Nervous System (VOCAB)

Autonomic Effector

Tissues to which autonomic neurons conduct impulses.

Autonomic Nervous System:

Division of the human nervous system that regulates involuntary actions.

Autonomic Neuron:

Motor neuron that make up the Autonomic Nervous System (ANS).

Axon:

Nerve cell process that transmits impulses away from the cell body.

Basal Ganglia:

Group of islands of gray matter located in the base of the cerebrum that are responsible for autonomic movements and postures; AKA Basal Nucleus.

Basal Nuclei:

Group of nerve cells deep within the brain that help control voluntary movements, posture, and muscle tone.

Blood Brain Barrier (BBB):

Two-ply structure formed by the wall of a capillary and the surrounding extensions of a glial cell called an astrocyte; functions to prevent harmful chemicals from entering vital brain tissue.

Cell Body:

The main part of a neuron from which the dendrites and axons extended.

Central Nervous System:

Portion of the nervous system that includes the brain and spinal cord.

Cerebellum:

The second largest part of the human brain that plays an essential role in the production of normal movements.

Cerebral Cortex:

Thin layer of gray matter, made up of neuron dendrites and cell bodies, that composes the surface of the cerebrum.

Cerebrospinal Fluid:

Fluid that fills the subarachnoid space in the brain and spinal cord and the cerebral ventricles.

Cerebrovascular Accident (CVA):

Hemorrhage or cessation of blood flow through cerebral blood vessels resulting in destruction of neurons; commonly called a stroke.

Cerebrum:

The largest and uppermost part of the human brain that controls consciousness, memory, sensations, emotions, and voluntary movements.

Cholinergic Fiber:

Axon whose terminals release acetylcholine (ACh).

Choroid Plexus:

A network of brain capillaries that are involved with the production of cerebrospinal fluid.

Corpus Callosum:

Where the right and left cerebral hemispheres are joined.

Cranial Nerve:

Any of the 12 pairs of nerves that attach to the undersurface of the brain and conduct impulses between the brain and structures in the head, neck, and thorax.

Dendrite:

Branching or tree like; a nerve cell process that transmits impulses toward the body.

Dermatome:

Any of the skin surface areas supplied by a single spinal nerve.

Diencephalon:

Between the brain; parts of the brain between the cerebral hemispheres and the mesencephalon or midbrain.

Dopamine:

Chemical Neurotransmitter

Dura Mater:

Literally “Strong or hard mother”; outermost layers of the meningies.

Effector:

Responding organ; EX: voluntary and involuntary muscles, the heart, and glands.

Efferent Neuron:

Neuron that transmits impulses from the central nervous system to the periphery; opposite of afferent neuron.

Endoneurium:

The thin wrapping of fibrous connective tissue that surrounds each axon in a nerve.

Endorphin:

Any group of chemical in the CNS that influence pain perception; a natural painkiller.

Enkephalin:

Peptide chemical in the CNS that acts as a natural painkiller.

Epineurium:

A tough fibrous sheath that covers the whole nerve.

Fascicle:

Small bundle of fibers, such as a small bundle of nerve or muscle fibers.

Fight or Flight Response:

The changes produced by increased sympathetic impulses, allowing the body to deal with any type of stress.

Ganglion:

A region of gray (unmyelinated) nerve tissue.

Glia:

Supporting cells of nervous tissue; also called neuroglia.

Glioma:

One of the most common types of brain tumors.

Gray Matter:

Tissue comprising cell bodies and unmyelinated axons and dendrites.

Gyri:

Ridge.

Herpes Zoster:

Shingles; viral infection that affects the skin of a single dermatome.

Hydrocephalus:

Abnormal accumulations of cerebrospinal fluid; water on the brain.

Hypothalamus:

Vital neuroendocrine and autonomic control center beneath the thalamus.

Interneuron:

Nerve that conducts impulses from sensory neurons to motor neurons; sometimes called a central neuron or connecting neuron.

Limbic System:

A collection of various small regions of the brain that act together to produce emotion and emotional response; sometimes called the emotional brain.

Lumbar Puncture:

When some cerebrospinal fluid is withdrawn from the subarachnoid space in the lumbar region of the spinal cord.

Medulla Oblongata:

The lowest part of the brainstem; an enlarged extension of the spinal cord; the vital centers are located within this area.

Meninges:

Surrounds the brain and spinal cord.

Microglia:

One type of neuroglia cell found in the brain and spinal cord.

Midbrain:

One of the three parts of the brain stem.

Motor Neuron:

Transmits nerve impulses from the brain and spinal cord to muscles and glandular epithelial tissues.

Multiple Sclerosis:

The most common primary disease of the CNS; myelin disorder.

Myelin:

Lipoid substance found in the myelin sheath around some nerve fibers

Myelin Disorder:

Any of several disorders characterized by loss or improper development of the myelin sheath that surrounds many axons of the nervous system.

Myelinated Fiber:

Axons outside the CNS that surrounded by a segmented wrapping of myelin.

Nerve:

Collection of nerve fibers

Neurilemma:

Nerve sheath

Neuroglia:

Types of supporting cells in the nervous system

Neurologist:

Physician specializing in the treatment of nervous system disorders

Neuron:

Nerve cell including its processes (axons and dendrites)

Neuroscientist:

Scientist specializing in research concerning the structure and function of the nervous system

Neurotransmitter:

Chemicals by which neurons communicate

Nitric Oxide:

Compound composed of one nitrogen and one oxygen atom in each molecule, often acting as a small molecule neurotransmitter.

Nodes of Ranvier:

Indentations found between adjacent Schwann cells

Norepinephrine:

Hormone secreted by the adrenal medulla; released by the sympathetic nervous system.

Oligodendrocyte:

A cell that holds nerve fibers together and produces the myelin sheath around axons in the central nervous system.

Paralysis:

Loss of the power of motion, especially voluntary movement

Parasympathetic Division:

Part of the ANS that controls many visceral effectors under normal maintenance conditions; ganglia are connected to the brain stem and the sacral segments of the spinal cord (carniosacral segments).

Parasympathetic Postganglionic Neuron:

ANS neuron with dendrites and cell body located in a parasympathetic ganglion, and axon travels to a variety of visceral effectors

Parasympathetic Preganglionic Neuron:

ANS neuron with dendrites and cell body located in the gray matter of the brainstem and saran cord segments; the axon terminates in a parasympathetic ganglion.

Parkinson Disease:

A chronic disease of the nervous system characterized by a set of signs called Parkinsonism that results from a deficiency of the neurotransmitter dopamine in certain regions of the brain that normally inhibit overstimulation of skeletal muscles; Parkinsonism is characterized by a muscle rigidity and trembling of the head and extremities, forward tilt of the body, and a shuffling manner of walking.

Perineurium

Area between the anus and genitals

Peripheral Nervous System:

The nerves connecting the brain and spinal cord to other parts of the body

Pharmacist

Healthcare worker trained to dispense drugs and educate patients in their proper use

Pharmacologist:

Scientist specializing in the study of drug actions

Pharmacy Tech:

Healthcare worker trained to dispense drugs. under the supervision of a pharmacist

Pia Mater:

The vascular innermost covering of the brain and spinal cord

Pineal Gland:

Endocrine gland located near the roof of the third ventricle of the brain; produces melatonin

Plexus:

Literally a braid or network; any structure involving convergence and divergence of pathways, as in each plexus of a spinal nerve or the choroid plexus of blood vessels in the brain’s ventricles.

Pons:

The part of the brain stem between the medulla oblongata and the midbrain

Postganglionic Neuron:

Autonomic neuron that conducts nerve impulses from a ganglion to cardiac or smooth muscle or glandular epithelial tissue

Postsynaptic Neuron:

A neuron situated distal to a synapse

Preganglionic Neuron:

autonomic neuron that conducts nerve impulses between the spinal cord and a ganglion

Presynaptic Neuron:

A neuron situated proximal to a synapse

Psychiatrist:

Physician specializing in mental health

Psychologist:

Someone who studies mental processes or treats mental conditions through counseling or related therapies.

Receptor:

Peripheral beginning of a sensory neurons dendrite

Reflex:

Involuntary action

Reflex Arc:

Pattern of nerve signaling that resembles an arch curving back on itself, as when an impulse triggered by a sensory stimulus is conducted along a sensory neuron, perhaps transmitted to an interneuron in the brain or spinal cord, then out to a motor neuron, and finally to a muscle.

Reticular Formation:

Meshwork of netlike tissue that forms the framework of spleen, lymph nodes, and bone marrow.

Saltatory Conduction:

Occurs when a nerve impulse encounters myelin and jumps from one node ranvier to the next.

Schwann Cell:

Large nucleated cell that forms a myelin sheath around peripheral neurons.

Sensory Neuron:

Neuron that transmits impulses to the spinal cord and brain from any of various parts of the body.

Serotonin:

A neurotransmitter that belongs to a group of compounds called amines

Shingles:

Viral infection that affects the skin of a single dermatome.

Spinal Nerve:

Nerve that connects the spinal cord to peripheral structures such as the skin and skeletal muscles

Spinal Tract:

Any of the white columns of the spinal cord that provide two way conduction paths to and from the brain ascending tract carries information to the brain, whereas descending tracts conduct impulses from the brain.

Sulci:

Furrow or groove

Sympathetic Division:

Part of the ANS; ganglia are connected to the thoracic and lumbar regions of the spinal cord; functions as an emergency system.

Sympathetic Postganglionic Neuron:

ANS neuron with dendrites and cell body in a sympathetic ganglion; the axon travels to a variety of visceral effectors

Sympathetic Preganglionic Neuron:

ANS neuron with dendrites and cell body in the gray matter of the thoracic and lumbar segments of the spinal cord; the axon leaves the cord through an anterior root of a spinal nerves and terminates in a collateral ganglion

Synapse:

Junction between adjacent neurons

Synaptic Cleft:

The space between a synaptic knob and the plasma membrane of a postsynaptic neuron

Synaptic Knob:

A tiny bulge at the end of a terminal branch of a presynaptic neuron’s axon that contains vesicles with neurotransmitter