Topic 5 - NERVOUS SYSTEM III - Integration & Control (spinal cord) Flashcards
overview
- sensory (afferent) division “_____” info into _____ and _______ (control centers)
sensory (Afferent) division “inputs” info into brain and spinal cord (control centers)
overview
brain and spinal ______ info and _____ effectors through ____________ (“output”)
brain and spinal integrate info and control effectors through motor (efferent) division (“output”)
spinal cord: reflexes
- ______, _______ response to stimuli
- stimulus always causes what?
- usually ________
- involve how many neurons?
- rapid, automatic response to stimuli
- stimulus always causes the same motor response
- usually protective
- involve 2 or more neurons
reflexes
no hints (4)
- rapid, automatic response to stimuli
- stimulus always causes the same motor response
- usually protective
- involve 2 or more neurons
reflex pathway or arc = pathway of impulses
draw diagram
spinal cord: reflexes
reflexes are categorized according to (3 things)
- effector
- which sides of the body the sensory + motor neurons are located
- number of synapses and neurons in arc
reflexes are categorized according to effector:
- i. somatic reflex = effector is skeletal muscle
- ii. visceral (autonomic) reflex = effector is smooth muscle, cardiac muscle or glands
reflexes are categorized according to which sides of the body the sensory and motor neurons are located:
- i. ipsilateral reflex = sensory + motor neurons are on same side
- ii. contralateral = sensory + motor neurons are on opposite sides
reflexes are categorized according to number of synapses and neurons in arc:
- i. monosynaptic reflex = one synapse between 1 sensory + 1 motor neuron
- ii. polysynaptic reflex = 2 or more synapses → 3 or more neurons
name 2 general reflex examples
- somatic spinal reflexes
- autonomic spinal reflexes
what are 3 examples of somatic spinal reflexes
- stretch reflex
- flexor (withdrawal) reflex
- crossed extensor reflex
stretch reflex
- what kind of reflex is this?
- name an example
- what muscle contracts?
- stimulus =
- receptor =
- effector =
- ipsilateral or contralateral?
- monosynaptic or polysynaptic?
- somatic spinal reflex
- knee jerk reflex
- extensor muscle contracts
- stimulus = tapping pattelar ligament, which stretches the quadriceps femoris muscle
- receptor = muscle spindle (in quadriceps)
- effector: skeletal muscle (quadriceps) - it contracts
- ipsilateral
- monosynaptic
flexor (withdrawal) reflex
- what kind of reflex is this?
- name an example
- what muscles contract?
- stimulus =
- receptor =
- effector =
- ipsilateral or contralateral?
- monosynaptic or polysynaptic?
- somatic spinal reflex
- in leg
- hamstrings (flexors) contract
- stimulus = stepping on nail
- receptor = touch, pressure, pain
- effector = hamstrings (flexors)
- ipsilateral
- polysynaptic
crossed extensor reflex
- what kind of reflex is this?
- name an example
- what muscle contracts?
- stimulus =
- receptor =
- effector =
- ipsilateral or contralateral?
- monosynaptic or polysynaptic?
how does this accompany the flexor (withdrawal) reflex?
- somatic spinal reflex
- in leg
- quadriceps femoris (extensor)
- stimulus = stepping on nail
- receptor = touch, pressure, pain
- effector = quadriceps femoris in the opposite leg (extensor)
- contralateral
- polysynaptic
keeps you from falling down when flexor reflex occurs
reciprocal inhibition
- what muscle contracts?
- agonist or antagonist?
- at same time, what is prevented from contracting? (what kind of neurons are firing?)
- skeletal muscle (or group) contracts
- agonist
- at same time, antagonist prevented from contracting (inhibitory neurons firing)
