Term
|
Definition
| • Composed of glands that pour secretions into blood instead of into ducts (ductless) |
|
|
Term
| • Chemicals produced are called |
|
Definition
|
|
Term
| – Nervous system (nerve impulses) produce |
|
Definition
| rapid, short-lasting responses |
|
|
Term
|
Definition
| slower, longer-lasting effect |
|
|
Term
| – Cells that are acted on and respond to hormones are called |
|
Definition
| target organ cells (contain receptors) |
|
|
Term
|
Definition
| paracrine factors chemicals that affect neighboring cells; autocrines act on cell that secreted them |
|
|
Term
| Endocrine system function |
|
Definition
help maintain homeostasis
Regulate chemical composition and volume of internal environment
Help regulate metabolism and energy balance (Thyroxin)
Help regulate contraction of smooth and cardiac muscle fibers and secretion of glands
Regulate some activities of immune system
Play role in smooth, sequential integration of growth and development (Growth Hormone and Thyroid Hormone)
Contribute to basic process of reproduction (FHS and LH-Female, |
|
|
Term
|
Definition
|
|
Term
| • Lipids structurally similar |
|
Definition
|
|
Term
| Lipid Soluble released by |
|
Definition
| by male and female reproductive organs, adrenal glands and kidneys |
|
|
Term
|
Definition
| both hormone and neurotransmitter |
|
|
Term
|
Definition
| – Amines, Peptide hormones, Eicosanoids |
|
|
Term
|
Definition
• Structurally similar to amino acids
• Released by adrenal medulla, thyroid, and pineal gland
• Most are synthesized from amino acid tyrosine |
|
|
Term
|
Definition
• Chains of amino acids
• Largest class and includes all hormones secreted by hypothalamus, pituitary gland, heart, thymus, digestive tract, and pancreas |
|
|
Term
|
Definition
• Small molecules with 5-carbon ring at one end
• Includes prostaglandins and leukotrienes and are important paracrine factors |
|
|
Term
| • For hormone to affect target cell, it must first |
|
Definition
| interact with appropriate receptor |
|
|
Term
| • Hormone receptors may be |
|
Definition
| on cell membrane or inside cell |
|
|
Term
| • Hormones and cell membrane |
|
Definition
| water soluble - cannot penetrate cell membrane |
|
|
Term
| – Receptors for catecholamines, peptide hormones, and eicosanoids are found in |
|
Definition
|
|
Term
|
Definition
| first messenger that causes appearance of second messenger in cytoplasm |
|
|
Term
| – Second messenger may serve as |
|
Definition
| enzyme activator, inhibitor, or cofactor (net result is change in rates of various metabolic reactions) |
|
|
Term
| – Most important second messengers are |
|
Definition
| cyclic AMP, cyclic GMP, and calcium ions |
|
|
Term
| – Binding of hormone to receptors may lead to |
|
Definition
| release of many (thousands) of 2nd messengers--called amplification |
|
|
Term
| – Link between 1st messenger and 2nd messenger usually involves |
|
Definition
| G-protein, an integral membrane protein that interacts with the membrane receptor |
|
|
Term
| • Two hormones may have opposing or |
|
Definition
|
|
Term
| • Two hormones may have additive or |
|
Definition
|
|
Term
|
Definition
| permissive effect on another |
|
|
Term
| first hormone is needed for |
|
Definition
| second to produce its effect |
|
|
Term
| • Hormones may produce different but |
|
Definition
| complimentary results (integrative effects) |
|
|
Term
| • Amount of hormone released by endocrine gland is determined by |
|
Definition
| body’s need for the hormone at any given time |
|
|
Term
| • Negative feedback is common method for hormonal control- |
|
Definition
| low level of substance may cause release of hormone |
|
|
Term
| • Hormone may be released as result of |
|
Definition
|
|
Term
| • Other hormones may regulate |
|
Definition
|
|
Term
|
Definition
– In sella turcica of sphenoid bone
– Consists of 2 endocrine glands: anterior lobe (adenohypophysis) and posterior lobe (neurohypophysis) |
|
|
Term
| • Anterior portion divided into |
|
Definition
| larger pars anterior and small pars intermedia |
|
|
Term
| – Hormones of anterior pituitary are stimulated by |
|
Definition
| releasing hormones of hypothalamus and suppressed by inhibiting hormones |
|
|
Term
| – Hypophyseal portal system connects pituitary to |
|
Definition
| hypothalamus and is means by which regulatory hormones travel to pituitary |
|
|
Term
| • Prolactin (lactogenic hormone or luteotropic hormone [LTH]) |
|
Definition
– During pregnancy, promotes breast development
– After delivery, initiates milk secretion
– Helps in maintaining corpus luteum |
|
|
Term
| • Growth hormone (somatotropin or somatotropic hormone) |
|
Definition
| – Accelerates protein anabolism (synthesis), so promotes growth; skeletal muscle cells and chondrocytes particularly sensitive |
|
|
Term
| • Disorders caused by excess growth hormone |
|
Definition
|
|
Term
| • Disorders caused by deficient growth hormone |
|
Definition
|
|
Term
| – Liver and other cells produce |
|
Definition
| insulinlike growth factors (IGFs) that increase amino acid uptake |
|
|
Term
| • Growth hormone tends to accelerate |
|
Definition
| fat mobilization from adipose cells and fat catabolism by other cells, thereby decreasing glucose catabolism and tending to increase blood glucose concentration (hyperglycemic effect); prolonged excess may produce diabetes |
|
|
Term
|
Definition
| hormones that have a stimulating effect on other endocrine glands) (18.4 table) |
|
|
Term
|
Definition
| - thyroid-stimulating hormone (TSH) |
|
|
Term
|
Definition
Promotes growth and development of thyroid gland
Stimulates thyroid gland to secrete thyroid hormone |
|
|
Term
| Adrenocorticotropin (ACTH) |
|
Definition
Promotes growth and development of adrenal cortex
Stimulates cortex to secrete cortisol and other glucocorticoids |
|
|
Term
| – Follicle-stimulating hormone (FSH) |
|
Definition
• Stimulates primary Graafian follicle to start growing and to develop to maturity
• Stimulates follicle cells to secrete estrogens
• In male, stimulates development of seminiferous tubules and maintains spermatogenesis by them |
|
|
Term
| – Luteinizing hormone (LH) |
|
Definition
| • Acts with FSH to cause complete maturation of follicle and brings about ovulation |
|
|
Term
| • Stimulates formation of |
|
Definition
| corpus luteum (luteinizing effect) and stimulates corpus luteum to secrete progesterone and estrogens |
|
|
Term
|
Definition
| interstitial cell stimulating hormone (ICSH); stimulates interstitial cells in testes to develop and secrete testosterone |
|
|
Term
|
Definition
stimulating hormone (MSH) or intermedin (Found in skin!)
– Produced by pars intermedia
– Tends to produce increased pigmentation of skin |
|
|
Term
|
Definition
| neurosecretions produced in hypothalamus that reach anterior pituitary gland via blood in pituitary portal system to regulate hormone production (pg 691) |
|
|
Term
| – Negative feedback mechanisms operate between |
|
Definition
| target glands and anterior lobe of pituitary |
|
|
Term
| • Antidiuretic hormone (ADH) or vasopressin |
|
Definition
| – Synthesized by neurons in supraoptic nucleus of hypothalamus |
|
|
Term
| – Stimulates water reabsorption by |
|
Definition
| distal and collecting tubules of kidney (causes retention of water) |
|
|
Term
| – In large (pharmacological) doses will |
|
Definition
| stimulate smooth muscle of blood vessels |
|
|
Term
| – Lack of ADH results in diabetes insipidus |
|
Definition
| (Urine production increases. no ADH=no water retention. YO GON’ BE THIRSTY!) |
|
|
Term
|
Definition
– Synthesized by neurons in the paraventricular nucleus of hypothalamus
– Stimulates contractions of pregnant uterus and release of milk by lactating breast |
|
|
Term
|
Definition
• Increased extracellular fluid osmotic pressure leads to decreased ADH secretion
• Decreased ECF leads to increased ADH secretion
• Stress leads to increased ADH secretion |
|
|
Term
|
Definition
| • Not fully known but stimulation of nipples by infant leads to increased oxytocin secretion and stretch receptors in cervix send impulses to hypothalamus during delivery |
|
|
Term
|
Definition
– In neck just below larynx
– Two lateral lobes connected by isthmus
– Contains microscopic spherical sacs called thyroid follicles |
|
|
Term
| • Follicular cells manufacture thyroid hormones by |
|
Definition
| attaching iodine to the amino acid tyrosine |
|
|
Term
| • Parafollicular or C cells produce |
|
Definition
|
|
Term
| – Thyroid hormone (thyroxine - T4; triiodothyronine - T3) (4 and 3= how much iodine is attatched) |
|
Definition
• Stimulates rate of oxygen consumption (metabolic rate) of all cells
-Essential for normal metabolism
• Regulates physical and mental development, development of sexual maturity, and numerous other processes (table 18.6) |
|
|
Term
|
Definition
• Decreases blood calcium concentration
• Inhibits bone breakdown with calcium release into blood and/or increases calcium deposition in bone |
|
|
Term
| – Hypersecretion leads to |
|
Definition
| exophthalmic goiter (Grave’s disease) (hungry-and losing weight, extra metabolism going on-because of all the muscle contractions (sweat easily, get hot easily. Have difficulties concentration. ) |
|
|
Term
| – Hypothyroidism in adult is |
|
Definition
| myxedema; in infant called cretinism |
|
|
Term
| – Lack of iodine leads to |
|
Definition
|
|
Term
|
Definition
– Attached to posterior surfaces of thyroid gland
– Small round bodies, usually 4 or 5 in number
– Contain principal (chief) cells which produce parathyroid hormone (parathormone-PTH) |
|
|
Term
| Parathyroid hormone Increases blood calcium by |
|
Definition
| stimulating bone breakdown releasing calcium and phosphate into blood from bone |
|
|
Term
| – Increases blood calcium by |
|
Definition
| by accelerating calcium absorption from kidney tubules |
|
|
Term
| – Accelerates kidney excretion of |
|
Definition
| phosphates from blood into urine |
|
|
Term
| – Acts on kidneys to promote |
|
Definition
| formation of calcitriol, active form of vitamin D, which acts on intestines to increase calcium, phosphate, and magnesium absorption |
|
|
Term
|
Definition
| decrease in bone mass with replacement by fibrous tissue; more easily fractured (Making bones weaker) (Calcium used for muscle contraction) |
|
|
Term
|
Definition
| hypocalcemia leading to muscle twitches, spasms, and convulsions (called tetany); may lead to death in few hours |
|
|
Term
|
Definition
– Located atop kidneys
– Outer portion of gland called cortex and inner portion called medulla |
|
|
Term
| • Zones or layers (from outside in) |
|
Definition
| Zona glomerulosa and – Zona fasciculata – Zona reticularis |
|
|
Term
|
Definition
| secretes mineralocorticoids |
|
|
Term
|
Definition
|
|
Term
|
Definition
| secretes small amounts of glucocorticoids and sex hormones |
|
|
Term
| • Glucocorticoids (mainly cortisol, smaller amounts of corticosterone) |
|
Definition
– Accelerate tissue protein mobilization; mobilized amino acids circulate to liver cells where they are changed to glucose
– Accelerate fat mobilization and catabolism
– Necessary for norepinephrine’s vasoconstricting effect on blood vessels and thus *** essential for maintaining normal blood pressure |
|
|
Term
| – Glucocorticoids plus epinephrine promote |
|
Definition
| normal recovery from injury by inflammatory agents (*** anti-inflammatory effect) |
|
|
Term
| – Blood concentration increases |
|
Definition
|
|
Term
|
Definition
– Accelerate renal tubule reabsorption of sodium ions and [Indirectly if you retain a negative ion, you lose a positive ion] excretion of potassium ions (or hydrogen ions)
– Increased renal tubule reabsorption of bicarbonate ions (or chloride ion) and water result from increased sodium reabsorption (Because of what aldosterone does, we get water retention as well) |
|
|
Term
| • Sex hormones (3rd layer) |
|
Definition
| – In both sexes, amount of male hormones secreted by adrenal cortex is physiologically significant, but amount of female hormones is insignificant |
|
|
Term
|
Definition
|
|
Term
|
Definition
| angiotensin mechanism, an important regulator of aldosterone |
|
|
Term
| – Blood potassium concentration also helps regulate |
|
Definition
|
|
Term
| high blood potassium conc. stimulates and low blood potassium conc. inhibits |
|
Definition
|
|
Term
|
Definition
| - hyposecretion of aldosterone and glucocorticoids; muscle weakness, mental lethargy, weight loss, increased ACTH may lead to pigmentation of certain areas of skin (resembles MSH) [Can’t Think] |
|
|
Term
|
Definition
| hypersecretion of glucocorticoids characterized by redistribution of fat |
|
|
Term
| – Congenital adrenal hyperplasia |
|
Definition
| lack of glucocorticoid production with increased ACTH; leads to virilism or masculinization (BEARED LAAADYY!!) |
|
|
Term
• Adrenal medulla (FYI we could get by without it)
HORMONES |
|
Definition
| mainly epinephrine; some norepinephrine |
|
|
Term
| • Functions of epinephrine |
|
Definition
– Affects visceral effectors (smooth and cardiac muscle, glands) in same way as sympathetic stimulation of these structures (Increase heart rate, increase respiratory rate, decrease gastrointestinal)
– Epinephrine from adrenal glands intensifies and prolongs sympathetic effects |
|
|
Term
• Adrenal medulla
Control of secretion |
|
Definition
| stress stimulates hypothalamus, which sends impulses to adrenal medulla via preganglionic sympathetic neurons, stimulating medulla to increase secretion of epinephrine |
|
|
Term
|
Definition
|
|
Term
|
Definition
| beta cells of islets of Langerhans |
|
|
Term
|
Definition
| alpha cells of islets of Langerhans |
|
|
Term
| – Growth hormone inhibiting hormone (GHIH) or somatostatin (delta cells) - [in pancreas] |
|
Definition
| acts as paracrine to inhibit secretion of insulin and glucagon |
|
|
Term
|
Definition
| pancreatic polypeptide which regulates release of pancreatic digestive enzymes |
|
|
Term
|
Definition
| decrease blood glucose levels |
|
|
Term
| • Promotes glucose transport into cells, thereby |
|
Definition
| increasing glucose utilization (catabolism) and glycogenesis and decreasing blood glucose levels |
|
|
Term
| • Promotes fatty acid transport into |
|
Definition
| cells and fat anabolism (lipogenesis or fat deposition) in them |
|
|
Term
| • Promotes amino acid transport into |
|
Definition
| cells and protein anabolism |
|
|
Term
|
Definition
increase blood glucose levels
• Accelerates liver glycogenolysis
• Promotes formation of glucose from lactic acid (gluconeogenesis)
Help proteins and fatty acids being turned into glucose!!
• Enhances release of glucose into blood |
|
|
Term
|
Definition
| • Deficiency of insulin leading to hyperglycemia |
|
|
Term
|
Definition
| Insulin-dependent (Type I) and Non-insulin dependent (NIDDM) (Type II)• Characterized by polyuria, polydipsia, and polyphagia |
|
|
Term
| – Hyperinsulinism leads to |
|
Definition
| hypoglycemia and insulin shock |
|
|
Term
|
Definition
– Ovarian (Graafian) follicles secrete estrogens
– Corpus luteum secretes progesterone |
|
|
Term
|
Definition
| hormones - androgens, most important of which is testosterone |
|
|
Term
| • Pineal gland (epiphysis cerebri) - |
|
Definition
| melatonin - may be involved with establishment or maintenance of circadian rhythms(sleep cycle, wake cycle) |
|
|
Term
| • Thymus – thymosin (decreases in size as we age |
|
Definition
– Needed for maturation and development of immune system
– Increases numbers of T cells in lymphocyte population
– Promotes an increase in many types of lymphocyte functions |
|
|
Term
|
Definition
| • Regulate endocrine activity at the cellular level by influencing adenyl cyclase and cyclic AMP activity |
|
|
Term
|
Definition
| help in regulation of blood pressure |
|
|
Term
|
Definition
| vascular effects involving rbc “deformability” and platelet aggregation; effect on HCL secretion in stomach |
|
|
Term
|
Definition
| important in reproductive function |
|
|
