Cranial nerves and ANS Flashcards
CNVII: name? function? test? exit from skull?
(1.) Facial Nerve
(2. ) Sensory = taste to anterior 2/3 tongue (via chorda tympani)
(3. ) Motor = facial expression muscles + platysma
(4. ) PNS = lacrimal, sublingual, submandibular glands
(5. ) Test
- Puff cheek, smile, raise eyebrows, squint
- Sugar, salt, vinegar
(6.) Exit = internal acoustic meatus
CNIX: name? function? test? exit from skull?
(1.) Glossopharyngeal
(2. ) Sensory = taste + general sensation to posterior 1/3 of tongue, carotid body + sinus, oropharynx
(3. ) Motor = stylopharyngeus
(4. ) PNS = parotid gland
(5. ) Test = Gag reflex (sensory)
(6. ) Exit = Jugular foramen
CNX: name? function? test? exit from skull?
(1.) Vagus
(2. ) Sensory = epiglottis, palate, vocal cords
(3. ) Motor = larynx, pharyngeal constrictors, soft palate
(4. ) PNS = heart, lungs, foregut, midgut
(5. ) Test = Gag reflex
(6. ) Exit = jugular foramen
CNXI: name? function? test? exit from skull?
(1. ) Accessory
(2. ) motor = trapezius and sternocleidomastoid
(3. ) Test= Shrug and turn head against resistance
(4. ) Exit = jugular foramen
CN XII: name? function? test? exit from skull?
(1. ) Hypoglossal
(2. ) Motor = muscles of the tongue
(3. ) Test = stick tongue out and look for any deviation
(4. ) Exit = hypoglossal canal
CNI: name? function? test? exit from skull?
(1. ) Olfactory nerve
(2. ) Sensory = smell
(3. ) Test = Ask pt to smell
(4. ) Exit = Cribriform plate
CNII: name? function? test? exit from skull?
(1. ) Optic nerve
(2. ) Sensory = vision
(3. ) Test = Snellen charts for visual acuity, test colour, if pupils constrict with torch or one eye covered
(4. ) Exit = optic canal
CNIV: name? function? test? exit from skull?
(1. ) Trochlear
(2. ) Motor = SO
(3. ) Test = Make them follow ‘H’
(4. ) Exit = Superior orbital fissure
CNV: name? function? test? exit from skull?
(1.) Trigeminal
(2. ) Sensory = face sensation, anterior 2/3 tongue
(3. ) Motor = muscles of mastication
(4.) Test = Cotton wool on face (sensory test), clench teeth + open jaw against resistance -> feel for temporalis and masseter
(5.) Exit =
Superior orbital fissure = V1
Foramen Rotundum = V2
Foramen Ovale = V3
CNVI: name? function? test? exit from skull?
(1. ) Abducens
(2. ) Motor = LR
(3. ) Test = abduct eye
(4. ) Exit = Superior orbital fissure
CNVIII: name? function? test? exit from skull?
(1. ) Vestibulococholear
(2. ) Sensory = hear and balance
(3. ) Test = Weber and Rinne tests are performed using tuning fork
(4. ) Exit = internal acoustic meatus
CNIII: name? function? test? exit from skull?
(1.) Occulomotor
(2. ) Motor = LPS (open eyelids), IO, SR, IR, MR
(3. ) PNS = pupil constrict
(4. ) Test = follow H
(5. ) Exit = superior orbital fissure
What is ANS divided into ? and what is their outflow?
(1. ) Peripheral and sympathetic nervous system
(2. ) PNS outflow = CN3, 7, 9, 10 + S2,3,4
(3. ) SNS outflow = T1 to L2
Describe the supply of the PNS outflow
(1. ) CN3 = constrict pupil
(2. ) CN7 = lacrimal, sublingual, submandibular gland
(3. ) CN9 = Parotid gland
(4. ) CN10 = heart, lungs, pharynx, larynx, foregut, midgut
(5.) S2, 3, 4 (pelvic splanchnic nerves) = hindgut (d.colon, rectum etc), uterus, bladder, prostate, testes, urethra.
Describe the supply of the SNS outflow?
SNS fibres originate from T1-L2
(1. ) Greater splanchnic nerves (T5-9) = foregut
(2. ) Lesser splanchnic nerves (T10-11) = midgut
(3. ) Least splanchnic nerves (T12) = hindgut
Sympathetic Cervical Trunk arises from T1-L2
(1. ) Comprises of superior, middle and inferior cervical ganglion
(2. ) Inferior cervical ganglion and T1 ganglion may fuse together to form a stellate ganglion.
What is Horner’s syndrome?
(1. ) Damage to stellate ganglion can cause Horner’s Syndrome
(2. ) Signs include (unilateral loss of symp innervation):
- No facial sweating (anhidrosis)
- Ptosis
- Constricted pupil (mihosis)
Describe the differences between sympathetic and parasympathetic?
Sympathetic - ‘Flight or fight’
(1. ) Dilate pupil
(2. ) Inc HR
(3. ) Inhibit digestion and salivation
(4. ) Stimulate glucose release
(5. ) Vasoconstriction
(6. ) Bronchodilation
(7. ) Relaxes bladder
Parasympathetic - ‘rest + digest’
(1. ) Constrict pupil
(2. ) Dec HR
(3. ) Stimulate digestion + salivation
(4. ) Vasodilation
(5. ) Bronchoconstriction
(6. ) Contracts bladder
What is a dermatome?
- area of skin supplied by single sensory nerve
- pain is felt where damage i.e. localised
- dermatome of abdominal wall starts at T5 (epigastrium), T10 (umbillicus), T12 (suprapubic).
- each dermatome starts at the back of the name vertebrae and runs downwards around the trunk
What is referred pain?
(1. ) Initiating painful stimulus is felt elsewhere
(2. ) Does not follow dermatome distribution
(3. ) Pain is poorly localised due to ‘sharing of pathways’.
Describe referred pain of abdominal organs
Poorly localised pain i.e. pain is felt elsewhere other than where the organ lies
(1. ) Foregut -> Epigastrium = Greater Splanchnic N (T5-9)
(2. ) Midgut -> Umbilical = Lesser Splanchnic N (T10-11)
(3. ) Hindgut -> Suprapubic = Least Splanchnic N (T12)
Describe referred pain in appendicitis
Appendicitis usually causes pain that starts in the middle of your tummy before moving towards the lower right side.
(1. ) Early inflammation = umbilical region (midegut referred pain)
(2. ) Late inflammation = right iliac fossa (localised due to parietal peritoneum involvement)
Describe referred pain in gallbladder
Pain may be felt in three places
(1. ) Right shoulder = diaphragm aggravated, phrenic nerve -> C3,4,5 [referred pain]
(2. ) Epigastrium = foregut structures, greater splanchnic nerve [referred pain]
(3. ) RUQ = aggravation of abdominal wall and peritoneum, sharp localised pain [dermatome]
Describe referred pain in organs adjacent to diaphragm
(1. ) Gallbladder, liver = right shoulder
(2. ) Spleen = left shoulder
Describe the route of the phrenic nerve + its motor and sensory innervations
Route
(1. ) Nerve roots at C3, 4, 5
(2. ) Phrenic nerve lies lateral to the vagus nerve
(3. ) Travel in PHront of trachea
(4. ) Passes over subclavian artery (left) + travels with SVC (right_
(5. ) Descends anterior to lungs hilum to diaphragm
Innervation
(1. ) Motor = diaphragm
(2. ) Sensory = central tendon of diaphragm, parietal pleura, pericardium, peritoneum
Describe the branches and their supply of the vagus nerve
(1.) Leaves the jugular foramen and branches off into the following:
(2. ) Pharyngeal branch
- forms pharyngeal plexus with CN 9,10,11
- supplies pharyngeal constrictor muscles
(3. ) Superior laryngeal n (branches at the level of ECA and ICA bifurcation)
- Supplies vocal cords
- Internal branch (sensory) supplies larynx mucosa
- external branch supplies cricothyroid muscles
(4. ) Recurrent laryngeal n (branches under R.subclavian A. + Aortic arch)
- Nerve is important for breathing, swallowing, vocalisation
- Sensation to larynx below vocal cords
- Intrinsic muscles (except cricothyroid muscle)
Describe the route of the left and right recurrent laryngeal nerves + which one is at more risk in thoracic disease
R.Recurrent Laryngeal Nerve
- Hooks under the right subclavian artery
L.Recurrent Laryngeal Nerve
- Hooks under the aortic arch
- Ascends up to the neck between trachea + oesophagus
- Passes under thyroid gland
- LRLN is at more risk of thoracic disease due to it descending into the thorax area more than the right
Describe what would happen in a brainstem stroke in relation to CN9 and 10?
(1. ) CN9 damage = loss of sensation to back of pharynx
(2. ) CN10 damage = loss of sensation to inside of the larynx
(3. ) Effects sensory + motor control of swallowing
(4. ) Larynx opens during swallowing
(5. ) Fluid enters lungs -> infection
Describe what you’d expect to see in unilateral and bilateral injury to recurrent laryngeal nerve and left lung tumour?
(1. ) Unilateral injury = hoarseness of voice due to movement of one vocal cord + shortage of breath
(2. ) Bilateral injury = breathing problems, snoring sounds, stridor (hi pitch wheezing), resp distress
(3. ) Left lung tumour = invade left recurrent laryngeal nerve -> cause paralysis of left VC -> hoarseness of voice
