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77 terms

Nervous System

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Central Nervous System
Nervous system subdivision that is composed of the brain and spinal cord
Somatic Nervous System
Subdivision of the PNS that controls voluntary activities such as the activation of skeletal muscle
Peripheral Nervous System
Nervous System subdivision that is composed of the cranial and spinal nerves and ganglia
Autonomic Nervous System
Subdivision of the PNS that regulates the activity of the heart and smooth muscle, and of glands; it is also called the involuntary nervous system
Central Nervous System
A major subdivision of the nervous system that interprets incoming information and issues orders
Peripheral Nervous System
A major subdivision of the nervous system that serves as communication lines, liking all parts of the body to the CNS
Neurons
Demonstrate irritability and conductivity, and thus transmit electrical messages from one area of the body to another area; release neurotransmitters; are amitotic
Neuroglia
Support, insulate, and protect cells; able to divide; therefor are responsible for most brain neoplasms
Axonal Terminal
Releases neurotransmitters
Dendrite
Conducts electrical currents toward the cell body
Myelin Sheath
Increases the speed of impulse transmission
Cell Body
Location of the nucleus
Axon
Generally conducts impulses away from the cell body
Cutaneous sense organs
Sensory receptors found in the skin, which are specialized to detect temperature, pressure changes, and pain
Schwann Cells
Specialized cells that myelinate the fivers of neurons found in the PNS
Synapse
Junction or point of close contact between neurons
Tract
Bundle of nerve processes inside the CNS
Association Neuron
Neuron, serving as part of the conduction pathway between sensory and motor neurons
Nodes of Ranvier
Gaps in a myelin sheath
Ganglion
Collection of nerve cell bodies found outside the CNS
Efferent Neuron
Neuron that conducts impulses away from the CNS to mucles and glands
Proprioceptors
Sensory receptors found in muscle and tendons that detect their degree of stretch
Stimuli
Changes, occurring within or outside the body, that affect nervous system functioning
Afferent Neuron
Neuron that conducts impulses toward the CNS from the body periphery
Neurotransmitters
Chemicals released by neurons that stimulate other neurons, muscles, or glands
Refractory period
period of repolarization of the neuron during which it cannot respond to a second stimulus
Depolarization
State in which the resting potential is reversed as sodium ions rush into the neuron
Polarized
Electrical condition of the plasma membrane of a resting neuron
Repolarization
Period during which potassium ions diffuse out of neuron
Action potential
Transmission of the depolarization wave along the neuron's membrane
Potassium Ions
The chief positive intracellular ion in a resting neuron
Sodium-potassium pump
process by which ATP is used to move sodium ions out of the cell and potassium ions back into the cell; completely restores the resting conditions of the neuron
Somatic Reflexes
Patellar reflex; Effectors are skeletal muscles; flexor reflex
Autonomic Reflexes
Pupillary light reflex; Effectors are smooth muscle and glands; regulation of blood pressure; salivary reflex
Cerebral hemisphere
the largest part of the human brain
brainstem and cerebellum
The other major subdivision of the brain
ventricles
the cavities found in the brain
cerebrospinal fluid
fills the cavities of the brain
gyrus
an elevated ridge of cerebral cortex tissue
surface area
the convolutions seen in the cerebrum are important because they increase the..
cell bodies
gray matter is composed of
myelinated fibers
white matter is composed of
basal ganglia
the lentiform nucleus, the caudate, and other nuclei are collectively called
hypothalamus
site of regulation of water balance and body temperature
pons
contains reflex centers involved in regulating respiratory rhythm in conjunction with lower brain-stem centers
cerebellum
responsible for the regulation of posture and coordination of skeletal muscle movement
thalamus
important relay station for afferent fibers traveling to the sensory cortex for interpretation
medulla oblongata
contains autonomic centers, which regulates blood pressure and respiratory rhythm, as well as coughing and sneezing centers
corpus callosum
larger fiber tract connecting the cerebral hemisphere
cerebraloqueduct
connects the third and fourth ventricles
thalamus
encloses the third ventricles
choroid plexus
forms the cerebrospinal fluid
cerebral peduncle
midbrain area that is largely fiber tracts; bulges anteriorly
hypothalamus
part of the limbic system; contains centers for many drivers (rage, pleasure, hunger, sex, etc.)
post central
the primary sensory area of the cerebral hemispheres is found in the _____ gyrus
temporal
cortical areas involved in audition are found in the _____ lobe
frontal
the primary motor area in the ____ lobe is involved in the initiation of voluntary movement
Brocol's
a specialized motor speech area located at the base of the precentral gyrus is called ____ area
left
The right cerebral hemisphere receives sensory input from the ____ side of the body
pyramidal
The ____ tract is the major descending voluntary motor tract
reticular system
Damage to the ____ impairs consciousness and the awake/sleep cycles
flat
A ___ EEG is evidence of clinical death
alert
Beta waves are recorded when an individual is awake and ____
Dura Mater
outermost covering of the brain, composed of tough fibrous connective tissue
pia mater
innermost covering of the brain; delicate and vascular
arachnoid villi
structures that return cerebrospinal fluid to the venous blood in the dural sinuses
arachnoid mater
middle meningeal layer; like a cobweb in structure
dura mater
its outer layer forms the periosteum of the skull
Concussion
slight and transient brain injury
contusion
traumatic injury that destroys brain tissue
coma
total nonresponsivesness to stimulation
intracranial hemorrhage
may cause medulla oblongata to be wedged into foramen magnum by pressure of blood
cerebral edema
after head injury, retention of water by brain
cerebrovascular accident
results when a brain region is deprived of blood or exposed to prolonged ischemia
Alzheimer's disease
progressive degeneration of the brain with abnormal protein deposits
Multiple sclerosis
autoimmune disorder with extensive demyelination
Transient ischemic attack
a mini-stroke; fleeting symptoms of CVA