Atlas of the Human Brain and Spinal Cord, 2nd Edition

Section 6 - Internal Structure of the Brain Stem

 

1 Transverse Section through the Caudal Medulla at the Level of the Pyramidal Decussation

image

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

image

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

image

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

image

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

image

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

image

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

image

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

image

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

image

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)

image

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)

image

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)

image

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

image

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

image

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

image

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)

image

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)

image

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


Previous
Page
Next
Page