Head and neck anatomy speech (phonation). In addition to the teeth, other structures that aid chewing are the lips, cheeks, tongue, hard palate, soft palate, and floor of the mouth. Several glands of the endocrine system are found within the head and neck. Endocrine means that the secretion is used within the body. Endocrine glands are termed as ductless and release their secretions directly into the blood. The endocrine system is under the direct supervision of the nervous system, using the negative feedback principal of homeostasis, to create hormones which act as chemical instant messengers. The hypothalamus connects directly to the pituitary gland, both
Obesity and the environment trigger." The theory of environmental obesogens proposes a different causal facet to obesity – that lifetime exposure to xenobiotic chemicals may change the body's metabolic system. Chemical obesogens are molecules that do not properly regulate lipid metabolism in the body and could therefore promote obesity. Data is scarce, but some in-vitro studies have found this model could be an accurate predictor of future obesity. A study suggested that smoking before and during pregnancy, for example, increases the risk of obesity twofold in children of school age. Many chemicals that are known or suspected to be obesogens are endocrine disruptors. These