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Drugs that stop you vomiting
Published in Daniel Cottle, Shondipon Laha, Peter Nightingale, Anaesthetics for Junior Doctors and Allied Professionals, 2018
Nicola Smith, Kenneth McGrattan
Nausea is defined as an unpleasant sensory experience with the urge to expel gastric contents via the vomiting reflex but it may be present without the physical act of vomiting. The vomiting reflex is a complex, protective mechanism designed to avoid ingestion of toxic substances. The reflex is coordinated by the vomiting centre located in the dorsolateral reticular formation of the medulla oblongata. Stimuli for nausea and vomiting come from many sources including the gastrointestinal tract, the chemoreceptor trigger zone, the vestibular system and higher centres of the brain. Afferent input into the vomiting centre is via the glossopharyngeal and vagus nerve from the pharynx, upper oesophagus and stomach. The vomiting centre coordinates incoming signals and brings about vomiting via the cranial and spinal nerves that supply the upper gastrointestinal tract, diaphragm and abdominal muscles.
The transport and exchange systems: respiratory and cardiovascular
Published in Nick Draper, Helen Marshall, Exercise Physiology, 2014
Cranial sensory nerves relay information about PCO2, PO2 and H+ concentrations to four areas in the brain stem. During breathing at rest the inspiratory area, located in the medulla oblongata, controls the rate and depth of breathing for inspiration and expiration. The inspiratory area stimulates the external intercostals and diaphragm to contract for two seconds. When this stimulus is removed (for three seconds) these muscle relax and expiration takes place. During exercise when active expiration is required, the expiratory area, also located in the medulla oblongata, sends nerve impulses to stimulate the internal intercostals, transversus thoracis and the abdominal muscles to contract. The pneumotaxic and apneustic centres, found within the Pons, are responsible during exercise for shortening the duration of inspiration and deepening breathing respectively.
The nervous system
Published in Laurie K. McCorry, Martin M. Zdanowicz, Cynthia Y. Gonnella, Essentials of Human Physiology and Pathophysiology for Pharmacy and Allied Health, 2019
Laurie K. McCorry, Martin M. Zdanowicz, Cynthia Y. Gonnella
The medulla, which is immediately superior to and continuous with the spinal cord, contains control centers for subconscious, involuntary functions such as cardiovascular activity, respiration, swallowing, and vomiting. The primary function of the pons is to serve as a relay for the transfer of information between the cerebrum and the cerebellum. Along with the medulla, it also contributes to the control of breathing. Continuing rostrally from the medulla and pons, the midbrain controls eye movement and relays signals for auditory and visual reflexes. It also provides linkages between components of the motor system including the cerebellum, the basal ganglia, and the cerebrum.
Measurement of Fetal Mesencephalon and Pons Via Ultrasonographic Cross Sectional Imagining
Published in Fetal and Pediatric Pathology, 2018
Ruiqi Yang, Rui Li, Xuejuan Liu, Limei Fan, Jialing Zhang, Libo Wang, Hong Teng
During the fourth and fifth weeks of gestation, three primary brain vesicles complete their development: forebrain vesicle, midbrain vesicle, and metencephalon vesicle (1). Midbrain vesicle will form mesencephalon or midbrain; metencephalon vesicle will form the pons, medulla oblongata, and cerebellum (2). The mesencephalon, pons, and inferior medulla oblongata compose brainstem, the region of the brain that connects cerebrum with spinal cord. Pons, a major portion of which appears as a broad anterior bulge, participates in the transmission of signals between the cerebrum and the rest of the body and is involved in the regulation of sleep, respiration, swallowing, bladder control, hearing, equilibrium, taste, eye movement, facial expressions, facial sensation, and posture (3).
Dopamine β hydroxylase as a potential drug target to combat hypertension
Published in Expert Opinion on Investigational Drugs, 2020
Sanjay Kumar Dey, Manisha Saini, Pankaj Prabhakar, Suman Kundu
BP and cardiovascular functions are regulated in the medulla oblongata that is further controlled by the chemoreceptors of the central nervous system components. The control also emanates from peripheral reflexes from baro-, chemo-, mechano-, thermo-, and noci- ceptor afferent neurons located in the peripheral organs including the heart, skeletal muscles, blood vessels, lungs, viscera including kidney, and skin [21]. Neural networks from the medullary nucleus tractus soliterius (NTS) innervate toward ventrolateral medulla and helps the later to control sympathetic outflow and sympathetic tone [22–24]. NTS also regulates the vagal outflow to the cardiovascular system via its preganglionic synapses with para-sympathetic neurons [21].
Medulla oblongata germinoma with Klinefelter syndrome
Published in British Journal of Neurosurgery, 2021
Li-Hsin Tai, Sheau-Fang Yang, Yu-Li Chen, Yoon Bin Chong, Ta-Chih Yu, Ann-Shung Lieu
The clinical manifestations of brain tumors have a close relation to the location of brain tumors. The most common regions of intracranial germinomas are the pineal and suprasellar regions, hence intracranial germinomas often demonstrate symptoms of polydipsia, polyuria, visual impairment, growth retardation and delayed puberty. The medulla oblongata is the cardiac, respiratory, vomiting and vasomotor functions center of the human body; it modulates the autonomic involuntary functions such as breathing, heart rate and blood pressure.2 In our case, the tumor, which compressed the medulla oblongata, interfered with autonomic function and the patient consequently presented with recurrent syncopal episodes.