Intro to Neurophys Flashcards
CNS contains
brain and spinal cord
PNS contains
Cranial nerves, spinal nerves, and sensory receptors in skin
Information flows into and out of the spinal
cord via
peripheral nerves
Information flows _ to the spinal cord from the brain and _ the spinal cord to the
brain
down, up
There are also local circuits within the spinal
cord that process
sensory information and
control movement
Receive inputs (synapses),
Integrate (sum) inputs
Dendrites
Inputs flow into _ from dendrites
soma
soma contains the
nucleus
Output structure of neuron
axon
Electrical signals (action potentials) are
propagated long distances along the
axon
Action potentials trigger release of
neurotransmitters that activate or inhibit other neurons or target cells
dorsal=
afferent
ventral=
efferent
White matter is comprised of
bundles of myelinated axon
Grey matter is comprised of
cell bodies and synapses
Axons are found in
bundles (tracts) running up and down the spinal cord white matter
Spinal cord is encased within the
meninges and vertebrae
responsible for Sensory
Innervation
dermotomes
Involved in perception,
initiation and control of
movement, cognitive
functions
cerebrum
Involved in regulation of
autonomic function,
mid-level sensory and
motor processes
brain stem
Involved in sensory
and motor functions,
motor learning
cerebellum
Involved in sensory-motor
processing (thalamus), and
control of thirst, satiety, sex
hormones, other hormones
diencephalon
Neurons are tightly packed in the
gray matter
Function of the CNS
processes sensory information including muscle contraction stimulation
How many pairs of spinal nerves
31
Two classes in the Peripheral NS
Afferent and Efferent
Conveys input into the CNS from sensory receptors, provides information about somatic senses, and special senses
Afferent NS
What NS deals with tactile, pain, thermal, smell, vision, taste, and hearing
Afferent
Conveys output from CNS to effectors
Efferent NS
Two classes of Efferent NS
somatic and autonomic
conveys output to skeletal muscles only, voluntary
Somatic NS
conveys output to smooth muscle, cardiac muscle, and glands; involuntary
Autonomic NS
Autonomic NS classes
Parasympathetic and Sympathetic and Enteric
Neurons in GI tract regulate activity of smooth muscle and glands of GI tract
Enteric NS
Nervous system functions
Sensory, integrative, motor
Nervous system consists of
neurons and neuroglia
Basic functional unit of the NS
neuron
Short, highly branched processes of neuron
dendrites
Long, thin process; generates chain of action potentials
axon
The axon connects to the cell body through the
axon hillock
Where do action potentials arise from, “trigger zone”
Axon hillock
Along the length of axons are branches known as
Axon collaterals
site of communication between neuron and target cell
synapse
What stores neurotransmitters
synaptic vesicles
Axonal transport uses what motor proteins to transport along microtubules of neurons
Kinesins and dyneins
Motor proteins, for transport, use…
ATP hydrolysis to walk along microtubule surface
Motor proteins move materials in what two ways and with what protein
anterograde (forward)- using kinesins
retrograde (down)–using dyneins
Moves organelles and synaptic vesicles from cell body to axon terminals
anterograde direction
Moves membrane vesicles from axon terminals to cell body to be degraded
retrograde direction
Substances that enter axon terminals enter via
retrograde
Bundle of axons in PNS vs CNS
PNS= nerve
CNS= tract
Sensory/afferent neurons have action potentials into
into CNS
Trigger zone for action potentials is at the
junction of the dendrites and axon of sensory neuron
Motor/efferent neurons action potentials are
away from CNS
efferent neurons consist of
somatic and autonomic motor neurons
Interneurons are located in
CNS between motor and sensory
Interneurons are responsible for __ and make up __ of neurons
integration, 99%
Make up 1/2 volume in CNS and can divide
neuroglia
nourish and protect neurons, maintain homeostasis in the interstitial fluid
neuroglia
isolates neurons from harmful agents
blood brain barrier
Neuroglia in the PNS and function
Schwann cell, forms myelin sheath around PNS axon and axon regeneration
myelin sheath is composed of
lipids and proteins
insulates axons of a neuron and speeds up conduction of axon potentials
myelin sheath
Gaps in myelin sheath
nodes of ranvier
In CNS there is little _ after injury
repair
In the CNS, once injured what proliferates and forms scar tissue
astrocytes
tough connective tissue covering that enclose the spinal cord and brain
meninges
Layers of the meninges
Outer= dura
Middle= arachnoid
Inner= pia
What meninge layers are in the subarachnoid space
Middle= arachnoid
Inner= pia
axons of sensory neurons and cell bodies of interneurons
dorsal gray horns
lateral gray horns are located where
in thoracic and upper segments of spinal cord
cell bodies of autonomic motor neurons
lateral gray horns
cell bodies of somatic motor neurons
ventral gray horns
_ pairs of cervical nerves, _ pairs of thoracic nerves, _pairs of lumbar and sacral nerves, and _ pair of coccygeal nerves
8, 12, 5, 5, 1
spinal nerves are connected to the spinal cord by
2 axon bundles (roots)
Dorsal root contains only
sensory axons
Conducts action potentials from sensory receptors in the effectors to the CNS
Dorsal root
Ventral root only contains
motor axons
Conducts potentials from CNS to effectors
ventral root
Central canal in gray matter is filled with
CSF
White matter has three columns…
- Dorsal white column
- Ventral white column
- Lateral white column
Each column in white matter contains
tracts (bundles of axons)
Sensory/ascending tracts in white matter conduct action potentials
toward brain
Motor/descending tracts in white matter carry action potentials
away from brain
Sensory input is conveyed from….
Sensory receptors to Dorsal horns of gray matter
Motor output is conveyed from…
Ventral and lateral gray horns to effectors
What matter receives and integrates incoming and outgoing info
gray
Two main functions in maintaining homeostasis (spinal cord)
action potential propagation and integration of info
Action potential propagation occurs in what matter
white
tracts that convey action potentials for touch, pressure, vibration, and proprioception
dorsal column
Spinal reflex occurs in the
gray matter
Integration of the brain stem is what reflex
Cranial reflex
What reflex is responsible for the contraction of skeletal muscles
somatic reflex
What reflex controls heart rate, digestion, urination, etc
Autonomic/visceral reflex
Region of gray matter in spinal cord or brain that processes sensory input
Integrating center
