Medulla Oblongata Medulla Oblongata (bulbus/medulla) (bulbus/medulla)

Medulla Oblongata Medulla Oblongata

(bulbus/medulla) (bulbus/medulla)

Prof. Dr. Selda Önderoğlu

Prof. Dr. Selda Önderoğlu

Medulla Oblongata Medulla Oblongata

• The most inferior The most inferior part of brain stem.

part of brain stem.

• It is like the It is like the

widening of spinal widening of spinal

cord upwards.

cord upwards.

surfaces of Medulla oblongata surfaces of Medulla oblongata

• ^{Anterior Anterior}

• ^{posterior posterior}

structures on the anterior surface structures on the anterior surface (from midline laterally)

(from midline laterally)

-Ant. Median fissure- -Pyramid

-pyramidal

Decussation

-Anterolateral Sulcus

exits:Hypoglossal N.

exits:Hypoglossal N.

-Olive

-Retroolivary Sulcus

Exits:

Exits:

Glossophryngeal N.

Glossophryngeal N.

vagus N.

vagus N.

accessory N.

accessory N.

Posterolateral surface of Posterolateral surface of

Medulla oblongata Medulla oblongata

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Inferior Cerebellar Peduncle Inferior Cerebellar Peduncle

connects medulla to cerebellum connects medulla to cerebellum

Contains fibers of:

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Spinocerebellar tr.

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Posterior surface of Medulla Oblangata is Posterior surface of Medulla Oblangata is

the lower triangle of rhomboid fossa

the lower triangle of rhomboid fossa

Rhomboid Fossa Rhomboid Fossa

• Is the space bw.

Medulla+pons&cereb ellum.

• Filled with

cerebrospinal fluid

• Lower triangle is related to: medulla oblongata

• Upper triangle to:

pons

inferior part of post. Surface of Medulla inferior part of post. Surface of Medulla Oblongata-from midline laterally has

Oblongata-from midline laterally has

• posterior median Sulcus

• Fasciculus gracilis

• Tuberculum

gracilis(medial)

• Tuberculum cuneatus (lateral)

• Fasciculus cuneatus

From midline laterally has:

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•

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Superior part of post. Surface of Medulla oblangata

( Rhomboid fossa’s lower triangle )

Vestibular Nuclei Vestibular Nuclei

• 4 vestibular nuclei 1- superior

2- inferior 3-medial 4-lateral

Medial&inferior are

at bulbus level

• Last 4 cranial nn. Last 4 cranial nn.

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Cranial nerves emerging from Cranial nerves emerging from

medulla oblongata

medulla oblongata

Cranial nerve Nuclei in

brainstem

Nuc. ambiguus Nuc. ambiguus

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the nuclei of those 3 nn. Unite and form the nucl. Ambiguus

Spinal tract and nucleus of Spinal tract and nucleus of

Trigeminal nerve Trigeminal nerve

• Related to pain and temperature sensation carried from head and neck regions.

• Located at pons, medulla and upper 1-2 segments of spinal cord.

• At medulla level it is

located posterolaterally

• Nuc. spinalis nervi

trigemini bu tractus’un medialinde bulunur.

Solitary Tract Nucleus

Solitary Tract Nucleus

Dorsal Nucleus of Vagus Nerve

Dorsal Nucleus of Vagus Nerve

Inferior Salivatory Nucleus

Inferior Salivatory Nucleus

Brain stem (Cranial nerves) Brain stem (Cranial nerves)

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Reticular Nuclei at medulla level Reticular Nuclei at medulla level

• Nuc. reticularis lateralis Nuc. reticularis lateralis

• Nuc. reticularis ventralisNuc. reticularis ventralis

• Nuc. reticularis Nuc. reticularis gigantocellularis gigantocellularis

• Nuc. reticularis Nuc. reticularis parvocellullaris parvocellullaris

• Nuc. reticularis Nuc. reticularis paramedianus paramedianus

• Nuclei raphesNuclei raphes

– Nn. raphes obscurusNn. raphes obscurus – N. raphes pallidusN. raphes pallidus – N. raphes magnusN. raphes magnus

Internal structure of Medulla Oblongata Internal structure of Medulla Oblongata

(transverse section at lower levels) (transverse section at lower levels)

Pyramidal Decussation Fasciculus gracilis

Fasciculus cuneatus

Transverse section at the level Transverse section at the level

of pyramidal decussation of pyramidal decussation

• Nuc. cuneatus

• Nuc. Gracilis

• Spinal tract&

nucleus of

trigeminal nerve

Transverse section through the Transverse section through the

inferior level of olive inferior level of olive

• Cuneate nucleus

• Accessorius

cuneate nucleus

• Nucleus gracilis

• Spinal tract&

nucleus of

trigeminal nerve

• lateral reticular

Nucleus

Transv.Section through the level Transv.Section through the level

of inferior olivary complex of inferior olivary complex

principal olivary nuc.

Nuc.olivarius accessorius posterior

Nuc. olivarius accessorius med.

accessory cuneate

Nuc.

Transv.Section through upper Transv.Section through upper

levels of medulla levels of medulla

• Medial vestibular nuc.

• ınf. vestibular nuc.

• Gigantocellullar reticular nuc.

• Dorsal cochlear nuc.

• inferior olivary nuc.

• ^Pyramis

• Vagus nerve

Transv. Section at teh junction Transv. Section at teh junction

of medulla and Pons of medulla and Pons

• 4th Ventricle

• Cerebellar nuclei

• inf. cerebellar Peduncle

• Ventral& dorsal cochlear Nuc.

• medial Lemniscus

• Arcuate Nuc.