Unit 2 Test: Chapter 8

Nervous System

Nerves that carry sensory signals (nerve impulses) toward the central nervous from the periphery.

Afferent nerves

Loss of language function.

Aphasia

Middle layer of the meninges named for the spider-web-like trabeculae that extend between it and the pia mater.

Arachnoid mater

Glial cell type of the central nervous system that provides support for neurons and maintains the blood-brain barrier.

Astrocyte

Functional division of the nervous system that is responsible for homeostatic reflexes that coordinate control of cardiac and smooth muscle, as well as glandular tissue.

Autonomic nervous system (ANS)

Single process of the neuron that carries an electrical signal (action potential) away from the cell body toward a target cell.

Axon

Tapering of the neuron cell body that gives rise to the axon.

Axon hillock

Single stretch of the axon insulated by myelin and bounded by nodes of Ranvier at either end (except for the first, which is after the initial segment, and the last, which is followed by the axon terminal).

Axon segment

End of the axon, where there are usually several branches extending toward the target cell.

Axon terminal

Cytoplasm of an axon, which is different in composition than the cytoplasm of the neuronal cell body.

Axoplasm

Dorsiflexion of the foot with extension and splaying of the toes in response to the plantar reflex, normally suppressed by corticospinal input.

Babinski sign

Shape of a neuron with two processes extending from the neuron cell body—the axon and one dendrite.

Bipolar

Physiological barrier between the circulatory system and the central nervous system that establishes a privileged blood supply, restricting the flow of substances into the central nervous system.

Blood-brain barrier (BBB)

The large organ of the central nervous system composed of white and gray matter, contained within the cranium and continuous with the spinal cord.

Brain

Region of the adult brain that includes the midbrain, pons, and medulla oblongata and develops from the mesencephalon, metencephalon, and myelencephalon of the embryonic brain.

Brain stem

Region of the frontal lobe associated with the motor commands necessary for speech production.

Broca's area

Mapping of regions of the cerebral cortex based on microscopic anatomy that relates specific areas to functional differences, as described by Brodmann in the early 1900s.

Brodmann's areas

Bundle of spinal nerve roots that descend from the lower spinal cord below the first lumbar vertebra and lie within the vertebral cavity; has the appearance of a horse's tail.

Cauda equina

Nucleus deep in the cerebrum that is part of the basal nuclei; along with the putamen, it is part of the striatum.

Caudate

Anatomical division of the nervous system located within the cranial and vertebral cavities, namely the brain and spinal cord.

Central nervous system (CNS)

Surface landmark of the cerebral cortex that marks the boundary between the frontal and parietal lobes.

Central sulcus

Pain in the head.

Cephalgia

Region of the adult brain connected primarily to the pons that developed from the metencephalon (along with the pons) and is largely responsible for comparing information from the cerebrum with sensory feedback from the periphery through the spinal cord.

Cerebellum

Process of recording the blood vessels of the cerebrum.

Cerebral angiography

Outer gray matter covering the forebrain, marked by wrinkles and folds known as gyri and sulci.

Cerebral cortex

Region of the adult brain that develops from the telencephalon and is responsible for higher neurological functions such as memory, emotion, and consciousness.

Cerebrum

One half of the bilaterally symmetrical cerebrum.

Cerebral hemisphere

A colorless fluid produced by the brain that cushions the brain and spinal cord within the posterior (dorsal) cavity.

Cerebrospinal fluid (CSF)

Formation of a blood clot in a blood vessel within the skull.

Cerebral thrombosis

Specialized structure containing ependymal cells that line blood capillaries and filter blood to produce cerebrospinal fluid in the four ventricles of the brain.

Choroid plexus

Large white matter structure that connects the right and left cerebral hemispheres.

Corpus callosum

One of many branchlike processes that extends from the neuron cell body and functions as a contact for incoming signals (synapses) from other neurons or sensory cells.

Dendrite

Central nervous system fibers carrying motor commands from the brain to the spinal cord or periphery.

Descending tract

Region of the adult brain that retains its name from embryonic development and includes the thalamus and hypothalamus.

Diencephalon

Connections within the basal nuclei from the striatum to the globus pallidus internal segment and substantia nigra pars reticulata that disinhibit the thalamus to increase cortical control of movement.

Direct pathway

Axons entering the posterior horn of the spinal cord.

Dorsal (posterior) nerve root

Tough, fibrous, outer layer of the meninges that is attached to the inner surface of the cranium and vertebral column and surrounds the entire central nervous system.

Dura mater

Nerve tissue that carries impulses away from the CNS towards the peripheral that result in motor response (movement).

Efferent nerves

The record of electrical activity of the brain.

Electroencephalogram

Process of recording the electrical activity of the brain.

Electroencephalography

An obstruction such as a blood clot or plaque that blocks the flow of blood in an artery or vein.

Embolus

Inflammation of the tissues of the brain.

Encephalitis

Softening of the tissues of the brain

Encephalomalacia

System of neural tissue associated with the digestive system that is responsible for nervous control through autonomic connections.

Enteric nervous system (ENS)

Glial cell type in the central nervous system responsible for producing cerebrospinal fluid.

Ependymal cell

Region of the diencephalon containing the pineal gland.

Epithalamus

Large opening in the occipital bone of the skull through which the spinal cord emerges and the vertebral arteries enter the cranium.

Foramen magnum

Region of the cerebral cortex directly beneath the frontal bone of the cranium.

Frontal lobe

Localized collection of neuron cell bodies in the peripheral nervous system.

Ganglion

Excision of a ganglion.

Ganglionectomy

One of the various types of neural tissue cells responsible for maintenance of the tissue, and largely responsible for supporting neurons.

Glial cell

A central nervous system tumor composed of developing glial tissue.

Glioblastoma

A tumor that begins in the glial tissue.

Glioma

Regions of the nervous system containing cell bodies of neurons with few or no myelinated axons; actually may be more pink or tan in color, but called gray in contrast to white matter.

Gray matter

Ridge formed by convolutions on the surface of the cerebrum or cerebellum.

Gyrus

Paralysis on one side of the body.

Hemiplegia

Disruption of blood flow to the brain caused by bleeding within the cranial vault.

Hemorrhagic stroke

The abnormal buildup of cerebrospinal fluid in the ventricles of the brain.

Hydrocephalus

Increased sensitivity to stimuli.

Hyperesthesia

A region of the forebrain below the thalamus; has function in both the autonomic and endocrine systems and regulates homeostasis.

Hypothalamus

Disruption of blood flow to the brain because blood cannot flow through blood vessels as a result of a blockage or narrowing of the vessel.

Ischemic stroke

Nervous system function that combines sensory perceptions and higher cognitive functions (memories, learning, emotion, etc.) to produce a response.

Integration

First part of the axon as it emerges from the axon hillock, where the electrical signals known as action potentials are generated.

Initial segment

A large separation along the midline between the two cerebral hemispheres.

Longitudinal fissure

Procedure used to withdraw cerebrospinal fluid from the lower lumbar region of the vertebral column.

Lumbar puncture

A part of the brain stem responsible for control of heart rate and breathing.

Medulla oblongata

The membranes that surround the central nervous system.

Meninges

tumor of the meninges.

Meningioma

Inflammation of the meninges, the tough membranes that surround the central nervous system.

Meningitis

Protrusion of the meninges.

Meningocele

Protrusion of the meninges and spinal cord.

Meningomyelocele

smaller than most of the other glial cells; they ingest and digest cells or pathogens that cause disease.

Microglia

A portion of the brainstem, positioned above the pons, also called mesencephalon, that assists in motor reflexes associated with visual, auditory, and somatosensory stimuli.

Midbrain

Disease affecting a single peripheral nerve.

Mononeuropathy

Peripheral, efferent, myelinated nerve tissue that stimulates muscle contraction.

Motor nerves

Shape of a neuron that has multiple processes—the axon and two or more dendrites.

Multipolar

Lipid-rich layer of insulation that surrounds an axon, formed by oligodendrocytes in the central nervous system and Schwann cells in the peripheral nervous system; facilitates the transmission of electrical signals.

Myelin sheath

Bundle of fibers that receives and sends messages between the body and the brain.

Nerves

Pain of the peripheral or cranial nerves.

Neuralgia

Inflammation of a peripheral or cranial nerve.

Neuritis

Supportive tissue of the nervous system, including the network of branched cells in the central nervous system (astrocytes, microglia, and oligodendrocytes) and the supporting cells of the peripheral nervous system (Schwann cells and satellite cells), also called glia.

Neuroglia

A doctor who has special training in diagnosing and treating disorders of the nervous system.

Neurologist

A medical specialty concerned with the study of the structures, functions, and diseases of the nervous system.

Neurology

Tumor made up of nerve cells.

Neuroma

Cells that propagate information via electrochemical impulses.

Neuron

A nerve problem that causes pain, numbness, tingling, swelling, or muscle weakness in different parts of the body.

Neuropathy

Chemicals that are made by nerve cells and used to communicate with other cells, including other nerve cells and muscle cells.

Neurotransmitters

Gap between two myelinated regions of an axon, allowing for strengthening of the electrical signal as it propagates down the axon.

Node of Ranvier

The cell's central organelle, which contains the cell's DNA.

Nucleus

Region of the cerebral cortex directly beneath the occipital bone of the cranium.

Occipital lobe

The sense of smell.

Olfaction

Glial cell type in the central nervous system that provides the myelin insulation for axons in tracts.

Oligodendrocyte

Partial paralysis wherein there is still some control of the muscles.

Paresis

Abnormal sensation in the extremities.

Paresthesia

Region of the cerebral cortex directly beneath the parietal bone of the cranium.

Parietal lobe

All nervous tissue that is outside of the brain and spinal cord.

Peripheral nervous system (PNS)

Thin, innermost membrane of the meninges that directly covers the surface of the central nervous system.

Pia mater

Acute infection by the poliovirus, especially of the motor neurons in the spinal cord and brainstem.

Poliomyelitis

Inflammation of several peripheral nerves at the same time.

Polyneuritis

Disease of multiple peripheral nerves at the same time.

Polyneuropathy