One. The Command Center: HPT Axis
One. The Command Center: HPT Axis
The Hypothalamic-Pituitary-Thyroid Axis is the feedback loop that maintains metabolic homeostasis.
TRH (Thyrotropin-Releasing Hormone): Released by the Hypothalamus.
TSH (Thyroid-Stimulating Hormone): Released by the Anterior Pituitary; tells the thyroid to get to work.
T three and T four: The actual hormones produced by the thyroid.
Negative Feedback: When T three over T four levels are high enough, they tell the brain to stop producing TRH and TSH.
Two. Hypothyroidism: The Slow Down
Two. Hypothyroidism: The Slow Down
Hypothyroidism occurs when the thyroid is underactive, leading to a "slowed" metabolism.
lodine Deficiency: lodine is a mandatory "ingredient" for making T three and T four. Without it, the thyroid enlarges (Goiter) trying to compensate.
Hashimoto's Thyroiditis: An autoimmune disorder where the body attacks its own thyroid. It is the most common cause of hypothyroidism in iodine-sufficient areas.
Cretinism (Congenital Hypothyroidism): Severe hypothyroidism in infants. If untreated, it leads to stunted physical and mental growth.
Myxedema Coma: The "Final Boss" of hypothyroidism. A life-threatening medical emergency characterized by extreme lethargy, hypothermia, and slowing of multiple organ systems.