Essay on The Endocrine System Billys Case - 1294 Words

Billys Remarkable Voice Introduction Billy is an elderly man who has experienced remarkable vocal changes throughout his life. Long-term growth and development occur as a consequence of hormone secration within the endocrine system. As an individual ages hormone secreation alters, changing how the human body is structured and functions. As a young boy Billy was a falsetto singer in a choir until he endured hormonal changes associated with puberty. He developed a broken tenor which was hard to control as well as his mood. During this period had also developed a larger muscle mass after taking up body building. After he participated in a choir, he engaged in rock and roll and country western singing. The current state his voice is†¦show more content†¦Table 1. Stimuli Mechanisms Example Humoral Secretion of a hormone is stimulated by changing blood levels of irons and nutrients. Parathyroid gland is stimulated by low calcium levels in the blood to release the hormone osteoclasts to break down bone and calcium Neural Secretion of a hormone is stimulated by nerve fibres. The adrenal medulla is stimulated by the sympathetic nervous system to release norepinephrane and epinephrine in response to stress. Hormonal Secreation of a hormone release is dependent on the secretion of another hormone. Gonadotropin is released from the hypothalamus. It travels through the hyposeal tract into the anterior pituitary lobe. The anterior pituitary lobe is stimulated by gonadotropin to release follicle-stimulating hormones (FSH) and lutenising hormones (LH) into the blood to stimulate the gonads to produce sex steroids such as testosterone. Growth hormones also operate using this mechanism. (Table adpated from Porterfield (2001), Finlayson Sanders (2007) and Marieb Hoehn (2014). The Pituitary Gland and Hormone Secretion Figure 2: The figure below illustrates how the interior structure of the pituitary gland and hypothalamus facilitate for hormone secretion. The pituitary gland consists of the posterior and anterior lobe. It is lined with