Unit 5 - Neuro Cranial Nerves, Eyes, Ears Flashcards
Are cranial nerves upper or lower motor neurons and why?
Although they enter and exit the brain, they are lower motor neurons because they have direct innervation to end point (muscle, organ)
Please indicate the name and function of the cranial nerve.
Cranial Nerve I
Olfactory Nerve - Controls sense of smell
Purely sensory nerve
Please indicate the name and function of the cranial nerve.
Cranial Nerve II
Optic Nerve - Controls central and peripheral vision
Sensory nerve
Please indicate the name and function of the cranial nerve.
Cranial Nerve III
Oculomotor - Motor, most EOM movement, opening of eyelids.
Mixed nerves
Please indicate the name and function of the cranial nerve.
Cranial Nerve IV
Trochlear - Down and inward movement of the eye
Motor nerves
Please indicate the name and function of the cranial nerve.
Cranial Nerve V
Trigeminal - Muscles of mastication (motor)
Sensation of face and scalp, cornea, mucous membranes of mouth and nose (sensory)
Mixed nerves
Please indicate the name and function of the cranial nerve.
Cranial Nerve VI
Abducens - Lateral movement of eye
Motor nerves
Please indicate the name and function of the cranial nerve.
Cranial Nerve VII
Facial - facial muscles, close eye, labile speech, close mouth (motor)
Taste on anterior two thirds of the tongue (sensory)
Saliva and tear secretion (parasympathetic)
Mixed nerves
Please indicate the name and function of the cranial nerve.
Cranial Nerve VIII
Auditory/Vestibulocochlear - Hearing and equilibrium
Sensory nerve
Please indicate the name and function of the cranial nerve.
Cranial Nerve IX
Glossopharyngeal - phonation and swallowing (motor)
taste on posterior one third of tongue, gag reflex (sensory)
Parotid gland, carotid reflex (parasympathetic)
Mixed nerves
Please indicate the name and function of the cranial nerve.
Cranial Nerve X
Vagus - talking and swallowing (motor)
General sensation from carotid body, carotid sinus, pharynx, viscera (sensory)
Carotid reflex (parasympathetic)
Mixed nerves
Please indicate the name and function of the cranial nerve.
Cranial Nerve XI
Spinal Accessory - movement of trapezius and sternomastoid muscles
Motor Nerve
Please indicate the name and function of the cranial nerve.
Cranial Nerve XII
Hypoglossal - movement of tongue
Motor nerve
How would you assess a patients Cranial Nerve I (Olfactory)?
Assess patency of nostrils first
Use familiar scents, ask pt to close their eyes and occlude one nostril, complete bilaterally
Ask them to identify what they are smelling
Do not use a substance with a harsh odour or a scent that may not be distinguishable in all cultures
Why do we ask the patient to close their eyes when we are testing the olfactory nerve?
Because senses work together, if they see what they are smelling, their eyes will distinguish what the substance may be without actually smelling it.
How do we assess the Cranial nerve II (Optic) in patients?
Visual acuity (20 ft)
Colour blindness tests
Confrontation test
If pt A has a visual acuity of 20/20, pt B tests acuity of 20/40, and pt C tests acuity is 20/15. How would they rank from highest visual acuity to least?
Pt C - Highest at 20/15
Pt A - normal 20/20
Pt B - Lowest at 20/40
If someone uses glasses for everyday tasks, will you test visual acuity with or without glasses?
With, we are mostly wanting to see what their daily visual abilities are. If asked to do without we will complete both.
Optometrist will test without to ensure their corrected vision is appropriate and accurate.
In the confrontation test, what are the 4 areas we will be testing for the expected peripheral vision (including the degrees)?
Superior @ 50 degrees
Nasal @ 60 degrees
Inferior @ 70 degrees
Temporal @ 90 degrees
What cranial nerves do we test that are responsible for eye movement? (6 Cardinal positions of gaze)
Cranial nerves III (Oculomotor), IV (Trochlear), VI (Abducens)
How tests do we complete when testing the Cranial nerves III (Oculomotor), IV (Trochlear), VI (Abducens)?
Checking pupils for size, regularity, equality, direct and consensual light reactions and accommodation. (PERRLA)
Inspect eyelids for ptosis (drooping)
6 Cardinal positions of gaze - follow your finger/pen light without turning their head.
When may you experience nystagmus and it be a normal response?
During extreme lateral rectus movement, normally people would turn their head so it is a normal response during this exam.
What is nystagmus?
Rapid involuntary movements of the eyes. (shaking/twitching eyes)
What does PERRLA stand for?
Pupils, Equal, Round, Reactive to Light and Accomodate
What three areas are we assessing for the Trigeminal (CNV)?
Forehead (Ophthalmic)
Cheek (Maxillary)
Jaw (Mandibular)
How do we assess the Motor portion of Cranial nerve V (Trigeminal)?
Palpate temporal and masseter muscles as teeth are clenched, try to separate jaw with clenched teeth.
How do we assess the sensory portion of Cranial nerve V (Trigeminal)?
With eyes closed, take a cotton ball and brush across each area (Forehead, cheek, jaw). Ask them to say “now” when they feel it.
If you have abnormal results when testing the Tigeminal nerve, what is the next test that you may perform?
Corneal Reflex
What face movements do we ask patients to make to test the motor function of Facial Nerve VII?
Smile, frown, close eyes tightly (attempt to open), Lift eyebrows, show teeth, puff cheeks (Press in and not if air
Although not routinely tested, how do we test the sensory portion of the Facial nerve (CNVII)?
Use salt, sugar or lemon on anterior 2/3 of tongue.
When using the whisper test, how is it performed and which nerve is it testing?
Mask ‘good’ hear by rapidly pushing in the tragus, or just push and hold the tragus down. Cover your mouth to avoid lip reading, 30-60 cm away from patient and state a 2 syllable word (milkshake), pt should be able to repeat it immediately after.
We are testing CN VIII Vestibulocochlear/Acoustic
What two cranial nerves are normally tested together ? What are we looking for with these nerves (both motor and sensory) ?
Glossopharyngeal (CNIX) and Vagus (CNX)
Motor - Midline rise of the uvula and soft palate, tonsillar pillars more medially in response to “ahhh” or a yawn. Normally touch the posterior pharyngeal wall with tounge blade and watch response (gag)
Sensory - CN IX mediates taste on the posterior one third of the tongue but it is hard to get tastes.
Which Cranial Nerve is the longest is the human body?
The vagus nerve (CNX). It is the longest of the cranial nerves, extending from the brainstem to the abdomen by way of multiple organs including the heart, esophagus, and lungs.
How do we test the motor nerve abilities in the Spinal Accessory nerve (CNXI)?
Examine the sternomastoid and trapezius, Ask the patient to rotate head each way against resistance, and ask patient to shrug shoulders against resistance. Should be equal on both sides.
How do we test the hypoglossal (CNXII) nerve?
Ask patient to stick tongue out (inspect for wasting, tremors, and that it is midline)
Ask patient to say “light, tight, dynamite” (This is assessing the sounds of l, t, d and n)
We assess a patient for pain by using varied dull and sharp stimuli over various bothy parts, what sensory system is this assessment a part of?
Spinothalamic Tract
If a patient is unable to distinguish between the sharp and dull stimuli, what is the next assessment that we can do to assess the sensory system of the spinothalamic tract?
Temperature - Use two test tubes, one with hot and one with cold water and place on various parts of the body to see if they can distinguish between the two.
How do we assess the light touch portion of the the spinothalamic tract?
cotton wisps over various parts of the body.
What 3 areas are we assessing within the Posterior column tract?
Vibration, Kinaesthesia, Fine touch
What is the term that is used for the ability to identify an object that is placed in your hand?
Stereognosis
How does the graphaesthesia assessment work?
You draw with your finger in the palm of your patient, one hand can be a letter and the other hand can be a number. The patient should be able to identify what you are writing while their eyes are closed.
What is the term thats describes how much the eye is open?
Palpebral fissure
What makes up the outer layer of the eye? Briefly define each term.
Sclera - tough protective white covering, it is continuous anteriorly with the smooth, transparent cornea which covers the iris and pupil.
Cornera - part of the refracting media of the eye, bends incoming light rays so they are focused on the retina within
What components make up the middle layer of the eye? Could you explain what each part does or a defining characteristic?
Choroid - prevents light reflecting internally, highly vascular to deliver blood to retina
Iris - functions as a diaphragm, varying the opening at its centre (the pupil), it controls what is let in for light or not
Pupil - round and regular (its size depends on the para or sympathetic nervous system)
lens- transparent biconvex disc that serves as a refracting medium, keeping objects in view (contain ciliary body)
anterior/posterior chambers (Which contains the aqueous humour that supplies nutrients to the surrounding tissues. )
What is contained within the inner layer of the eye? What are the functions of each?
Retina - is the visual receptive layer of the eye in which light waves are changed into nerve impulses.
Optic disc - is the area in which fibres from the retina converge to form the optic nerve (located nasally)
Retinal vessels - the only place in the body where we can visually see blood vessels.
Macule - is located on the temporal side of the fundus, slightly darker pigmentation surrounding the area of fovea centralis.
Fovea centralis - the area of sharpest and keenest vision
Visual pathways/ fields
Please see page 300 & 334 in jarvis
*retina flips the image
What does ciliary body control within the eye?
Thickness of the lens, it will bulge or flatten depending on the distance of an object.
If someone expresses during their subjective data that they have a black dot that started to float around but disappeared, should we be concerned? What do we think they were experiencing?
More then likely it would be a floater, these can be normal but should be noted. Frequent or prolonged floaters can be sign of damage of the retina.
In older adults (40+), they can experience decrease size of their pupils, loss of elasticity in their lens and it is becoming hard and glasslike. Due to this they are unable to accommodate for near vision. What is the term for these changes?
Presbyopia
At 70 years of age, a yellowing and thickening of the lens would indicate the presence of what?
Senile Cataract
What is macular degeneration?
A breakdown of cells in the macula of the retina. A loss of central vision, the area of clearest vision and is the most common cause of blindness.
A patient as increased intraocular pressure which can lead to gradual loss of peripheral vision. What is this condition called?
Glaucoma