The Importance of your Medulla Oblongata
Central nervous system
The central nervous system is the communication system of the body. It serves to convey messages passed between the brain and the rest of the body. These messages can be voluntary, involuntary or simultaneous. When major organ are excited simultaneously the central nervous system has the additional task of processing the data attained via several different effectors at once (Snell, 2001). This process takes place in the central axial portion of the nervous system and is mostly referred to as the central nervous system (CNS) (Young, Young, Tolbert, 2008). The CNS is connected to the sensory and motor nerves respectively through cable-like structures (Snell, 2001). The sensory and motor nerves make up the peripheral nervous system.
The CNS integrates received information and influences the responses and reactions of the entire bodily functions (Smith, 1971). All multicellular organisms relay on the CNS for survival. The CNS is divided into several segments that receive signals from and respond to specific parts of the body and synapse directly without intermediate ganglia on brain tissue (Smith, 1971). These segments are the, retina and the optic nerve; which respond to the eyes, the cranial nerve; that responds to the brain and brainstem, and the olfactory epithelium (Snell, 2001) The olfactory epithelium is the only central nervous tissue that is available for therapeutic treatments (Snell, 2001). Another important segment of the CNS lay in the spinal cavity where nerves intertwine with the vertebrates Smith, 1971).
Central Nervous System
The CNS is a tubular structure that is subdivided into a forebrain, a midbrain, and a hindbrain by two constrictions (Snell, 2001). Secondary constrictions further divide the forebrain and hindbrain into rostral and caudal sections. The rostral segment of the forebrain is call the telencephalon and the caudal part of the brain is known as the diencephalon (Smith, 1971). The largest part of the brain is formed by the telencephalon as it is elevated from the right and left cerebral hemispheres (Snell, 2001). He remaining portion of the telencephalon in the midbrain does not enlarge and is reduced to a thin membrane, stretching from one hemisphere to the other (Tolbert, 2008). Fibres from the right and left hemispheres cross over through this membrane in the midline.
In the rostral part of the brain lays the pons segment and in the caudal part is where the medulla oblongata is (Snell, 2001). On the dorsal part of the pons segment is where the cerebellum develops. It lays across the back of the pons and takes the shape of a dumbbell-like mass (Snell, 2008). Figure 1 (below), shows in relationship between the segments of the brain to the skull in a mid-sagittal section. The diagram shows the position of the stem consisting of the medulla oblongata, pons segment, midbrain and the diencephalon.
The medulla oblongata is responsible, primarily, for controlling one's heart rate, among other autonomic functions (meaning functions that are formed involuntarily and without your conscious control). Therefore, organisms are not able to survive without this vital part of the brainstem (Snell, 2001). Other functions that would be affected by a medulla oblongata that was damaged would include one's respiration, reflexes, defecation, blood pressure, swallowing, as the nerve signals between the brain and spinal cord would no longer be working (Snell, 2001).
If the medulla somehow gets damaged, vital functions of the brain such as breathing, regulating heart rate and blood pressure will be hazardously affected, which may overtime lead to death (Snell, 2001). Damage to the posterior lateral region of the medulla leads to lateral medullary plate syndrome, which is also known as the Wallenberg Syndrome (Tolbert, 2008). A rare neurological condition caused by a stroke (involving the cerebellar artery) and resulting in symptoms such as facial paralysis or weakness on one side of body (Snell, 2001) Symptoms of lateral medullary plate syndrome include difficulty in swallowing and sometimes hoarseness due to paralysis of the ipsilateral vocal cord (Snell, 2001). The disorder is generally caused by a blockage in a vertebral or cerebellar artery (Smith, 1971). The brain-regulated process of voluntarily responding to pain and temperature is inhibited, causing the individual to experience loss of pain and temperature sensation on the ipsilateral face and contralateral body because of damage to the spinal trigeminal tract and spinothalamic tract, respectively (Tolbert, 2008).
Although there aren’t many treatment options for lateral medullary syndrome, there are some that have has success over the past. One of those treatment options involves focusing on relief of symptoms and active rehabilitation to help those suffering from the stroke symptoms to recover their daily living activities and to cope with neurologic loss (Snell, 2001). Depressed mood and withdrawal from society can be seen in patients following the initial neurologic trauma (Smith, 1971). If swallowing is impaired, a feeding tube inserted through the mouth or gastrostomy may be necessary (Snell, 2001). Speech therapy may be beneficial in diet recommendations and helping to understand if there is risk for pneumonia. In some cases, medication may be used to reduce or eliminate pain. Some studies have reported success in mitigating the chronic neuropathic pain associated with the syndrome with anti-epileptics such as gabapentin (Talbert, 2008). One of the most unique and difficult ways to treat symptoms that occur due to Wallenberg syndrome are incessant, violent hiccups (Snell, 2001). The hiccups can be so severe that patients often struggle to eat, sleep and carry on conversations. Depending on the severity of the blockage caused by the stroke, the hiccups can last for weeks (Snell, 2001). Unfortunately there are very few successful medications available to mediate the inconvenience of constant hiccups.
Central Nervous System
Neuroanatomy - The Brainstem (Medulla Oblongata)
Snell, R. S. (2001). Clinical Neuroanatomy: A review with Questions and Explanations (3rd ed.). Philadelphia, PA.
Young, P. A., Young, P. H., Tolbert, D. L. (2008). Basic Clinical Neuroscience (2nd ed.). Philadelphia, PA.
Smith, C. G. (1971). Basic Neuroanatomy (2nd ed.). Toronto, Canada.
Santiago, R. C. (1990). New Ideas on the Structure of the Nervous System in Man and Vertebrates. Palatino, IL.