BIO211 Study Guide for EXAM 1 1 Know the definition of a hormone the types and the importance of the types bound 2nd messengers etc a Hormone long distance chemical signals secreted by cells that travel in the blood or lymph b Amino acid based hormones Most hormones are of this variety Amines thyroxine peptide and protein hormones c Steroids Synthesized from cholesterol Gonadal and adrenocortical hormones d Water soluble hormones all amino acid based hormones except thyroid hormone i Act via G protein second messengers Plasma membrane receptor ii Cannot enter cell e Lipid soluble hormones steroid and thyroid hormones even though it is an amine can enter the cell i Act on intracellular receptors that directly activate genes ii Can enter cell f 2nd messenger i Cyclic AM 1 Hormone first messenger 2 Adenylate cyclase converts ATP to cAMP second messenger 3 How do we change metabolism of cell Change protein g Hormone circulate blood in 2 forms bound and free i Free Steroids and thyroid hormone lipid soluble are attached to plasma proteins bound ii All others water soluble are unencumbered free without carriers 2 Know how hormones interact a Changes metabolism of cell changes how cell reacts b Humoral stimuli fluid blood Changing blood levels of ions and nutrients directly stimulate secretion of hormones c Neural stimuli Nerve fibers stimulate hormone release d Hormonal stimuli Hormones stimulate other endocrine organs to release their hormones i Hypothalamic pituitary target endocrine organ feedback loop 1 Hypothalamus is going to send signal to pituitary then pituitary will send it to target cell Interaction of hormones at target cells e Permissiveness one hormone cannot exert its effects without another hormone being present f Synergism more than one hormone produces the same effects on a target cell causes amplification g Antagonism one or more hormones opposes the action of another hormone 3 Receptors are specific and saturated 4 Know function of endocrine system a Reproduction b Growth and development c Maintenance of electrolyte water and nutrient balance of blood d Regulation of cellular metabolism and energy balance e Mobilization of body defenses 5 Be able to recognize the endocrine gland target site releasing stimuli major actions and any disorders know disorder and know symptoms for each of the following hormones a ADH ADH helps to avoid dehydration or water overload Prevents urine formation Hypothalamic osmoreceptors monitor the solute concentration of the blood the amount of water and the relationship amount of solute in the blood osmolarity i Diabetes insipidus Hyposecretion of ADH Huge output of urine and intense thirst ii Syndrome of inappropriate ADH secretion SIADH Hypersecretion of ADH Leads to fluid retention headache and disorientation due to brain edema weight gain b oxytocin positive feedback system Strong stimulant of uterine contractions during childbirth Triggers milk ejection letdown reflex in women producing milk Plays a role in sexual arousal and orgasm and sexual satisfaction in males and nonlactating females Walkers or runners high c ANP Heart Atrial natriuretic peptide ANP decreases blood Na concentration therefore blood pressure and blood volume d FSH stimulate production of sperm stimulates gamete egg or sperm production Triggered by gonadotropin releasing hormone GnRH e GH increases Blood sugar stimulates most cells but major targets are bone and skeletal muscle stimulates most cells but major targets are bone and skeletal muscle Most secreted During first 2 hours of deep sleep After vigorous exercise After high protein meals Hypoglycemia i Hypersecretion of GH In children results in gigantism Can reach heights of 8 feet ii In adults results in acromegaly Overgrowth of hands feet and face iii Hyposecretion of GH In children results in pituitary dwarfism only 4 ft tall f Thyroxine T4 iodine atoms Major metabolic hormone increases metabolic rate and heat production calorigenic effect by oxidizing glucose i Myxedema 1 Hypothyroidism hyposecretion in adults 2 Causes low metabolic rate coldness constipation puffy eyes thick and or dry skin edema lethargy mental sluggishness ii Congenital hypothyroidism or cretinism 1 Can be genetic deficiency of the fetal thyroid or maternal factors like lack of dietary iodine 2 Causes the same as myxedema but retardation instead of just mental sluggishness iii Toxic goiter Grave s disease 1 Hyperthyroidism created by autoantibodies which mimic TSH causing thyroid hypersecretion 2 Causes high metabolism sweating rapid and irregular heartbeat nervousness weight loss exophthalmos 3 Exophthalmos may result eyes protrude as tissue behind eyes becomes edematous and fibrous g cortisol stress hormone Released in response to ACTH patterns of eating and activity and stress Help the body resist stress by Keeping blood sugar levels relatively constant Maintain blood pressure by increasing action of vasoconstrictors Promotes rises in blood glucose fatty acids and amino acids Gluconeogenesis formation of glucose from noncarbohydrates i Hypersecretion Cushing s syndrome disease 1 Hyperglycemia depresses cartilage bone formation and immune system inhibits inflammation disrupts neural cardiovascular and gastrointestinal function 2 overuse of corticosteroids 3 Cushingoid signs moon face and buffalo hump 4 Treatment discontinuation of glucocorticoid drugs arthritis allergies ii Glucocorticoid hyposecretion Addison s disease h aldosterone retain sodium and secrete potassium Mineralocorticoids i Hypersecretion aldosteronism 1 Hypertension and edema due to excessive Na 2 Excessive excretion of K leading to muscle weakness eventually paralysis and eventually myocardial infarctions ii Hyposecretion Addison s disease 1 Hyposecretion of mineralocorticoids and glucocorticoids 2 Decrease in Na levels and glucose 3 Results in loss of weight severe dehydration hypotension bronzing of the skin i LH Luteinizing hormone LH Triggered by gonadotropin releasing hormone GnRH i In females 1 LH works with FSH to cause maturation of the ovarian follicle 2 LH works alone to trigger ovulation 3 LH promotes synthesis and release of estrogens and progesterone ii In males 1 LH is also referred to as interstitial cell stimulating hormone ICSH 2 LH stimulates interstitial cells of the testes to produce testosterone j Thymopoietin thymus involution as we age these hormones are essential for the development of the T lymphocytes T cells of the immune system k ACTH