Chapter 18 – Study Guide

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in general you should know: appearance of each gland & where in the body it is found

which glands secrete or release which hormones

which hormones have which functions

(know functions as a “package” - I won’t ask about individual functions in isolation from the other functions)

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hormone

exocrine gland

endocrine gland

down regulation

up regulation

circulating hormones

local hormones

paracrine cell

autocrine cell

transport protein

lipid soluble hormones

bind to receptors in the cytosol or nucleus

alter gene expression

alter protein synthesis

water soluble hormones

bind to receptors on the plasma membrane

activate one or several enzymes to catalyze reactions that produce physiologic responses

permissive effect

synergistic effect

antagonistic effect

ANTERIOR PITUITARY GLAND

hGH – human growth hormone (somatotropin)

stimulates several tissues to secrete insulin like growth factors

that stimulate general body growth

and regulate aspects of metabolism

TSH – thyroid stimulating hormone (thyrotropin)

controls secretions and activities of the thyroid gland

FSH – follicle stimulating hormone

& LH – luteinizing hormone

stimulate secretion of estrogens & progesterone

stimulate maturation of oocytes

stimulate secretion of testosterone

stimulate sperm production

PRL – prolactin

initiates milk production in mammary glands

ACTH – adrenocorticotropic hormone (corticotrophin)

stimulates secretion of glucocorticoids

POSTERIOR PITUITARY GLAND

OT – oxytocin

enhances contraction of smooth muscle cells in wall of uterus

stimulates milk ejection in response to suckling infant

ADH – antidiuretic hormone (vasopressin)

causes kidneys to return more water to the blood rather than going to urine output

decreases water loss through perspiration

raises blood pressure by constricting arterioles

THYROID

T₄ = thyroxine

T₃ = triiodothyronine

thyroid hormones (T₄ and T₃)

stimulate use of cellular oxygen to produce ATP

stimulate synthesis of Na⁺ / K⁺ pumps

increase heat generated

increase protein synthesis, lipolysis, cholesterol excretion

increase use of glucose & fatty acids for ATP production

enhance some actions of norepinephrine & epinephrine

accelerate body growth – particularly of nervous tissue

calcitonin

inhibits osteoclasts

PARATHYROID GLANDS

PTH – parathyroid hormone – parathormone

regulates blood levels of Ca²⁺, Mg²⁺, HPO₄^2-

increases number and activity of osteoclasts

decreases Ca²⁺ and Mg²⁺ loss in urine

increases HPO₄^2- loss in urine

promotes formation of calcitriol by kidneys

which increases GI absorption of Ca²⁺, Mg²⁺, HPO₄^2-

ADRENALS – CORTEX

MINERALOCORTICOIDS

aldosterone

regulates blood levels of Na⁺, K⁺

helps adjust blood pressure & volume

GLUCOCORTICOIDS

cortisol (hydrocortisone), corticosterone, cortisone

results in increased protein breakdown, glucose formation, lipolysis

resistance to stress

anti-inflammatory effects

depression of immune response

ANDROGENS

DHEA dehydroepiandrosterone

promote libido

get converted to estrogens by other body tissues

ADRENAL MEDULLA

epinephrine (adrenalin) and norepinephrine (noradrenalin)

produce effects that enhance those of the sympathetic division of the ANS during stress

PANCREAS – PANCREATIC ISLETS – ISLETS OF LANGERHANS

glucagon

stimulates liver cells to accelerate the breakdown of glycogen into glucose

stimulates the formation of glucose from other nutrients (lactic acid, amino acids)

raises blood glucose

insulin

accelerates transport of glucose into cells

stimulates conversion of glucose into glycogen

decreases formation of glucose from other molecules (decreases glycogenolysis & gluconeogenesis)

increases protein & lipid synthesis

lowers blood glucose

somatostatin

inhibits secretion of insulin & glucagon

pancreatic polypeptide

inhibits somatostatin secretion

TESTES

testosterone

stimulates development & maintenance of male secondary sex characteristics

(beard growth, deepening of voice, etc.)

OVARIES

estrogen (estradiol & estrone)

progesterone

regulate menstrual cycle

maintain pregnancy

prepare mammary gland for lactation

help stimulate development & maintenance of female secondary sex characteristics

(big breasts, wide hips, etc.)

PINEAL GLAND

melatonin

thought to contribute to setting the body’s biological clock

THYMUS

thymosin, THF thymic humoral factor, TF thymic factor, thymopoietin

promote maturation of T cells of immune system