Neuro 1 Flashcards
how many cranial nerves and how many spinal nerves do we have?
12 cranial
31 spinal
what is a bundle of hundreds to thousands of axons plus associated connective tissue and blood vessels that live outside the Brian and spinal cord?
nerves
what are the three basic functions of the nervous system?
sensory
integrative
motor
what are the two subdivisions of peripheral nerves?
sensory
motor
is sensory considered afferent or efferent?
afferent (sends signals towards the central nervous system)
what are some examples of somatic senses?
tactile
thermal
pain
proprioceptive
what are some examples of special sense?
smell
taste
vision
hearing
equilibrium
how would you describe somatic motor senses?
voluntary control
how would you describe autonomic motor senses?
involuntary control
what are the three branches of autonomic senses?
sympathetic (fight or flight)
parasympathetic (rest and digest)
enteric (regulation of smooth muscles)
what is electrical excitability?
ability to respond to stimulus and convert into action potential
what is action potential?
electric signal that propagates along the surface of the membrane
what are the three structures to a neuron?
cell body (nucleus)
dendrites (receiving input)
axon (propagates nerve signals)
what is the trigger zone?
junction of axons hillock and initial segments where most nerve impulses arise
what is a ganglion?
cell bodies found outside the CNS
what is the term for cytoplasm of an axon?
axoplasm
what is the term for a plasma membrane of the axon?
axolemma
what are axon terminals ?
fine processes at the end of the axon and collaterals
how long would slow axonal transport take?
do they go in one or two directions?
1-5 mm / day
one direction
how long would fast axonal transport take?
do they go in one or two directions?
200-400 mm / day
two directions
there are three types of structural classifications of neurones
multipolar
bipolar
unipolar
which one have several dendrites and one axon?
multipolar
there are three types of structural classifications of neurones
multipolar
bipolar
unipolar
which one has one dendrite and one axon?
bipolar
there are three types of structural classifications of neurones
multipolar
bipolar
unipolar
which one has dendrite and one axon that are fused together and emerges from the cell body?
unipolar
there are three types of structural classifications of neurones
multipolar
bipolar
unipolar
which one is found in the retina, inner ear and olfactory areas of the Brian?
bipolar
there are three types of structural classifications of neurones
multipolar
bipolar
unipolar
which are considered sensory?
unipolar
do neuroglia generate action potentials?
what do they do?
no
perform supportive functions
what are the four type of neuroglia in the CNS?
astrocytes
oligodendrocytes
microglia
ependymal
what is the functions of astrocytes? (5 total)
provide strength
help build blood brain barriers
secrete chemicals for growth
help maintain chemical environments
play role in learning and memory
what is the function of oligodendrocytes?
responsible for forming and maintaining myelin sheath around axons
what is the function of microglia?
remove cellular debris formed during normal development and remove damaged nervous tissue
what is the function of ependymal cells?
produce, monitor and assist in the circulation of cerebrospinal fluid
what are the two types of neuroglia in the PNS?
Schwann
satellite
what is the function of Schwann cells?
help participate axons in regeneration
what is the function of satellite cells?
regulate exchange of material between cell bodies and fluids
what is the myelin sheath?
multilayered lipid and protein covering
what is the function of the myelin sheath?
increases speed of nerve impulse conduct
do Schwann cells undergo neurolemma? (repairing itself after damage)
yes
do oligodendrocyte cells undergo neurolemma? (repairing itself after damage)
no
does white matter or grey matter surrounds the inner core of the other?
white matter surrounds grey matter
what are the two types of electrical signals?
graded potenial
action potenial
which potential is used for communication over a larger distance?
action potenial
what two features of the membrane permits the two potentials graded and action?
existence of membrane potentials
presences of ion channels
which of the following ion channels is described:
randomly opening and closing of gated channels found in all cells
leak channels
which of the following ion channels is described:
open in response to binding of ligand or chemical stimulus. Found on pain receptors
ligand-gated channels
which of the following ion channels is described:
open In response to mechanical stimulus such as touch or pressure.
mechanically gated channels
which of the following ion channels is described:
open in response to voltage stimulus and found on all types of neurons
voltage gated channels
what is the resting membrane potential?
-70 mV
what three things can influence resting membrane potential?
-unequal distribution of ions in extracellular fluids
-inability of most negative ions to leave the cell
-electrogenic nature of NA K pump
is resting membrane more negative inside or outside?
inside
what are the two types of channels present in graded potential?
mechanically gated
ligand gated
which potential (graded or action) will die out after traveling?
graded
what are the two phases of action potential?
depolarizing
repolarizing
what is the all or none principle?
action potential happens completely or not at all
what is the point of threshold?
-55 mV
what can create a local anestheic for a client with present pain? (pg 4 LP 2-3)
ice
what three things effect propagation?
amout of myelination
axon diameter
temperature
what is depolarization?
becoming less negative
what is repolarizaton?
returning to resting membrane potential
what is the refectory period?
a period after an action potential where you cannot regenerate another action poteintal
what is relative refractory period?
period of time where a second action potential can occur but must be very strong to do so
what are the three type of fibres found on nerves ?
a fibers
b fibers
C fibers
which fibre (A, B, C) are:
largest
myelinated
have a refractory period
A
which fibre (A, B, C) are:
2-3 mm in length
myelinated
b
which fibre (A, B, C) are:
smallest
unmyelinated
longest refectory period
c
what type of channels are present in action potential?
voltage gated
match the following terms:
axodendritic
axosomatic
axoaxonic
axon to cell body
axon to axon
axon to dendrtie
axondendritic = axon to dendrite
axosomatic = axon to cell body
axoaxonic = axon to axon
what is a gap junction?
used for action potential to travel quickly between plasma membranes
how is electrical synapses at more of an advantage then chemical synapses?
faster communication
synchronization (can produce AP in unison if they are connected by gap junction)
what areas of the body would electrical synapses be used in?
cardiac muscles, smooth muscles, developing embryo
do the presynaptic and postsynaptic touch during chemical synapses?
no, they are separated by synaptic clefts
what is presynaptic cells?
nerve cells that carry a nerve impulse towards a synapse
what is a postsynaptic cell?
receive signals
how does communication happen with chemical synapses?
they do not directly communication the same as electrical. they are separated by synaptic clefts which means the presynaptic cells must send out neurotransmitters across the cleft to the postsynaptic cells
is graded or action potential involved with chemical synapses?
graded
what is excitatory postsynaptic potential?
cause depolarization and brings the membrane closer to threshold
what is inhibitory postsynaptic potential?
causes hyperpolarization and becomes more negative and away from threshold
what is spatial summation?
stimuli that occur in different locations of the membrane at the same time
what is temporal summation?
stimuli the occurs in the same location of the membrane at different times
what are the six type of neurotransmitters?
acetycholine
amino acids
biogenic amines
ATP and other purines
nitric oxide
carbon monoxide
what are the two natural body pain killers?
endorphins and dynorphins
what is substance P?
neuropeptides which causes pain signals