🧠 Hypothalamo–Pituitary System
Hormones that stimulate the anterior pituitary.
Releasing hormones
Two main hormones secreted by the thyroid gland
T3 (triiodothyronine) and T4 (thyroxine)
Hormone secreted by the parathyroid glands
Parathyroid hormone (PTH)
Type of hormones secreted by the adrenal cortex
Steroid hormones
Two hormones secreted by the adrenal medulla
Epinephrine and norepinephrine
The blood vessel system connecting hypothalamus and adenohypophysis
Hypothalamo–hypophyseal portal system
Essential trace element required for thyroid hormone synthesis
Iodine
Main ion regulated by PTH
Calcium (Ca²⁺)
Hormone secreted by zona glomerulosa
Aldosterone
Nervous system controlling the adrenal medulla
Sympathetic nervous system
Hypothalamic hormone that inhibits prolactin secretion
Dopamine
Which hormone is more biologically active: T3 or T4
T3
Effect of PTH on bone tissue
Increased bone resorption
Main metabolic effect of cortisol
Increased blood glucose via gluconeogenesis
Physiological response known as “fight or flight”
Acute stress response
Pituitary hormone responsible for water reabsorption in kidneys
ADH (vasopressin)
Effect of thyroid hormones on basal metabolic rate
Increase in basal metabolic rate
Relationship between PTH and vitamin D
Activation of vitamin D leading to increased intestinal calcium absorption
Cortical zone that secretes androgens
Zona reticularis
Effect of adrenaline on heart rate
Increased heart rate
Main regulatory mechanism controlling pituitary hormone secretion
Negative feedback regulation
Disease caused by thyroid hormone deficiency in infancy
Cretinism
Condition caused by low PTH characterized by muscle spasms
Hypocalcemic tetany
Hormone responsible for sodium retention and potassium excretion
Aldosterone
Amino acid precursor for catecholamine synthesis
Tyrosine