From the Guidelines
The medulla oblongata contains nuclei of cranial nerves IX through XII, which are crucial for various vital functions, including swallowing, taste, and motor control of the tongue and other muscles. These nuclei are located in the dorsal tegmentum of the medulla oblongata, as described in the study by 1. The specific nuclei present in the medulla oblongata include:
- The nucleus solitarius, which processes taste information and visceral sensations
- The nucleus ambiguus, which controls swallowing and some aspects of speech
- The hypoglossal nucleus, which controls tongue movements
- The dorsal motor nucleus of the vagus nerve, which regulates parasympathetic functions These nuclei are essential for maintaining homeostasis and basic life functions, and their damage can lead to severe consequences, including respiratory and cardiovascular problems, as mentioned in the study by 1. The location of these nuclei at the junction between the brain and spinal cord allows them to integrate information from higher brain centers and relay commands to the body, making them critical for survival. Lesions affecting the medulla oblongata, such as brainstem infarctions and hemorrhages, can lead to multiple cranial nerve palsies affecting CN IX through CN XII, as discussed in the study by 1. A thorough neurologic examination and tailored imaging protocols can help localize the process to the brainstem and identify the affected nuclei, as recommended in the study by 1.
From the Research
Nuclei of the Medulla Oblongata
The medulla oblongata contains several nuclei that play crucial roles in various functions, including:
- Nucleus of the solitary tract (nTS): a major site of brainstem control of vital functions, such as cardiovascular reflexes and respiration 2
- Dorsal motor nucleus of the vagus: involved in parasympathetic visceral control 3
- Nucleus ambiguus complex/ventral respiratory group: related to autonomic and respiratory control 2
- Rostral ventrolateral medulla (RVLM) and caudal ventrolateral medulla (CVLM): involved in the regulation of arterial blood pressure 4, 5
- Arcuate nucleus: located on the ventral aspect of the pyramid, sends numerous branches to the corticospinal portion of the pyramidal tract 6
- Nucleus raphe pallidus: contains stellate cells that project to the nucleus of the solitary tract, potentially participating in chemoreception and central regulation of cardiorespiratory reflexes 2
Specific Nuclei and Their Functions
Some of the nuclei in the medulla oblongata have specific functions, including:
- The nucleus tractus solitarius (NTS) as the primary site of cardiorespiratory reflex integration 5
- The RVLM as critical to the tonic and reflexive regulation of arterial pressure 5
- The CVLM as receiving baroreceptor input and relaying rostrally to control the activity of the RVLM 5
- The Vagal Trigone as a landmark for the underlying Dorsal Motor Nucleus of the Vagus, but only partially corresponding with it 3