hypothalamus: Quick Facts

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Labeled diagram of a mammalian pituitary gland showing key structures, including the paraventricular and supraoptic nuclei, neurosecretory cells, blood vessels, and pathways for hormone release and blood flow.

Diagram of a typical endocrine cell showing labeled internal structures, including the nucleus, endoplasmic reticulum, Golgi apparatus, cytoplasm, and secretory granules, with arrows illustrating the pathway of hormone synthesis and exocytosis.

Neurohormones are released from neurosecretory nerve cells. These nerve cells are considered true endocrine cells because they produce and secrete hormones that enter the circulation to reach their target cells.

Diagram showing the female reproductive system with labeled ovaries, fallopian tubes, uterus, and vagina, alongside hormone pathways and the process from ovulation to fertilization and early embryo development.

Major glands of the human endocrine system. The hypothalamus stimulates the pituitary gland and influences food intake, weight regulation, fluid intake and balance, thirst, body heat, and the sleep cycle. Pituitary hormones stimulate growth, egg and sperm development, milk secretion, and release of hormones by other glands. The pineal gland may play a significant role in sexual maturation and the circadian rhythm. Thyroid hormones regulate the metabolic rate of tissues, stimulate the contraction of heart muscle, and are necessary for normal growth and brain development before birth and during infancy. Parathyroid hormone regulates calcium, phosphorus, and magnesium levels. The adrenal glands regulate salt and water retention, some reactions of the immune system, and blood pressure. The islets of Langerhans regulate blood sugar levels. The ovaries and testes produce hormones that regulate the reproductive system and that produce male and female secondary sex characteristics.

The principal glands of the female and male human endocrine systems.

Diagram of the human brain highlighting the pineal gland within the endocrine system, with labeled structures including the cerebral cortex, hypothalamus, optic chiasm, pituitary gland, and third ventricle.

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mammillary body chemoreceptor trigger zone neuroendocrine cell thirst centre ventromedial hypothalamus diabetes insipidus hypogonadism somatostatin gonadotropin-releasing hormone corticotropin-releasing hormone ovary thyroid gland adrenal gland pancreas pituitary gland testis pineal gland thymus parathyroid gland kidney

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Andrew V. Schally

Andrew V. Schally

American endocrinologist

Roger Guillemin

Roger Guillemin

American physiologist

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