1 Transverse Section through the Caudal Medulla at the Level of the Pyramidal Decussation
1. Nucleus gracilis, mediates proprioception, leg
2. Solitary tract, mediates gustation
3. Nucleus cuneate, mediates proprioception, arm
4. Nucleus CN XI
5. Lateral corticospinal tract, is concerned with volitional skilled motor activity
6. Central sympathetic pathway
7. Lateral spinothalamic tract, mediates pain and temperature sensation
8. Pyramidal decussation
9. Tectospinal tract
10. Anterior pyramidal tract
11. Medial longitudinal fascicle, mediates lateral conjugate gaze
12. Ventral spinocerebellar tract, transmits unconscious proprioceptive information to the cerebellum (VSCT crossed)
13. Anterior horn, innervates striated muscles
14. Dorsal spinocerebellar tract, transmits unconscious proprioceptive information to the cerebellum (DSCT not crossed)
15. Spinal nucleus of CN V, mediates pain and temperature sensation from face.
16. Substantia gelatinosa, mediates pain and temperature sensation
2 Transverse Section through the Medulla at the Level of the Inferior Olivary Nucleus
1. Nucleus gracilis, mediates proprioception, leg
2. Lateral cuneate nucleus, mediates unconcious proprioceptive information to cerebellum
3. Cuneate nucleus, mediates proprioception from arm and neck to the thalamus
4. Solitary tract, mediates gustation
5. Nucleus CN, XII, innervates intrinsic and extrinsic muscles of tongue
6. Nucleus CN XI, innervates the sternocleidomastoid and trapezius mm
7. Central sympathetic pathway
8. Rubrospinal tract
9. Lateral spinothalamic tract, mediates pain and temperature sensation
10. Inferior olivary nucleus, projects climbing fibers to the cerebellum
11. CN XII, innervates striated muscles of the tongue
12. Tectospinal tract
13. Ventral spinocerebellar tract, mediates proprioceptive information to the spinocerebellum
14. Medial lemniscus, mediates posterior-column modalities to the thalamus
15. Medial longitudinal fasciculus, mediates turning the head in visual orientation
16. Dorsal spinocerebellar tract, mediates proprioceptive information to the cerebellum, e.g., muscle spindles and Golgi tendon organs
17. Reticular formation
18. Spinal nucleus of CN V, mediates pain and temperature sensation from face
3 Transverse Section through the Medulla at the Level of the Dorsal Motor Nucleus of CN X
1. Dorsal motor nucleus of CN X, projects preganglionic parasympathetic fibers to visceral organs
2. Solitary tract, projects gustatory (taste) fibers to the solitary nucleus
3. Nucleus of CN XII, innervates the muscles of the tongue
4. Central sympathetic pathway
5. Nucleus ambiguus, innervates the muscles of the larynx (except the cricothyroid) and heart
6. Rubrospinal tract
7. Lateral spinothalamic tract, mediates pain and temperature sensation
8. Inferior olivary nucleus, projects climbing fibers to the cerebellum
9. CN XII, innervates the muscles of the tongue
10. Pyramidal tract
11. Decussation lemnisci, transmits dorsal column modalities to the contralateral thalamus (VPL)
12. Medial lemniscus, conducts dorsal column modalities to the thalamus (VPL)
13. Reticular formation
14. Ventral spinocerebellar tract (VSCT), transmits unconscious proprioceptive information to the cerebellum (VSCT is crossed)
15. Medial longitudinal fasciculus, mediates turning the head in visual orientation
16. Nucleus of the spinal tract of CN V, projects pain and temperature sensation to the VPM nucleus of the thalamus
17. Dorsal spinocerebellar tract (DSCT), transmits unconscious proprioceptive information to the cerebellum (DSCT not crossed)
18. IV Ventricle
19. Tenia of IV Ventricle
4 Transverse Section through the Medullo-Pontine Junction Showing the Cochlear Nerve Nuclei and the Hypoglossal Nucleus
1. Nucleus hypoglossus, innervates the muscles of the tongue
2. Dorsal motor nucleus of CN X, provides parasympathetic innervation to intramural ganglia of the viscera
3. Solitary tract, mediates gustation (taste)
4. Central sympathetic pathway
5. Cochlear nuclei, receive input from the organ of Corti
6. Nucleus ambiguus, innervates the muscles of the larynx (except the cricothyroid) and heart
7. Rubrospinal tract
8. Lateral spinothalamic tract, mediates pain and temperature sensation to the thalamus (VPL)
9. CN XII, innervates the skeletal muscles of the tongue
10. Inferior olivary nucleus, projects climbing fibers to the cerebellum
11. Pyramidal tract, corticospinal tract, innervates motor neurons in the anterior horns in the spinal cord and in the cranial nerve motor nuclei
12. Nuclei arcuati
13. Medial lemniscus
14. Central tegmental tract
15. Reticular formation
16. Ventral spinocerebellar tract (VSCT), transmits unconscious proprioceptive information to the cerebellum (VSCT is crossed)
17. Nucleus of spinal tract of CN V, mediates pain and thermal sensation from face
18. Inferior cerebellar peduncle, contains the olivio-cerebellar tract and the DSCT
19. Tectospinal tract
20. Medial longitudinal fasciculus (MLF), mediates turning the head in visual orientation
5 Transverse Section at the Level of Cerebellar Nuclei and the Cranial Nerve Nuclei CNN: CN VI and VII
1. Fastigial nucleus, projects via the vestibular nucleus to the spinal cord
2. Emboliform nucleus, projects to the red nucleus and VL of the thalamus
3. Globose nucleus, see emboliform nucleus (above)
4. Dentate nucleus, projects to the red nucleus and the VL nucleus of the thalamus
5. Inferior cerebellar peduncle, receives input from the interior olivary nucleus and the DSCT
6. Nucleus of CN VI, innervates the lateral rectus muscle
7. Solitary tract, contains gustatory fibers from the geniculate, petrosal, and nodose ganglia
8. Central sympathetic pathway
9. Nucleus of CN VII, innervates the muscles of facial expression
10. Trapezoid body, conducts auditory fibers to the superior olivary nuclei
11. Rubrospinal tract
12. Lateral spinothalamic tract, mediates pain and temperature sensation
13. Corticospinal tract, innervates anterior horn cells of spinal cord
14. Pontine nuclei, project to the cerebellum
15. Inferior olivary nucleus
16. Medial lemniscus
17. Lateral lemniscus
18. Anterior spinocerebellar tract
19. Reticular formation
20. Central tegmental tract, contains rubro-olivary fibers
21. Spinal tract of CN V, mediates pain and temperature sensation from the face
22. Medial longitudinal fasciculus (MLF), mediates turning the head in visual orientation
Vestibular nuclei
23. Inferior vestibular nucleus, projects to the thalamus (VPL and VPI)
24. Lateral vestibular nucleus, receives input from the superior vestibular nucleus
25. Medial vestibular nucleus, receives spinovestibular input
26. Superior vestibular nucleus, receives input from the fastigial nucleus
6 Transverse Section through the Rostral Pons at the Level of the Anterior Medullary Velum and the Principal Sensory Nucleus of the CN V
1. Anterior medullary velum, part of the roof of the fourth ventricle
2. Central sympathetic pathway
3. Principle sensory nucleus of CN V, receives discriminative tactile input from the face
4. Trigeminal spinal tract, Receives nociceptive fibers from the face and oral cavity
5. Motor nucleus of CN V, innervates the muscles of mastication
6. Rubrospinal tract, plays a role in the control of flexor tone
7. Tectospinal tract
8. Lateral spinothalamic tract, contains nociceptive fibers CN V
9. Trigeminal nerve
10. Pyramidal tract, located in the basilar pons
11. Pontine nuclei, found in the base of the pons
12. Middle cerebellar peduncle, receives ponto-cerebellar input
13. Medial lemniscus, projects to the thalamus VPL
14. Lateral lemniscus, projects to the nucleus of the inferior colliculus
15. Central tegmental tract, contains gustatory fibers, rubroolivo fibers
16. Reticular formation
17. Medial longitudinal fasciculus (MLF), mediates the oculovestibular reflexes
18. Superior cerebellar peduncle
19. Ventral spinocerebellar tract, second order neurons are found in the marginal nucleus of spinal gray
7 Transverse Section through the Mesencephalo-Pontine Junction and Decussation of CN IV
1. Dorsal longitudinal fasciculus, extends to the hypothalamus and spinal cord
2. Mesencephalic tract of CN V, mediates the jaw jerk
3. Central sympathetic pathway
4. Trigeminal lemniscus, contains nociceptive fibers of the face and oral cavity
5. Lateral spinothalamic tract, contains nociceptive fibers from the body and extremities
6. Rubrospinal tract, plays a role in the control of flexor tone
7. Tectospinal tract
8. Corticobulbar fibers, found in the middle third of the basilar pons
9. Corticospinal fibers, found in the middle third of the basilar pons
10. Decussation of superior cerebellar peduncles, located at the level of the nucleus of the inferior colliculus
11. Middle cerebellar peduncle, receives ponto-cerebellar input
12. Reticular formation
13. Medial lemniscus, mediates posterior column modalities
14. Superior cerebellar peduncle, contains dentatothalamic fibers
15. Central tegmental tract, contains rubro-olivary fibers and gustatory fibers
16. Medial longitudinal fasciculus, mediates the oculo-vestibular reflexes
17. Lateral lemniscus, projects to the nucleus of the inferior colliculus
18. Locus ceruleus, contains neuromelanin
8 Transverse Section through the Midbrain at the Level of the Inferior Colliculus
1. Cerebral aqueduct, connects the third and fourth ventricles
2. Brachium of the inferior colliculus, connects the nucleus of the inferior colliculus to the medial geniculate body (MGB)
3. Mesencephalic tract and nucleus of CN V, supply the afferent limb of the jaw-jerk
4. Trochlear nucleus CN IV, innervates the superior oblique muscle
5. Lateral lemniscus, projects to the nucleus of the inferior colliculus
6. Spinal lemniscus, contains nociceptive fibers
Crus cerebri
7. Corticopontine tract
8. Cerebral peduncle
9. Corticospinal tract, located in the middle third of the crus cerebri
10. Corticopontine and corticobulbar tracts
11. Decussation of superior cerebellar peduncles, contain dentatorubrothalamic fibers
12. Substantia nigra, projects to the striatum
13. Medial lemniscus, mediates posterior-column modalities
14. Central tegmental tract, contains gustatory fibers, rubro-olivary fibers
15. Periaqueductal gray, plays a role in pain modulation
16. Commissure of the inferior colliculus, auditory way-station in the acoustic pathway
9 Transverse Section through the Midbrain at the Level of the Red Nucleus
1. Periaquaductal gray, plays a role in pain regulation
2. Mesencephalic tract of the CN V, mediates the jaw-jerk
3. Lateral spinothalamic tract, mediates protopathic sensation (e.g., pain and temperature)
4. Central sympathetic pathway
5. Oculomotor nucleus of CN III, ocular motility
6. Red nucleus
7. Substantia nigra, projects to the striatum
8. Temporooccipitopontine tracts
9. & 10. Corticospinal and corticobulbar fibers, located in the bases peduncles
11. Frontopontine fibers, found in the medial third of the crus cerebri
12. Tegmental decussation
13. Tectospinal tract
14. Medial leminiscus
15. Medial longitudinal fasciculus
16. Reticular formation
17. Brachium of inferior colliculus
18. Spinotectal tract
19. Cerebral aqueduct, interconnects the third ventricle and fourth ventricle
20. Superior colliculus, plays a role in visual orientation
10 Dorsolateral Medulla Syndrome (Wallenberg's Syndrome)
1. Inferior vestibular nucleus, nystagmus and ipsilateral inclination to fall
2. Dorsal nucleus of vagus nerve, tachycardia and dyspnea
3. Inferior cerebellar peduncle, ataxia and ipsilateral asynergia
4. Nucleus of solitary tract, ageusia ipsilateral
5. Ambiguus nucleus, ipsilateral paralysis of palate, larynx, and pharynx
6. Nucleus of cochlear nerve, hypacusia
7. Nucleus of trigeminal spinal tract, ipsilateral analgesia and thermanesthesia of face
8. Central sympathetic pathway, Horner's syndrome. Hypohidrosis, ipsilateral vasodilation in face
9. Anterior spinocerebellar tract, ataxia, ipsilateral hypotonia
10. Lateral spinothalamic tract, analgesia and thermanesthesia contralateral over body
11. Central tegmental tract, myorhythmia in the area of velum and pharynx
12. Reticular substance (center of respiration), hiccup
13. Pyramidal tract
11 Medial Oblongata Syndrome (Dejerine's Syndrome)
1. Medial longitudinal fasciculus, nystagmus
2. Medial lemniscus, contralateral decrease of touch, vibration, and position sensations
3. Olive, ipsilateral myorhythmia in velum and pharynx
4. Hypoglossal nerve, ipsilateral flaccid paralysis of hypoglossal muscle with atrophy
5. Pyramidal tract, contralateral, spastic hemiplegia with positive Babinski reflex
12 Syndrome of Caudal Pontine Base (Millard-Gubler or Foville's Syndrome)
1. Medial lemniscus, contralateral decrease of touch, position and vibration sensations in the lower extremities
2. Lateral lemniscus, hypacusia
3. Nucleus of facial nerve, peripheral ipsilateral paralysis of facial muscles
4. Anterior spinothalamic tract, contralateral analgesia and thermanesthesia of body
5. Pyramidal tract, contralateral spastic hemiplegia
6. Abducent nerve, ipsilateral peripheral paralysis of lateral rectus muscle
13 Syndrome of Caudal Pontine Tegmentum
1. Medial longitudinal fasciculus, nystagmus, gaze paralysis toward lesion
2. Nucleus of abducent nerve, ipsilateral nuclear destruction of abducent nerve
3. Middle cerebellar peduncle, hemiataxia, intention tremor, adiadochokinesia, cerebellar speech
4. Vestibular nuclei, nystagmus, vertigo
5. Central sympathetic pathway, Horner's syndrome, hypohidrosis, ipsilateral vasodilation
6. Nucleus of trigeminal spinal tract, ipsilateral analgesia and thermanesthesia in face
7. Nucleus of facial nerve, ipsilateral nuclear paralysis of facial muscles (atrophy)
8. Central tegmental tract, myorhythmias, ipsilateral in velum and pharynx
9. Anterior spinocerebellar tract, asynergia, ipsilateral hypotonia
10. Lateral lemniscus, hypacusia
11. Lateral spinothalamic tract, analgesia and thermanesthesia, contralateral over body
12. Medial lemniscus, contralateral decrease of touch, vibration and position sensations (ataxia)
14 Syndrome of Rostral Pontine Tegmentum
1. Superior cerebellar peduncle, hemiataxia, intention tremor, adiadochokinesia, cerebellar speech
2. Principal sensory nucleus of trigeminal nerve, decrease of epicritic sensitivity, ipsilateral in face
3. Nucleus of trigminal spinal tract, analgesia and thermanesthesia, ipsilateral in face
4. Motor nucleus of trigeminal nerve, flaccid paralysis of ipsilateral muscles for chewing (nuclear)
5. Central tegemental tract, myorhythmia in soft palate and pharynx
6. Lateral spinothalamic tract, analgesia and thermanesthesia contralateral in body
7. Lateral lemniscus, hypoacusia
8. Medial lemniscus, decrease in sensations of touch, position and vibration, contralateral in body, ataxia
9. Corticonuclear tract (branching fibers), paralysis of facial, glossopharyngeal, vagus, and hypoglossal nerves
10. Tectospinal tract, loss of neck reflexes
15 Syndrome of Midpontine Base
1. Root fibers of trigeminal nerve, ipsilateral hemianesthesia for all qualities on face, ipsilateral flaccid paralysis of chewing muscles
2. Middle cerebellar peduncle, hemiataxia, ipsilateral asynergia
3. Corticospinal tract, contralateral spastic hemiparesis
4. Pontine nuclei, ipsilateral dystaxia
16 Syndrome of Lower Red Nucleus (Benedikt's Syndrome)
1. Medial lemniscus, contralateral decrease in sensations of touch, position, and vibration
2. Red nucleus, contralateral hyperkinesia (chorea, athetosis)
3. Substantia nigra, contralateral akinesia (parkinsonism)
4. Root fibers of oculomotor nerve, ipsilateral oculomotor paralysis, wide fixed pupil
17 Syndrome of Peduncle of Midbrain (Weber's Syndrome)
1. Substantia nigra, akinesia (parkinsonism)
2. Corticospinal fibers, contralateral spastic hemiplegia
3. Corticonuclear fibers, contralateral lower facial and hypoglossal paralysis, supranuclear
4. Corticopontine tract, contralateral dystaxia
5. Root fibers of oculomotor nerve, ipsilateral oculomotor paralysis with wide fixed pupil
18 Syndrome of Quadrigeminal Roof of Aqueduct (Parinaud's Syndrome)
A. Pinealoma compressing superior colliculi and aqueduct. B. Nuclei of III (IV) and medial longitudinal tracts are within range of deformation. |
1. Cerebral aqueduct, stenosis with occlusive hydrocephalus
2. Superior colliculi, conjugated upwards gaze paralysis
3. Oculomotor nucleus, eventual oculomotor paralysis and ptosis (trochlear paralysis)
4. Medial longitudinal fasciculus, nystagmus