Somatotropic Axis and Thyroid Hormone Regulation Quiz

Somatotropic Axis and Thyroid Hormone Regulation

• The somatotropic axis involves hormones such as Growth Hormone Releasing Hormone (GHRH) from the hypothalamus, Growth Hormone (GH) from the pituitary, and Insulin-like Growth Factor 1 (IGF-1) from the liver.
• GH has negative feedback on GHRH secretion and positive action on somatostatin, which is downregulated in the absence of GH feedback.
• GHRH neurons are in the arcuate nucleus and regulate feeding, while somatostatin neurons, affected by metabolic substances, regulate GH release.
• GHRH and somatostatin receptors play a role in the regulation of GH, involving neurotransmitters and hormonal regulation.
• GH has pulsatile and daily release patterns, with pulse frequency every 1-3 hours, often connected with sleep.
• IGF-1 is synthesized in the liver and brain, exerting negative feedback on GHRH and GH release, and can stimulate somatostatin release.
• Disruptions in the somatotropic axis, such as mutations in IGF-1 or GH systems, can lead to conditions like dwarfism, giantism, and acromegaly.
• The somatotropic axis has implications for mind-body interaction, as the brain can regulate hormones that influence the body, and body hormones can influence the brain.
• The brain-pituitary-thyroid axis controls metabolic activity and calorigenic processes in target cells, playing an important role during development.
• Thyrotropin Releasing Hormone (TRH) in the hypothalamus regulates the release of Thyroid Stimulating Hormone (TSH) from the anterior pituitary.
• Thyroid hormone receptors (TR) are part of the nuclear hormone superfamily and are found throughout the brain, peripheral and autonomic nervous system, pituitary gland, and other organs.
• Thyroid disorders such as hypothyroidism and hyperthyroidism can lead to various symptoms and conditions, including developmental deficits, goiter, and autoimmune diseases like Hashimoto's thyroiditis and Graves' disease.