Biology Research Paper-Gigantism is a condition characterized by abnormal or excessive growth and height significantly above average
by
cherno (student)
Cherno Okafor
Aida Stefani
SBI4U
November 10th, 2012
Gigantism is a condition characterized by abnormal or excessive growth and height significantly above average. It is divided into two parts: cerebral gigantism and pituitary gigantism. Cerebral gigantism occurs in the absence of increased levels of growth hormone, attributed to a cerebral defect; infants are large, and accelerated growth continues for the first 4 or 5 years, the rate being normal thereafter. The hands and feet are large, the head is large, narrow and long, and the eyes have an antimongoloid slant with an abnormally wide space between them. The child is clumsy, and mental retardation of varying degree is usually present. On the other hand, pituitary gigantism, in humans, is caused by over-production or secretion of the growth hormone in childhood before the long bone epiphyses (growth plates) close resulting in persons between 7 feet (2.13m) and 9 feet (2.74m) in height. The term is typically applied to those whose height is not just in the upper 1% of the population but several standard deviations above mean for persons of the same sex, age, and ethnic ancestry. The term “gigantism” does not apply to those who are simply “tall” or “above average” whose heights appear to be the healthy result of normal genetics and nutrition. If excess growth hormone occurs after normal bone growth has stopped in adulthood, the condition is known as acromegaly, which is a long-term condition in which there is too much growth hormone and the body tissues get larger over time. Symptoms include: congestive heart failure, glucose intolerance, and diabetes if left untreated.
Gigantism is usually caused by a benign (non-cancerous) tumor on the pituitary gland of the brain. It causes growth of the hands, face, feet, and other muscles and organs. In some cases, the condition can be passed on genetically through a mutated gene. Many of those who have been identified with gigantism have suffered from multiple health issues involving their circulatory or skeletal system. Pituitary tumours can be small in size (micro-adenoma) or large (macro-adenoma). However, in gigantism they are frequently large and invade nearby brain tissue. The size of the adenoma directly affects the signs and symptoms experienced by the individual. Larger adenomas can damage the function of the normal pituitary gland causing failure of secretion of other hormones (). In some cases, puberty may be delayed if pressure from the adenoma on the pituitary gland results in failure of sex hormone secretion and thus allows further growth of the skeleton.
