Medulla-oblongata :::
It is a conically expanded continuation of upper part of the spinal cord extending upto lower margin of the pons Anteriorly medulla oblongata shows two elevation separated by anterior median fissure Two elevations indicate pyramidal tracts About three fourth of these pyramidal tracts cross at a level of medulla oblongata posteriorly there is the fourth ventricle Cardiac vasomotor vomiting and deglutition centres lie in the floor of fourth ventricle Besides these there are nuclei of VII, IX, X,XI and XII cranial nerves Lateral part of medulla oblongata consists of olivary nucleus nucleus of vth cranial nerve and lateral funiculus
FIG- Medulla-oblongata
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Functions of medulla-oblongata :
(1) Control of cardiovascular system through pressor and depressor centres
(2) Control of respiration through inspiratory and expiratory centres
(3) Integrated reflexes such as coughing sneezing swallowing salivary sucking vomiting etc are mediated through medulla oblongata for vomiting there is the chemoreceptor trigger zone (CTZ) centre in the medulla oblongata
(4) Interconnection with pons cerebellum and spinal cord
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