Nervous System Structures and Functions

A comprehensive set of flashcards covering key vocabulary and concepts related to the structures and functions of the nervous system for exam preparation.

Nervous System

The intricate network that regulates bodily functions through electrical and chemical signals.

CNS

Central Nervous System, which comprises the brain and spinal cord.

PNS

Peripheral Nervous System, the part of the nervous system that connects the CNS to the rest of the body.

Oligodendrocytes

Glial cells in the CNS that produce myelin to insulate neurons.

Schwann Cells

Glial cells in the PNS that also produce myelin.

Myelinated Axons

Axons surrounded by a myelin sheath, which increases the speed of electrical impulses.

Unmyelinated Axons

Axons that lack a myelin sheath, resulting in slower signal transmission.

Membrane Potential

The electrical charge difference across a neuronal membrane.

Resting Membrane Potential

The voltage maintained by neurons when not transmitting signals.

Ions

Charged particles (like Na+, K+, Ca2+) that are critical for neuron function.

Depolarization

The process where the membrane potential becomes less negative, leading to action potential generation.

Hyperpolarization

An increase in the membrane potential, making the inside of the neuron more negative.

Graded Potentials

Variations in membrane potential that can influence the likelihood of neuron firing.

Action Potential

A rapid rise and fall in membrane potential that propagates signals along neurons.

Continuous Conduction

A method of nerve impulse transmission in unmyelinated axons.

Saltatory Conduction

A method of impulse transmission that occurs in myelinated axons, where signals jump from node to node.

Neurotransmitters

Chemicals released by neurons to communicate with target cells.

Excitatory Neurotransmitters

Chemicals that promote the firing of a neuron.

Inhibitory Neurotransmitters

Chemicals that inhibit the firing of a neuron.

Synapse

The junction where communication occurs between neurons.

Spatial Summation

The process by which multiple presynaptic neurons stimulate a postsynaptic neuron simultaneously.

Temporal Summation

The process where rapid successive stimuli from one presynaptic neuron can induce an action potential.

Reflex Arc

The neural pathway that mediates a reflex action.

Meninges

The protective membranes covering the brain and spinal cord.

Grey Matter

Region of the CNS rich in neuronal cell bodies.

White Matter

Region of the CNS composed mainly of myelinated axons.

Ascending Nerve Tracts

Pathways that carry sensory information to the brain.

Descending Nerve Tracts

Pathways that carry motor commands from the brain to the body.

Cerebellum

Part of the brain responsible for coordinating voluntary movements and balance.

Thalamus

The brain's relay station for sensory messages.

Hypothalamus

A brain region responsible for maintaining homeostasis and regulating the autonomic nervous system.

Basal Nuclei

Groups of neurons in the brain that help control movement.

Limbic System

A complex system of nerves and networks in the brain associated with emotions and drives.

Cerebrospinal Fluid

Clear fluid that surrounds and protects the brain and spinal cord.

Blood-Brain Barrier

A selective permeability barrier that protects the brain from unwanted substances.

Cranial Nerves

Twelve pairs of nerves that arise directly from the brain.

Sensory Innervation

The supply of sensory nerves to a particular part of the body.

Motor Innervation

The supply of motor nerves to muscles or glands.

Somatic Nervous System

The part of the PNS that controls voluntary movements.

Autonomic Nervous System

The part of the PNS that regulates involuntary functions.

Sympathetic Division

Part of the ANS that prepares the body for 'fight or flight' responses.

Parasympathetic Division

Part of the ANS that conserves energy and promotes 'rest and digest' functions.

Enteric Nervous System

A complex network of neurons that governs the function of the gastrointestinal system.

Dual Innervation

The process where organs receive signals from both the sympathetic and parasympathetic divisions.

Contralateral Processing

Processing of sensory information on one side of the body by the opposite side of the brain.

Cerebral Cortex

The outer layer of the brain involved in complex functions like thought and consciousness.

Primary Somatosensory Cortex

Brain region processing sensory information from the body.

Primary Motor Cortex

Brain region responsible for the planning and execution of voluntary movements.

Wernicke's Area

Brain area involved in language comprehension.

Broca's Area

Brain region associated with speech production.

Cerebellar Comparator Function

The process by which the cerebellum compares intended movements with actual movements.

Vital Homeostatic Functions

Essential physiological processes maintained by the autonomic nervous system.

Stretch Reflex

A simple reflex action that does not involve the brain.

Cranial Nerve X

The vagus nerve, which plays a crucial role in autonomic control.

Vital Processes

Essential functions that are regulated to maintain the internal environment of the body.