CH 10: The Nervous System

Nervous System

Complex network that coordinates and controls body functions through sensory, integrative, motor, and homeostatic functions.

Brain

Main control center of the body responsible for processing information and regulating body functions.

Spinal Cord

Cord-like column of nerve tissue connecting the brain to the peripheral nervous system.

Cerebrum

Largest part of the brain responsible for thought, memory, reasoning, emotion, and voluntary movement.

Cerebral

Pertaining to the cerebrum.

Cerebellum

Brain region responsible for coordination, balance, muscle tone, and motor learning.

Brainstem

Structure connecting the brain to the spinal cord.

Frontal Lobe

Brain lobe involved in reasoning, movement, speech, and decision-making.

Occipital Lobe

Brain lobe responsible for vision.

Temporal Lobe

Brain lobe involved in hearing, memory, and language.

Parietal Lobe

Brain lobe involved in sensory processing and spatial awareness.

Blood-Brain Barrier

Protective barrier that regulates movement of substances between blood and brain.

Cerebral Hemispheres

Right and left halves of the cerebrum.

Cerebral Cortex

Outer layer of the brain responsible for higher cognitive functions.

Longitudinal Fissure

Deep groove separating the cerebral hemispheres.

Gyrus

Raised fold of the cerebral cortex.

Sulcus

Shallow groove of the cerebral cortex.

Ventricle

Cavity within the brain that produces cerebrospinal fluid.

Meninges

Three protective membranes surrounding the brain and spinal cord.

Epidural Space

Space between the skull/vertebral canal and dura mater.

Dura Mater

Tough outer meningeal layer.

Subdural Space

Space between dura mater and arachnoid mater.

Arachnoid Mater

Middle meningeal layer with a spiderweb appearance.

Subarachnoid Space

Space between arachnoid mater and pia mater containing cerebrospinal fluid.

Pia Mater

Thin inner meningeal layer attached to the brain and spinal cord.

Thecal Sac

Dural sheath containing the spinal cord and cerebrospinal fluid.

Intrathecal

Pertaining to within the thecal sac.

Midbrain

Upper portion of the brainstem involved in visual and auditory reflexes.

Pons

Middle brainstem region that relays signals and regulates breathing.

Medulla Oblongata

Lower brainstem region controlling vital functions such as breathing and heart rate.

Cauda Equina

Bundle of spinal nerves resembling a horse's tail.

Central Canal

Small CSF-filled channel in the center of the spinal cord.

Vertebral Canal

Passageway housing the spinal cord.

Cerebrospinal Fluid (CSF)

Fluid that cushions and protects the brain and spinal cord.

Myelin

Fatty insulating sheath around axons that speeds nerve conduction.

White Matter

CNS tissue composed primarily of myelinated axons.

Gray Matter

CNS tissue composed primarily of neuron cell bodies and unmyelinated axons.

Neuron

Specialized nerve cell that transmits electrical impulses.

Cell Body (Soma)

Part of a neuron containing the nucleus and organelles.

Nucleus

Organelle containing chromosomes and genetic material.

Dendrite

Neuron extension that receives signals.

Axon

Neuron extension that carries impulses away from the cell body.

Nerve

Bundle of axons in the peripheral nervous system.

Nerve Tract

Bundle of axons within the central nervous system.

Sensory (Afferent) Tract

Nerve pathway carrying sensory information toward the brain.

Motor (Efferent) Tract

Nerve pathway carrying motor information away from the brain.

Cranial Nerve

One of 12 pairs of nerves emerging from the brain.

Spinal Nerve

One of 31 pairs of nerves emerging from the spinal cord.

Nerve Root

Connection point between a cranial/spinal nerve and the CNS.

Ganglion

Cluster of neuron cell bodies in the peripheral nervous system.

Neuroglia (Glial Cells)

Support cells that protect, nourish, and support neurons.

Synapse

Junction where a neuron communicates with another cell.

Synaptic Cleft

Gap between communicating neurons.

Neurotransmitter

Chemical messenger released by neurons.

Presynaptic Terminal

Axon ending that releases neurotransmitters.

Postsynaptic Receptor

Receptor that receives neurotransmitters.

Central Nervous System (CNS)

Brain and spinal cord.

Peripheral Nervous System (PNS)

All nervous tissue outside the brain and spinal cord.

Motor Division

PNS division carrying signals away from the CNS.

Sensory Division

PNS division carrying signals toward the CNS.

Somatic Nervous System

Controls voluntary skeletal muscle activity.

Voluntary

Under conscious control.

Autonomic Nervous System

Controls involuntary body functions.

Involuntary

Not under conscious control.

Sympathetic Nervous System

Fight-or-flight division of the ANS.

Parasympathetic Nervous System

Rest-and-digest division of the ANS.

Anencephaly

Congenital absence of portions of the brain.

Aphasia

Loss of ability to communicate through speech or writing.

Dysphasia

Difficulty speaking.

Ataxia

Loss of muscle coordination.

Cephalgia

Headache.

Cerebral Aneurysm

Ballooning of a brain artery.

Cerebral Concussion

Mild traumatic brain injury.

Cerebral Contusion

Bruising of brain tissue.

Cerebral Palsy

Movement disorder caused by early brain damage.

Coma

State of deep unconsciousness.

Encephalitis

Inflammation of the brain.

Hydrocephalus

Excess cerebrospinal fluid in the brain.

Meningitis

Inflammation of the meninges.

Microcephaly

Abnormally small head.

Migraine

Severe throbbing headache.

Narcolepsy

Disorder causing sudden sleep attacks.

Syncope

Fainting due to reduced blood flow to the brain.

Intracranial Hematoma

Collection of blood within the skull.

Intracerebral Hemorrhage

Bleeding within brain tissue.

Epidural Hematoma

Collection of blood above the dura mater.

Subarachnoid Hemorrhage

Bleeding into the subarachnoid space.

Subdural Hematoma

Collection of blood below the dura mater.

Stroke (CVA)

Brain injury caused by interrupted blood flow or bleeding.

Ischemic Stroke

Stroke caused by a blocked artery.

Ischemia

Inadequate blood supply to tissue.

Embolic Stroke

Stroke caused by a traveling clot.

Embolus

Traveling clot lodged in a blood vessel.

Thrombotic Stroke

Stroke caused by a stationary clot.

Thrombus

Clot attached to a vessel wall.

Hemorrhagic Stroke

Stroke caused by rupture of a blood vessel.

Cerebral Infarct

Area of brain tissue death due to ischemia.

Transient Ischemic Attack (TIA)

Temporary stroke-like episode.

Myelitis

Inflammation of the spinal cord.

Poliomyelitis (Polio)

Inflammation of spinal cord gray matter causing paralysis.