Medulla begins at the lower edge of the bridge and continue t Xia radicular filaments to the first cervical segment. From the side of the diamond on the prominent pits its upper boundary strips are brain 4th zhel have a daughter. In contrast to the spinal cord gray matter represented in the medulla oblongata clusters of neurons – nuclei are separated by layers of white matter and form reticular structures and of In the medulla, nuclei V and VII – XII pairs of cranial nerves are located, separated by conductive paths passing through the medulla, both in the ascending and descending directions. These nuclei lie at the bottom of the 4th ventricle, in the rhomboid fossa and partly in the bridge. Medulla oblongata, as well as the spinal cord, has two Ba in -valued functions: the introducer (conducting sensory and efferent and m ripple) and reflex (somatic and autonomic reflexes). You can also talk about the presence in the medulla of the three systems – motor, sensory and autonomic.
Conductor function. Through the medulla are all in the walking, or afferent, ways and descending or efferent, the ways of the spinal cord. In the medulla oblongata, the paths from the cerebral cortex of the brain — the cortical-bulbar paths — end. Here, the ascending pathways of proprioceptive sensitivity from the spinal cord end and the medial loop begins, carrying this information to the nuclei of the thalamus.
Brain structures such as the bridge, midbrain, cerebellum, thalamus, hypothalamus, and cerebral cortex have two-sided connections with the medulla. The presence of these links’s Certificate e ments on the participation of the medulla oblongata in the regulation of skeletal muscle tone, vegetative and higher integrative functions in the analysis of sensory stimuli.
The sensory functions of the medulla oblongata consist in the primary processing of sensory flows coming from the receptors. In caudineural of tons affairs of the medulla oblongata are paths of skin, proprioceptive, visceral sensitivity, some of which are switched to the second neuron. At the level of the medulla oblongata, the function of determining the biological significance of afferentation is performed.
Most of the autonomic reflexes medulla impl at etsya through disposed therein vegetative nucleus of the vagus nerve. These nuclei receive information on the state of the activity of the heart, the stomachs, the digestive tract, the lungs, the digestive glands, etc. In response to this information, the nuclei regulate the motor and secretory reactions of these organs by the mechanism of vegetative reflexes. The h and stnosti, excitation of neurons its vegetative nucleus (core back blu w authorizing nerve) increases gastric smooth muscle contraction, intestinal and the gallbladder and simultaneously relaxes the sphincters of these organs. At the same time the work of the heart slows down and weakens, the lumen of the bronchi decreases. In addition, the excitation of the nuclei of the vagus nerve enhances the secretory function of the stomach, bowel, pancreas, se to retornyh liver cells, and enhances the secretion of bronchial w e climb. The medulla has slyunootdeleleniya center at the asset and tion nuclei which increases the secretion of saliva. The reticular formation of the medulla oblongata located respiratory center, as well as angry h ny and vascular (vasomotor centers). The peculiarity of these tse n ters that their neurons are able to be excited by reflex, and under the influence of chemical irritants. The vessel-motor center regulates and rubs the vascular tone. The heart center regulates the activity of the heart (with the excitation of this center, the strength and frequency of heart contractions, as well as the conductivity and excitability of the heart muscle decrease). Both centers operate in conjunction with the hypothalamus and other senior Vegeta and active center. The medulla oblongata, together with the bridge and the midbrain, is involved in the control of movements . This is mainly due to the activity of the motor nuclei of cranial nerves, providing w boiling functions such as capturing, processing, and food ingestion. With the participation of the vestibular nuclei, and nuclei of the reticular formation prodolgov and This brain regulates posture. At the level of the medulla oblongata ra to rely monoaminergic system, which consists of a cluster of noradrenergic neurons (blue spot) and serotonergic neurons. Noradrenergic neurons of the locus coeruleus, together with d of faminergicheskimi neurons of the substantia nigra (placed at the cFe d therein brain) and serotonergic neurons form a so-called monoaminergic system , which is involved in the regulation of the cycle “sleep – wakefulness” emotional state and modulates higher mental processes – memory, attention, thinking.