Chapter 10 - Nervous System, Vocabulary

Acetylcholine

Neurotransmitter chemical released at the end of nerve cells.

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 in the nervous system.

Autonomic nervous system

Nerves that control involuntary body functions of muscles, glands, and internal organs.

Axon

Microscopic fiber that is part of a neuron and carries nervous impulses along a nerve cell.

Blood-brain barrier

Protective separation between blood and brain cells, making it difficult for substances to penetrate and enter the brain.

Brainstem

Posterior portion of the brain that connects the cerebrum with the spinal cord; includes the midbrain, pons, and medulla oblongata.

Cauda equina

Collection of spinal nerves below the spinal cord.

Cell body

Part of a nerve cell that contains the nucleus.

Central nervous system (CNS)

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)

Watery fluid that circulates throughout the brain and spinal cord.

Cerebrum

Largest part of the brain, responsible for vision, speech, taste, hearing, thoughts, and memory.

Cranial nerves

Nerves that carry messages to and from the brain to all parts of the head and neck; there are 12 pairs.

Dendrite

Microscopic branching fiber of a nerve cell (neuron) that is the first part to receive nervous impulses.

Dura mater

Thick, outermost layer of the meninges surrounding and protecting the brain and spinal cord.

Efferent nerves

Nerves that carry messages away from the brain and spinal cord; motor nerves.

Ependymal cell

Glial cell that lines membranes within the brain and spinal cord and helps form cerebrospinal fluid.

Ganglion, Ganglia

Collection of nerve cell bodies in the peripheral nervous system.

Glial cells

Supportive and connective cells that do not carry nervous impulses; examples include astrocytes, microglial cells, ependymal cells, and oligodendrocytes.

Gyrus, Gyri

Sheet of nerve cells on the surface of the cerebral cortex.

Hypothalamus

Portion of the brain below the thalamus; controls sleep, appetite, body temperature, and sexual desires.

Medulla oblongata

Part of the brain just above the spinal cord; controls breathing, heartbeat, and size of blood vessels.

Meninges

Three protective membranes that surround the brain and spinal cord.

Microglial cells

Phagocytic glial cells that remove waste products from the central nervous system.

Midbrain

Uppermost portion of the brainstem.

Motor nerve

Nerves that carry messages away from the brain and spinal cord to muscles and organs.

Myelin sheath

Covering of white fatty tissue that surrounds and insulates the axon of a nerve cell.

Nerve

Macroscopic cord-like fibers (axon) that carry electrical impulses.

Neuron

Nerve cell that is necessary for impulses to be carried throughout the nervous system.

Neurotransmitter

Chemical messenger released at the end of a nerve cell that stimulates or inhibits another cell.

Oligodendroglia cell

Glial cell that forms the myelin sheath covering axons.

Parasympathetic nerves

Involuntary autonomic nerves that regulate normal body functions such as heart rate and digestion.

Parenchyma

Essential, distinguishing tissue of any organ or system.

Peripheral nervous system

Nerves outside the brain and spinal cord including cranial, spinal, and autonomic nerves.

Pia mater

Thin, delicate inner membrane of the meninges.

Plexus, plexuses

Large, interlacing networks of nerves; examples include lumbosacral, cervical, and brachial plexuses.

Pons

Part of the brain anterior to the cerebellum; connects various parts of the brain.

Receptor

Organ that receives and transmits a stimulus to sensory nerves.

Sciatic nerve

Nerve extending from the base of the spine down the leg to the foot.

Sensory nerve

Nerves that carry messages toward the brain and spinal cord from a receptor.

Spinal nerves

Pairs of nerves in the spinal column that transmit messages to and from the spinal cord.

Stimulus, Stimuli

Agent of change in the environment that evokes a response.

Stroma

Connective and supporting tissue of an organ, glial cells make up the stromal tissue of the brain.

Sulcus, Sulci

Depression or groove in the surface of the cerebral cortex.

Sympathetic nerves

Autonomic nerves that influence bodily functions involuntarily during times of stress.

Synapse

Space through which a nervous impulse travels; a point of contact.

Thalamus

Main relay center of the brain; conducts impulses between the spinal cord and cerebrum.

Vagus nerve

Tenth cranial nerve; leaves the head and extends into the abdominal and thoracic cavities.

Ventricles of the brain

Canals in the brain that contain cerebrospinal fluid.