Test 3: Chapter 12 Flashcards
The part of the central nervous system contained within the cranial cavity
Brain
A mass of nerve tissue located in the vertebral canal from which 31 pairs of spinal nerves originate
Spinal Cord
One of 12 pairs of nerves that leave the brain; pass through formina in the skull; and supply sensory and motor neurons to the head, neck, part of the trunk, and viscera of the thorax and abdomen. Each is designed by a Roman numeral and a name
Cranial Nerves
One of 31 pairs of nerves that originate on the spinal cord from posterior and anterior roots
Spinal Nerves
A group of neuronal cell bodies lying outside the central nervous system
Ganglion
Highly specialized cells in the sense organs that detect and respond to one type of sensory stimuli - light, sound, or odor, for example - and transduce (convert)the stimuli into neural impulses
Sensory Receptor
Conscious awareness of a sensation, A person’s cognitive (mental) interpretation of events
Perception
Neuron that carries sensory information from cranial and spinal nerves into the brain and spinal cord or from a lower to a higher level in the spinal cord and brain. Also called an afferent neuron
Sensory Neurons
Neurons whose axons extend only for a short distance and contact nearby neurons in the brain, spinal cord, or a ganglion; they comprise the vast majority of neurons in the body. Also called association neurons
Interneurons
Neurons that conduct impulses from the brain toward the spinal cord or out of the brain and spinal cord into cranial or spinal nerves to effectors that may be either muscles or glands. Also called efferent neurons
Motor Neurons
A neuron conducting impulses outwards from the brain or spinal cord
Efferent Neurons
An organ in the body, either a muscle or gland, that is innervated by somatic or autonomic motor neurons
Effectors
The portion of the nervous system that consists of the brain and spinal cord
Central Nervous System
The part of the nervous system that lies outside the central nervous system, consisting of nerves and ganglia
Peripheral Nervous System
One of the two subdivisions of the autonomic nervous system, having cell bodies of preganglionic neurons in the lateral gray columns of the thoracic segment and the first two or three lumbar segments of the spinal cord; primarily concerned with processes involving the expenditure of energy. Also called the thoracolumbar division
Sympathetic Division
One of the two subdivisions of the autonomic nervous system, having cell bodies of preganglionic neurons in nuclei in the brain stem and in the lateral gray horn of the sacral portion of the spinal cord; primarily concerned with activities that conserve and restore body energy. Also known as the craniiosacral division
Parasympathetic Division
Any stress that chanfes a controlled condition; any change in the internal or external environment that excites a sensory receptor, a neuron, or a muscle fiber
Stimulus
An electrical signal that propagates along the membrane of a neuron a neuron or muscle fiber; a rapid change in membrane potential that involves a depolarization followed by a repolarization. Also called a nerve action potential or nerve impulse as it relates to a neuron, and a muscle action potential as it relates to a muscle fiber
Aciton Potential
General term for any process (axon or dendrite) projecting from the cell body of a neuron
Nerve Fiber
A neuronal process that carries electrical signals, usually graded potentials, toward the cell body
Dendrite
The usually single, long process of a nerve cell that propagates a nerve impulse toward the axon terminals
Axon
Cytoplasm of the axon
Axoplasm
The plasma membrane of the axon
Axolemma
Branches off of the axon to communicate with other neurons
Axon Collaterals
Terminal branch of an axon where synaptic vesicles undergo exocytosis to release neurotransmitter molecules. Also called telodendria
Axon Terminal
The functional junction between two neurons or between a neuron and an effector, such as a muscle or gland; may be electrical or chemical
Synapse
Expanded distal end of an axon terminal that contains synaptic vesicles. Also called synaptic knob
Synaptic End Bulb
Membrane-enclosed sac in a synaptic end bulb that stores neurotransmitters
Synaptic Vesicles
One of a variety of molecules within axon teminals that are released into the synaptic cleft in response to a nerve impulse and that change the membran potential of the postsynaptic neuron
Neurotransmitter
Rough endoplasmic reticulum in neuron
Nissl Bodies
Axoplasmic flow; moves enzymes and cytoskeleton components down the axon, renews worn-out axoplasmic components in mature neurons; governs speed of damaged nerve fiber regeneration
Slow Axonal Transport
Process by which neurotransmitter-containing vesicles are moved from the cell body to the axon terminal of a neuron; requires molecular motors.
Fast Axonal Transport
A neuron with a single axon and multiple dendrites; the most common type of neuron in the nervous system.
Multipolar Neuron
Only has 2 processes: one dendrite and one axon; Dendrite often specialized to receive stimulus, axon conducts action potentials to CNS; EX - sensory in retina of eye and nose
Bipolar Neuron
A neuron with one axon attached to its soma; the axon divides, with one branch receiving sensory information and the other sending the information into the central nervous system.
Unipolar Neuron
Cells of the nervous system that perform various supportive functions. The neuroglia of the central nervous system are the astrocytes, oligodendrocytes, microglia, and ependymal cells; neuroglia of the peripheral nervous system include Schwann cells and satellite cells. Also called glia
Neuroglia
A tumor composed of neuroglial cells is known as a
Glioma
A neuroglia cell having a star shape that participates in brain development and the metabolism of neurotransmitters, helps form the blood-brain barrier, helps maintain the proper balance of K+ for generation of nerve impulses, and provides a link between neurons and blood vessels
Astrocytes
A neuron glial cell that supports neurons and produces a myelin sheath around axons of neurons of the central nervous system
Oligodendrocytes
Act as phagocytes, eating damaged cells and bacteria, act as the brains immune system
Microglia
Neuroglial cells that cover choroid plexuses and produce cerebrospinal fluid; they also line the ventricles of the brain and probably assist in the circulation of CSF
Ependymal Cells
A neuroglial cell of the peripheral nervous system that forms the myelin sheath and neurolemma around a nerve axon by wrapping around the axon in a jelly-roll fashion
Neurolemmocytes (Schwann Cells)
Flat neuroglial cells that surround cell bodies of peripheral nervous system ganglia to provide structural support and regulate the exchange of material between a neuronal cell body and interstitial fluid
Satellite Cells
Multilayered lipid and protein covering, formed by Schwann cells and oligodendrocytes, around axons of many peripheral and central nervous system neurons
Myelin Sheath
Myelinated vs. Unmyelinated
The peripheral, nucleated cytoplasmic layer of the Schwann cell. Also called the sheath of schwann
Neurolemma
A space alonf a myelinated axon between the individual Schwann cells that form the myelin sheath and the neurolemma
Node of Ranvier
Aggregations or bundles of myelinated and unmyelinated axons located in the brain and spinal cord
White Matter
Areas in the central nervous system and ganglia containing neuronal cell bodies, dendrites, unmyelinated axons, axon terminals, and neuroglia; Nissl bodies impart a gray color and there is little or no myelin in gray matter
Gray Matter
An electrical potential established across the plasma membrane of all cells by the Na+/K+ ATPase and the K+ leak channels. IN most cells it is approximately -70 mV with respect to the outside of the cell
Resting Membrane Potential
The combined difference in concentration and charge; influences the distribution and direction of diffusion of ions
Electrochemical Gradient
Protein channels that open or close in response to stimuli and allows ions to pass through
Gated Ion Channels
Some chemicals get through the gated channels
Leakage
A class of transmembrane ion channels that are activated by changes in electrical membrane potential near the channel; these types of ionchannels are especially critical in neurons, but are common in many types of cells
Voltage-Gated Channel
Group of transmembrane ion channel proteins which open to allow ions such as Na+, K+, Ca2+, or Cl− to pass through the membrane in response to the binding of a chemical messenger, such as a neurotransmitter
Chemically/Ligand-Gated
Are ion channels which open their pores in response tomechanical deformation of a neuron’s plasma membrane
Mechanically-Gated
A group of transmembrane proteins that form ion channels; pores which open or close in response to light
Light-Gated
Reduction in membrane potential
A positive shift in the electrical charge in the neuron’s resting potential, making it less negatively charged
Depolarization
Cell returned to a more negative potential
after Na+ ions have rushed into the cell, K+ ions rush out of the cell to restore the balance and the original polarity
Repolarization
The level of stimulation required to trigger a neural impulse
Threshold
The movement of the membrane potential of a cell away from rest potential in a more negative direction
Hyperpolarization
Minimum length of time after an action potential during which another action potential cannot begin
Absolute Refractory Period
A period after firing when a neuron is returning to its normal polarized state and will fire again only if the incoming message is much stronger than usual
Relative Refractory Period
Propagation of an action potential in a step-by-step depolarization of each adjacent area of an axon membrane
Continuous Conduction
Rapid transmission of a nerve impulse along an axon, resulting from the action potential jumping from one node of Ranvier to another, skipping the myelin-sheathed regions of membrane
Saltatory Conduction
A neuron that propagates nerve impulses toward a synapse
Presynaptic Neuron
The nerve cell that is activated by the release of a neurotransmitter from another neuron and carries nerve impulses away from the synapse
Postsynaptic Neuron
A type of synapse in which the cells are connected by gap junctions, allowing ions (and therefore an action potential) to spread easily from cell to cell, usually in smooth and cardiac muscle
Electrical Synapse
A type of synapse at which a neurotransmitter is released from the axon of a neuron into the synaptic cleft where it binds to receptors on the next structure in sequence, either another neuron or an organ
Chemical Synapse
A voltage change at the receptor site on a postsynaptic cell membrane
Postsynaptic Potential
What opens on the axon terminal as action potential is traveling?
Voltage-Gated Ca2+Channels
A protein that captures and reacts to molecules of a neurotransmitter or hormone.
Embedded in plasma membrane of post-synaptic cell. Either are ion channels themselves or interface with ion channels
Neurotransmitter Receptors
A postsynaptic potential that depolarizes the neuronal membrane, making the cell more likely to fire an action potential
Excitatory Postsynaptic Potential
A postsynaptic potential that hyperpolarizes the neuronal membrane, making a cell less likely to fire an action potential
Inhibitory Postsynaptic Potential
Individual signals from separate synapses located at different locations across the neuron, occur close enough in time that they converge and “add up” as they travel across the neuron
Spatial Summation
Occurs when a single synapse generates EPSPs so quickly that each is generated before the previous decays. This allows the EPSPs to add up to reach a threshold voltage that triggers an action potential
Temporal Summation
A hormone secreted by the adrenal medulla that produces actions similar to those that result from sympathetic stimulation. Also called noradrenaline
Norepinephrine
Hormone secreted by the adrenal medulla that produces actions similar to those that result from sympathetic stimulation. Aslo called adrenaline
Epinephrine
Treats circulation problems caused by heart attack, heart failure, kidney failure, low blood pressure, or surgery
Dopamine
A compound present in blood platelets and serum that constricts the blood vessels and acts as a neurotransmitter
Serotonin
A colorless toxic gas formed in many reactions in which nitric acid is reduced, as in reaction with copper. It reacts immediately with oxygen to form nitrogen dioxide
Nitric Oxide
Either of two compounds that occur naturally in the brain. They are peptides related to the endorphins, with similar physiological effects
Enkephalins
Any of a group of hormones secreted within the brain and nervous system and having a number of physiological functions. They are peptides that activate the body’s opiate receptors, causing an analgesic effect
Endorphins
A biologically active substance found in plants and in brain and other animal tissues; it is a neurotransmitter that inhibits activation of neurones
GABA (Gamma-Aminobutyric Acid)
Growth anew of lost tissue or destroyed parts or organs
Regeneration
The study of the normal functioning and disorders of the nervous system
Neurology
A doctor who specializes in treating diseases of the nervous system
Neurologist
A poison that acts on the nervous system
Neurotoxin
Anesthesia that affects a restricted area of the body
Local Anesthetics
Used to cause numbness or loss of feeling in an area of your body. This medicine is a type of anesthesia.
(before and during surgery, childbirth, or other procedures)
Novacaine
A synthetic compound used as a local anesthetic
(for dental surgery, and in treating abnormal heart rhythms)
Lidocaine
A chronic, typically progressive disease involving damage to the sheaths of nerve cells in the brain and spinal cord, whose symptoms may include numbness, impairment of speech and of muscular coordination, blurred vision, and severe fatigue
Multiple Sclerosis (MS)
A neurological disorder marked by sudden recurrent episodes of sensory disturbance, loss of consciousness, or convulsions, associated with abnormal electrical activity in the brain
Epilepsy
Disease or dysfunction of one or more peripheral nerves, typically causing numbness or weakness
Neuropathy
A contagious and fatal viral disease of dogs and other mammals that causes madness and convulsions, transmissible through the saliva to humans
Rabies
A tumor composed of neuroglial cells is known as a
Glioma
The prolonged contraction of a muscle caused by rapidly repeated stimuli.
Muscles not allowed to relax
Tetanus
Can be fatal to humans and other animals and can occur by inhalation, swallowing or absorption through eyes or mouth. It produces some of the most dramatic and painful symptoms of any known toxic reaction
Strychnine Poisoning
