Chapter 10: Nervous System: Vocabulary Flashcards
acetylcholine
Neurotransmitter chemical released at the ends of nerve cells.
afferent nerve
Carries messages toward the brain and spinal cord (sensory nerve).
arachnoid membrane
Middle layer of the three membranes (meninges) that surround the brain and spinal cord.
astrocyte
Type of glial (neuroglial) cell that transports water and salts from capillaries.
autonomic nervous system
Nerves that control involuntary body functions of muscles, glands, and internal organs.
axon
Microscopic fiber that carries the nervous impulse along a nerve cell.
blood-brain barrier
Protective separation between the blood and brain cells. This makes it difficult for substances (such as anticancer drugs) to penetrate capillary walls and enter the brain.
brainstem
Posterior portion of the brain that connects the cerebrum with the spinal cord.
Includes: midbrain, pons, and medulla oblongata.
cauda equina
Collection of spinal nerves below the end of the spinal cord.
cell body
Part of a nerve cell that contains the nucleus.
central nervous system (CNS)
The brain and spinal cord.
cerebellum
Posterior part of the brain that coordinates muscle movements and maintains balance.
cerebral cortex
Outer region of the cerebrum, containing sheets of nerve cells; gray matter of the brain.
cerebrospinal fluid (CSF)
Circulates throughout the brain and spinal cord.
cerebrum
Largest part of the brain. Responsible for voluntary muscular activity, vision, speech, taste, hearing, thought, and memory.
cranial nerves
Twelve pairs of nerves that carry messages to and from the brain with regard to the head and neck (except the vagus nerve).
dendrite
Microscopic branching fiber of a nerve cell that is the first part to receive the nervous impulse.
dura mater
Thick, outermost layer of the meninges surrounding and protecting the brain and spinal cord.
efferent nerve
Carries messages away from the brain and spinal cord (motor nerve).
ependymal cell
Glial cell that lines membranes within the brain and spinal cord and helps form cerebrospinal fluid.
ganglion
(singular)
ganglia
(plural)
Collection of nerve cell bodies in the peripheral nervous system.
glial cell (neuroglial cell)
Supportive and connective nerve cell that does not carry nervous impulses.
Examples: astrocytes, microglial cells, ependymal cells, and oligodendrocytes.
Can reproduce themselves.
gyrus
(singular)
gyri
(plural)
Sheet of nerve cells that produces a rounded ridge on the surface of the cerebral cortex; convolution.
hypothalamus
Portion of the brain beneath the thalamus.
Controls sleep, appetite, body temperature, and secretions from the pituitary gland.
medulla oblongata
Part of the brain just above the spinal cord. Nerve fibers cross over here.
Controls breathing, heartbeat, and the size of blood vessels.
meninges
Three protective membranes that surround the brain and spinal cord.
microglial cell
Phagocytic glial cell that removes waste products from the central nervous system.
midbrain
Uppermost portion of the brainstem.
motor nerve
Carries messages away from the brain and spinal cord to muscles and organs; efferent nerve.
myelin sheath
Covering of white fatty tissue that surrounds and insulates the axon of a nerve cell. Myelin speeds impulse conduction along axons.
nerve
Macroscopic cord-like collection of fibers (axons and dendrites) that carry electrical impulses.
neuron
Nerve cell that carries impulses throughout the body; parenchyma of the nervous system.
neurotransmitter
Chemical messenger released at the end of a nerve cell. It stimulates or inhibits another cell, which can be a nerve cell, muscle cell, or gland cell.
Examples: acetylcholine, norepinephrine, dopamine, and serotonin.
oligodendroglial cell
Glial cell that forms the myelin sheath covering axons. Also called oligodendrocyte.
parasympathetic nerves
Involuntary, automatic nerves that regulate normal body functions such as heart rate, breathing, and muscles of the gastrointestinal tract.
parenchyma
Essential, distinguishing tissue of any organ or system.
The parenchyma of the nervous system includes neurons and nerves that carry nervous impulses.
peripheral nervous system
Nerves outside the brain and spinal cord: cranial, spinal, and autonomic nerves.
pia mater
Thin, delicate inner membrane of the meninges.
plexus
(singular)
plexuses
(plural)
Large, interlacing network of nerves.
Examples: lumbosacral, cervical, and brachial plexuses.
pons
Part of the brain anterior to the cerebellum and between the medulla and the rest of the midbrain. It is a bridge connecting various parts of the brain.
receptor
Organ that receives a nervous stimulus and passes it on to afferent nerves.
The skin, ears, eyes, and taste buds are receptors.
sciatic nerve
Nerve extending from the base of the spine down the thigh, lower leg, and foot.
sensory nerve
Carries messages toward the brain and spinal cord from a receptor (afferent nerve).
spinal nerves
Thirty-one (31) pairs of nerves arising from the spinal cord.
stimulus
(singular)
stimuli
(plural)
Agent of change in the internal or external environment that evokes a response.
Examples: light, sound, touch, pressure, and pain.
stroma
Connective and supporting tissue of an organ. Glial cells make up the stromal tissue of the brain.
sulcus
(singular)
sulci
(plural)
Depression or groove in the surface of the cerebral cortex (fissure).
sympathetic nerves
Autonomic nerves that influence bodily functions involuntarily in times of stress.
synapse
Space through which a nervous impulse travels between nerve cells or between nerve and muscle or glandular cells.
thalamus
Main relay centre of the brain. It conducts impulses between the spinal cord and the cerebrum. Incoming sensory messages are relayed through the thalamus to appropriate centres in the cerebrum.
vagus nerve
Tenth cranial nerve (cranial nerve X). Its branches reach to the larynx, trachea, bronchi, lungs, aorta, esophagus, and stomach.
ventricles of the brain
Canals in the brain that contain cerebrospinal fluid.
