A&P Chapter 9 Nervous System
Nerve Impulse
a self propagating wave of electrical disturbance that travels along the surface of a neurons plasma membrane; sometimes called action potentials
Autonomic Nervous System
a subdivision of peripheral nervous system that consists of structures that regulate the bodys automatic or involuntary functions
Synaptic Knob
a tiny bulge at the end of a terminal branch of a presynaptic neurons axon; contains small sacs or vesicles
Reflex Arc
allows an impulse to travel in only one direction
Multiple Neurofibromatosis
an inherited disease characterized by numerous benign fibrous neuromas throughout the body
Cell Body
main part of the neuron
Hypothalamus
maintain body's water balance, maintain body temperature and produce ADH are functions of the...
Epilepsy
many forms all chracterized by recurring seizures
Multiple Sclerosis
most common primary disease of CNS; characterized by myelin loss in central nerve fibers and results in conduction impairments
Neurons
nerve cells that conduct impulses
Nitric Oxide
neurotransmitter that diffuses directly across the plasma membrane of neurons rather than being released from vesicles; important in male sexual response
Catecholamines
norepinephrine, dopamine and serotonin are a group of compunds called...
Glioma
one of the most common types of brain tumor that develops from Glia
Hemiplegia
paralysis of one whole side of the body
Bell Palsy
paralysis of some or all of the facial features innervated by the facial nerve including eyelids and mouth
Cerebral Palsy
permanent nonprogressive damage to motor control areas of brain before, during or shortly after birth causes paralysis of one or more limbs
Dementia
progressive loss of memory, shortened attention span, personality changes, reduced intellectual capacity and motor control deficit are characteristics of this
Spinal Cord Tracts
provide two way conduction paths, ascending and descending, to and from the brain
Trigeminal Neuralgia
recurring episodes of stabbing pain along one or more branches of the fifth cranial nerve in the head
Acetylcholine
released at some of the synapses in the spinal cord and at neuromuscular junctions
Arachnoid Mater
resembles cobweb with fluid in its spaces; the membrane between the dura mater and pia mater
Cerebellum
second largest part of brain; helps muscle contractions so we can maintain balance, move smootly and sustain normal posture
Sympathetic Nervous System
serves as emergency or stress system controlling visceral effectors during strenuous exercise and with strong emotions; fight or flight response
Two Neuron Arc
simplest of reflex arcs consisting of sensory neurons and motor neurons
Dermatomes
skin surface areas that are supplied by a single spinal nerve are called...
Diencephalon
small but important part of brain located between midbrain below and cerebrum above; consists of hypothalamus and thalamus
Microglia
small cells that move in inflamed brain tissue carrying on phagocytosis
Astrocytes
star shaped cells; their threadlike branches attach to neurons and small blood vessels holding these structures close to each other
Seizure
sudden burst of abnormal neuron activity that results in temporary changes in brain function
Glia
support cells that support neurons; bringing the cells of nervous tissue together structurally and functionally
Perineurium
surrounds a group (fascicle) of nerve fibers
Endoneurium
surrounds individual fibers within a nerve
Epineurium
surrounds the whole nerve
Synapse
synaptic knob. synaptic cleft and plasma membrane makes up what...
Parasympathetic Preganglionic Neurons
terminate in parasympathetic ganglia located in head, throacic and abdominal cavities close to visceral effectors; synapses with postganglionic neurons to only one effector
Receptors
the beginnings of dendrites of sensory neurons; located some distance from spinal cord in tendons, skin and mucous membranes
Central Nervous System
the brain and spinal cord make up the...
Pia Mater
the innermost membrane covering the spinal cord itself
Peripheral Nervous System
the nerves connecting the brain and spinal cord to other parts of the body
Neurilemma
the outer cell membrane of a Schwann cell
Synapse
the place where impulses are transmitted from one neuron called the presynaptic neuron to another neuron called the postsynaptic neuron
Skeletal
the somatic nervous system carries impulses to which muscles
Synaptic Cleft
the space between a synaptic knob and the plasma membrane of a postsynaptic neuron
Astrocytes, Microglia and Oligodendrocytes
the three main types of connective tissue cells (Glia) of the CNS are called...
Neurons and Glia
the two types of cells found in the nervous system are called...
Endorphins and Enkephalins
these are released at various spinal cord and brain synapses in the pain conduction pathway; natural pain killers
Cerebral Cortex
thin layer of gray matter made up of neuron dendrites and cell bodies that makes up the surface of the cerebrum
Gray Matter
tissue in the CNS made up of cell bodies and unmyelinated axons and dendrites
Visceral Effectors
tissues to which autonomic neurons conduct impulses (i.e. cardiac muscle, smooth muscle and glandualr epithelial tissue)
Dura Mater
tough outer layer that lines the vertebral canal
Three Neuron Arc
type of reflex arc consisting of sensory neurons, interneurons and motor neurons
Herpes Zoster
viral infection caused by chickenpox virus that has invaded the dorsal root ganglion and remained dormant until an episode of shingles; affect a single dermatome
Medulla Oblongata
vital centers are located in the...
Base of Brain to Top of Tail Bone
where does the spinal cord start and end
Hypothalamus
where is appetite controlled?
Myelin
white fatty substance formed by Schwann cells that wrap around some axons outside the CNS
Cerebrum
white matter made up of bundles of nerve fibers (tracts) composes most of the interior of the...
Tract
a bundle of nerve fibers (axons) in the CNS
Ganglion
a group of nerve cell bodies located in the PNS
Nerve
a group of peripheral nerve fibers (axons) bundled together like strands of a cable
Cerebrum
largest and uppermost part of brain; mental processes including sensations, consciousness, memory and voluntary control of movements
Cranial Nerves
12 pairs attached to undersurface of the brain; connect brain with the neck and structures in the thorax and abdomen
Spinal Nerves
31 pairs; contain dendrites of sensory neurons and axons of motor neurons; conduct impulses necessary for sensation and voluntary movements
Preganglionic Neurons
autonomic neurons that conduct impulses between the spinal cord and a ganglion
Cholinergic Fibers
axon whose terminals release acetylcholine
Myelinated Fiber
axons outside the CNS that are surrounded by a segmented wrapping of myelin
Adrenergic Fibers
axons whose terminals release norepinephrine and epinephrine
Neurotransmitters
bind to specific receptor molecules in membrane of a postsynaptic neuron, opening ion channels and thereby stimulating impulse conduction by the membrane
Dendrites
braching projections that conduct impulses to cell body of neuron
Alzheimer Disease
brain disorder of the middle and late adult years characterized by dementia
White Matter
brain or cord tissue made up of nerve tracts covered with white myelin
Parkinson Disease
characterized by abnormally low levels of dopamine in motor control areas of the brain; pts usually exhibit involuntary trembling and muscle rigidity
Spinal Cord
columns of white matter composed of bundles of myelinated nerve fibers form the outer portion; inner composed of gray matter made up of neuron dendrites and cell bodies
Postganglionic Neurons
conduct from autonomic ganglia to cardiac muscle, smotth muscle and glandular epithelial tissue
Motor Neurons
conduct impulses away from brain and spinal cord to muscles and glands; also called efferent neurons
Interneurons
conduct impulses from sensory neurons to motor neurons; also called central or connecting neurons
Sensory Neurons
conduct impulses to the spinal cord and brain; also called afferent neurons
Autonomic Nervous System
consists of certain motor neurons that conduct impulses from spinal cord or brainstem to cardiac muscle, smooth muscle and glandular epithelial tissue
Hypothalamus
consists of posterior pituitary gland, pituitary stalk and gray matter; controls ANS and functioning of most internal organs
Brainstem
consists of three parts in ascending order medulla oblongata, pons and midbrain; all 3 parts are two way conduction paths; important reflex centers lie here
Hypothalamus
controls hormone secretion by anterior and posterior pituitary glands; controls appetite, wakefulness, pleasure, etc.
Parasympathetic Nervous System
dominates control of many visceral effectors under normal everyday conditions
Thalamus
dumbbell shaped mass of gray matter; relays sensory impulses to cerebral cortex from sense organs; associates sensations with emotions
Cell Body, Dendrites and Axon
each neuron consists of what three parts
Axon
elongated projection that conducts impulses away from cell body of neuron
Meninges
fluid containing membranes surrounding the brain and spinal cord
Oligodendrocytes
form myelin sheath that envelops nerve fibers located in brain and spinal cord; help hold nerve fibers together
Electroencephalogram
graphic representation of voltage changes in the brain used to evaluate brain activity
Sympathetic Postganglionic Neurons
have dendrites and cell bodies in sympathetic ganglia
Parasympathetic Preganglionic Neurons
have dendrites and cell bodies in the gray matter of the brainstem and the sacral segments of spinal cord
Sympathetic Preganglionic Neurons
have dendrites and cell bodies in the gray matter of the thoracic and upper lumbar segments of the spinal cord
Cerebrovascular Accident
hemorrhage from or cessation of blood flow through cerebral blood vessels; also called a stroke
Neuroblastoma
highly malignant tumor of the sympathetic nervous system primarily affecting young children
Motor Tracts
in the brainstem conduct impulses from the higher parts of the brain to the spinal cord
Sensory Tracts
in the brainstem conduct impulses to the higher parts of the brain
Nodes of Ranvier
indentations between adjacent Schwann Cells are what
Nodes of Ranvier
indentations between adjacent Schwann cells
Huntington Disease
inherited disorder characterized by chorea (purposeless movement) progressing to severe dementia
Central or Connecting
interneurons can also be called what neurons
Schwann Cells
large nucleated cells that form myelin only in the PNS