35 terms

Ch. 9 Hormones

Again, sorry about the typos!
Anterior pituitary hormones...
1. Are proteins (or peptides)
2. Act through secondary messenger systems
3. Are regulated by hormonal stimuli, and in most cases negative feedback
Growth hormone (GH)
Anterior pituitary: General metabolic hormone causing GROWTH OF SKELTAL MUSCLES AND LONG BONES; plays an important role in determining final body size; protein-sparing and anabolic hormone that causes amino acids to be built into proteins and stimulates cell growth and division as well as break down of fats; it also helps maintain blood sugar homeostasis by sparing glucose
Prolactin (PRL)
Anterior pituitary: Protein hormone known to target the breast; after childbirth it STIMULATES AND MAINTAINS MILK PRODUCTION in the mother's breasts; function in men is not known
Adrenocorticotropic hormone (ACTH)
Thyroid-stimulating/thyrotropic hormone (TSH/TH)
Gonadotropic hormones
Anterior pituitary: REGULATE HORMONAL ACTIVITY OF THE GONADS (ovaries and testes)
Follicle-stimulating hormone (FSH)
Luteinizing hormone (LH)
Anterior pituitary: TRIGGERS OVULATION of an egg from the ovary and CAUSES THE RUPTURED FOLLICLE TO PRODUCE PROGESTERONE and some estrogen; in men it STIMULATES TESTOSTERONE PRODUCTION by the interstitial cells of the testes
Posterior pituitary: Released in significant amounts during childbirth and in nursing women, this STIMULATES POWERFUL CONTRACTIONS OF THE UTERINE MUSCLE during labor, sexual relations, and breastfeeding; it also causes milk-ejection (LET-DOWN REFLEX) in nursing women; synthetic and natural drugs modeled after this hormone are used to induce labor, quicken labor, or even stop postpartum bleeding and stimulate let-down reflex
Antidiuretic hormone (ADH)
Posterior pituitary: Inhibits urine production by causing the kidneys to reabsorb more water, decreasing the volume of urine while increasing the volume of blood; therefore it can also increase blood pressure and can allow constriction of arterioles
Another name for ADH
Thyroid hormone
Thyroxine and triiodothyronine; both are constructed from two tyrosine amino acids linked together; controls metabolism (rate glucose is "burned"); targets all cells since all rely on chemical energy; also important for normal tissue growth and development, especially in the reproductive and nervous systems
Thyroid: Major hormone secreted by thyroid follicles; has four bound iodine atoms
Thyroid: Formed at target tissues by conversion of thyroxine; has three bound iodine atoms
Thyroid: Decreases blood calcium levels by causing calcium to be deposited into bones, acting antagonistically to PTH
Parathyroid hormone/parathormone (PTH)
Most important regulator of calcium homeostasis in the blood, as when calcium levels drop this is released to stimulate bone destruction cells (osteoclasts) to break down bone matrix and release calcium into the blood; it is therefore a hypercalcemic hormone, as it acts to increase calcium levels in the blood; forms a negative feedback connection with calcitonin, a hypocalcemic hormone; the skeleton is its main target, but it also stimulates kidneys and intestine to absorb more calcium
Steroid hormones produced by the adrenal cortex
Mineralocorticoids (mainly aldosterone)
Produced by the outermost adrenal cortex layer, these are important in regulating salt content of the blood (sodium/potassium!); they target kidney tubules that selectively reabsorb minerals or allow them to be flushed out as urine; when blood levels of this rise, kidney tubules reclaim sodium and secrete potassium into the urine, and as sodium is reabsorbed, water follows; thus, these help regulate both water and electrolyte balances for the body
Enzyme produced by kidneys when blood pressure drops, causes aldosterone to be released by triggering reactions that form angiotensin II, which stimulates aldosterone release to raise the pressure
Atrial natriuretic peptide (ANP)
Hormone secretes by the heart which prevents aldosterone release to reduce blood volume and pressure
Glucocorticoids (include cortisone and cortisol)
Promote normal cell metabolism and help the body cope with long-term stress, primarily by increasing blood glucose levls; when levels of these are high, fats and even proteins are turned to glucose, so they are hyperglycemic hormones; they also control inflammation by decreasing edema, and reduce pain by inhibiting prostaglandins; often prescribed as drugs for RA; they are released from the middle layer of the adrenal cortex in response to rising blood levels of ACTH
Sex hormones
Produced in small amounts (in men and women) by the inner layer of the adrenal cortex (throughout life); most are androgens, but some are estrogens
Epinephrine (adrenaline) and norepinephrine (noradrenaline)
Hormones released by the adrenal medulla; collectively known as catecholamines; they give the adrenal medulla the sense of being a "misplaced SNS ganglion," and help control fight-or-fligh responses
Pancreas: Hypoglycemic hormone that sweeps glucose out of the blood, decreasing blood sugar levels and bringing glucose to cells to be converted to energy or stored
Pancreas: Hyperglycemic hormone that helps regulate blood glucose levels and is stimulated by low blood sugar; its primary target is the liver, which it stimulates to break down stored glycogen to glucose and release the glucose into the blood
Pineal gland: Levels rise and fall, with peak levels occuring at night to make us drowsy, and lowest levels occuring around noon; it is believed to trigger sleep and help establish a day-nigh cycle, as well as be involved with fertility and inhibition of reproductive system before maturation
Thymus: Helps develop T cells (T lymphocytes) and the immune response
Develop the sex characteristics in women as well as secondary sex characteristics at puberty; with progesterone they promote breast development and menstruation
Helps estrogen control menstruation, quiets the uterus muscles during pregnancy to keep the implanted embryo from being aborted, and helps prepare breast tissue for lactation
Androgens (testosterone)
Promotes growth and maturation of sex organs at puberty, causes secondary sex characteristics, and stimulates sex drive; it is necessary for sperm production
Human chorionic gonadotropin (hCG)
Embryo then placenta: Keeps the uterine lining from being sloughed off during pregnancy
Human placental lactogen (hPL)
Placenta: Works with estrogen and progesterone in preparing the breasts for lactation
Placenta: Causes the mother's pelvic ligaments and pubic symphysis to relax and become more flexible, easing birth passage