1. CRANIAL NERVE NUCLEI - LECTURE A NBIO 401 – Wednesday, October 3, 2012

2. Objective for the first two cranial nerve lectures, those about cranial nerve nuclei: -Be able to summarize the function and location of each cranial nerve nucleus.

3. Cranial Nerve Nuclei Introductory Organization

4. V VI VII VIII IX X XII III I Optic Nerve II

5. V VI VII VIII IX X XII III I Optic Nerve II ONLY III - XII

6. V VI VII VIII IX X XII III I Optic Nerve II CRANIAL NERVE NUCLEI A = III - V

7. V VI VII VIII IX X XII III I Optic Nerve II CRANIAL NERVE NUCLEI B = VI - XII

8. Mesencephalic Trigeminal V (jaw muscle spindles) Main Sensory Trigeminal V (face touch & proprioception) Spinal Trigeminal V (face pain) Vestibular/ Cochlear VIII (vestibular & auditory signals from the inner ear) Oculomotor III (eye muscles) Trochlear IV (eye muscles) Abducens VI (eye muscles) Hypoglossal XII (tongue muscles) Sensory GSA and SSA Motor GSE GENERAL SOMATIC CRANIAL NERVE NUCLEI

9. Solitarius (caudal half) VII, IX, X (sensory information for autonomic control) Edinger-Westphal III (constricts pupil - parasympathetic) Superior salivatory VII (drives salivary glands - parasympathetic) Inferior salivatory IX (drives salivary glands - parasympathetic) Dorsal motor n. of X (parasympathetic drive to smooth muscles & organs in chest and abdomen) Sensory GVA Motor GVE GENERAL VISCERAL CRANIAL NERVE NUCLEI

10. Solitarius (rostral half) VII, IX, X (taste) Motor Trigeminal V (chewing muscles) Facial VII (muscles of facial expression) n. Ambiguus IX, X (muscles of the pharynx & larynx) Sensory SVA Motor SVE SPECIAL VISCERAL CRANIAL NERVE NUCLEI

11. sulcus limitans (divides motor nuclei [medial] and sensory nuclei (lateral]).

12. sulcus limitans (divides motor nuclei [medial] and sensory nuclei (lateral]).

13. sulcus limitans

14. Motor nuclei locations

15. General Somatic Efferents lie close to the midline

16. General Visceral Efferents lay laterally to the General Somatic Efferents

17. Cranial Nerve Nuclei III-V The Oculomotor (IIIrd) Nucleus

20. Oculomotor nucleus (motoneurons for eye muscles) Oculomotor nerve (to eye muscles & pupil muscles) Edinger Westphal nucleus (constricts the pupil)

21. General Somatic Efferents lie close to the midline

22. Mesencephalic Trigeminal V (jaw muscle spindles) Main Sensory Trigeminal V (face touch & proprioception) Spinal Trigeminal V (face pain) Vestibular/ Cochlear VIII (vestibular & auditory signals from the inner ear) Oculomotor III (eye muscles) Trochlear IV (eye muscles) Abducens VI (eye muscles) Hypoglossal XII (tongue muscles) Sensory GSA and SSA Motor GSE GENERAL SOMATIC CRANIAL NERVE NUCLEI

23. Cranial Nerve Nuclei The Trochlear (IVth) Nucleus

24. Trochlear nerve (to eye muscles) Trochlear nucleus (motoneurons for eye muscles)

25. General Somatic Efferents lie close to the midline

26. Mesencephalic Trigeminal V (jaw muscle spindles) Main Sensory Trigeminal V (face touch & proprioception) Spinal Trigeminal V (face pain) Vestibular/ Cochlear VIII (vestibular & auditory signals from the inner ear) Oculomotor III (eye muscles) Trochlear IV (eye muscles) Abducens VI (eye muscles) Hypoglossal XII (tongue muscles) Sensory GSA and SSA Motor GSE GENERAL SOMATIC CRANIAL NERVE NUCLEI

27. Cranial Nerve Nuclei III-V The Trigeminal Nuclei

28. Sensory Axons signals for conscious touch & muscle spindle/joint receptors (cell body in ganglion outside CNS) Sensory Axons of 1° sensory neuron for unconscious muscle spindle & joint receptors (cell body in mesencephalic trigeminal nucleus - the only 1° sensory cell body inside CNS) To Thalamus Sensory Axons signals for pain & temperature (cell body in ganglion outside CNS) Motor Axons carrying motor signals to jaw muscles (cell body motor trigeminal nucleus) Trigeminal nerve (sensory & motor axons of 4 types listed to the right) Mesencephalic trigeminal nucleus (1° sensory neurons for muscle spindles & joint receptors in head) Mesencephalic trigeminal tract (axons bringing unconscious signals from muscle spindles & joints in head)

29. Main sensory trigeminal nucleus Trigeminal nerve Spinal trigeminal nucleus Motor trigeminal nucleus Spinal trigeminal nucleus (pain & temperature from head) Motor trigeminal nucleus (motoneurons for jaw muscles) Main sensory trigeminal nucleus (touch, conscious spindle & joint from head) Trigeminal nerve (afferent: touch, muscle spindle/joint, pain & temperature from head efferent: chewing muscles)

30. Main sensory trigeminal nucleus (left) Motor Trigeminal Nucleus (right) Mesencephalic trigeminal tract (left) Mesencephalic trigeminal nucleus (left) Spinal trigeminal nerve (left) (1° axons on way to terminate in spinal trigeminal nucleus) Main sensory trigeminal nucleus (right) Spinal Trigeminal Nucleus (right) Trigeminal Nerve (left) Trigeminal Nerve (right) Spinal trigeminal nucleus (left)

34. Special Visceral (Branchial) Efferents lie most lateral of the motor nuclei.

35. Solitarius (rostral half) VII, IX, X (taste) Motor Trigeminal V (chewing muscles) Facial VII (muscles of facial expression) n. Ambiguus IX, X (muscles of the pharynx & larynx) Sensory SVA Motor SVE SPECIAL VISCERAL CRANIAL NERVE NUCLEI

36. Medial lemniscus Spinothalamic tract Pyramidal Tract Medial Longitudinal Fasciculus Pontine Gray matter Superior Cerebellar peduncle Mesencephalic trigeminal tract & nucleus ROSTRAL PONS

37. Medial lemniscus Spinothalamic tract Pyramidal Tract Middle Cerebellar peduncle MLF Pontine Gray matter Motor trigeminal nucleus Superior cerebellar peduncle Trigeminal nerve ( sensory & motor for the head) Mesencephalic trigeminal tract & nucleus (muscle spindles from chewing muscles & jaw joint receptors) MID PONS

38. Medial lemniscus Spinothalamic tract Pyramidal Tract Middle Cerebellar peduncle MLF Pontine Gray matter Superior cerebellar peduncle (fibers coming out of cerebellum) Main sensory trigeminal Nucleus (face touch) Motor nucleus of trigeminal (chewing muscle motoneurons) Spinal trigeminal tract & nucleus MID PONS

39. Medial lemniscus Spinothalamic Tract Pyramidal Tract Spinal trigeminal nucleus & tract Abducens Nucleus (eye muscle motoneurons) Vestibular nuclei Middle Cerebellar peduncle MLF Pontine Gray matter Inferior cerebellar peduncle Facial nerve fibers (looping around abducens nucleus) Facial motor nucleus CAUDAL PONS

40. Cuneate Fasciculus (touch-arm) Pyramidal Decussation (corticospinal fibers crossing midline) Spinothalamic Tract (body pain) Spinocerebellar Tract (sensory fibers - Muscle spindle & joint information to cerebellum - leg) Pyramids (corticospinal fibers) Spinal trigeminal nucleus & tract (head pain & temp) Cuneate Nucleus (touch-arm) Gracile Nucleus (touch-leg) Gracile Fasciculus (touch-leg) Central canal Medial Longitudinal Fasciculus (MLF) (vestibular & oculomotor information) Spinal Accessory Nucleus (motoneurons for trapezius & sternocleidomastoid muscles)

41. Fini