L4 - Hypothalamic-Pituitary-Adrenal Axis

Hypothalamic - pituitary - adrenal axis

A complex set of interactions among the hypothalamus, pituitary gland, and adrenal glands that regulate various bodily functions.

Endocrinology

Branch of physiology and anatomy that studies the endocrine glands and hormones.

Hormone

Mediator molecule which is released in one part of the body but regulates the function of cells in other parts of the body.

Proteins and polypeptides

Hormones secreted by anterior and posterior pituitary gland, pancreas (insulin and glucagon), and parathyroid gland (PTH).

Steroids

Hormones produced by adrenal cortex (cortisol, aldosterone), ovaries/placenta (E2 and P4), and testes (testosterone).

Derivatives of tyrosine

Hormones produced by the thyroid (T4 and T3) and adrenal medulla (epinephrine and norepinephrine).

Hypothalamus

Anatomical structure located in the diencephalon that regulates the autonomic nervous system and endocrine system.

Hypophysis/Pituitary gland

Endocrine organ that secretes various hormones and is divided into anterior and posterior lobes.

Epiphysis/Pineal Gland

Endocrine organ that produces melatonin and regulates sleep-wake cycles.

Adrenal Glands

Endocrine organs located on top of the kidneys that produce hormones like cortisol and adrenaline.

Thyroid

Endocrine gland that produces thyroid hormones (T4 and T3) which regulate metabolism.

Parathyroid

Endocrine glands that produce parathyroid hormone (PTH) which regulates calcium levels in the blood.

Thyrotropin releasing hormone (TRH)

Hormone released by the hypothalamus that stimulates the release of thyroid-stimulating hormone (TSH) from the pituitary gland.

Corticotropic releasing hormone (CRH)

Hormone released by the hypothalamus that stimulates the release of adrenocorticotropic hormone (ACTH) from the pituitary gland.

Gonadotrophin-releasing hormone (GnRH)

Hormone released by the hypothalamus that stimulates the release of gonadotropins (LH and FSH) from the pituitary gland.

Growth hormone releasing hormone (GRH)

Hormone released by the hypothalamus that stimulates the release of growth hormone (GH) from the pituitary gland.

Prolactin releasing hormone (PRLH)

Hormone released by the hypothalamus that stimulates the release of prolactin from the pituitary gland.

Melanocyte stimulating releasing hormone (MSRH)

Hormone that stimulates the intermediate lobe of the pituitary gland.

Somatostatin

Hormone that inhibits growth, secretion, and proliferation, but is not a releasing hormone.

Neurohypophysis

Posterior lobe of the pituitary gland that is an extension of the hypothalamus and contains neurosecretory neurons.

Vasopressin (ADH)

Antidiuretic hormone produced in the posterior pituitary that regulates water balance in the body.

Oxytocin

Hormone produced in the posterior pituitary that stimulates uterine contractions and milk letdown.

ADH

Antidiuretic hormone, involved in water balance and acts on kidney tubules.

Oxytocin

Hormone that causes contraction of uterine muscles.

Anterior Pituitary

Also known as adenohypophysis, controlled by hypothalamic releasing/inhibitory hormones.

FSH

Follicle-stimulating hormone, involved in reproductive processes.

ACTH

Adrenocorticotropic hormone, stimulates glucocorticoid synthesis in the adrenal cortex.

TSH

Thyroid-stimulating hormone, regulates metabolism and calcium deposition.

PRL

Prolactin, stimulates milk production in mammary glands.

GHRH

Growth hormone-releasing hormone, stimulates growth hormone secretion.

GH (STH)

Growth hormone, regulates somatic growth and metabolism.

CRH

Corticotropin-releasing hormone, stimulates ACTH release.

GnRH

Gonadotropin-releasing hormone, stimulates follicular development and ovulation.

Mineralocorticoids

Hormones like aldosterone that regulate electrolytes and blood pressure.

Glucocorticoids

Stress hormones like cortisol that regulate glucose levels and immune response.

Androgens

Steroid hormones that are precursors for all estrogens.

Pineal Gland

Small gland in the diencephalon that secretes melatonin in response to light changes.

Adrenal Glands

Paired structures that produce steroid hormones and catecholamines.

Catecholamines

Hormones like epinephrine and norepinephrine that are involved in the sympathetic response.

HPA axis

Hypothalamic-pituitary-adrenal axis, regulates glucocorticoid release.

Hyperadrenocorticism (HAC)

Increased production of corticosteroids, also known as Cushing's disease.

Hypoadrenocorticism

Decreased production of mineralocorticoids and glucocorticoids, known as Addison's disease.

Melanocyte stimulating hormone (MSH)

Hormone produced by the pars intermedia, involved in pigmentation.

Adrenal Cortex

Outer part of the adrenal gland that produces steroid hormones.

Adrenal Medulla

Inner part of the adrenal gland that produces catecholamines.

Zona Glomerulosa

Outer layer of the adrenal cortex, produces mineralocorticoids.

Zona Fasciculata

Middle layer of the adrenal cortex, produces glucocorticoids.

Zona Reticularis

Inner layer of the adrenal cortex, produces androgens.