Content:
0:00 Introduction
1:02 Topography of Midbrain
1:35 Anterior Surface of Midbrain
3:06 Posterior Surface of Midbrain
6:10 Internal Surface of Midbrain
7:05 Gray Matter of Midbrain
13:27 White Matter of Midbrain
13:44 White Matter: Ascending Tracts
16:40 White Matter: Descending Tracts
21:51 QUIZ!
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Topograpgy of the Mesencephalon:
- Lies above the Pons, Below Diencephalon, In front of the Cerebellum
- Anterior Surface
- Postrior Surface
Anterior Surface of the Mesencephalon:
- Cerebral Peduncles (Pedunculus Cerebri)
- Interpeduncular Fossa (Fossa Interpeduncularis)
○ Posterior Perforated Substance (Substantia Perforata Posterior)
○ Oculomotor Sulcus of Mesencephalon (Sulcus Nervi Oculomotorii)
○ 3rd Cranial Nerve (Oculomotor nerve)
Posterior View of the Mesencephalon:
- Cerebral Peduncles (Pedunculus Cerebri)
- Tectal Plate (Lamina Tecti)
○ Superior Colliculus (Colliculi Superior)
§ Visual Pathway:
§ Receptors of Optic Nerve (CNII)
§ Optic Chiasm
§ Lateral Geniculate Body (Metathalamus)
§ Primary Visual Cortex
§ Brachium of the Superior Colliculi (Brachium Colliculi superior)
○ Inferior Colliculus (Colliculi Inferior)
§ Auditory Pathway:
§ Cochlear Nerve
§ Cochlear Nuclei
§ Lateral Lemniscus
§ Inferior Colliculi
§ Brachium of the Inferior Colliculi (Brachium Colliculi Inferior)
§ Primary Auditory Cortex (Superior Temporal Gyrus)
- Lateral Sulcus of Mesencephalon (Sulcus Lateralis Mesencephali)
- Trigone of Lateral Lemniscus (Trigonum Lemnisci Lateralis)
- Trochlear Nerve (CN IV)
Internal Surface of the Mesencephalon:
- Tectum of Midbrain
- Tegmentum of Midbrain
- Cerebral Peduncles
Gray Matter of Mesencephalon:
- Red Nucleus (Nucleus Ruber)
○ Corticopontine Tract
○ PontoCerebellar Tract (Transverse Pontine Fibers)
○ Cerbellorubral Tract
○ Rubrospinal Tract
- Substantia Nigra
○ Substantia Nigra pars Reticulata
○ Sibstantia Nigra pars Compacta
§ Part of Basal Ganglia (Putamen, Globus Pallidus, Caudate, Thalamus, Subthalamus, Striatum, Lentiform Nucleus)
§ Help Start Movement, Stop Movement Modulate Movement
§ Disease here causes Parkinsons Disease and TRAP symptoms (Tremor, Rigidity, Akinesia, Postural Instability)
- Superior Colliculi level:
○ Nucleus of oculomotor nerve (Nuclei nervi oculomotorii)
○ Posterior Accessory Nucleus of Oculomonor Nerve (Nucleus accessorii nervi oculomotorii)
- Inferior Colliculi level:
○ Nucleus of Trochlear nerve (Nuclei nervi trochlearis)
○ Mesencephal nucleus of Trigeminal Nerve (Nucleus mesencephalicus nervi trigemini)
- Periaqueductal Grey Substance (Substantia Grisea Centralis)
- Reticular Formation (Formatio Reticularis)
White Matter of Mesencephalon:
Ascending Tracts
- Medial Lemniscus (Lemniscus Medialis)
○ Gracile Fascicle (Fasciculus Gracilis) to Gracile Nucleus
○ Cuneate Fascicle (Fasciculus Cuneatus) to Cuneate Nucleus
○ Medial Lemniscus is formed through Internal Arcuate Fibers (Fibrae Arcuatae Internae)
○ Epicritic Sensibility (Proprioception and Mechanoreceptios)
- Spinal Lemniscus (Lemniscus Spinalis)
○ Anterior Spinothalamic Tract (Tractus Spinothalamicus Anterior)
○ Lateral Spinothalamic Tract (Tractus Spinothalamicus Lateralis)
- Trigemincal Lemniscus (Lemniscus Trigeminalis)
- Anterior Spiniocerebellar Tract (Tractus Spinocerebellaris Anterior)
- Lateral Lemniscus (Lemniscus Lateralis)
○ From Cochlear Nerve
Descending Tracts
○ Vestibulospinal Tract (Tractus Vestibulospinalis)
○ Rubrospinal Tract (Tractus Rubrospinalis)
○ Tectospinal Tract (Tractus Tectospinalis)
○ Posterior Tegmental Decussation (Decussatio Tegmentalis Posterior)
○ Reticulospinal Tract (Tractus Reticulospinalis)
○ Anterior Tegmental Decussation (Decussatio Tegmentalis Anterior)
○ Medial Longitudinal Fasciculus (Fasciculus Longitudinalis Medialis)
- In the Cerebral Peduncles
○ Corticospinal Tract (Tractus Corticospinalis)
○ Corticonuclear Tract (Corticobulbar tract)
○ Corticopontine tract (Tractus Corticopontineus)
§ Frontopontine Tract
§ Parietopontine Tract
§ Temporopontine Tract
§ Occipitopontine Tract
QUIZ
Sources used in this video:
- Memorix Anatomy 2nd Edition by Hudák Radovan (Author), Kachlík David (Author), Volný Ondřej (Author)
- Biorender
- University notes and lectures