II. Definitions
- Brainstem
- Brainstem is the wiring closet of the Central Nervous System
- Brainstem communicates between the spinal cord and the Cerebrum and Cerebellum
- Composed of three segments: Midbrain, pons and Medulla
- Circle of Willis, the interconnected blood supply of the brain, overlies the posterior aspect of the Brainstem
- Contains Cranial Nerve nuclei associated with motor and sensory control of the head and neck
- Traversed by ascending tracts carrying sensory signals from the Peripheral Nervous System to the Cerebrum
- Example: Spinothalamic Tract (carries pain and Temperature sense)
- Traversed by descending tracts carrying motor signals from the Cerebrum to the Muscles.
- Example: Corticospinal tract (carries motor movement signals)
III. Anatomy: Components
-
Midbrain
- Most superior aspect of the Brainstem
- Lies immediately inferior to the Diencephalon
-
Pons Cerebri
- Lies deep to the Pituitary Gland and Circle of Willis
-
Medulla Oblongata
- Immediately superior to the spinal cord
- Lies deep to the clivus (slanted bony surface)
- Lies just above the foramen magnum (hole at skull base)
- With Cerebral Herniation, the Medulla is the first to drop through the foramen magnum
IV. Anatomy: Cranial Nerve Nucleii
- Brain stem Cranial Nerve origins follow a consistent pattern of distribution
- Nucleii are located anterior to the ventricles
- Nucleii are organized in anterior-to-posterior bands
- Images
- Somatic Motor Nucleii (most medial)
- CN 3: Oculomotor Nerve (eye)
- CN 4: Trochlear Nerve (eye)
- CN 6: Abducens Nerve (eye)
- CN 11: Spinal Accessory nerve (neck/Shoulders)
- CN 12: Hypoglossal Nerve (motor, Tongue)
- Somatovisceral nerves (Branchiomeric Nerves)
- CN 5: Trigeminal Nerve (motor nucleus 5, chew)
- CN 7: Facial Nerve (facial nucleus, lips/eyes)
- Nucleus Ambiguous (CN 9, CN 10, swallow)
- Visceral Motor Nucleii
- CN 3: Oculomotor Nerve (Edinger-Westphal Nucleus)
- CN 7: Facial Nerve (Superior Salivatory Nucleus)
- CN 9: Glossopharyngeal Nerve (Inferior Salivatory nucleus)
- CN 10: Vagus Nerve (Dorsal motor nucleus )
- Visceral Sensory Nucleii
- Somatic Sensory Nucleii (most lateral)
- Exceptions
- CN 1 and CN 2 are not included as they originate superior to the Brainstem in the Diencephalon
V. Anatomy: Pass-Through Tracts
- Sensory and motor tracts to and from the extremities pass through the Brainstem without synapsing
- Most of the tracts decusate (cross over the midline) in the Medulla, with two exceptions
- Spinothalamic Tract crosses over the midline within 1-2 levels of spinal cord entry
- Spinocerebellar Tract does not cross over
- Ascending Sensory Tracts
- Spinothalamic Tract (Pain Sensation)
- Spinocerebellar Tract
- Dorsal Columns (proprioception, vibration sense)
- Descending Motor Tracts
- Corticospinal tract
- Corticobulbar Tract
VI. Anatomy: Shared Cranial Nerve Nucleii
- Nucleus Solitarius
- Located in the Medulla, visceral sensory region
- Multiple Cranial Nerve functions
- Nucleus Ambiguous
- Located in the Medulla, somatovisceral region
- Multiple Cranial Nerve functions
- Swallowing (CN 9, CN 10)
- Speech via vocal cord innervation (CN 10)
VII. Anatomy: Images
- High-Level Anatomic Relationships
Lewis (1918) Gray's Anatomy 20th ed (in public domain at Yahoo or BartleBy)
Lewis (1918) Gray's Anatomy 20th ed (in public domain at Yahoo or BartleBy)
Lewis (1918) Gray's Anatomy 20th ed (in public domain at Yahoo or BartleBy)
Lewis (1918) Gray's Anatomy 20th ed (in public domain at Yahoo or BartleBy)
Lewis (1918) Gray's Anatomy 20th ed (in public domain at Yahoo or BartleBy)
-
Cranial Nerves Brainstem exits
Lewis (1918) Gray's Anatomy 20th ed (in public domain at Yahoo or BartleBy)
Lewis (1918) Gray's Anatomy 20th ed (in public domain at Yahoo or BartleBy)
-
Cranial Nerve Nucleii
Lewis (1918) Gray's Anatomy 20th ed (in public domain at Yahoo or BartleBy)
Lewis (1918) Gray's Anatomy 20th ed (in public domain at Yahoo or BartleBy)
- Miscellaneous
Lewis (1918) Gray's Anatomy 20th ed (in public domain at Yahoo or BartleBy)
Lewis (1918) Gray's Anatomy 20th ed (in public domain at Yahoo or BartleBy)
Lewis (1918) Gray's Anatomy 20th ed (in public domain at Yahoo or BartleBy)
Lewis (1918) Gray's Anatomy 20th ed (in public domain at Yahoo or BartleBy)
Lewis (1918) Gray's Anatomy 20th ed (in public domain at Yahoo or BartleBy)
Lewis (1918) Gray's Anatomy 20th ed (in public domain at Yahoo or BartleBy)
Lewis (1918) Gray's Anatomy 20th ed (in public domain at Yahoo or BartleBy)
Lewis (1918) Gray's Anatomy 20th ed (in public domain at Yahoo or BartleBy)
Lewis (1918) Gray's Anatomy 20th ed (in public domain at Yahoo or BartleBy)
Lewis (1918) Gray's Anatomy 20th ed (in public domain at Yahoo or BartleBy)
VIII. Pathophysiology
IX. Signs: Brain Lesions
- Cranial Nerve dysfunction
- Ataxia
- Papillary abnormalities
- Nystagmus
- Hemiparesis
- Autonomic Dysfunction
X. References
- Gilman (1989) Manter and Gatz Essentials of Neuroanatomy and Neurophysiology, Davis, p. 81-96
- Goldberg (2014) Clinical Neuroanatomy, Medmaster, p. 24-39
- Netter (1997) Atlas Human Anatomy, ICON Learning, p. 108-12
- Newton (1994) Am Fam Physician 49(4): 787-97 [PubMed]
Calculation (FPnotebook.com: DrBits) Open in New Window
Images: Related links to external sites (from Bing)
Related Studies
Definition (NCI) | The part of the brain that connects the cerebral hemispheres with the spinal cord. It consists of the mesencephalon, pons, and medulla oblongata.(MeSH) |
Definition (NCI_NCI-GLOSS) | The part of the brain that is connected to the spinal cord. |
Definition (NCI_CDISC) | The part of the brain that connects the cerebral hemispheres with the spinal cord. It consists of the mesencephalon, pons, and medulla oblongata. (NCI) |
Definition (MSH) | The part of the brain that connects the CEREBRAL HEMISPHERES with the SPINAL CORD. It consists of the MESENCEPHALON; PONS; and MEDULLA OBLONGATA. |
Definition (CSP) | axial portion of the brain exclusive of the cerebellum and the forebrain; includes midbrain, medulla, and pons. |
Concepts | Body Part, Organ, or Organ Component (T023) |
MSH | D001933 |
SnomedCT | 15926001 |
English | Brain Stem, Brain Stems, Brainstem, Brainstems, brain stems, brain stem, brainstem, Truncus encephali, truncus cerebri, Truncus encephalicus, BRAIN STEM, BRAIN, BRAIN STEM, Truncus Cerebri, Cerebri, Truncus, Cerebrus, Truncus, Truncus Cerebrus, Brain stem, Brainstem structure, Brainstem structure (body structure) |
Swedish | Hjärnstam |
Czech | mozkový kmen |
Finnish | Aivorunko |
Russian | STVOL MOZGA, СТВОЛ МОЗГА |
Japanese | 脳幹 |
Croatian | MOŽDANO DEBLO |
Latvian | Stumbrs, smadzeņu, Smadzeņu stumbrs |
Polish | Pień mózgu |
Norwegian | Truncus cerebri, Hjernestamme |
Spanish | Tronco Cerebral, Tallo Encefálico, Tallo Cerebral, Tronco del Encéfalo, estructura del tronco cerebral (estructura corporal), estructura del tronco cerebral, tronco del encéfalo, tronco encefálico, Tronco Encefálico |
Portuguese | Tronco Cerebral, Tronco do Encéfalo, Tronco Encefálico |
French | Tronc cérébral |
German | Hirnstamm, Truncus cerebri |
Italian | Tronco cerebrale |
Dutch | Hersenstam |
Ontology: Structure of nucleus ambiguus (C0152400)
Definition (NCI) | A very slender, longitudinal column of motor neurons in the ventrolateral medulla oblongata; its efferent fibres leave with the vagus and glossopharyngeal nerve and innervate the striated muscle fibres of the pharynx (including the musculus levator veli palatini) and the vocal cord muscles of the larynx.(On-line Medical Dictionary) |
Concepts | Body Part, Organ, or Organ Component (T023) |
MSH | D008526 |
SnomedCT | 2083001 |
English | Ambiguus nucleus, Amb, ambiguus nucleus, nucleus ambiguus, ambiguous nucleus, Nucleus innominatus, Ambiguous Nucleus, Nucleus, Ambiguous, Ambiguus, Nucleus, Nucleus Ambiguus, Nucleus ambiguus, Structure of nucleus ambiguus (body structure), Structure of nucleus ambiguus |
Spanish | estructura del núcleo ambiguo (estructura corporal), estructura del núcleo ambiguo, núcleo ambiguo |
Ontology: Nucleus solitarius (C0175518)
Definition (NCI) | Gray matter located in the dorsomedial part of the medulla oblongata associated with the solitary tract. The solitary nucleus receives inputs from most organ systems including the terminations of the facial, glossopharyngeal, and vagus nerves. It is a major coordinator of autonomic nervous system regulation of cardiovascular, respiratory, gustatory, gastrointestinal, and chemoreceptive aspects of homeostasis. The solitary nucleus is also notable for the large number of neurotransmitters which are found therein. (MeSH) |
Definition (MSH) | GRAY MATTER located in the dorsomedial part of the MEDULLA OBLONGATA associated with the solitary tract. The solitary nucleus receives inputs from most organ systems including the terminations of the facial, glossopharyngeal, and vagus nerves. It is a major coordinator of AUTONOMIC NERVOUS SYSTEM regulation of cardiovascular, respiratory, gustatory, gastrointestinal, and chemoreceptive aspects of HOMEOSTASIS. The solitary nucleus is also notable for the large number of NEUROTRANSMITTERS which are found therein. |
Definition (CSP) | gray matter located in the dorsomedial part of the medulla oblongata associated with the solitary tract; receives inputs from most organ systems including the terminations of the facial, glossopharyngeal, and vagus nerves; major coordinator of autonomic nervous system regulation of cardiovascular, respiratory, gustatory, gastrointestinal, and chemoreceptive aspects of homeostasis. |
Concepts | Body Part, Organ, or Organ Component (T023) |
MSH | D017552 |
SnomedCT | 61538008, 280182005 |
English | Solitary Nucleus, Nucleus Tractus Solitarii, Nucleus Solitarius, Nucleus Tractus Solitarius, Nucleus, Solitary, Nucleus of the Tractus Solitarius, solitary tract nucleus, NTS, Nucleus of solitary tract, Nuclei of solitary tract, Solitary tract nuclear complex, Solitary nucleus, Solitary nuclei, Nucleus tractus solitarius, nucleus of solitary tract, nucleus of the solitary tract, solitary nucleus, Sol, solitary nuclear complex, nucleus of tractus solitarius, Nucleus tracti solitarii, Nucleus fasciculus solitarius, Nuclei tractus solitarii, Nucleus tractus solitarii, Nucleus solitarius (body structure), Nuclei Tractus Solitarii, Nuclei Tractus Solitarius, Solitarius, Nuclei Tractus, Tractus Solitarius, Nuclei, Complex, Solitary Nuclear, Solitary Nuclear Complex, Nuclear Complices, Solitary, Solitary Nuclear Complices, Nuclear Complex, Solitary, Tractus Solitarius Nucleus, Nucleus of Solitary Tract, Nucleus of Tractus Solitarius, Solitarii, Nuclei Tractus, Solitarius Nucleus, Tractus, Tractus Solitarii, Nuclei, Complices, Solitary Nuclear, Nucleus of tractus solitarius, Structure of nucleus of tractus solitarius (body structure), Structure of nucleus of tractus solitarius, Nucleus solitarius, nucleus tractus solitarius, Nucleus of the Solitary Tract, Nucleus, Solitary Tract, Solitary Tract Nucleus |
French | Nucleus solitarius, Noyaux du tractus solitaire, Noyau du tractus solitaire, Noyau solitaire, Noyau du faisceau solitaire |
Swedish | Solitärkärna |
Czech | nucleus solitarius |
Finnish | Erillistumake |
Russian | SOLITARNOE IADRO, IADRO SOLITARNOE, NUCLEUS SOLITARIUS, СОЛИТАРНОЕ ЯДРО, ЯДРО СОЛИТАРНОЕ |
Japanese | 孤束核 |
Italian | Nucleo del tratto solitario, Nucleo solitario |
Polish | Jądro samotne |
Norwegian | Nucleus tractus solitarii, Nucleus solitarius |
Spanish | núcleo solitario, núcleo solitario (estructura corporal), estructura del núcleo del tracto solitario (estructura corporal), estructura del núcleo del tracto solitario, núcleo del tracto solitario, Núcleo Solitario, Nucleus Solitarius |
German | Nucleus solitarius, Nucleus tractus solitarii |
Dutch | Nucleus solitarius |
Portuguese | Núcleo Solitário, Nucleus Solitarius |
Ontology: Nucleus of origin of cranial nerve (C0926501)
Concepts | Body Part, Organ, or Organ Component (T023) |
English | Nucleus of origin of cranial nerve, Nucleus originis |