Central Nervous System (CNS)

Flashcards covering the key vocabulary and definitions related to the Central Nervous System.

Central Nervous System (CNS)

The integrating center of the nervous system, consisting of the brain and spinal cord.

Peripheral Nervous System (PNS)

Consists of the sensory division (afferent neurons) and the efferent division (autonomic and somatic motor neurons).

Efferent Neurons

Neurons that take information from the CNS to target cells.

Afferent Neurons

Sensory neurons that send information to the CNS.

Glial Cells

Cells that outnumber neurons and support them in various ways, essential for the normal function of the nervous system.

Membrane Potential

Electrical potential difference across the cell membrane due to differences in charge between the inside and outside of the cell.

Resting Membrane Potential

The membrane potential of a cell at rest (not actively signalling).

Voltage-gated channels

Open and close in response to membrane potential changes and are selective for particular ions.

Ligand-gated channels

Open and close in response to the binding of ligands, such as neurotransmitters, to the extracellular side of the channel proteins.

Mechanically-gated channels

Open and close in response to physical forces such as vibration or stretch.

Na+/K+ ATPase

Membrane transporter that pumps 3 Na+ out of the cell and 2 K+ into the cell for every ATP hydrolyzed to maintain ionic composition.

Equilibrium Potential

The potential at which there is no net flux of an ion across the membrane because chemical and electrical forces are balanced, described by the Nernst equation.

Graded Potentials

Local potentials whose amplitude is proportional to the stimulus strength and lose strength with distance.

Action Potentials

All-or-none signals that occur if a stimulus reaches threshold, with no reduction in strength over distance.

Saltatory Conduction

Rapid conduction of signals along myelinated axons due to the presence of Nodes of Ranvier.

White Matter

Areas of the CNS that contain a high number of myelinated axons.

Grey Matter

Areas of the CNS that contain a high number of cell bodies, dendrites, and unmyelinated axons.

Meninges

Protective membranes between the bone and nervous tissue (dura mater, arachnoid membrane, and pia mater).

Cerebrospinal Fluid (CSF)

Fluid produced by the choroid plexus that cushions neural tissue and provides chemical protection.

Blood-Brain Barrier

Functional barrier between blood and brain interstitial fluid consisting of specialized capillaries with tight junctions.

Cerebrum

The largest region of the brain, responsible for higher brain functions.

Cerebellum

The second largest region of the brain, responsible for movement coordination.

Basal ganglia

Group of subcortical nuclei in the brain responsible for motor control, as well as other functions such as motor learning, executive functions and behaviors, and emotions.

Limbic System

A set of brain structures, including the amygdala and hippocampus, that deal with emotions and memory.

Spinal Cord

Transmits sensory information from the spinal cord to brain via ascending tracts and motor information from brain to spinal cord via descending tracts.