Fundamentals of Anatomy and Physiology †MyAssignmenthelp.com

Question: Discuss about the Fundamentals of Anatomy and Physiology. Answer: Introduction The control of food intake in humans is a very complicated process. Hunger as well as satiety are being affected by different physiological factors and process, each of which has salient features of its own. The hypothalamus has two distinct centers which act during the regulation of food intake. A feeding center that is tonically active and a satiety center that inhibits the feeding center thereby stopping food intake. Signals from these centers results in the changes in feeding habits of an animal and creates their sensation of hunger or fullness management (Soria-Gmez et al., 2014). The glucostatic theory suggests that if the glucose level is high it inhibits the feeding center by not suppressing the satiety center and as a result the animal loses its desire to eat. When blood glucose level decreases due to excess of insulin the satiety center is suppressed and as a result the feeding center gets activated and hence the animal senses hunger or has the desire to eat. Hence in case of a diabetic patient whose glucose level is already high that person will have less desire to eat. The lipostatic theory is another theory that states that the bodies eating behavior is dependent on the amount of fat present in the body. The body usually tries to balance its eating behavior by modulating the brain so that it can maintain a certain amount of body weight. If the fat storage increases then eating decreases and vice versa. Obesity is the result when this mechanism gets hampered. A hormone called leptin is also responsible for maintaining the body weight of an animal. It is secreted from adipocytes and acts as a messenger between the adipose tissue and the brain. This protein is produced under the control of the gene obese (ob). It has been found that the animals lacking the gene leptin as well as animals having a defective leptin gene tends to become obese (Hall, 2015). Nucleus tractus solitaries (NTS) management are a group of sensory nuclei which form a column of grey matter which is embedded into the medulla oblongata. One of the main functions of it is that it provides the sensation of taste from the facial nerve as it makes up around two third portion of the anterior part of our tongue. If it is active more then it increases the food intake whereas if it is damaged or less active then the person loses the desire to eat as the food seems tasteless. The hormone ghrelin is produced from stomach when the feeding center is active and this hormone is responsible for the sensation of hunger. When the satiety center is active it stops the synthesis of this hormone which results in loss of appetite and the desire to eat. Neuropeptide Y (NPY) is a peptide which is composed of around thirty six amino acids which acts between the autonomic nervous system and the brain as a neurotransmitter. It is mainly acts as a vasoconstrictor and also helps in the buildup of fat tissue in the abdominal region. It also interferes with the production of leptin and makes the gene mutated at high concentrations which in turn results in excess food intake by the organism and results in obesity. Melanocortins are group of peptides which are released from the pituitary gland that acts as receptors for various corticotropin hormones. Corticotropin-releasing hormone (CRH) is a forty one amino acid peptide which is involved in stress response. It is released from the hypothalamus and excess of CRH results in lowering of the NPY peptide and hence reduces the food intake by the organism (Rizzo, 2015). Peptide YY (PYY) or peptide tyrosine-tyrosine is present in humans management. It is made up of thirty-six amino acids and is secreted from the ileum and colon in response to feeding. PYY secretion inhibits feeding which is an antagonist to the function of ghrelin which induces feeding by the sensation of hunger. Obese people become resistant to leptin and tend to have less amount of PYY in their body (Crespo et al., 2014). Orexin builds the desire to eat food, and associates with the capacity of the substances that increases its production. Orexin is likewise appeared to increase the size of the meal by the suppression of postingestive feedback. They are inhibited by the action of leptin and becomes active by the action of ghrelin and hypoglycaemia (Sherwood, 2015). Conclusion From the above discussion, it is indicated that the sensation of hunger and satiety is not dependent only on one or two factors but is a complex mechanism where various factors play a crucial role. Each of these mechanisms is interlinked and function in collaboration to maintain the balance of food intake as required by an individual. References Crespo, C. S., Cachero, A. P., Jimnez, L. P., Barrios, V., Ferreiro, E. A. (2014). Peptides and food intake.Frontiers in endocrinology,5. Hall, J. E. (2015).Guyton and Hall Textbook of Medical Physiology E-Book. Elsevier Health Sciences. Rizzo, D. C. (2015).Fundamentals of anatomy and physiology. Cengage Learning. Sherwood, L. (2015).Human physiology: from cells to systems. Cengage learning. Soria-Gmez, E., Bellocchio, L., Reguero, L., Lepousez, G., Martin, C., Bendahmane, M., ... Wiesner, T. (2014). The endocannabinoid system controls food intake via olfactory processes.Nature neuroscience,17(3), 407-415.