Medulla Oblongata Anatomy PDF

Prof. Dr. Selda Önderoğlu Near East University Faculty of Medicine Dept. Of Anatomy Oblongata The most inferior part of brain stem. It is like the widening of spinal cord upwards.  surfaces of Medulla oblongata Anterio r posteri or  anterior surface: external featur...

Prof. Dr. Selda Önderoğlu Near East University Faculty of Medicine Dept. Of Anatomy Oblongata The most inferior part of brain stem. It is like the widening of spinal cord upwards.  surfaces of Medulla oblongata Anterio r posteri or  anterior surface: external features (from midline laterally) -Ant. Median fissure -Pyramid -pyramidal Decussation -Anterolateral Sulcus exits:Hypoglossal N. -Olive -Retroolivary Sulcus Exits: Glossophryngeal N. vagus N. accessory N. olive  Posterolateral surface of Medulla oblongata  glossopharyngeal N.  Vagus N.  Accessory N.  Inferior cerebellar Peduncle  Inferior Cerebellar Peduncle connects medulla to cerebellum Contains fibers of: post. Spinocerebellar Tract Some fibers of ant. Spinocerebellar tr.  cuneocerebellar tr. Olivocerebellar tr.  vestibulocerebellar tr. fibers from cerebellum to vestibular&reticular nuclei so, tracts from cerebellum to medulla or the opposite  Posterior surface of Medulla Oblangata is the lower triangle of rhomboid fossa(floor of 4th ventricle)  4th ventricle &Rhomboid Fossa 4th ventricle :Is the space bw. Medulla&pons- cerebellum.Filled with cerebrospinal fluid Rhomboid fossa: floor of 4th ventricle shape:quadrangular its Lower triangle is related to: medulla oblon gata Upper triangle to: pons of Medulla Oblongata-from midline laterally has posterior median Sulcus Tuberculum gracilis(medial)- Fasciculus gracilis Tuberculum cuneatus (lateral)- Fasciculus cuneatus  Superior part of post. Surface of Medulla oblangata ( Rhomboid fossa’s lower triangle) From midline laterally has:  post. Median sulcus Medial Eminence Sulcus limitans vestibular Area Stria medullaris  emerging from medulla oblongata Last 4 cranial nn.  glossopharyngeal n. (9)  Vagus n. (10)  Accessory n. (11)  Hypoglossal n. (12) The nuclei of these nn are located at medulla level(internal structure) Cranial nerve Nuclei in brainstem(9-12)  Nuc. ambiguus It is the The motor nucleus of 9-10-11th CN): glossopharyngeal n. (CN9)+Vagus n. (CN10)+Cranial part of accessory nerve (CN11) the nuclei of those 3 nn. Unite and form the nucleus Ambiguus  nucleus of Trigeminal nerve(CN V) F: 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 kin innervation of the face: is by the trigeminal nerve branches: ophthalmic,maxillary& mandibular nn. olitary Tract Nucleus Related to taste sensation Facial(7th) and glossopharyng eal(9th) cranial nerves Dorsal Nucleus of Vagus Nerve Parasympathe tic nucl.of vagus n.  Inferior Salivatory Nucleus Salivation. P-symp. Nucleus of glossopharyngeal n. (9th.cranial nerve)  Brain stem (Cranial nerves) Medulla oblongata Pons mesencephalo n  Vestibular Nuclei 4 vestibular nuclei 1- superior 2- inferior 3-medial 4-lateral Medial&inferior are at medulla oblongata level  Nuclei at medulla level  Nuc. reticularis lateralis  Nuc. reticularis ventralis  Nuc. reticularis gigantocellularis  Nuc. reticularis parvocellullaris  Nuc. reticularis paramedianus  Nuclei raphes – Nn. raphes obscurus – N. raphes pallidus – N. raphes magnus  Internal structure of Medulla Oblongata (transverse section at lower levels) Pyramidal Decussation Fasciculus gracilis Fasciculus cuneatus  Transverse section at the level of pyramidal decussation Nuc. cuneatus Nuc. Gracilis Spinal tract& nucleus of trigeminal nerve  Transverse section through the inferior level of olive Cuneate nucleus Accessorius cuneate nucleus Nucleus gracilis Spinal tract& nucleus of trigeminal nerve lateral reticular Nucleus  the level of inferior olivary complex principal olivary nuc. Nuc.olivarius accessorius posterior Nuc. olivarius accessorius med. accessory cuneate Nuc.  through upper levels of medulla Medial vestibular nuc. ınf. vestibular nuc. Gigantocellullar reticular nuc. Dorsal cochlear nuc. inferior olivary nuc. Pyramis Vagus nerve  medulla oblongata- level? 4th Ventricle Cerebellar nuclei inf. cerebellar Peduncle Ventral& dorsal cochlear Nuc. medial Lemniscus Arcuate Nuc.