Neural Exam - 3 month cranial nerves

From Embryology
03mo 02.jpg
This infant is almost 3 months old.
  • The vestibulo-ocular reflex evokes a full range of conjugate eye movements.
    • vestibulo-ocular reflex - (VOR) a reflex eye movement that stabilizes images on the retina during head movement by producing an eye movement in the opposite direction to the head movement. The purpose of this movement is to keep the image located on the centre of the visual field.
  • The baby should also be able to visually track 180 degrees in the horizontal plane.
  • Facial expression is full and symmetric.
Cranial Nerves 
Nerve Number Name Type Origin Function
CN I Olfactory sensory telencephalon smell placode
CN II Optic sensory retinal ganglial cells vision
CN III Oculomotor motor anterior midbrain extraocular muscles eye movements and pupil dilation (motor)
CN IV Trochlear motor dorsal midbrain extraocular muscles (superior oblique muscle)
CN V Trigeminal motor/sensory pons proprioception, mastication
CN VI Abducent motor extraocular muscles control eye movements (lateral rectus muscle)
CN VII Facial motor/sensory pons facial expression, taste (tongue anterior and central regions) regulate salivary production.
CN VIII Acoustic sensory vestibular and cochlear nuclei hearing/balance placode
CN IX Glossopharyngeal motor/sensory medulla swallowing and speech, taste (tongue posterior region)
CN X Vagus motor/sensory medulla larynx and pharynx muscles (speech and swallowing), regulates heartbeat, sweating, and peristalsis
CN XI Accessory motor motor neurons sternocleidomastoid and trapezius muscles
CN XII Hypoglossal motor motor neurons tongue muscles (speech, eating and other oral functions)


Cranial Nerve Development: Newborn - Normal | Newborn - Abnormal | 3 months | 12 months | 18 months | Neural - Cranial Nerve Development

3 Months Neural Exam Movies: normal behaviour | cranial nerves | Tone - head and trunk control | upper extremity‎ | hand movements | lower extremity Positions - supine | prone | ventral suspension | vertical suspension | Reflexes - Deep tendon reflexes | Plantar reflex‎ | Root | Moro | Galant | Grasp | Asymmetric tonic neck‎ | Neural Exam Movies | Neonatal Diagnosis
Movie Source - Paul D. Larsen  
Movies from the PediNeuroLogic Exam website are used by permission of Paul D. Larsen, M.D., University of Nebraska Medical Center and Suzanne S. Stensaas, Ph.D., University of Utah School of Medicine. Additional materials were drawn from resources provided by Alejandro Stern, Stern Foundation, Buenos Aires, Argentina; Kathleen Digre, M.D., University of Utah; and Daniel Jacobson, M.D., Marshfield Clinic, Wisconsin. The movies are licensed under a Creative Commons Attribution-NonCommerical-ShareAlike 2.5 License.
Links: Neural Exam Movies | Movies



Cite this page: Hill, M.A. 2017 Embryology Neural Exam - 3 month cranial nerves. Retrieved September 25, 2017, from https://embryology.med.unsw.edu.au/embryology/index.php/Neural_Exam_-_3_month_cranial_nerves

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© Dr Mark Hill 2017, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G