the CNS.

Motor Neurons

Refers to the neurons that carry information from the CNS to effectors such as muscles or glands.

Interneurons

Refers to the neurons found only in the brain and spinal cord that integrate and interpret sensory signals.

Dendrites

Refers to the short, branching projections of a neuron that receive signals from other cells.

Cell Body

Refers to the part of a neuron that contains the nucleus and other organelles.

Axon

Refers to the long extension of a neuron that carries information away from the cell body to other neurons or effectors.

Nerves

Refers to bundles of parallel axons, dendrites, or both from many neurons, covered with tough connective tissue.

Myelin Sheath

Refers to the insulating sheath around axons that increases the rate of conduction of a nerve impulse.

Nodes of Ranvier

Refers to the gaps between adjacent Schwann cells in the myelin sheath where electrical signals travel faster.

Saltatory Conduction

Refers to the fast conduction of nerve impulses in myelinated neurons, where the signals jump from one node of Ranvier to the next.

Multiple Sclerosis (MS)

Refers to an autoimmune disease that progressively destroys the myelin sheaths in the brain and spinal cord.

Resting Potential

Refers to the electrical potential difference across the membrane of a neuron when it is not conducting a nerve impulse.

Sodium-Potassium Pump

Refers to the proteins in the cell membrane that actively transport sodium and potassium ions across the membrane to maintain the resting potential.

Action Potential

Refers to the electrochemical signal that occurs during a nerve impulse, involving the movement of sodium and potassium ions across the cell membrane.

Threshold

Refers to the minimum electrochemical charge that causes the sodium gates to open and initiate an action potential.

Depolarization

Refers to the phase of an action potential where sodium ions enter the axon and the membrane potential becomes less negative.

Repolarization

Refers to the phase of an action potential where potassium ions rush out of the axon and the membrane potential returns to below threshold.

Propagation

Refers to the transmission of an action potential along an axon in a wave-like manner.1. Action Potential:A brief electrical signal that travels along the axon of a neuron.

Refractory Period

A brief period following an action potential where the neuron cannot be stimulated again.

Synapse

The junction between a neuron and another cell where communication occurs.

Neurotransmitter

Chemical messengers that transmit signals across the synapse.

Receptor Site

The specific location on the membrane of the postsynaptic neuron where neurotransmitters bind.

Synaptic Transmission

The process of communication between a neuron and an adjacent cell using neurotransmitters.

Synaptic Cleft

The gap between two cells where neurotransmitters diffuse across.

Presynaptic Neuron

The neuron that releases the neurotransmitter.

Postsynaptic Neuron

The neuron that receives the neurotransmitter.

Excitatory Synapse

A synapse where the binding of neurotransmitter increases the chance of an action potential.