Lab 3 - Reflexes, Reactions, and Motor Control Flashcards
What is the corneal reflex?
When you move your hand toward someone’s eyes and they instinctively close them. Source: Any primary school ever
The Achilles reflex (ankle jerk) involves what spinal levels?
L5, S1
What is the Jendrassik manoeuvre?
When a deep reflex is tested and there is no/little response from the pt, you can ask them to turn their head, or clench their teeth, etc. In doing so, because the anterior horns (grey matter) are not really separated well from one another, you can lower the stimulus required to achieve threshold.
It has to be done at the same time (otherwise the potency degrades), so as soon as you ask them to clench their teeth you tap the tendon, and record the response.
What is the plantar reflex?
How does this relate to the Babinski reflex?
A blunt probe is scraped sharply (with force) across the lateral plantar surface of the foot towards the big toe. A normal adult response is flexion of all of the toes.
If the toes fan out and the big toe extends, this is a Babinski positive test
What is a Babinski positive test associated with and why is it normal in children under 1?
It is often associated with pyramidal tract fibre damage.
In children under 1, as they are still undergoing myelination and the corticospinal tract is not fully developed, therefore a Babinski positive response is normal
What is the ciliospinal reflex?
How does one do one?
Pinch the side of the nape of the neck and note the dilation of the eye on the ipsilateral side.
This is a reflex response where pain sensation enters the spinal cord at C8-T2 with motor output via the sympathetic nervous system to the ciliary ganglion.
Why is the term reaction used instead of reflex under certain circumstances?
A reflex is a rapid, unlearnt, basic response that occurs at the spinal cord or brainstem level - with as few neurons involved as possible.
A reaction refers to a much more complex set of neural pathways and processing involved. For instance, testing information that is processed then turning it into a response; such as visual stimulus into clicking a flashing icon (visual to motor)
