Health Assessment, part 26: Cranial Nerve VI - Abducens & Cranial Nerve VII - Facial

Hi. I'm Meris, and in this video, I'm going to be reviewing the type, functions, and assessment of cranial nerves 6 and 7, abducens and facial. I'm going to be following along using our health assessment flashcards. These are available on our website, leveluprn.com, if you want to get a set for yourself. Or if you prefer a digital version of a flashcards, you can check out our Flashables, which is the digital version of our health assessment and all of our other flashcards. All right. Let's go ahead and get started.

So first up, talking about cranial nerve number 6. This is a motor nerve that is also responsible for eye movement, but specifically outward eye movement. The name of this nerve is abducens because it abducts, it moves away the eyes. So it's a very easy thing to remember if you can remember that abducens means it abducts the eye. We have outward or lateral eye movement controlled by this cranial nerve. If you watch my other videos on cranial nerves, you may remember that cranial nerves 3, 4, and 6 make your eyes do tricks. So 3, 4, and 6 are assessed simultaneously. So if you are interested in more information about the assessment of cranial nerve 6, go watch my video on assessing cranial nerve 3, oculomotor, and you will see the assessment for cranial nerve 6.

All right. Now we're going to talk about cranial nerve number 7, which is the facial nerve. So this one is a mixed nerve, meaning that it has both sensory and motor functions. The sensory function of this nerve is that it controls taste on the anterior two-thirds of the tongue. So this means that the frontmost portion of the tongue, the part that sticks out when the patient sticks out their tongue, two-thirds of that tongue from that point backwards, that taste is controlled by the facial nerve, not the last one-third, just the first two-thirds. And then the motor function here is going to be facial movement, salivary, and lacrimal gland function. So facial movement, and then also it controls the function of the salivary glands that produce saliva and the lacrimal glands that produce tears.

So how do we assess cranial nerve 7? That's a great question. Well, so when we are assessing for the motor function, this is where you will hear this said over and over in the medical setting where we have the patient smile, frown, puff out their cheeks, and raise their eyebrows. I can't raise my eyebrows very well because I get Botox for migraines. But this is an important note that I'm making here is that you could have a patient where you ask them to raise their eyebrows, and they attempt to-- and I mean, I can somewhat, but that's because it's starting to wear off.

But if you have a patient with recent Botox, they may not be able to raise their eyebrows. So if you see that your patient is unable to do that, that doesn't necessarily mean that they have some sort of dysfunction with cranial nerve 7. That means that you need to ask a clarifying question of, "Is there any reason that you can't raise your eyebrows? Do you have Botox or any other sort of--" like Dysport, all of these different cosmetic injectables that can cause paralysis of certain muscles, which that is the function.

I get Botox for migraines, but if I were getting it for cosmetic reasons, the reason is that I can't get wrinkles in this area if I cannot raise my eyebrows and wrinkle that portion of my forehead. So when you ask your patient to smile, frown, puff out their cheeks, and raise their eyebrows, if you find that they have any dysfunction with that, you may want to assess for any sort of paralyzing or neurotoxic agents that they have intentionally used to cause that paralysis rather than jumping to the conclusion that they have a defect or some sort of a pathological condition affecting cranial nerve number 7.

All right. So that is it for cranial nerve 6 and 7. I'm so glad you stayed until the end because I've got some quiz questions for you to test your knowledge of key facts I provided in this video. What is the sensory function of cranial nerve 7? Taste on the anterior two-thirds of the tongue. How should the nurse assess the motor function of cranial nerve 7? Have the patient smile, frown, puff out their cheeks, and raise their eyebrows. Assessment of the function of cranial nerve 6 is done while assessing which other cranial nerves? Cranial nerves 3 and 4, oculomotor and trigeminal.

All right. That is it for this video. I do hope you learned something or that you found this review useful. And if you did, I would love it if you would leave me a comment so that I can see. And if you have a great way to remember something, definitely leave me a comment with that as well. And I know other students like to see that as well. All right. Thanks so much, and happy studying.