F24 2200 ExamFinal4

CNS (Central Nervous System)

The part of the nervous system composed of the brain and spinal cord.

PNS (Peripheral Nervous System)

The part of the nervous system that includes all the nerves and ganglia outside of the CNS.

Neuron

A nerve cell that transmits electrical signals.

Nerve Fiber

An axon or a group of axons that conduct impulses.

Nerve

A bundle of axons wrapped in connective tissue.

Afferent Signal

Signals that carry sensory information from sensory receptors to the CNS.

Efferent Signal

Signals that carry motor commands from the CNS to effectors such as muscles.

Myelin Sheath

An insulating layer that surrounds axons, facilitating faster transmission of electrical impulses.

Saltatory Conduction

The process by which action potentials jump from one Node of Ranvier to another in myelinated axons.

EPSP (Excitatory Post Synaptic Potential)

A temporary depolarization of a postsynaptic membrane potential caused by the flow of positive ions into the cell.

IPSP (Inhibitory Post Synaptic Potential)

A temporary hyperpolarization of a postsynaptic membrane potential caused by the flow of negative ions into the cell or positive ions out of the cell.

Neurotransmitter

Chemical messengers that transmit signals across a synapse from one neuron to another.

Gray Matter

Regions of the brain and spinal cord that are rich in neuron cell bodies.

White Matter

Regions of the CNS that contain axons and are usually myelinated.

Temporal Summation

The process by which multiple signals at a single synapse accumulate in time.

Spatial Summation

The process by which multiple signals at different synapses accumulate simultaneously.

Somatic Nervous System

The part of the PNS that controls voluntary movements through skeletal muscles.

Autonomic Nervous System

The part of the PNS that controls involuntary functions such as heart rate and digestion.

Sympathetic Division

Part of the autonomic nervous system responsible for the fight or flight response.

Parasympathetic Division

Part of the autonomic nervous system responsible for rest and digest activities.

Reflex Arc

The neural pathway that mediates a reflex action.

Neuroglia

Supporting cells in the nervous system that do not transmit nerve impulses.

Schwann Cells

PNS glial cells that produce myelin sheaths around neuronal axons.

Oligodendrocytes

CNS glial cells that produce myelin sheaths around multiple axons.

Astrocytes

CNS glial cells that support neurons and maintain the blood-brain barrier.

Microglia

CNS glial cells that act as immune cells, cleaning up debris and infection.

Sensory Receptor

A structure specialized to detect a stimulus and convert it into an action potential.

Transduction

The process of converting one form of energy into another, such as converting a stimulus energy into action potentials.

Proprioceptors

Sensory receptors that provide information about body position and movement.

Nociceptors

Sensory receptors that detect pain.

Phasic Receptors

Sensory receptors that adapt rapidly to a stimulus.

Tonic Receptors

Sensory receptors that adapt slowly to a stimulus.

Bradykinin

A potent chemical released during tissue injury that stimulates nociceptors.

Substance P

A neuropeptide involved in the transmission of pain and other sensory signals.

Endogenous Opioids

Natural pain-relieving chemicals produced by the body, including endorphins.