Reflexes Flashcards
1
Q
Reflex
A
sudden, autonomic, involuntary response to a stimulus
-spinal reflex or cranial reflex depending on where integration takes place
2
Q
Classification types Processing site complexity of circuit response development
A
- spinal vs cranial
- monosynaptic vs polysynaptic
- somatic vs visceral
- innate vs acquired
3
Q
Reflex arc
A
- sensory receptor
- sensory neuron
- integrating center
- motor neuron
- effector
4
Q
Stretch reflex
A
- regulates muscle length
- stimulus = muscle stretch
- receptor = muscle spindle
- sensory neuron = synapses with motor neuron in anterior gray horn
- integration: monosynaptic (agonist) and polysynaptic (antagonist)
- motor neuron = alpha exits through ventral root
- effector = skeletal muscle–> contraction of agonist and relaxation of antagonist
5
Q
Muscle spindles
A
- interspersed among muscle fibers parallel
- measure stretching
- intrafusal muscle fibers = special inside fibers and gamma motor neurons
- extrafusal muscle fibers = surround muscle fibers suppplied by alpha motor nerons
6
Q
Tendon Reflex
A
- polysynaptic
- control muscle tension by causing musle relaxation when tension is great
- sensory receptors = golgi tendon organs
- tension –> tendon organ stiumulation –> nerve impulse –> spinal cord –> motor neuron causes muscle relaxation
7
Q
Tendon organs
A
- at junction of tendon and muscle
- protect tendons and muscles from excess tension
- thin capsule of connective tissue that encloses a few tendon fascicles
8
Q
Flexor reflex
A
- withdrawal reflex
- polysynaptic
- ipsilateral
- step on tack –> nerve impulse–> activate interneuron –> activate motor neuron –> muscle contraction –> withdrawal of leg
9
Q
Crossed Extensor Reflex
A
- polysynaptic
- contralateral
- contraction of muscles that extend joints in opposite limb in response to painful stimulus
- Step on tack–> nerve impulse –> activation of several interneurons –> activate motor neurons –> muscle contraction causing flexion of the leg steppin on tack and extension of opposite leg
