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58 Cards in this Set
- Front
- Back
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What do hormones control? |
- reproduction - growth and development - mobilization of body defenses - maintenance of much homeostasis - regulation of metabolism |
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HORMONES |
class of signaling molecules produced by glands that are transported by the circulatory system to target distant organs in order to regulate physiology and behavior
produced by specialized cells
regulate active of all other cells |
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AMINO ACID-BASED HORMONES |
proteins, peptides and amines |
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STEROIDS |
made from cholesterol |
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PROSTAGLANDINS |
made from highly active lipids
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DIRECT GENE ACTIVATION (aka Steroid Hormone Action) |
Process: Diffuse through PM of target cells --> enter nucleus --> bind to a specific protein within the nucleus --> bind to specific sites on cell's DNA --> activate genes that result in synthesis of new proteins |
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SECOND-MESSENGER ACTIVATION (aka Nonsteroid Hormone Action) |
Process: Hormone binds to membrane receptor --> hormone does not enter cell -->sets of series of rxns that actives an enzyme --> catalyzes a reaction that produces a second-messenger molecule (ex cAMP) --> oversees addtl intracellular changes to promote a specific response |
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EFFECTS OF HORMONES |
- changes in PM permeability or electrical state - synthesis of proteins, such as enzymes - activation or inactivation of enzymes - stimulation of mitosis - promotion of secretory activity |
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NEGATIVE FEEDBACK |
When gland X releases hormone X, this stimulates target cells to release hormone Y. When there is an excess of hormone Y, gland X senses this and inhibits its release of hormone X |
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HORMONAL STIMULI OF ENDOCRINE GLANDS |
- most common - endocrine glands are activated by other hormones - ex: anterior pituitary hormones travel to target thyroid gland to prompt release of thyroid hormone |
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HUMORAL STIMULI OF ENDOCRINE GLANDS |
- changing blood levels of certain ions stimulate hormone release - "humoral" = body fluids (blood, bile etc) - ex: insulin is produced in response to changing levels of blood glucose levels - ex: parathyroid hormone and calcitonin are produced in response to changing levels of blood glucose |
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NEURAL STIMULI OF ENDOCRINE GLANDS |
- nerve impulses stimulate hormone release - most are under control of sympathetic nervous system - ex: release of norepinephrine and epinephrine by the adrenal medulla |
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MAJOR ENDOCRINE ORGANS |
- pituitary gland - thyroid gland - parathyroid glands - adrenal glands - pineal gland - thymus gland - pancreas - gonads (ovaries and testes) - hypothalamus |
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PITUITARY GLAND |
- "master endocrine gland" - location: sella tursica, hangs from the hypothalmus - protected by sphenoid bone - 2 functional lobes: anterior (glandular) and posterior (nervous)
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ANTERIOR PITUITARY HORMONES |
- Growth hormone (non-endocrine target) - Prolactin (non-endocrine target) - Thyrotropic hormone - Adrenocroticotropic hormone - Two different gonadotropic hormones
ALL ARE - proteins (or peptides) - act through second-messenger systems - regulated by hormonal stimuli, mostly negative feedback |
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GROWTH HORMONE |
- anterior pituitary gland - general metabolic hormone - growth of skeletal muscles and long bones; plays a role in determining final body size - causes amino acids to be built into proteins - causes fats to be broken down for energy
GH DISORDERS - Pituitary dwarfism: hyposecretion of GH - acromegaly: hypersecretion of GH post puberty, often associated with gigantism |
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PROLACTIN (PRL) |
- anterior pituitary gland - stimulates and maintains milk production following childbirth - function in males: unknown |
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ADRENOCORTICOTROPIC HORMONE (ACTH) |
- anterior pituitary gland - regulates endocrine activity of the adrenal cortex |
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THYROID-STIMULATING HORMONE (TSH) |
- anterior pituitary gland - influences growth and activity of thyroid gland |
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GONADOTROPIC HORMONES |
Regulate hormonal activity of the gonads - follicle stimulating hormone (FSH): stimulates follicle development in ovaries, sperm development in testes - luteinizing hormone (LH): triggers ovulation of an egg in females, testosterone production in males |
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HYPOTHALAMUS |
Regulates the release of hormones in the posterior pituitary gland - Oxytocin - Antidiuretic |
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OXYTOCIN |
- stimulates contractions of the uterus during labor, sexual relations, and breastfeeding - causes milk ejection in nursing woman |
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ANTIDIURETIC HORMONE (ADH) |
- inhibits urine production by promoting H2O reabsorption by the kidneys - in large amounts, causes vasoconstriction leading to increased blood pressure - AKA vasopressin |
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THYROID GLAND |
- location: base of throat - consists of two lobes and a connecting isthmus - produces thyroid hormone, calcitonin |
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THYROID HORMONE |
- major metabolic hormone - composed of 2 active iodine-containing hormones: T3 and T4
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Thyroxine (T4) |
secreted by thyroid follicles |
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Triiodothyronine (T3) |
- conversion of T4 at target tissues |
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GOITER |
enlarged thyroid gland due to lack of iodine |
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CRETINISM |
hyposecretion of thyroxine resulting in dwarfism during childhood |
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MYXEDEMA |
hypothyroidism in adults, results in physical and mental sluggishness, weight gain, heat intolerance |
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GRAVE'S DISEASE |
caused by hyperthyroidism, results in increased metabolism, heat intolerance, rapid heartbeat, weight loss, exophthalmos (eye bulge) |
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CALCITONIN |
- produced by parafollicular cells - found between the follicles - decreases blood calcium levels by causing its deposition on bone - antagonistic to parathyroid hormone |
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PARATHYROID GLANDS |
- 4 small glands on posterior surface of the thyroid gland, tiny masses - secrete parathyroid hormone (PTH) |
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PARATHYROID HORMONE (PTH) |
- stimulate osteoclasts to remove calcium from bone - stimulate kidneys and intestine to absorb more clacium - raise calcium in blood |
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TETANY |
- muscle seizure, produced by lack of calcium |
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ADRENAL GLANDS |
- "suprarenal glands" - location: on top of kidneys - 2 regions: adrenal cortex (outer glandular region, 3 layers) and adrenal medulla (inner neural tissue |
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MINERALOCORTICOIDS (ALDOSTERONE) |
- produced in outer adrenal cortex - aldosterone - regulate mineral content in blood - regulate water/electrolyte balance - target organ is kidney - production stimulated by renin & aldosterone - inhibited by atrial natriuretic peptide (ANP) |
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GLUCOCORTICOIDS (CORTISONE AND CORTISOL) |
- produced in middle layer of adrenal cortex - promote normal cell metabolism - help resist long-term stressors - released in response to creased levels of ACTH - cortisone, cortisol |
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SEX HORMONES (ANDROGENS/ESTROGENS) |
- produced in inner layer of adrenal cortex - small amounts are made throughout life - mostly androgens (male sex hormones) but some estrogens (female sex hormones) |
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ADDISON'S DISEASE |
- adrenal cortex disorder - hyposecretion of all adrenal cortex hormones - bronze skin tone, weak muscles, burnout, susceptibility to infection |
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HYPERALDOSTERONISM |
- may result from an ACTH-releasing tumor - excess water and sodium are retained, leading to high blood pressure and edema |
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CUSHING'S SYNDROME |
- results from tumor in middle cortical area of adrenal cortex - hump on upper back, high blood pressure, hyperglycemia, weakening of bones, depression
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MASCULINIZATION |
- results from hypersecretion of sex hormones - beard, mail distribution of hair growth |
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CATECHOLAMINES |
- epinephrine (adrenaline) and norepinephrine (noradrenaline) - prepare body to deal with short-term stress (fight or flight) - increase heart rate, blood pressure, blood glucose levels - dilate small passageways of lungs
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INSULIN |
- produced in the pancreas (islets) - allows glucose to cross plasma membranes into cells from beta cells - maintain blood sugar homeostasis |
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GLUCAGON |
- produced in the pancreas (islets) - allows glucose to enter the blood from alpha cells - maintain blood sugar homeostasis |
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DIABETUS MELLITUS |
- caused by lack of insulin - type 1) does not produce at all - type 2) does not produce enough - symptoms: polyuria, polydipsia, hyperphagia, hyperglycemia and glycosuria |
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PINEAL GLAND |
- location: third ventricle of the brain - secretes melatonin - helps establish the body's wake/sleep cycles |
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THYMUS GLAND |
- location: posterior to the sternum - largest in infants and children - secretes thymosin |
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THYMOSIN |
- secreted by thymus gland - matures some types of white blood cells - important in developing the immune system |
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GONADS |
- ovaries/testes - produce eggs/sperm - produce estrogens, progesterone, and androgens (such as testosterone) |
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ESTROGEN |
- stimulate development of secondary female characteristics - mature female reproductive organs - with progesterone, also promote breast development and regulate menstrual cycle |
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PROGESTERONE |
- acts with estrogen to bring about period - helps with implantation of embryo in uterus - helps prepare breasts for lactation |
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ANDROGENS (MOSTLY TESTOSTERONE) |
- responsible for adult male secondary sex characteristics - promotes growth and maturation of male reproductive system - required for sperm cell production |
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GUT-SECRETED HORMONES |
- gastrin - somatostatin - secretin - cholecystokinin (CCK) - incretins - ghrelin |
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ERYTHROPOIETIN |
secreted by the kidneys, along with vitamin D3 |
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Atrial Natriuretic Peptide |
secreted by the heart |
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PLACENTA ENDOCRINE FUNCTIONS |
- produces hormones that maintain pregnancy - some hormones play part in delivery of baby - produces human chorionic gonadotropin (hCG) in addition to estrogen, progesterone, and other hormones |
