Neurosciences 2 Flashcards
What is the name of the musle that raises the eyelid?
Levator palpebrae superioris
Which muscles have direct pulls from anatomical position?
Lateral rectus and medial rectus
What does superior rectus do?
Pulls the eye up medially and rotates it inwards in torsion
What does inferior rectus do?
It pulls the eye down and medially and rotates it outwards extortion
When is the action of superior oblique used the most?
when you look down the stairs. maximal extorsion of both eyes from the inferior rectus
Which muscle is important when looking up?
The inferior oblique as superior rectus causes extorsion.
What conditions are needed for testing eyes?
Directly in front, eyes at same level, 2 arms lengths apart
which muscles are tested first?
Lateral and medial rectus. as their action is isolated.
What muscle is tested after lateral/medial rectus?
Superior and inferior rectus
How is the movement of superior and inferior rectus isolated?
Get patient to look laterally slightly so that the pull of superior and inferior rectus is pulling in line with the axis of the eye.
What is the last set of muscles to be tested?
the obliques
How do you test obliques?
For superior look down and medial for inferior look up and medial look that there is no rotation of the eye.
What is the snail shaped structure called?
Cochlea for hearing
What are the 3 looped structures in the hear called
the semi-circular canals
What bone are the organs of balance and hearing in?
petrous part of the temporal bone
Where does the vestibulocochlea nerve leave the skull? and what does it leave with
with the facial nerve it passes through the internal acoustic meatus
What is the arrangement of the semicircular canals?
Three at 90 degrees to each other lateral anterior and posterior
How do the semicircular canals sense movement?
They are filled with fluid and at one pount ther is the ampula which sticks out from the wall beneath it is the cupula. This cupula has hair cells and nerve fibres which detect movement and transduce to nerve signals
What is the fluid in the semicircular canals called?
endolymph.
When are the semicurcular canals not working?
When you are not accelerating
What is nystagmus?
They have darting eyes
What can cause dizzyness
They can be from spinning or inflamation of the hair cells from the virus
What is the vestibulo-ocular reflex?
they eyes moving the opposite way to spinning
How can the vestibulo-ocular reflex be tested?
put cold water in the ear to cause convection currents and cause nystagmus slowly towards cold water