Neuromuscular: Reflexes Flashcards
Reflexes
Involuntary responses to stimuli
Reflexes: Upper Motor Neuron Lesions
- Hyper-reflexic
- Pathologic Reflexes
Reflexes: Lower Motor Neuron Lesions
- Hyporeflexia
- Low Tone
Reflexes: Stretch Reflex: Stimulus
- Muscle stretch
Reflexes: Stretch Reflex: Reflex Arc
- Afferent Ia fiber from muscle spindle to alpha motor neurons, that project back to the muscle of origin.
- Monosynaptic
Reflexes: Stretch Reflex: Function
- Maintenance of muscle tone
- Support agonist muscle contraction
- Feedback about muscle length
Reflexes: Stretch Reflex: Clinical Testing
- Apply a tap to the deep tendons eliciting a muscle stretch reflex called a deep tendon reflex.
Reflexes: Stretch Reflex: Reason for clinical testing
- Sensitivity of the DTR
- Intactness of the spinal cord
Reflexes: Stretch Reflex: Reciprocal Inhibition
- Via inhibitory interneuron
- The stretch reflex inhibits the antagonist muscle
Reflexes: Stretch Reflex: Reciprocal Innervation
- Describes the effects of a stretch stimulus on an:
- Agonist: Autongenic facilitation
- Antagonist: Reciprocal Inhibition
- Synergistic Muscles: Facilitation
Reflexes: Inverse Stretch Reflex: Stimulus
- Muscle contraction
Reflexes: Inverse Stretch Reflex: Reflex Arc
- Multiple sensory receptors activate inhibitory neuron rtf muscle of origin.
Reflexes: Inverse Stretch Reflex: Function
- Provides agonist inhibition.
- Diminution of force of agonist contraction.
- Stretch protection reflex.
Reflexes: Gamma Reflex Loop
- Stretch reflex forms part of this loop.
- Allows for muscle tension to come under controls of descending pathways.
Reflexes: Gamma Reflex Loop: Function
- Descending pathways excite gamma motor neurons. causing contraction of muscle spindle.
- Contraction of the muscle spindle causes increased stretch sensitivity and increased rate of firing from spindle afferents.
- Impulses then conveyed to alpha motor neurons.
