Neuron Anatomy, Support, Spinal Cord & Brain Logic, Muscle Physiology

These flashcards cover key terminology and definitions related to neuron anatomy, CNS and PNS neuroglial cells, muscle physiology, and related neuroanatomy concepts.

Dendrites

The antennas of a neuron that receive chemical signals from other neurons.

Cell Body (Soma)

The part of the neuron that integrates incoming signals and keeps the cell alive.

Axon Hillock

The cone-shaped region of a neuron that decides if an electrical impulse will be sent.

Axon

The long tube of a neuron that carries impulse away from the cell body.

Axon Terminals

The part of a neuron that releases neurotransmitters to communicate with the next cell.

Astrocytes

Neuroglial cells that support neurons and form the Blood-Brain Barrier.

Microglia

Neuroglial cells that function as the immune system by eating debris and bacteria.

Ependymal Cells

Cells that line the ventricles/central canal and produce and pump cerebrospinal fluid (CSF).

Oligodendrocytes

Neuroglial cells that wrap axons in Myelin to speed up signals.

Satellite Cells

PNS neuroglial cells that surround cell bodies in ganglia to protect and regulate the environment.

Schwann Cells

PNS neuroglial cells that surround axons and form Myelin sheaths.

Multipolar Neurons

The most common type of neuron, characterized by multiple extensions.

Somatic Motor

The voluntary control of skeletal muscles.

Autonomic Motor

The involuntary control of smooth muscle, cardiac muscle, and glands.

Anterior (Ventral) Horn

The location in the spinal cord where somatic motor neuron cell bodies are found.

Amiotic Neurons

Neurons that generally do not divide.

Ganglion

A cluster of neuron cell bodies located in the PNS.

Synapse

The area where communication occurs between neurons, consisting of presynaptic neuron, synaptic cleft, and postsynaptic neuron.

Interneurons

CNS neurons that decide how to respond to sensory input.

Reflex Arc Sequence

The path of a reflex action: Receptor → Sensory Neuron → Integration Center (Interneuron) → Motor Neuron → Effector.

White Matter

The part of the CNS that contains myelinated axons.

Myelin

A substance that provides electrical insulation and increases signal speed.

Endoneurium

Innermost connective tissue around a single axon.

Perineurium

Connective tissue surrounding a fascicle of axons.

Epineurium

Outermost connective tissue surrounding the whole nerve.

Neurotransmitters

Chemicals released by neurons to communicate with other cells.

Gray Matter

Part of the CNS containing cell bodies and dendrites, involved in processing.

Cerebrum Lobes

Frontal, Parietal, Temporal, Occipital, and Insula, each responsible for different functions.

Broca's Area

Brain region responsible for speech production.

Wernicke's Area

Brain region responsible for language comprehension.

Meninges

Three protective layers surrounding the CNS: Pia Mater, Arachnoid Mater, Dura Mater.

Tracts

Bundles of nerve fibers in the white matter of the spinal cord, either ascending (sensory) or descending (motor).

Gyrus

A ridge or bump on the surface of the brain.

Sulcus

A groove or valley on the surface of the brain.

Posterior Horn

CNS gray matter that receives sensory input.

Lateral Horn

CNS gray matter that contains autonomic motor neurons.

Anterior Horn

CNS gray matter that contains somatic motor neurons.

Alzheimer’s Disease

A condition caused by the buildup of beta-amyloid plaques and tau tangles that kill neurons.

Cerebrospinal Fluid (CSF) Production

CSF is produced in the ventricles of the brain by the choroid plexus.

Vertebral Canal

The location where the spinal cord sits.

Corpus Callosum

A thick bridge of white matter connecting the left and right brain hemispheres.

Hydrocephalus

A condition known as 'water on the brain' caused by an accumulation of CSF.

Hypothalamus

Major control center for involuntary functions such as heart rate and body temperature.

Parasympathetic Cranial Nerves

CN III, VII, IX, and X, responsible for various bodily functions.

Intramural Ganglia

Ganglia that are located inside or right next to the organ being controlled.

Adrenal Medulla

Part stimulated by sympathetic neurons to release adrenaline.

Parasympathetic Origin

Predominantly from the brainstem and sacral spinal cord.

Basal Ganglia

A group of structures responsible for smoothing out movements.

Sympathetic Origin

From the lateral horn of spinal levels T1–L2.

Effects Comparison

Differences in responses between sympathetic (fight/flight) and parasympathetic (rest/digest) systems.

Brain Stem Parts

Includes Midbrain, Pons, and Medulla Oblongata.

Thoracolumbar

Nickname for the sympathetic nervous system.

Craniosacral

Nickname for the parasympathetic nervous system.

Acetylcholine (ACh)

The neurotransmitter that signals muscles to contract.

Myoglobin

A protein that stores oxygen inside muscle cells.

Titin

An elastic protein that helps muscle return to shape after stretching.

Muscle Hypertrophy

Growth of muscle fibers that get thicker.

Excitability

The ability of muscle cells to respond to stimuli.

Contractility

The ability of muscle to shorten and generate force.

End Plate

The specific part of a muscle's sarcolemma where ACh receptors are located.

Acetylcholinesterase (AChE)

Enzyme that breaks down ACh for muscle relaxation.

Motor Units

Groups of muscle fibers innervated by a single motor neuron.

Hypertrophy vs. Atrophy

Hypertrophy is muscle growth; Atrophy is muscle wasting away from disuse.