Anterior Pituitary Hormones Flashcards
Growth hormone (GH)
From what cells?
Somatotrophs, protein
Growth hormone (GH)
Target organ(s)?
Liver, muscle, bone, cartilage & other tissues
Growth hormone (GH)
Effects?
Anabolic hormone – stimulates somatic growth, mobilizes fats, spares glucose
Stimulates insulin-like growth factor 1 release from liver
Growth hormone (GH)
Malfunction?
Decrease – pituitary dwarfism in children
Increase - gigantism in children, acromegaly in adults
Thyroid-stimulating hormone (TSH)
From which cells?
Thyrotrophs, glycoprotein
Thyroid-stimulating hormone (TSH)
Target organ(s)?
Thyroid gland
Thyroid-stimulating hormone (TSH)
Effects?
Stimulates thyroid gland to release thyroid hormone
Stimulates throxine (T4) and triiodothyronine (T3) synthesis and release from thyroid gland
Stimulates iodine absorption by thyroid gland
Thyroid-stimulating hormone (TSH)
Malfunction?
Decrease – cretinism in children, myxedema in adults
Increase – hyperthyroidism
Adrenocorticotropic hormone (ACTH)
From which cells?
Corticotrophs,
Polypeptide of 39 amino acids
Adrenocorticotropic hormone (ACTH)
Target organ(s)?
Adrenal cortex
Adrenocorticotropic hormone (ACTH)
Effects?
Promotes release of glucocorticoids & androgens (mineralocorticoids to a lesser extent)
Stimulates corticosteroid, glucocorticoid and mineralocorticoid, and androgen synthesis and release from adrenocortical cells
Adrenocorticotropic hormone (ACTH)
Malfunction?
Decrease – rare
Increase – cushing’s disease
Follicle-stimulating hormone (FSH)
From which cells?
Gonadotrophs, glycoprotein
Follicle-stimulating hormone (FSH)
Target organ(s)?
Ovaries & Testes
Follicle-stimulating hormone (FSH)
Effects?
Females – stimulates ovarian follicle maturation & estrogen production
Males – stimulates spermatogenesis
Males – stimulates maturation of seminiferous tubules
Males – stimulates production of androgen-binding protein from Sertoli cells of the testes
Follicle-stimulating hormone (FSH)
Malfunction?
Decrease – failure of sexual maturation
Increase – no important effects
Luteinizing hormone (LH)
From which cells?
Gonadotrophs,
glycoprotein
Luteinizing hormone (LH)
Target organ(s)?
Ovaries & Testes
Luteinizing hormone (LH)
Effects?
Females – triggers ovulation & stimulates ovarian production of estrogen & progesterone
Females – stimulates ovulation and formation of corpus luteum
Males – stimulates testosterone synthesis from Leydig cells (interstitial cells)
Males – promotes testosterone production
Luteinizing hormone (LH)
Malfunction?
Decrease – failure of sexual maturation
Increase – no important effects
Prolactin (PRL)
From which cells?
Lactotrophs, protein
Prolactin (PRL)
Target organ(s)?
Breast secretory tissue
Prolactin (PRL)
Effects?
Stimulates milk synthesis & release from mammary glands
Mediates sexual gratification
Prolactin (PRL)
Malfunction?
Decrease – poor milk production in nursing women
Increase
Females - inappropriate milk production (galactorrhea), cessation of menses
Males – impotence, breast enlargement (gynecomastia)
Oxytocin
From which cells?
Magnocellular neurosecretory cells
Oxytocin
Target organ(s)?
Uterus, Breast
Oxytocin
Effects?
Stimulates uterine contractions, initiates labor, initiates milk ejection (letdown reflex)
Oxytocin
Malfunction?
Unknown
Antidiuretic hormone (ADH)
From which cells?
Parvocellular neurosecretory neurons
Antidiuretic hormone (ADH)
Target organ(s)?
Kidneys
Antidiuretic hormone (ADH)
Effects?
Stimulates kidney tubule cells to reabsorb water
Increases water permeability in the distal convoluted tubule & collecting duct of nephrons, thus promoting water reabsorption & increasing blood volume
Antidiuretic hormone (ADH)
Malfunction?
Decrease – diabetes insipidus
Increase – syndrome of inappropriate ADH secretion (SIADH)
