what are inborn (intrinsic) refelexes?
learned (aquired) reflex?
refelx that is unearned, unpremediated, involuntary
results from practce or repetition
site of stimulus
transmits affrent elec. impuses to CNS
where the synapse takes place
conducts effrent impulses from the integ. center to the effector organ
muscle or gland that responds to the impuses making it contract or secrete.
what is monosynaptic refelx?
a simpe synapse between a sensory neuron and a motor neuron
what is a polysynaptic refelex?
multiple synapses with chains of interneurons
what do somatic reflexes do?
activate skeetal muscles
what to autonomic (visceral) reflexes do?
activate visceral effectors (smooth muscles,glands)
why is testing of the somatic reflexes important?
to test teh condition of the nervous system
what does teh gogli tendon organ do?
senses teh amount of tension in a muscle and it surrounding tndons
what does the muscle spindle do/
it senses the length of a muscle
what are the 2 ways a muscle spindle is stretched ans excited?
an externa force lengthens the entire muscle
internal motor neurons stim. internal fibers to contract thus stretching the middle of teh spindle (internal stretch)
what is the purpose of the stretch reflex?
to make sure a muscle stays the certain length set by the brain
in an untretched muscle the AP is?
in anstretched musce the AP is?
all stetch reflexes are _____________ and ___________. they invlove a single synapse and motor activity on the same side of body.
a positive kne e jerk provides what 2 important pieces of info?
that senory and motor connect. between muscle and spinal cord are intact
the vigor of the response idicates the degree of excitibilaty of teh spinal cord
is the gogli tendon reflex monosyapntic?
what does it do?
no it is ploysynaptic
it makes the muscle reax and lengthenin response to tension
what is reciprocal activation?
mmotor neurons suppplying the contracting muscle are inhibited and antagonist muscles are activated.
contracted muscle become relaxed and antagonst muscles contract to prevent the tears
what is a flexor refex?
started by a painful stim. causes automatic withdrawl of the threatened body part from the stim.
flexor reflexes are _________ and______ .
what is a crosed extensor reflex?
important in maintaining balance offten accompanies the flexor reflex (pushing away an attacker)
whst are superfiscial reflexes?
activated by gentle stim. of teh skin
what is plantar refelx?
tests the spina cord from L7 to S2 drawing a blunt object down the sole of foot
what is babiski's refelx
abnormal refelx where big to dorsiflexes small toes fan lat.
autonomic nervous system:
what type od neuron?
what does it innervate?
what does it regualte?
involuntay nervos system
- motor neurons
- visceral motor division
- smooth muscle and glands
- HR,BP,digest. urination
somatic motor division;
_____motor neuronextends from the CNS to the ________ muscle. axons are _______ myeinated and conduct impulses______.
visceral motor division:
chain of ___ motor neurons.
postganglionic (postsynaptic) motor neurons?
is conduction slower or faster?
before the synapse or before the gnaglion
after teh synapse or after the ganglion
slower dues to thinly or unmylenated axons
fight or flight
excercise, excitement, emergencies
blood supply to skeletal musces HR respirs.
its job is to ?
- rest and digest
- conserve energy
- sleep and rest
- HRrespirs., bllod supply
- increases blod supply to organs
length of preganglionic fibers:
length of post ganglionic fibers:
sympathetic fibers connec to __________ before the organs?
sympathetic chain ganglia
parasympathetic and sympathetic preganglionic motor neurons release ______.
sympathetic postganglionic neurons release____________.
parasympathetic postganglioic neurons release___________
what do neuro toxins do?
they inhibit the cells excytotic apparatus preventign the release of the neurootransmitter
what is a agonist
what is a anotagonist?
molecule that binds to a receptor and mimics a response
a substance that opposes the action of another.
what are nictoine receptors?
what is their effect?
found on plates of skeletal muscles all preganglioinc neurons
what are muscarinic receptors?
what is there binding?
named for a muschroom poison
binding can be both inhibitory or stimulatory
what are adrenegeric receptors?
- bind to noreprine or epinephrines
- aplha beta
both inhib. excit.
location an effect of binding?
B) B1: mostly heart but also kindney and adipose tissue. effect:increase HR and strength stim. renin release.
B2:lungs and symp.organs. effects:most inhibitoryndil. blood vessels relax smooth muscle
B3:adipose tissueeffects: stim. lypolysis by fat cells
effects of binding?
A1: most important blood vessels, all sym. target organs except heart. effects:constricts blood vessels and visceral organ sphincters. dialtes pupil
A2: membrane of adgrenic axon terminals. pancreas blood platelets. effects: inhibits NE release inhibits insulin secretion. promotes blood clotting
all ganglionic neurons in CNS
stim of sympathetic effects: irreg HR, elevted BP
used in smoking cessation products
pilocarpine and berthanechol:
muscarinic ACh receptors
mimics ACh enhances PNS effects
berthanechol use: diff. urinating.
neostigmine and sarin:
prolongd teh effect of ACH
sarin:used as chemical warefare
albuterol and phenylephrine:
- adgrenic receptor
- enhances symp. activityby increasing NE
- decreses sym. actvity by blockin NE
parasymp and symp. effects:
- bulg of lense close vision,
- flatten lense for far vision
arrector pili muscle
no effect, stim sweating
- no effect
- contracts hair goose bumps
- promotes voiding
- inhibits voiding
digestive tract organs
- constrits bronchioles
- dialates broncioles
- increases peristalisis
- decreases activity constricts sphincters
- no effect
- vasocontriction decreases urine output
- no effect
- constricts vessels increase BP
- causes erection vasodialate
- causes ejactulation
- vasodialation of clit
- contract. of vagina increases secretion
what channels in presynaptic neuron open in response to an action pot?
voltage gated Ca++ channels
presence of what ion inside the cell causes teh synaptic vesciles to fuse with the membrane?
what is the name foe the chemicals stored in the synaptic vesicles?
what do chemicals diffuse across?
where do these chemcials bind to receptors?
postsynaptic neuron(postganglionic neuron)
whatbtype of gated channels do these open?
2 ways these chemicals can be removed from teh synaptic cleft?
pumped back into the presynaptic terminal
broken down by enzymes then taken back by teh presynaptic cell
response on teh post synaptic cell depends on what 2 factors?
which neurotransmitter is involved
te specific receptor found on the postsynaptic cell
autonomic nerves innervate whatv3 things?
smooth muscle cardiac mucle and glands
the most common neurotransmitter in teh CNS is?
what drug alter synaptic transmition by blocking the action at teh postsynaptic membrane?
curare alpha bungarotoxin in snake venom