Contents
The medulla oblongata (Latin medulla oblongata) is an important part of the hindbrain and is the lowest part of the brain stem, which additionally consists of the midbrain and the bridge. It is the central part of the autonomic nervous system.
An elongated core is also known as a pad. It is shaped like a flattened cone and about 3 cm long. Its truncated end connects the spinal cord to the brain, and its base connects to the posterior part of the bridge. The border between the medulla and the spinal cord is conventional and is located in the great occipital opening. It consists of two surfaces – basal and dorsal. It is there that the nerve centers that regulate the independent respiratory, vasomotor, cardiac and reflex functions, such as chewing, sucking and swallowing, are located. Injury to the medulla is a direct threat to life. The reason for this is that it contains reflex centers that are extremely important for human life. In this article, you will learn about the functions of the medulla, what its internal and external structure looks like, and what the spinal cord is.
Core elongated – functions
Centers in the medulla are responsible for many important life functions. The blood circulation center controls the heart rate and is responsible for maintaining the proper blood pressure by the proper tension of the walls in the arteries. The breathing center regulates the rhythm of breathing and stimulates the muscles of the respiratory system. There are also centers for many reflexes in the medulla, such as, for example, the mechanisms of coughing, sneezing, swallowing, chewing, vomiting, hiccuping, and salivation. In addition, there are also some thermoregulatory centers responsible, for example, for the secretion of sweat and the narrowing and widening of blood vessels.
In addition, the medulla also includes those centers that are involved in the functioning of the senses of taste, hearing and balance. The vestibulocochlear nerve, for example, mediates the taste sensation from the tongue. Part of the equilibrium system receives signals from the cerebellum and the inner ear, which are in turn transmitted to the brain and spinal cord.
Extended core – internal structure
The elongated white matter of the medulla contains all the sensory and motor nerve pathways that run between the spinal cord and other parts of the brain. The front part of the extension core is shaped like a bulge or thicker cords. They consist of pyramids through which the cortico-spinal tract (one of the pathways in the extremely important reticular formation of the brainstem) passes. They are located along the core and are separated from each other by a groove. On the side of the pyramids there are side cords topped with an anatomical structure called an olive at the top. They intersect at the bottom of the medulla where the spinal cord begins. If, for example, the left side of the body is paralyzed, it means that the right side of the body is damaged. The involuntary reflexes are performed thanks to the spinal nerves coming from the spinal cord and 5 of the 12 cranial nerves (V trigeminal, VII facial, VIII vestibulo-cochlear, IX lingual pharynx, X vagus and XII sublingual).
Extended core – external structure
Nerve fibers are located on the dorsal part of the medulla. At the top, the core goes into the lower limbs of the cerebellum, which plays a large role in motor control and which may also participate in human cognitive functions (e.g. attention, memory, language, thinking). There is gray matter inside the medulla.
Medulla and the spinal cord
The central nervous system, apart from the brain, also includes the spinal cord (Latin medulla spinalis) located in the spinal canal running in the spine. It is shaped like a cylindrical cord. The outer part of the spinal cord is symmetrically divided into two halves by two furrows: shallower and deeper. In addition, these core halves have an anterior lateral furrow extending from the front and a rear lateral furrow extending from the rear. There is both gray and white matter in the center of the vertebral trunk. It is characterized by thickening around the neck and loins. The relatively thin tubular extension of the CNS, which is the spinal cord (about 1 cm thick), extends from the brain to the spine and is closed by the vertebrae. The spinal cord is made up of 31 segments (8 cervical, 12 thoracic, 5 lumbar, 5 sacral and 1 coccygeal / caudal) called neuromers, or segments from which one pair of spinal nerves depart each. Its main role is to mediate the nerve impulses sent between the brain and the peripheral organs of the body. In addition, it is responsible for the proper innervation of muscles, glands and skin. The average length of the spinal cord is approximately 45 cm.
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