What are the nerve roots for all the reflexes?
S1, 2 - "buckle my shoe" (Achilles reflex)
L3, 4 - "kick the door" (patellar reflex)
C5, 6 - "pick up sticks" (biceps reflex)
C7, 8 - "lay them straight" (triceps reflex)
L1, 2 - "testicles move" (cremaster reflex)
S3, 4 - "winks galore" (anal wink reflex)
What are the nerve roots for the Achilles reflex?
S1, 2 - "buckle my shoe"
What are the nerve roots for the patellar reflex?
L3, 4 - "kick the door"
What are the nerve roots for the biceps reflex?
C5, 6 - "pick up sticks"
What are the nerve roots for the triceps reflex?
C7, 8 - "lay them straight"
What are the nerve roots for the cremaster reflex?
L1, 2 - "testicles move"
What are the nerve roots for the anal wink reflex?
S3, 4 - "winks galore"
What are primitive reflexes?
CNS reflexes that are present in a healthy infant, but that are absent in a neurologically intact adult
When do primitive reflexes normally disappear?
Within the first year of life
What causes the primitive reflexes to disappear?
Inhibition by a mature/developing frontal lobe
When do we see reemergence of primitive reflexes?
Frontal lobe lesions - loss of the normal inhibition
What are the 6 primitive reflexes?
2 involve the mouth:
1. Rooting reflex
2. Sucking reflex
2 involve fingers/toes
1. Palmar reflex
2. Plantar reflex
2 involve whole body:
1. Moro reflex
2. Galant reflex
What is the Moro reflex?
Abduct/extend limbs when startled, and then draw together
"Hang on for life" reflex
What is the rooting reflex?
Movement of head toward one side if cheek or mouth is stroked (nipple seeking)
What is the sucking reflex?
Sucking response when roof of mouth is touched
What is the palmar reflex?
Curling of fingers if palm is stroked
What is the plantar reflex?
Dorsiflexion of the large toe and fanning of others with plantar stimullation
(AKA Babinski sign)
What is the Galant reflex?
Stroking along one side of the spine while newborn is in ventral suspension (face down) causes lateral flexion of lower body toward stimulated side
Know where the cranial nerves are located in the brain stem.
1. 4 in the midbrain or above, 4 in the pons, 4 in the medulla
2. CN III, IV, VI, XII in the middle (factors of 12, except for 2)
3. CN IV is the only one that exits on the dorsal side
What 2 processes is the pineal gland involved in?
Melatonin secretion and circadian rhythms
Are the colliculi located on the ventral or dorsal side of the brain stem?
Which brain stem colliculi are involved in vision and which ones are involved in hearing?
Superior = visual
Inferior = auditory
Think: Your eyes are above your ears
What is Parinaud syndrome?
Paralysis of conjugate vertical gaze due to lesion in superior colliculi (e.g. pinealoma)
What are the cranial nerves?
I - olfactory
II - optic
III - oculomotor
IV - trochlear
V - trigeminal
VI - abducens
VII - facial
VIII - vestibulocochlear
IX - glossopharyngeal
X - vagus
XI - accessory
XII - hypoglossal
What are the components (sensory, motor, or both) or each of the cranial nerves?
Mnemonic: Some Say Marry Money But My Brother Says Big Brains Matter More.
Components: I - sensory, II - sensory, III - motor, IV - motor, V - both, VI - motor, VII - both, VIII - sensory, IX - both, X - both, XI - motor, XII - motor
Which is the only cranial nerve without thalamic relax to cortex and what does it mediate?
CN I - smell
What are the three cranial nerves that mediate eye movement?
CN III (superior rectus, inferior rectus, medial rectus, inferior oblique)
CN IV (superior oblique)
CN VI (lateral rectus)
What two muscles does the accessory nerve innervate?
What are the functions of the facial nerve?
1. Facial movement
2. Taste from anterior 2/3 of tongue
4. Salivation (submandibular and sublingual glands)
5. Eyelid closing (orbicularis oculi)
6. Stapedius muscle in the ear
Does the facial nerve innervate the parotid gland?
No - it just courses through it
What does CN III mediate besides extraocular movement?
Pupillary constriction, accommodation, eyelid opening
What does CN IX mediate?
1. Taste and somatosensation from posterior 1/3 of the tongue
3. Salivation (parotid gland)
4. Monitoring carotid body and sinus chemo- and baroreceptors
5. Stylopharyngeus (elevates the pharynx and larynx)
What are the functions of the vagus nerve?
Mnemonic: VAGUS TEN
Aortic arch chemo and baroreceptors
Taste from the epiglottis
Elevation of the soft palate
How are the motor vs. sensory cranial nerve nuclei laid out in the brain stem?
Motor = Medial
Sensory = Lateral (on the Side)
What are the 5 cranial nerve reflexes?
3. Jaw jerk
What are the afferent and efferent branches of the corneal nerve reflex?
Afferent: V1 ophthalmic
Efferent: VII (temporal branch: orbicularis oculi)
What are the afferent and efferent branches of the lacrimation reflex?
Is lacrimation reflex the same as emotional tears?
No, loss of the lacrimation reflex does not preclude emotional tears
What are the afferent and efferent branches of the jaw jerk reflex?
Afferent: V3 (sensory - muscle spindle from masseter)
Efferent: V3 (motor - masseter)
What are the afferent and efferent branches of the pupillary reflex?
What are the afferent and efferent branches of the gag reflex?
What are the 3 vagal nuclei?
1. Nucleus solitarius
2. Nucleus ambiguus
3. Dorsal motor nucleus
What three cranial nerves make up the nucleus solitarius?
VII, IX, X
What information is carried in the nucleus solitarius?
Visceral sensory information (e.g. taste, baroreceptors, gut distention)
What three cranial nerves make up the nucleus ambiguus?
IX, X, XI
What is the function of the nucleus ambiguus?
Motor innervatino of pharynx, larynx, and upper esophagus (e.g. swallowing, palate elevation)
What is the function of the dorsal motor nucleus?
Sends autonomic (parasympathetic) fibers to the heart, lungs, and upper GI
Which cranial nerve nuclei make up the dorsal motor nucleus?
Where does CN I pass through?
Which cranial nerves are found in the middle cranial fossa?
CN II - VI
Which cranial nerves are found in the posterior cranial fossa?
CN VII - XII
What is contained in the optic canal?
CN II, ophthalmic artery, central retinal vein
What passes through the superior orbital fissure?
CN III, IV, V1, VI, ophthalmic vein, sympathetic fibers
Where do the different divisions of CN V exit the skull from?
Mnemonic: CN V exits due to Standing Room Only (SRO)
V1 - Superior orbital fissue
V2 - foramen Rotundum
V3 - foramen Ovale
What passes through the foramen spinosum?
Middle meningeal artery
Where do CN VII and CN VIII exit the skull?
Internal auditory meatus
What passes through the jugular foramen?
CN IX, X, XI, jugular vein
Where does CN XII exit the skull?
What passes through the foramen magnum?
CN XI, brain stem, vertebral arteries
The cranial nerves in the middle cranial fossa pass through which bone?
The cranial nerves in the posterior cranial fossa pass through which bone(s)?
Temporal or occipital bone