Nervous System Flashcards
Neurotransmitter chemical released at the ends of nerve cells.
acetylcholine
Carries messages toward the brain and spinal cord (sensory nerve).
afferent nerve
Middle layer of the three membranes (meninges) that surround the brain and spinal cord.
arachnoid membrane
Type of glial (neuroglial) cell that transports water and salts from capillaries in the nervous system.
astrocyte
Nerves that control involuntary body functions of muscles, glands, and internal organs.
autonomic nervous system
Microscopic fiber that is part of a neuron and carries nervous impulse along a nerve cell.
axon
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.
blood-brain barrier
Posterior portion of the brain that connects the cerebrum with the spinal cord; includes the midbrain, pons, and medulla oblongata.
brainstem
Collection of spinal nerves below the end of the spinal cord.
cauda equina
Part of a nerve cell that contains the nucleus.
cell body
Brain and spinal cord.
central nervous system (CNS)
Posterior part of the brain that coordinates muscle movements and maintains balance.
cerebellum
Outer region of the cerebrum, containing sheets is nerve cells; gray matter of the brain.
cerebral cortex
Circulates throughout the brain and spinal cord.
cerebrospinal fluid (CSF)
Largest part of the brain; responsible for voluntary muscular activity, vision, speech, taste, hearing, thought, and memory.
cerebrum
Nerves carry messages to and from the brain to all parts of head and neck and also (in the case of the vagus nerve) to other parts of the body. There are 12 pairs.
cranial nerves
Microscopic branching fiber of a nerve cell that is the first part to receive the nervous impulse.
dendrite
Thick, outermost layer of the meninges surrounding and protecting the brain and spinal cord. Latin for “hard mother.”
dura mater
Carries messages away from the brain and spinal cord; motor nerve.
efferent nerve
Glial cell that lines membranes within the brain and spinal cord and helps form cerebrospinal fluid.
ependymal cell
Collection of nerve cell bodies in the peripheral nervous system.
ganglion (plural ganglia)
Supportive and connective nerve cell that does not carry nervous impulses. Examples are astrocytes, microglial cells, ependymal cells, and oligodendrocytes. Can reproduce themselves, as opposed to neurons.
glial cell (neuroglial cell)
Sheet of nerve cells that produces a rounded ridge in the surface of the cerebral cortex; convolution.
gyrus (plural gyri)
Portion of the brain beneath the thalamus; controls sleep, appetite, body temperature, and secretions from the pituitary gland.
hypothalamus
Part of the brain just above the spinal cord; controls breathing, heartbeat, and the size of blood vessels; nerve fibers cross over here.
medulla oblongata
Three protective membranes that surround the brain and spinal cord.
meninges
Phagocytic glial cell that removes waste products from the central nervous system.
microglial cell
Uppermost portion of the brainstem.
midbrain
Carries messages away from the brain and spinal cord to the muscles and organs; efferent nerve.
motor nerve
Covering of white fatty tissue that surrounds and insulates the axon of a nerve cell. Speeds impulse conduction along axons.
myelin sheath
Macroscopic cord-like collection of fibers (axons) that carry electrical impulses.
nerve
Nerve cell that is necessary for impulses to be carried throughout the nervous system; parenchyma of the nervous system.
neuron
Chemical messenger released at the end of a nerve cell. It stimulates or inhibits another cell, which can be a nerve cells muscle cell, or gland cell. Examples are acetylcholine, norepinephrine, dopamine, and serotonin.
neurotransmitter
Glial cell that forms the melin sheath covering axons.
oligodendroglial cell (oligodendrocyte)
Involuntary autonomic nerves that regulate normal body functions such as heart rate, breathing, and muscles of the gastrointestinal tract.
parasympathetic nerves
Nerves outside the brain and spinal cord; cranial, spinal, and autonomic nerves.
peripheral nervous system
Thin, delicate inner membrane of the meninges.
pia mater
Large, interlacing network of nerves. Examples are lumbosacral, cervical, and brachial.
plexus (plexuses)
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.
pons
Organ that receives and transmits a stimulus to sensory nerves. The skin, ears, eyes, and taste buds.
receptor
Nerve extending from the base of the spine down the thigh, lower leg, and foot.
sciatic nerve
Carries messages toward the brain and spinal cord from a receptor; afferent nerve.
sensory nerve
Pairs of nerves, arising one on each side of the spinal column. They transmit messages to and from the spinal cord.
spinal nerves
Agent of change in the internal or external environment that evokes a response. It may be light, sound, touch, pressure, or pain.
stimulus (plural stimuli)
Depression or groove in the surface of the cerebral cortex; fissure.
sulcus (plural sulci)
Autonomic nerves that influence bodily functions involuntarily in times of stress.
sympathetic nerves
Space through which a nervous impulse travels between nerve cells or between nerve and muscle or glandular cells.
synspse
Main relay center of the brain. It conducts impulses between the spinal cord and the cerebrum; incoming sensory messages are related through it to appropriate centers in the cerebrum.
thalamus
Tenth cranial nerves (cranial nerve X). Its branches reach to the larynx, trachea, bronchi, lungs, aorta, esophagus, and stomach.
vagus nerve
Canals in the brain that contain cerebrospinal fluid.
ventricles of the brain
