Medulla oblongata

Changed by Craig Hacking, 18 Aug 2016

Updates to Article Attributes

Body was changed:

Show markup changes

The medulla oblongata (or simply medulla) is the most caudal part of the brainstem and sits between the pons inferiorly and spinal cord superiorly. It is the transition from the spinal cord to the brain.

The medulla contains the vital autonomic cardiovascular and respiratory centers controlling heart rate, blood pressure, and breathing. It is composed of grey matter, cranial nerve (CN) nuclei IX-to-XII, and white matter tracts^2,3.

Gross anatomy

The medulla is approximately 3cm in length and 2cm in greatest diameter². The ~~caudal~~ caudal border of the medulla is the 1st cervical spinal nerves. The superior broad part of the medulla joins the pons ^2,3.

Medulla is separated into two main parts:

ventral (anterior) medulla which contains the olive, pyramidal tracts, and CN 9-12 rootlets
tegmentum (dorsal) medulla which contain the CN nuclei and white matter tracts

Ventral medulla

Pyramids are paired structures located at the medial aspect of ventral medulla and flank the anterior median fissure. It contains the anterior and lateral corticospinal tracts. At the caudal end of pyramids the corticospinal tracts decussate^2,3.

Olivary bodies are paired structures located at lateral aspect of ventral medulla, lateral to the pyramids. They are separated from the pyramids by an anterolateral sulcus (pre-olivary sulcus). There is also a post-olivary sulcus lateral to the olivary bodies. Olivary bodies contain the superior and larger inferior olivary nuclei².

Medulla tegmentum

The dorsal aspect of the medulla contains the posterior median sulcus (most dorsal medial sulcus) and more lateral posterolateral sulcus. Between these sulci are the fasciculus gracilis and nuclei forming gracilis tubercle at the midline and fasciculus cuneatus and nuclei forming cuneate tubercle more laterally^2,3.

The superior dorsal aspect of medulla forms the floor of the inferior 4th ventricle. It is occupied by the inferior cerebellar peduncle situated between the lower part of the fourth ventricle. The inferior dorsal and lateral aspect of the medulla is surrounded by the cisterna magna (posterior cerebellomedullary cistern), and lateral cerebellomedullary cistern^2,3.

The median aperture (foramen of Magendie) and the more superior lateral apertures (foramina of Luschka) open at the level of the pons, with the canals projecting to the level of the medulla region and terminating into the cisterna magna and lateral cerebellomedullary cistern respectively ¹.

Cranial nerves

The nuclei of the cranial nerves in the medulla originate in the tegmentum, but the nerve roots exit ventrally. Cranial nerves IX and X as well as the roots of XI exit the lateral medulla at the post-olivary sulcus, posterior to olivary bodies. Cranial nerve XII emerges between the pyramid and the olive at the pre-olivary sulcus as a number of rootlets ^2,3.

Blood supply

posterior inferior cerebellar artery (PICA) supplies the lateral aspect of the medulla ^2,3
anterior spinal artery supplies the entire medial aspect^2,3
direct branches of the vertebral artery supplies an area between the other two main arteries^2,3

Embryology

The myelencephalon aspect of the rhombencephalon (or hindbrain) becomes the medulla.

Related pathology

Wallenberg syndrome (also callsed lateral medullary syndrome or PICA syndrome)
medial medullary syndrome
Wallerian degeneration
demyelinating lesions
syringobulbia
brainstem glioma
trauma

-<p>The <strong>medulla oblongata</strong> (or simply <strong>medulla</strong>) is the most caudal part of the <a href="/articles/brainstem">brainstem</a> and sits between the <a href="/articles/pons">pons</a> inferiorly and <a href="/articles/spinal-cord">spinal cord</a> superiorly. It is the transition from the spinal cord to the brain.</p><p>The medulla contains the vital autonomic cardiovascular and respiratory centers controlling heart rate, blood pressure, and breathing. It is composed of grey matter, cranial nerve (CN) nuclei IX-to-XII, and white matter tracts <sup>2,3</sup>.</p><h4>Gross anatomy</h4><p>The <strong>medulla</strong> is approximately 3cm in length and 2cm in greatest diameter <sup>2</sup>. The caudal border of the medulla is the 1st cervical spinal nerves. The superior broad part of the medulla joins the <a href="/articles/pons">pons</a> <sup>2,3</sup>.</p><p>Medulla is separated into two main parts:</p><ul>
~~-<li>ventral (anterior) medulla which contains the olive, pyramidal tracts, and CN 9-12 rootlets</li>~~
+<p>The <strong>medulla oblongata</strong> (or simply <strong>medulla</strong>) is the most caudal part of the <a href="/articles/brainstem">brainstem</a> and sits between the <a href="/articles/pons">pons</a> inferiorly and <a href="/articles/spinal-cord">spinal cord</a> superiorly. It is the transition from the spinal cord to the brain.</p><p>The medulla contains the vital autonomic cardiovascular and respiratory centers controlling heart rate, blood pressure, and breathing. It is composed of grey matter, cranial nerve (CN) nuclei IX-to-XII, and white matter tracts <sup>2,3</sup>.</p><h4>Gross anatomy</h4><p>The <strong>medulla</strong> is approximately 3cm in length and 2cm in greatest diameter <sup>2</sup>. The caudal border of the medulla is the 1st cervical spinal nerves. The superior broad part of the medulla joins the <a href="/articles/pons">pons</a> <sup>2,3</sup>.</p><p>Medulla is separated into two main parts:</p><ul>
+<li>ventral (anterior) medulla which contains the olive, <a title="Anterior corticospinal tract" href="/articles/anterior-corticospinal-tract">pyramidal tracts</a>, and CN 9-12 rootlets</li>
-</ul><h5>Ventral medulla</h5><p>Pyramids are paired structures located at the medial aspect of ventral medulla and flank the anterior median fissure. It contains the the <a href="/articles/corticospinal-tracts">corticospinal tracts</a>. At the caudal end of pyramids the corticospinal tracts decussate <sup>2,3</sup>.</p><p>Olivary bodies are paired structures located at lateral aspect of ventral medulla, lateral to the pyramids. They are separated from the pyramids by an anterolateral sulcus (pre-olivary sulcus). There is also a post-olivary sulcus lateral to the olivary bodies. Olivary bodies contain the superior and larger inferior olivary nuclei <sup>2</sup>.</p><h5>Medulla tegmentum</h5><p>The dorsal aspect of the medulla contains the posterior median sulcus (most dorsal medial sulcus) and more lateral posterolateral sulcus. Between these sulci are the fasciculus gracilis and nuclei forming gracilis tubercle at the midline and fasciculus cuneatus and nuclei forming cuneate tubercle more laterally <sup>2,3</sup>.</p><p>The superior dorsal aspect of medulla forms the floor of the inferior <a href="/articles/fourth-ventricle">4th ventricle</a>. It is occupied by the inferior cerebellar peduncle situated between the lower part of the fourth ventricle. The inferior dorsal and lateral aspect of the medulla is surrounded by the <a href="/articles/cisterna-magna">cisterna magna</a> (posterior cerebellomedullary cistern), and lateral cerebellomedullary cistern <sup>2,3</sup>.</p><p>The median aperture (<a href="/articles/foramen-of-magendie-1">foramen of Magendie</a>) and the more superior lateral apertures (<a href="/articles/lateral-apertures-of-luschka">foramina of Luschka</a>) open at the level of the pons, with the canals projecting to the level of the medulla region and terminating into the <a href="/articles/cisterna-magna">cisterna magna</a> and lateral cerebellomedullary cistern respectively <sup>1</sup>.</p><h5>Cranial nerves</h5><p>The nuclei of the <a href="/articles/cranial_nerves">cranial nerves</a> in the medulla originate in the tegmentum, but the nerve roots exit ventrally. <a href="/articles/glossopharyngeal-nerve">Cranial nerves IX</a> and <a href="/articles/vagus-nerve">X</a> as well as the roots of <a href="/articles/spinal-accessory-nerve">XI</a> exit the lateral medulla at the post-olivary sulcus, posterior to olivary bodies. <a href="/articles/hypoglossal-nerve">Cranial nerve XII </a>emerges between the pyramid and the olive at the pre-olivary sulcus as a number of rootlets <sup>2,3</sup>.</p><h4>Blood supply</h4><ul>
+</ul><h5>Ventral medulla</h5><p>Pyramids are paired structures located at the medial aspect of ventral medulla and flank the anterior median fissure. It contains the <a title="Anterior corticospinal tract" href="/articles/anterior-corticospinal-tract">anterior</a> and <a title="lateral corticospinal tract" href="/articles/lateral-corticospinal-tract">lateral corticospinal tracts</a>. At the caudal end of pyramids the corticospinal tracts decussate <sup>2,3</sup>.</p><p>Olivary bodies are paired structures located at lateral aspect of ventral medulla, lateral to the pyramids. They are separated from the pyramids by an anterolateral sulcus (pre-olivary sulcus). There is also a post-olivary sulcus lateral to the olivary bodies. Olivary bodies contain the superior and larger inferior olivary nuclei <sup>2</sup>.</p><h5>Medulla tegmentum</h5><p>The dorsal aspect of the medulla contains the posterior median sulcus (most dorsal medial sulcus) and more lateral posterolateral sulcus. Between these sulci are the fasciculus gracilis and nuclei forming gracilis tubercle at the midline and fasciculus cuneatus and nuclei forming cuneate tubercle more laterally <sup>2,3</sup>.</p><p>The superior dorsal aspect of medulla forms the floor of the inferior <a href="/articles/fourth-ventricle">4th ventricle</a>. It is occupied by the inferior cerebellar peduncle situated between the lower part of the fourth ventricle. The inferior dorsal and lateral aspect of the medulla is surrounded by the <a href="/articles/cisterna-magna">cisterna magna</a> (posterior cerebellomedullary cistern), and lateral cerebellomedullary cistern <sup>2,3</sup>.</p><p>The median aperture (<a href="/articles/foramen-of-magendie-1">foramen of Magendie</a>) and the more superior lateral apertures (<a href="/articles/lateral-apertures-of-luschka">foramina of Luschka</a>) open at the level of the pons, with the canals projecting to the level of the medulla region and terminating into the <a href="/articles/cisterna-magna">cisterna magna</a> and lateral cerebellomedullary cistern respectively <sup>1</sup>.</p><h5>Cranial nerves</h5><p>The nuclei of the <a href="/articles/cranial-nerves">cranial nerves</a> in the medulla originate in the tegmentum, but the nerve roots exit ventrally. <a href="/articles/glossopharyngeal-nerve">Cranial nerves IX</a> and <a href="/articles/vagus-nerve">X</a> as well as the roots of <a href="/articles/spinal-accessory-nerve">XI</a> exit the lateral medulla at the post-olivary sulcus, posterior to olivary bodies. <a href="/articles/hypoglossal-nerve">Cranial nerve XII </a>emerges between the pyramid and the olive at the pre-olivary sulcus as a number of rootlets <sup>2,3</sup>.</p><h4>Blood supply</h4><ul>
~~-<a href="/articles/anterior-spinal-artery">anterior spinal artery</a> supplies the entire medial aspect <sup>2,3</sup>~~
+<a href="/articles/anterior-spinal-artery">anterior spinal artery</a> supplies the entire medial aspect <sup>2,3</sup>
~~-<li>direct branches of the <a href="/articles/vertebral-artery">vertebral artery</a> supplies an area between the other two main arteries <sup>2,3</sup>~~
+<li>direct branches of the <a href="/articles/vertebral-artery">vertebral artery</a> supplies an area between the other two main arteries <sup>2,3</sup>

ADVERTISEMENT: Supporters see fewer/no ads

{"current_user":null,"inclusions":[{"imageId":23651,"studyId":37828,"caseSlug":"brainstem-dorsal-grays-anatomy-illustration-1","caption":"Figure 1: dorsal brainstem - Gray's anatomy illustration","thumbnail":"https://prod-images-static.radiopaedia.org/images/23651/ea187b9c4024432ab7074d859512ef_big_gallery.jpeg","isStack":false,"diagnosticCertainty":"not_applicable"},{"imageId":23646,"studyId":37823,"caseSlug":"brainstem-grays-anatomy-illustration-3","caption":"Figure 2: lateral brainstem - Gray's anatomy illustration","thumbnail":"https://prod-images-static.radiopaedia.org/images/23646/07a853b364250ce23587523d4d0f94_big_gallery.jpeg","isStack":false,"diagnosticCertainty":"not_applicable"},{"imageId":23643,"studyId":37820,"caseSlug":"brainstem-grays-anatomy-illustration-2","caption":"Figure 3: brainstem - Gray's anatomy illustration","thumbnail":"https://prod-images-static.radiopaedia.org/images/23643/76f8ba3daff8e364564c76439ab144_big_gallery.jpeg","isStack":false,"diagnosticCertainty":"not_applicable"},{"imageId":5439151,"studyId":26770,"caseSlug":"medulla-oblongata","caption":"Figure 4: brainstem ","thumbnail":"https://prod-images-static.radiopaedia.org/images/5439151/29eaffc7b3dd65a296b7e546fd48c6_big_gallery.jpg","isStack":false,"diagnosticCertainty":"not_applicable"},{"imageId":53432157,"studyId":95719,"caseSlug":"mid-level-medulla-anatomy-grays-illustration","caption":"Figure 5: mid-level medulla anatomy (Gray's illustration)","thumbnail":"https://prod-images-static.radiopaedia.org/images/53432157/Gray695_big_gallery.jpeg","isStack":false,"diagnosticCertainty":"not_applicable"},{"imageId":53432125,"studyId":95716,"caseSlug":"decussation-of-fibres-in-the-brainstem-grays-illustration","caption":"Figure 6: decussation of fibers in the brainstem (Gray's illustration)","thumbnail":"https://prod-images-static.radiopaedia.org/images/53432125/Gray690_big_gallery.jpeg","isStack":false,"diagnosticCertainty":"not_applicable"},{"imageId":545665,"studyId":11258,"caseSlug":"cerebral-vascular-territories-illustration","caption":"Figure 8: arterial vascular territories (illustration)","thumbnail":"https://prod-images-static.radiopaedia.org/images/545665/c0cc03ff54855a0714645faf43edec_big_gallery.jpeg","isStack":true,"diagnosticCertainty":"not_applicable"},{"imageId":53146095,"studyId":93394,"caseSlug":"brain-venous-vascular-territories-diagram","caption":"Figure 9: venous vascular territories (illustration)","thumbnail":"https://prod-images-static.radiopaedia.org/images/53146095/e996ff33ae3c07bcadc22feee3260c_big_gallery.jpeg","isStack":true,"diagnosticCertainty":"not_applicable"},{"imageId":53433316,"studyId":95736,"caseSlug":"pyramids-and-olives-grays-illustration","caption":"Figure 10: pyramids and olives (Gray's illustration)","thumbnail":"https://prod-images-static.radiopaedia.org/images/53433316/Gray679_big_gallery.jpeg","isStack":false,"diagnosticCertainty":"not_applicable"},{"imageId":53466272,"studyId":95923,"caseSlug":"brainstem-cross-sectional-anatomy-diagrams","caption":"Figure 11: lower medulla axial section (diagrams)","thumbnail":"https://prod-images-static.radiopaedia.org/images/53466272/Brainstem_images.008_big_gallery.jpeg","isStack":false,"diagnosticCertainty":"not_applicable"},{"imageId":53466271,"studyId":95923,"caseSlug":"brainstem-cross-sectional-anatomy-diagrams","caption":"Figure 12: mid medulla axial section (diagrams)","thumbnail":"https://prod-images-static.radiopaedia.org/images/53466271/Brainstem_images.007_big_gallery.jpeg","isStack":false,"diagnosticCertainty":"not_applicable"},{"imageId":53466270,"studyId":95923,"caseSlug":"brainstem-cross-sectional-anatomy-diagrams","caption":"Figure 13: upper medulla axial section (diagrams)","thumbnail":"https://prod-images-static.radiopaedia.org/images/53466270/Brainstem_images.006_big_gallery.jpeg","isStack":false,"diagnosticCertainty":"not_applicable"},{"imageId":53626608,"studyId":95925,"caseSlug":"brainstem-arterial-territories-diagrams","caption":"Figure 14: brainstem arterial territories","thumbnail":"https://prod-images-static.radiopaedia.org/images/53626608/Brainstem_images.001_big_gallery.jpeg","isStack":true,"diagnosticCertainty":"not_applicable"}],"ddx_inclusions":[],"lang":"us"}