Growth Hormone
Acromegaly — caused by excess growth hormone (GH) in an adult (after closure of epiphyseal plates).
Growth Hormone (GH / Somatotropin)
- Type: A protein hormone (191 amino acids).
- Functions: Essential for somatic growth and development, primarily by stimulating the liver and other tissues to produce Insulin-like Growth Factor 1 (IGF-1) and IGF-2. GH also has direct metabolic effects:
- Anabolic Phase (e.g., fed state): Promotes protein synthesis, amino acid uptake, and works synergistically with insulin to promote growth.
- Catabolic Phase (e.g., fasting state): Antagonizes insulin action, promoting gluconeogenesis in the liver and lipolysis in adipose tissue (glucose-sparing effect) to ensure glucose availability for the brain.
- Regulation: Regulated by GHRH (stimulatory) and somatostatin (inhibitory) from the hypothalamus, as well as negative feedback from GH and IGF-1.
Read this in Hypothalamic Hormones: Master Regulators of the Endocrine System
What our notes say
- Acromegaly — caused by excess growth hormone (GH) in an adult (after closure of epiphyseal plates). (END YEAR PP1 & PP2 2025 Physiology: MCQs for Medical School Exams)
- The causative hormone is Growth Hormone (GH), secreted by somatotroph cells of the anterior pituitary. (END YEAR PP1 & PP2 2025 Physiology: MCQs for Medical School Exams)
- Growth failure and delayed puberty (from acidosis, poor nutrition, bone disease and growth hormone resistance) (Paediatrics and Child Health end of semester examination (MBPE): 10 January 2023)
- Growth hormone and sex steroids at puberty raise insulin needs. (Paediatrics Year 6 MBChB end of semester CAT: clinical case MCQs, 29 of 30 quest)
- Hormones: growth hormone, thyroid hormone, insulin and sex hormones. (Growth and Development in Children)
- Acromegaly — excess growth hormone induces peripheral insulin resistance (Medical MCQs: Chemical Pathology & Haematology Exam Review)
Study material on Growth Hormone
- Receptors and Growth Hormone Signaling
- Endocrine and Metabolic Pathology MCQs for Medical Students
- Endocrine and Metabolic Pathology MCQs: Practice Questions
- Hypothalamic Hormones: Master Regulators of the Endocrine System
- Chemical pathology and Endocrine pathology
- Medical Physiology Pp2 Year 2
- LECTURE 1: Principles of Endocrinology
- Clinical Endocrinology Cases: Pituitary Tumour, PCOS, Type 1 Diabetes, and HHS
- MBMP2300: Medical Physiology II MCQs
- MBMP2300: Medical Physiology II - Complete Study Guide
- Medical Physiology GIT MCQs
- Chemical Pathology
- Weekly Year 2: Physiology Exam - June 5, 2026 (Section A: MCQs)
Practice questions on Growth Hormone
All of the following are stimuli for growth hormone release except:
- Hypoglycemia
- Stress
- Obesity
- Exercise ✅ Answer: C. Obesity
Answer: A. Obesity is the physiologically correct answer per standard MBChB-level teaching on this topic. ---
Which is true regarding growth hormone?
- Is secreted by the anterior pituitary
- Maximal secretion occurs during the day
- Deficiency leads to acromegaly
- Is the main hormone essential for growth in a fetus ✅ Answer: A. Is secreted by the anterior pituitary
Answer: A. Is secreted by the anterior pituitary is the physiologically correct answer per standard MBChB-level teaching on this topic. ---
Growth hormone excess in adults causes:
- Gigantism
- Acromegaly
- Dwarfism
- Diabetes insipidus
- Addison disease
Answer: B. Growth hormone excess occurring after epiphyseal plate closure in adults leads to acromegaly, characterized by enlargement of hands, feet, and facial features. Gigantism occurs if excess GH is present before epiphyseal closure.
Excessive secretion of growth hormone (GH) in pre-pubertal individuals likely causes
- Hyperglycemia
- Hypoglycemia
- Gigantism
- a and c
- b and c
Answer: A. Excess GH in children causes gigantism (excessive linear growth) and hyperglycemia (due to GH's anti-insulin effects on glucose metabolism). ---
Growth hormone excess before epiphyseal fusion causes
- Acromegaly
- Gigantism
- Cushing syndrome
- Prolactinoma
Answer: B. Gigantism results from GH excess before growth plate closure; after fusion, the same excess causes acromegaly. ---
What is the gold standard test to assess both ACTH and Growth Hormone (GH) reserve simultaneously?
- CRH stimulation test
- Short Synacthen test
- Glucagon stimulation test
- Insulin tolerance test (ITT)
Answer: D. The Insulin Tolerance Test (ITT), which induces hypoglycemia, is considered the gold standard for simultaneously assessing the integrity of the hypothalamic-pituitary-adrenal (HPA) axis (cortisol response to ACTH) and the somatotropic axis (GH response). ---