Chapter 14: Nervous System Flashcards
cephal/o
Head
cerebell/o
Little brain
cerebr/o
Cerebrum
chrom/o
Color
cran/i
Skull
crani/o
Skull
cyt/o
Cell
dendr/o
Tree
disk/o
A disk
dur/o
Dura, hard
electr/o
Electricity
encephal/o
Brain
esthesi/o
Feeling
fibr/o
Fiber
gli/o
Glue
hypn/o
Sleep
lamin/o
Thin plate
later/o
side
lob/o
Lobe
mening/i
Membrane, meninges
mening/o
Membrane, meninges
ment/o
Mind
my/o
Muscle
myel/o
Bone marrow, spinal cord
narc/o
Numbness, sleep, stupor
neur/I
Nerve
neur/o
Nerve
pallid/o
Globus, pallidus
papill/o
Papilla
phe/o
Dusky
poli/o
Gray
somn/o
Sleep
spin/o
A thorn, spine
spondyl/o
Vertebra
vag/o
Vagus, wandering
ventricul/o
Ventricle
Nervous System
Has two interconnected divisions: The central nervous system (CNS) and the peripheral nervous system (PNS)
Neurons
Structural and functional units of the nervous system. Specialized conductors of impulses that enable the body to interact with its internal and external environments. Involved in impulse transmission.
Neuroglia
In the brain and spinal cord. Act as supporting tissues.
Nerve fibers and tracts
Conduct impulses from one location to another.
Central nervous system
Receives impulses from throughout the body, processes the information and responds with an appropriate action.
Brain
Governs sensory perception, emotions, consciousness, memory, and voluntary movements
Spinal cord
Conducts sensory impulses to the brain and motor impulses from the brain to body parts; also serves as a reflex center for impulses entering and leaving the spinal cord without involvement of the brain.
Peripheral Nervous System
Links the central nervous system with other parts of the body.
Cranial nerves (12 pairs)
Provide sensory input and motor control, or a combination of these
Spinal nerves (31 pairs)
Carry impulses to the spinal cord and to muscles, organs, and glands
Autonomic nervous system (sympathetic and parasympathetic divisions)
Controls involuntary bodily functions such as sweating, secretion of glands, arterial blood pressure, smooth muscle tissue, and the heart. Also stimulates the adrenal gland to release epinephrine (adrenaline), the hormone that causes the familiar adrenaline rush or the “fight-or-flight response”
Motor neurons in the PNS
Called efferent processes because they transmit impulses away from the cell body to the muscles or organs
Axon
Long and covered with a fatty substance or myelin sheath that acts as an insulator and increases the transmission velocity of the nerve fiber it surrounds.
Dendrites
Resemble the branches of a tree, they are short and unsheathed an transmit impulses to the cell body.
Sensory neurons in the PNS *
Are afferent nerves because they carry impulses from the sensory receptors to the synaptic endings in the central nervous system
Interneurons in the CNS
Called central or associative neutrons function to mediate impulses between sensory and motor neurons
Nerve fiber
Is a single elongated process, the axon of a neuron.
Neurilemma *
The outer sheath composed of Schwann cells of the myelinated fiber.
Tracts
Groups of nerve fibers within the CNS
Largest tract
The brain has numerous tracts, the largest is the corpus callosum joining the right and left hemispheres of the brain.
Receptor *
Stimulation of a nerve occurs here.
All-or-none principle*
The transmission of an impulse is based on this in that no transmission occurs until the stimulus reaches a set minimum strength, which can very from different receptors
Grey matter
Consists of unsheathed cell bodies and true dendrites