Nervous System Flashcards
Nerve impulse
Action potential
Nerve fibers that secrete norepinephrine
Adrenergic fibers
Sensory nerve that carries impulses toward the central nervous system
Afferent neuron
Receptors to norepinephrine that generally produce an
excitatory response
Alpha-adrenergic receptors
Subdivision of the nervous system responsible for
regulating activities that maintain homeostasis; also called visceral motor system
Autonomic nervous system
Fiber extending from a neuron’s cell body that conducts impulses
Axon
Receptors to norepinephrine that generally produce an
inhibitory response
Beta-adrenergic receptors:
Stem-like portion of the brain that connects the cerebral hemispheres to the
spinal cord; consists of the midbrain, pons, and medulla oblongata
Brainstem
Portion of the nervous system consisting of the brain and spinal
cord
Central nervous system
Portion of the brain responsible for coordination of voluntary movement and
balance
Cerebellum
The surface of the cerebrum consisting of a thin layer of gray matter
Cerebral cortex
Clear, colorless fluid that fills the brain’s ventricles and central canal
and also bathes the outside of the brain and spinal cord
Cerebrospinal fluid
- Largest portion of the brain
Cerebrum
Nerve fibers that secrete acetylcholine
Cholinergic fibers
Nerves of the peripheral nervous system that arise directly from the brain
(instead of from the spinal cord)
Cranial nerves
A specific area of the skin innervated by a spinal nerve
Dermatome
Motor nerve that carries impulses away from the central nervous system
Efferent neuron
Small space between the outer covering of the spinal cord and the vertebrae
Epidural space
Portion of the cerebrum responsible for decision making, reasoning,
memory, and voluntary movements
Frontal lobe
Nervous tissue containing mostly cell bodies of motor neurons and interneurons
Gray matter
The bottom half of the diencephalon of the brain, which is responsible for
many vital body functions
Hypothalamus
Complex set of structures in the brain responsible for emotion and learning
Limbic system
Attaches brain to spinal cord; contains centers that govern heart rate,
blood pressure, and breathing
Medulla oblongata
Layer of fibrous connective tissue covering the brain and spinal cord
Meninges
Nerve that contains both sensory and motor fibers
Mixed nerve
Receptors to acetylcholine on target cells that exhibit a variable
response
Muscarinic receptors
- Fatty sheath encasing the axons of many neurons; formed by Schwann cells in
the peripheral nervous system and oligodendrocytes in the central nervous system
Myelin
A bundle of neurons that transmits impulses between the brain and spinal cord and
the rest of the body
Nerve
Cells in the nervous system that support neurons but do not conduct impulses
Neuroglia
Nervous system cells that conduct impulses
Neurons
Receptors to acetylcholine on target cells that produce an excitatory
response
Nicotinic receptors
Portion of the cerebrum responsible for analyzing and interpreting visual
information
Occipital lobe
- Division of the autonomic nervous system that primarily has a
calming effect; also called craniosacral division
Parasympathetic division
Portion of the cerebrum concerned with bodily sensations and
proprioception
Parietal lobe
Portion of the nervous system consisting of the network of
nerves throughout the body
Peripheral nervous system
A network of nerves
Plexus
The electrical state of a cell membrane that has an excess of positive ions
on one side of the membrane and an excess of negative ions on the other
Polarization
A neural circuit that bypasses regions of the brain where conscious decisions
are made
Reflex arc
Reflex involving contraction of a skeletal muscle after being stimulated by
a somatic motor neuron
Somatic reflex
Division of the autonomic nervous system responsible for “fight or
flight” response; also called thoracolumbar division
Sympathetic division
Space between the junction of two neurons in a neural pathway
Synapse
Portion of the brain responsible for hearing, smell, and visual recognition
Temporal lobe
Bundles of axons in the spinal cord that serve as routes of communication to and
from the brain
Tracts
Reflex of the autonomic nervous system affecting organs
Visceral reflexes
Nervous tissue containing bundles of axons that carry impulses from one
part of the nervous system to another
White matter
CNS
brain and spinal cord
PNS
all all neurons outside CNS
Neuron Structures
Dendrite
Cell body
Axon
receives
stimulus from other
neurons or sensory
receptors
Dendrite
processes
stimulus; contains a
nucleus
Cell body
transmits
stimulus to a gland,
muscle, organ, or
other neuron
Axon
Types of Neurons
Multipolar
Bipolar
Psudo-Unipolar
many dendrites and a single axon
Multipolar
many dendrites and a single axon
Bipolar
one axon and no dendrites
Pseudo-Unipolar
Supporting cells for neurons
Glial Cell
Types of Neuroglia
Astrocytes Ependymal Microglia Oligodendrocytes Schwann cells
fatty, proctective wrapping around axons
myelin sheaths
always open (K+)
leak ion channels
closed until opened by specific signal (Na+)
gated ion channels
where an axon attaches to a muscle, gland, organ, or other neuron involved with release of neurotransmitters
the synapse
involuntary response to a stimulus
reflexes
extends from foramen magnum to 2nd lumbar vertebra
spinal cord
center of spinal cord
gray matter
outside of spina cord
white matter
arise along spinal cord from union of dorsal roots and ventral roots
spinal nerves
spinal nerves C1-4
Cervical Plexus
Originates from spinal nerves C5-T1
Brachial Plexus
Originates from spinal nerves L1 to S4
Lumbosacral Plexus
protective wrapping around brain and spinal cord
meninges
superficial, thickest layer
dura mater
2nd layer
arachnoid mater
3rd layer, surface of brain
pia mater
infection of meninges (bacterial or viral)
meningitis
in vertebral column between dura and vertebra
epidural space
in subarachnoid space where cerebrospinal fluid can be removed or anesthetic inject : numbs spinal nerves
spinal block and spinal tab
cavities in CNS that contains fluid
ventricles
fluid that bathes the brain and spinal cord, provides a protective cushion around the CNS
cerebrospinal fluid
Major parts of the brain
brainstem
cerebellum
diencephalon
cerebrum
regulates cyclical motor function, respiration, walking, chewing, arousing and maintaining consciousness, regulates sleep-wake cycle
brainstem
regulates heart rate, blood vessel
diameter, breathing, swallowing, vomiting,
hiccupping, coughing, sneezing, balance
Medulla Oblangata
breathing, chewing, salivation, swallowing
Pons
coordinated eye movement, pupil
diameter, turning head toward noise
Midbrain
controls balance, muscle tone, coordination of fine
motor movement
Cerebellum
Located between the brainstem and cerebrum
Diencephalon
emotional and visceral response to odors
Thalamus
controls homeostasis, body temp,
thirst, hunger, fear, rage, sexual emotions
Hypothalamus
largest portion of brain
Cerebrum
controls thinking, communicating,
remembering, understanding, and initiates
involuntary movements
Cerebral Cortex
controls right side of body
responsible for math, analytic, and speech
Left hemisphere
controls left side of body
responsible for music, art, abstract ideas
Right hemisphere
connection between 2 hemispheres
Corpus callosum
Lobes of the Brain
Frontal Lobe
Parietal Lobe
Temporal Lobe
Occipital Lobe
controls voluntary motor functions, aggression, moods,
smell
Frontal Lobe
evaluates sensory input such as touch, pain, pressure,
temperature, taste
Parietal Lobe
hearing, smell, memory
Temporal Lobe
vision
Occipital Lobe
