Hi there, my name is Tammy and I just want to help you out with your cranial
nerves by using a memory aid. On the left hand side you'll notice I have a table
that lists the cranial nerves, their function, and how we assess them. On the
right side of the page I'm going to start to put together the face of the
cranial nerves. So cranial nerve number one is known as the olfactory. I've got
one nose and the first thing I notice about factories is the smell so we test
that using the sniff test. I'm going to bring down cranial nerve number two, is
our optic nerve and I've got two eyes so I'm going to put them in here; and how I
test those is by visual acuity. It's another sensory nerve. I'm going to
do the Snellen chart, check for near vision and check peripheral vision.
Cranial nerve number three: oculomotor is a mixed nerve. I'm going to draw in
the eyebrows using cranial nerve number three, and you'll notice that the middle
part points towards the pupils, and this is where our PEARLA comes from - pupils
equal and reactive to light and accommodation. Now three, four, and six
work together. Four is known as the trochlear I like to think of it as to
the other ear because it pulls our eyes in and down, and number six abducens - to
abduct, to move away from, moves our eyeballs outwards. Both of those are
mixed, but primarily motor nerves. Coming back to cranial nerve number five, this
is known as the trigeminal. It's the largest of the cranial nerves. Tri
meaning three. It has three branches. It's also a mixed nerve and we test the
sensory by using the cotton ball and we will wisp it across the forehead to test
the ophthalmic nerve, then we will wisp it on the cheek to test the maxillary
nerve, and then again on the chin to test the mandibular nerve. The motor test
comes from having our patients clench their teeth and we will test the
masseter and the temporal nerves um by having them clenching teeth and resist
opening. Cranial nerve number seven is going to finish off our face. It's known
as the facial nerve, again a mixed nerve and what we do is we ask our
patience to raise their eyebrows, show their teeth, puff out their cheeks, and do
some of these activities against pressure - looking for symmetry.
That brings us to cranial nerve number eight. Known as the acoustic or the
vestibulocochlear. Acoustic is sound, and cochlear is the ear. Again another
mixed nerve and we test this using the whisper test, the Rhine, and the Weber -
looking for proprioception as well. Now cranial nerve number nine- I'm going to
put in here as the uvula and it's tested with cranial nerve number ten usually at
the same time. Number nine is known as the glossopharyngeal - think pharynx - and
number 10 is the vagus nerve. You're going to take your tongue depressor ask,
your patient to say "ah" and you should notice the midline rise of the uvula and
the soft palate. The other test that goes with this is the gag reflex. Cranial
nerve number 11; I think I've got two arms and when they're standing beside me
they look like a number 11, so I'm going to draw in my shoulders here, and we test
those by looking for symmetry on the muscles. We have our hands on their
shoulders and ask them to raise them against resistance and we also test the
head rotation movement against resistance.
That's the vagus, or sorry excuse me that's the accessory muscle, accessory
nerve. Cranial nerve number 12, last but not least. Hypoglossal. Think under the
tongue and what's happening here is with speech if you notice that when you talk
the tip and the underside of your tongue touch your teeth and your soft palate,
we're going to assess this by asking our patients to say light, tight, and dynamite.
And you should notice a very sound, a clear and distinct sound on
the letters L, T, D, and N. And now you can carry on your learning with some future
textbooks.