The Role of Hypothalamus in Food Intake

A mechanism is a process involved in various activities of the body. The major events being ingestion and digestion. The process of food intake begins from the mouth where food took through the mouth mixed with fluids such as acids and enzymes hence enabling absorption. Saliva in the mouth plays a significant role in metabolism because the food is broken down into smaller pieces. Some of the food ingested is broken down into other substances. Food containing carbohydrates is broken down to sugar and starch. The food generates energy to the body that supports it in its activities. In most cases, the amount of food consumed does not relate to energy expenditure, though power generation depends on food for human beings. The hormonal and neural signals play a critical role in food intake. Hunger and satiety control lies with the hormones secreted by the hypothalamus. The hormones regulate food intake and ensure that the levels are not high neither are they low. The brain contributes much since it is the center of all body activities. The brain helps in regulating body heat. Therefore, the brain checks on all body operations including regulation (Morton, Cummings, Baskin, Barsh, & Schwartz, 2006).

Hypothalamus contribution

The hypothalamus is the commander center of the endocrine system. It conducts both the neural and endocrine functions. It produces and secretes many hormones that perform different roles in the body system. The pituitary grand suspend from the hypothalamus consists of neural tissue and glandular tissue. The glandular tissue develops from the digestive tract (Murphy, & Bloom, 2006). The hormones secreted by the hypothalamus help in digestion of food ingested. It means that food is changed into useful substances that help the body to perform its functions. Such changes include food modified to useful substances like sucrose, galactose, and starch.

Leptin as a regulator

Adipose tissue produces Leptin. Leptin decreases locomotor activity and neuroendocrine and immunological abnormalities. It is important in maintaining and regulating the body weight (Sherwood, 2015). Therefore, human beings without leptin are obese and also hyperphagic. The functionality of the hypothalamus ensures receipt and integration of neural, metabolic, and humoral signals. The melanocortin antagonist Agouti-related peptide and Neuropeptide are appetite stimulating peptides that help the body to yearn for food. The hypothalamic leptin control food intake by people and animals.

The orexins peptide

The orexins are peptides produced in the lateral hypothalamus. The principle function of orexins is to control food intake and alertness with genetic or acquired deficiency of orexin signaling resulting in narcolepsy. Administered of leptin decreases orexin expression. Fasting by human beings fasts chances of increasing orexin levels in the body is high.

The PYY peptide

The PYY is a 36 amino acid peptide secreted from the endocrine cells of the gut. When a person is fasting, the PYY levels are low hence when PYY1–36 and PYY3–36  circulates in the body; it leads to increase in postprandially. Both peptides when administered into the cerebrospinal fluid they develop an ability to increase food intake. The peptide PYY3–36  peripherally administered reduces food intake. Melanocortin system mediates the appetite- suppressing effects. In case of disruption, melanocortin system permits anorexigenic effects. Weight loss indicates the level of the peptide.

Ghrelin stimulator

Fasting, weight loss, and insulin-induced hypoglycemia increased ghrelin expression and peptide secretion. Ghrelin stimulates food intake and decreases fat utilization. Ghrelin is an enteric signal included in energy homeostasis. Ghrelin stimulates appetite rather than acting as a satiety signal. Insulin concentration is mainly within the olfactory bulb, cerebral cortex, hippocampus, and the arcuate nucleus found within the hypothalamus. Insulin regulates food intake into and within the body. The pancreatic signals take control of food intake. Insulin major function is to increase glucose uptake in most peripheral tissues. Similarly, insulin lowers the level of glucose in the blood. The induced insulin or the one that exists in the body can elicit hunger and stimulate eating to an individual. It results in increased food intake hence insufficient glucose reaches the brain. During fasting, the plasma insulin is little and always increases after someone has ingested food. The amount of insulin in the plasma conveys a signal indicating the degree of adiposity to any insulin-sensitive tissue. Weight loss leads to less insulin secretion, and low insulin reaches the receptors in the hypothalamus. Therefore, insulin that is in the brain reduces food intake hence food intake increases until body weight is back to normal. Overindulging leads to gaining body weight, increasing insulin signal and reducing food intake until the weight loss. Insulin is an adiposity signal integrated to determine food intake. Therefore, the presence of insulin is crucial in the body system. Its contribution assists the body in many different ways and absence of insulin leads to complications such as diabetes. It has a significant role in controlling blood sugar level is unique to a human being.

Corticotropin-releasing hormone (CRH)               

It is the peptide hormone that induces secretion of the adrenocorticotropic hormone. The hormone directs the body’s reaction to many forms of stress. The ACTH varies due to the variations in the secretion by the hypothalamus (Rolls, 2007).

Conclusion

Food intake regulation depends on various body hormone and neural signals. They create a conducive environment for digestion in the body. They help change food into useful substances that help in generation of energy. Therefore, more attention needed by the hormones is granted by the brain which is the center of all activities carried in the body.

References

Morton, G. J., Cummings, D. E., Baskin, D. G., Barsh, G. S., & Schwartz, M. W. (2006). Central nervous system control of food intake and body weight. Nature, 443(7109), 289.

Murphy, K. G., & Bloom, S. R. (2006). Gut hormones and the regulation of energy homeostasis. Nature, 444(7121), 854.

Rolls, E. T. (2007). Understanding the mechanisms of food intake and obesity. Obesity reviews, 8(s1), 67-72. Sherwood, L. (2015). Human physiology: from cells to systems. Cengage learning.

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