Summary
A pituitary hormone stimulating growth of bone and muscle and affecting metabolism.
In depth
Secreted in pulses, mostly during sleep; stimulates liver to make IGF-1. Deficiency causes dwarfism in children; excess causes gigantism or acromegaly. Recombinant GH is used therapeutically and misused in sport.
Secreted mainly at night. Acts directly and via IGF-1. Used medically for short stature due to deficiency.
Remember: excess in adults causes acromegaly with enlarged hands and face.
Growth hormone (GH, somatotropin) is a protein secreted by the anterior pituitary in pulses, mostly during deep sleep, under control of GHRH (stimulating) and somatostatin (inhibiting). It acts directly and also by stimulating the liver to make insulin-like growth factor 1 (IGF-1), which promotes growth of bone cartilage, muscle and organs.
Metabolically, GH raises blood glucose and promotes fat breakdown. Excess in childhood causes gigantism, in adults acromegaly (enlarged hands, feet and jaw); deficiency in childhood causes dwarfism, treated with recombinant GH. GH misuse in sport is banned. Levels fall with age.
Example: recombinant human GH was one of the early products of genetic engineering.
Key idea: much of GH's growth effect is mediated by IGF-1.
Frequently asked questions
What is Growth Hormone?
A pituitary hormone stimulating growth of bone and muscle and affecting metabolism.
Which area of biology covers Growth Hormone, and how advanced is it?
Growth Hormone is one of the 54 topics in Reproduction & Endocrinology. It is rated Intermediate, so it suits learners who already know the core vocabulary. Related topics in this area include Negative Feedback in Endocrine Control, Hormones, Adrenal Cortex Hormones.
Can you give an example of Growth Hormone?
Robert Wadlow, the tallest man, had gigantism.
What should I learn before Growth Hormone?
Work through the Beginner topics in Reproduction & Endocrinology first, such as Reproduction, Asexual Reproduction, Sexual Reproduction, then return to Growth Hormone. Intermediate topics assume the Beginner vocabulary.
What topics are related to Growth Hormone?
The closest topics to Growth Hormone are Negative Feedback in Endocrine Control, Hormones, Adrenal Cortex Hormones, Hypothalamic-Pituitary Axis. Comparing them side by side is a good way to see how the ideas connect.
How can I check that I understand Growth Hormone?
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Growth Hormone. To practise the whole of Reproduction & Endocrinology, use the Reproduction & Endocrinology quiz.
How is Growth Hormone different from Negative Feedback in Endocrine Control?
Growth Hormone: A pituitary hormone stimulating growth of bone and muscle and affecting metabolism. Negative Feedback in Endocrine Control: Rising hormone levels inhibit further secretion, as with thyroxine and TSH. Read both side by side and note what each one explains.
How should I study Growth Hormone step by step?
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Negative Feedback in Endocrine Control and explain the difference aloud. Finally, take the Reproduction & Endocrinology quiz and come back to this page for any question you miss.