Final answer:
The hormone that decreases with age and affects growth is the growth hormone (GH). It is released by somatotroph cells in the anterior pituitary gland and is crucial for stimulating muscle growth and body fat loss. Deficiencies in GH can lead to disorders such as Turner Syndrome and Prader-Willi Syndrome.
Step-by-step explanation:
Growth Hormone and Aging
The hormone that decreases with age, affecting children more than adults, is the growth hormone (GH) or somatotropin. This hormone is released by somatotrophs cells in the anterior pituitary gland. GH is critical for growth and development, stimulating muscle mass growth and body fat loss.
A deficiency in GH can lead to various disorders, including Turner Syndrome in females, which is characterized by short stature, lack of ovarian development, and heart defects, and Prader-Willi Syndrome, where individuals have insufficient levels of GH leading to symptoms like weak muscle tone, feeding difficulties, and poor growth.
As individuals age, the production of GH declines, evident by reduced muscle mass in the elderly. The regulation of GH is under the control of hormones released from the hypothalamus, specifically GHRH and GHIH (somatostatin). Moreover, the physiological changes in the anterior pituitary over time, such as decreased vascularization, affect its capacity to produce GH, among other hormones.
Furthermore, GH influences the rate of muscle and bone growth, with its actions being mediated indirectly by insulin-like growth factors (IGFs). Disorders such as pituitary dwarfism may occur in children with abnormally low levels of GH, whereas oversecretion can lead to gigantism in children and acromegaly in adults.