Reflex Movements Flashcards
Are reflexes voluntary or involuntary?
Involuntary
Where can you find motor neuron cell bodies?
Spinal chord
Brain stem
Where do motor efferent leave spinal chord?
Ventral horn
What are muscle spindles composed of?
Intrafusal fibres wrapped in sensory endings which are mechanoreceptors
What axons do the sensory afferents and motor efferents both have in the stretch reflex pathway?
AALPHA
Why is the latency for the jaw jerk reflex less than the ankle jerk reflex?
Shorter distance to brainstem
Why is the amplitude for the jaw jerk reflex less than ankle jerk reflex?
Masseter is a smaller muscle
What is different about the flexion withdrawal reflex?
Disynaptic pathway, the interneuron splits into 2
How does the flexion withdrawal give a slower latency?
Because there are 2 synapses involved
What are the sensory endings on muscle tendons which prevent the muscle from being overloaded?
Golgi tendon organs giving rise to group 1B afferents
How are golgi tendon organs activated?
Stretch and contraction of muscle
How is bite force controlled?
Increasing load on to periodontal ligament
What does anaesthesia do to bite force?
Increase bite force
What activates the pharyngeal reflex?
Mechanoreceptor afferents from posterior part of tongue
What initiates salivary reflexes?
Taste stimuli
Visual
Olfactory
Chewing forces
