Chapter 10 - Nervous System, Vocabulary

Acetylcholine – neurotransmitter chemical released at the end of nerve cells

(sensory nerves)

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 impulse along a nerve cell

Blood-brain barrier – Protective separation between blood and brain cells, making it difficult for substances to penetrate the walls 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 carry messages to and from the brain to all parts of the head and neck. There are 12 pairs of cranial nerves

Dendrite – microscopic branching fiber of a nerve cell (neuron) that is the first part to receive nervous impulse

Dura mater – thick, outermost layer of the meninges surrounding and protecting the brain and spinal cord

Efferent nerves – carry 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, Ganglia – Collection of nerve cell bodies in the peripheral nervous system

Glial cells (neuroglial cells) – supportive and connective nerves that do not carry nervous impulses examples are ; astrocytes, microglial cells, ependymal cells and oligodendrocytes. Glial cells can reproduce themselves

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, sexual desires and body temperature. Hypothalamus also controls the secretions from the pituitary gland

Medulla oblongata – part of the brain just above the spinal cord, controls breathing, heartbeat, and size of blood vessels; nerve fibers cross over here

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 – 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 as well as speeds impulse conduction

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; parenchyma of the nervous system

Neurotransmitter – chemical messenger released at the end of a nerve cell, it stimulates or inhibits another cell. Examples are acetylcholine, norepinephrine, dopamine and serotonin

Oligodendroglia cell – glial cell that forms the myelin sheath covering axons, also called oligodendrocyte

Parasympathetic nerves – involuntary autonomic 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

Peripheral nervous system – nerves outside the brain and spinal cord such as the cranial, spinal and autonomic nerves

Pia mater – thin, delicate inner membrane of meninges

Plexus, plexuses – large, interlacing network of nerves. Examples are lumbosacral, cervical and brachial plexuses

Pons – part of the brain anterior to the cerebellum and between the medulla and rest of the midbrain, it is a bridge connecting varies parts of the brain

Receptor – organ that receives and transmits a stimulus to sensory nerves, the skin, eyes, ears and taste buds are receptors

Sciatic nerve – nerve extending from the base of the spine down the leg to the foot. Sciatica is pain or inflammation along the course of the nerve

Sensory nerve – carries messages toward the brain and spinal cord from a receptor; afferent nerve

Spinal nerves – pairs or nerves in the spinal column that transmit messages to and from the spinal cord

Stimulus, Stimuli – Agent of change in the internal or external environment that evokes a response. It may be light, sound, touch, pressure or pain

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; fissure

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 brain, decides what is and isn’t important. It conducts impulses between the spinal cord and cerebrum.

Vagus nerve – tenth cranial nerve, that leaves the head and wonders into the abdominal and thoracic cavities unlike other cranial nerves

Ventricles of the brain – canals in the brain that contain cerebrospinal fluid, also found in the heart