Growth Hormone

Flashcards to help review key concepts related to Growth Hormone, its regulation, effects, and associated disorders.

Growth Hormone (GH)

A peptide hormone produced by the anterior pituitary gland that stimulates growth, cell reproduction, and regeneration.

Somatotrophic axis

The system involving the hypothalamus, pituitary, and the somatic tissues responsible for growth hormone secretion.

GHS

Growth Hormone Secretagogues, natural or synthetic compounds that stimulate GH release.

GHRP

Growth Hormone-Releasing Peptides, a class of compounds that promote the secretion of GH.

IGF-1

Insulin-like Growth Factor 1, a hormone that mediates many growth-promoting effects of GH.

Somatomedin Hypothesis

The theory that GH is inactive itself but induces the production of IGF that mediates its effects.

Dual Effector Theory

The idea that both GH and IGF-1 are necessary for growth stimulation in target tissues.

GH Binding Proteins (GHBP)

Proteins that bind growth hormone, extending its half-life and modulating its activity.

IGF Binding Proteins (IGFBP)

Proteins that regulate the availability and activity of IGF in circulation.

Gigantism

Excessive growth due to GH overproduction before the closure of the epiphyseal plates.

Acromegaly

A disorder resulting from excess GH production in adults, characterized by enlarged bones and tissues.

Dwarfism

Abnormally low growth due to GH deficiency or insensitivity.

Hypothalamic-Pituitary-Somatotropic Axis

The regulatory system controlling GH secretion and its effects on growth.

Ghrelin

A hormone that stimulates appetite and promotes GH release from the pituitary gland.

Somatostatin

A hormone that inhibits GH secretion from the pituitary gland.

Hyperglycaemia

An abnormally high blood glucose level that inhibits GH secretion.

Hypoglycaemia

An abnormally low blood glucose level that stimulates GH secretion.

Thyroid hormones

Hormones necessary for normal growth and metabolic processes.

Pubertal Growth Spurt

Rapid growth during puberty induced by sex steroids and GH.

Insulin

A hormone that assists in glucose metabolism and has an anabolic effect on growth.

Calcitonin

A hormone produced by the thyroid that helps regulate calcium levels in the body.

Laron syndrome

A genetic disorder caused by GH receptor insensitivity leading to dwarfism.

Mitogenic Effect

The stimulation of cell division and growth, primarily produced by IGF-1.

Protein Anabolism

The process of building up proteins in the body, promoted by IGF-1.

Metabolic Effects of GH

Changes in metabolism induced by GH, including increased lipolysis and gluconeogenesis.

Acromegalic Features

Physical characteristics associated with acromegaly, such as enlarged limbs and facial features.

Pins and Needles

Nerve sensations that may occur due to pressure or inflammation, sometimes seen in GH-related conditions.

Hormonal Control of Growth

The regulation of growth processes by various hormones, including GH, IGF-1, and sex steroids.

Epiphyseal Plate

Growth plate area in bones where lengthening occurs during growth.

Insulin-like growth factors

Hormones that are similar to insulin and aid in growth and development.

Nutritional Regulation

The influence of nutrients on the secretion of growth hormones.

Performance Enhancement

Improvement of physical capabilities, often improperly achieved through substances like GH.

Muscle Growth

Increase in muscle size due to hypertrophy and protein synthesis.

Fat Catabolism

The breakdown of fats to provide energy for the body.

Sleep and GH Release

A significant portion of daily GH secretion occurs during slow-wave sleep.

Ghrelin's Appetite Effect

Ghrelin increases hunger signals and stimulates GH release.

Oral Glucose Tolerance Test

A test that measures the body's response to sugar and influences GH secretion.

Somatopause

The age-related decline in GH secretion and response.

Effects of Aging on GH

Decreased GH secretion and action leading to metabolic changes in older adults.

GH Treatment for Acromegaly

Therapies aimed at reducing GH excess, often using somatostatin analogs.

Cortisol's Effect on GH

A hormone that can suppress GH secretion, particularly under stress.

Physiological States and GH

Various body conditions, such as stress and exercise, that influence GH release.

GH and Insulin Resistance

Effects of GH that impair insulin action, leading to higher blood sugar levels.

Sarcopenia

The loss of muscle mass and strength associated with aging and GH deficiency.

Hypothalamic Control

The hypothalamus regulates the release of GH via hormones like GHRH and somatostatin.

Ectopic GH Production

GH production from non-pituitary tumors, leading to excess GH symptoms.

Bitemporal Hemianopia

Visual field defect often seen in patients with pituitary tumors affecting GH secretion.

IGFBP Functions

Binding proteins that modulate the action of IGF by controlling its availability.