front 1 Endocrine tissues are ___ | back 1 Diverse and decentralized |
front 2 Hypothalamus | back 2 Inhibitory hormones |
front 3 Pituitary gland | back 3 Systemic hormones |
front 4 Pineal gland | back 4 Melatonin |
front 5 Adipose | back 5 Leptin |
front 6 Heart | back 6 Atrial natriuretic factor |
front 7 Liver | back 7 Erythropoietin, IGF |
front 8 Adrenal glands | back 8 Steroids, catcholamine |
front 9 Ovaries | back 9 Estrogen, inhibin |
front 10 Testes | back 10 Testosterone, inhibin |
front 11 Intestine | back 11 Secretin |
front 12 Kidneys | back 12 Calcitriol, angiotensin II |
front 13 Pancreas | back 13 Insulin, glucagon |
front 14 Stomach | back 14 Gastrin |
front 15 Thyroid gland | back 15 - Thyroxine (T4) - Triiodothyronine (T3) - Calcitonin |
front 16 Parathyroid glands | back 16 Parathyroid hormone (PTH) |
front 17 Hypothalamus is considered ___ | back 17 Neuroendocrine |
front 18 Anterior pituitary | back 18 - Thyroid stimulating hormone - Adrenocorticotropic hormone - Luteinizing hormone - Follicle stimulating hormone - Growth hormone - Prolactin |
front 19 Posterior pituitary | back 19 - Antidiuretic hormone - Oxytocin |
front 20 Adrenal cortex | back 20 - Mineralocorticoids (aldosterone) - Glucocorticoids (cortisol) - Gonadocorticoids |
front 21 Adrenal medulla | back 21 Epinephrine and norepinephrine (catecholamines) |
front 22 Thymus | back 22 - Thymosin - Thymopoietin |
front 23 Endocrine cell | back 23 Releases chemical messengers (hormones) into the bloodstream - Only cells with receptors for that particular hormone will respond |
front 24 Hormones | back 24 Long-distance chemical messengers, traveling in the blood or lymph to bind to receptors on their target organs |
front 25 Tropic hormones | back 25 Hormones which target organ is another endocrine gland, affecting its activity |
front 26 Autocrine | back 26 Chemical messengers that exerts effects on the same cells that secrete them (not considered endocrine) |
front 27 Paracrine | back 27 Chemical messengers that affect neighboring cells (not considered endocrine) |
front 28 Amino acid-based hormones | back 28 Amino acid derivatives, peptides, and proteins |
front 29 Steroids | back 29 Synthesized from cholesterol and gonadal and adrenocortical hormones |
front 30 Steroids | back 30 - Lipophilic - Plasma, cytosolic, and nuclear receptors - Endocrine - Ex: estrogen |
front 31 Peptides (1) | back 31 - Lipophilic - Cytosolic and nuclear receptors - Endocrine - Ex: thyroxine |
front 32 Peptides (2) | back 32 - Hydrophilic - Plasma receptors - Endocrine - Ex: adrenocorticotropic hormone |
front 33 Proteins | back 33 - Hydrophilic - Plasma receptors - Endocrine - Ex: growth hormone |
front 34 Purinergic | back 34 - Hydrophilic - Plasma receptors - Paracrine - Ex: ATP |
front 35 Prostaglandins | back 35 - Lipophilic - Plasma receptors - Endocrine like - Ex: prostaglandin f2a |
front 36 Gases | back 36 - Lipophilic - Cytosolic receptors - Paracrine - Ex: nitric oxide |
front 37 Neurotransmitters | back 37 - Hydrophilic - Plasma receptors - Paracrine - Ex: acetylcholine |
front 38 Properties of hormones | back 38 - Regulation of physiological processes - Variety in chemical structure - Released in low quantities - Movement through diffusion or plasma - Bind to receptors on target cells - Released in response to changes in homeostasis |
front 39 Hormones regulate the ___ ___ of other hormones | back 39 Receptor levels |
front 40 Upregulation | back 40 Increasing receptor levels on target cells |
front 41 Downregulation | back 41 Decreasing receptor levels on target cells |
front 42 Permissiveness | back 42 The process of hormones regulating the receptor levels of other hormones |
front 43 Hormone release is ___ ___ | back 43 Amplitude-modulated |
front 44 Neurotransmitters | back 44 - Release in "all or nothing" - Vary in frequency |
front 45 Hormones | back 45 - Levels never approach zero - Fluctuate between high and low |
front 46 Peptide and protein hormones are synthesized in an ___ ___ | back 46 Inactive form |
front 47 Peptide and protein hormones | back 47 - Encoded by genes - Multiple peptide hormones can be encoded by one gene - Signal peptide: directs hormone to correct intracellular organelle for processing |
front 48 Synthesis of amino acid derivative hormones | back 48 - Biochemically synthesized from amino acids - Store within vesicles - Ex: epinephrine |
front 49 Processes that influence hormone secretion | back 49 - Changes in a critical physiological factor (ex: ions) - Direct input from the nervous system through neurohormone release - Actions of other hormones (ex: hypothalamic regulation of pituitary gland) - Mechanical stresses or cellular metabolism |
front 50 Hormones are ___ through the blood | back 50 Transported |
front 51 Fat/lipid-soluble hormone | back 51 - >99% bound to transport protein, <1% free - Some excreted in urine (if chemically modified to be more water-soluble) - Otherwise excreted in GI tract |
front 52 Water-soluble hormone | back 52 - 100% free - Smaller than kidney filtration barrier - Excreted in urine |
front 53 Half life | back 53 Time required to reduce blood concentration of a hormone by 50% |
front 54 Increases half life | back 54 - Increased synthesis - Increased secretion - Binding to transport proteins - Modification of structure |
front 55 Decreases half life | back 55 - Decreased synthesis - Decreased secretion - Excretion by kidney or bile - Enzymatic degradation, addition of a side chain, or reabsorption by the kidney |
front 56 ___ can change hormone levels or activity | back 56 Metabolism |
front 57 Hormones act in one of two ways | back 57 1. based on their chemical structure 2. based on their receptor location (integral protein on plasma membrane vs. intracellular receptor) |
front 58 Water-soluble hormones (hydrophilic) all amino acid-based hormones, except thyroid hormone | back 58 Act on integral protein receptors on plasma membrane or via second-messenger systems, since they are not able to enter the cell |
front 59 Lipid-soluble hormones (hydrophobic) all steroid (cholesterol) and thyroid hormones | back 59 Act on intracellular receptors that can directly activate enzymes or regulatory sequences on DNA, as they can enter the cell |
front 60 Water-soluble hormones (hydrophilic) | back 60 1. Integral plasma membrane receptor 2. Second-messenger system |
front 61 Integral plasma membrane receptor | back 61 Receptor embedded on plasma membrane |
front 62 Second-messenger system | back 62 - Receptors on plasma membrane exert effects of hormone binding by activating a 2nd intracellular messenger - cAMP (cyclic adenosine monophosphate) - PIP2- calcium (phosphatidyl inositol bisphosphate calcium) |
front 63 G-protein coupled receptors (GPCRs) | back 63 - Integral membrane proteins - Extracellular region binds hormone - Intracellular region interacts with G-proteins |
front 64 Subunits of G-proteins | back 64 - Gas - Gai - Gaq |
front 65 Gas | back 65 - Activates adenylate cyclase (AC) - Converts ATP to cAMP |
front 66 Gai | back 66 - Inhibits adenylate cyclase (AC) |
front 67 Gaq | back 67 Activates phospholipase C (PLC) - Breaks down PIP2 into IP3 and DAG |
front 68 Effects of cAMP | back 68 - Activates protein kinase A (PKA) - Degraded by phosphodiesterase (PDE) |
front 69 Effects of DAG and IP3 | back 69 - IP3 causes Ca2+ release from ER - DAG activates protein kinase C (PKC) |
front 70 One-transmembrane spanning receptors (1-TMS) | back 70 - Integral membrane proteins - Extracellular region binds hormone - Intracellular region contains a kinase domain; directly activates enzymes without G-proteins |
front 71 Nuclear receptors | back 71 - Found inside the cell - Act as transcription factors - Generally cytoplasmic proteins complexed with heat shock proteins (HSPs) - Hormone binding leads to dissociation of HSPs, dimerization to a second bound receptor, and translocation to the nucleus |
front 72 Thyroid stimulating hormone receptor causes | back 72 Grave's disease (hyperthyroidism) |
front 73 Parathyroid hormone receptor causes | back 73 Jansen's metaphyseal chondrodysplasia |
front 74 Follicle-stimulating hormone receptor causes | back 74 Ovarian dysgenesis type I |
front 75 Melanocortin/adrenocorticotropic hormone receptor causes | back 75 Familial glucocorticoid definciency |
front 76 Luteinizing hormone receptor causes | back 76 Familial male precocious puberty |
front 77 Antidiuretic hormone receptor causes | back 77 Familial hypocalciuric hypercalcemia |
front 78 Gonadotropin-releasing hormone receptor | back 78 Hypogonadotropic hypogonadism |
front 79 Anatomy of the hypothalamus | back 79 - Located inferior to the thalamus; part of the limbic system - Contains many distinct nuclei that produce and release unique hormones - Is sexually dimorphic (different between men and women) - Hypophyseal portal system connects hypothalamus and anterior pituitary via two capillary beds in series |
front 80 Hypothalamus releases hormones that act on ___ ___ | back 80 Pituitary gland |
front 81 Thyrotropin releasing hormone (TRH) (hypothalamic hormone) | back 81 Effect at anterior pituitary: TSH and prolactin release |
front 82 Corticotropin releasing hormone (CRH) (hypothalamic hormone) | back 82 Effect at anterior pituitary: ACTH release |
front 83 Growth hormone releasing hormone (GHRH) (hypothalamic hormone) | back 83 Effect at pituitary: GH release |
front 84 Gonadotropin releasing hormone (GnRH) (hypothalamic hormone) | back 84 Effect at pituitary: FSH and LH release |
front 85 Prolactin inhibitory hormone (PIH or dopamine) | back 85 Effect at pituitary: inhibition of prolactin release |
front 86 Growth hormone inhibitory hormone (GIRH, somatostatin) | back 86 Effect at pituitary: inhibition of GH and TSH release |
front 87 Anatomy of the pituitary gland | back 87 - Located inferior to the hypothalamus - Composed of anterior, intermediate and posterior lobes - Anterior lobe: subdivided into pars tuberalis and pars distalis - Two pituitary areas do not regulate each other |
front 88 Hormones secreted by the posterior pituitary gland | back 88 - Oxytocin - Antidiuretic hormone |
front 89 Oxytocin | back 89 - Movement of mammary milk into subaereolar sinuses (milk ejection/letdown) - Stimulation of uterine contraction during pregnancy - Social behavior: feelings of contentment, reduced anxiety, calmness |
front 90 Antidiuretic hormone | back 90 - Renal system: increased expression of aquaporin channels (increased water absorption); increased interstitial osmolarity (increased water, Na+ reabsorption) - Cardiovascular system: vasoconstriction - CNS: aggression, blood pressure, body temperature regulation |
front 91 Types of pituitary adenoma | back 91 - Benign (65% of the time) - Invasive (0.1%) - Carcinoma (35%) |
front 92 Symptoms of pituitary adenoma | back 92 - Over-secretion of one or two hormones - Eye disorders (compression of optic nerve) - Severe headaches - Under-secretion of some hormones |
front 93 Anatomy of the thyroid gland | back 93 - Found lateral to the upper trachea - Made up of two lobes connected by highly vascularized band of tissues called isthmus - Contains follicles that store thyroglobulin, the substrate for thyroxine - Parafollicular cells are scattered between follicles and secrete calcitonin |
front 94 Effects of thyroxine throughout the body | back 94 - Cold, nutrient status - Increased lung ventilation - Increased metabolic rate (liver) - Increased lipolysis in adipose tissue - Increased protein catabolism in muscle - Increased heart rate, force contraction, cardiac output |
front 95 Thyroxine synthesis in the thyroid gland | back 95 1. Iodide ions transported into follicular cells 2. TSH stimulates TG synthesis and storage within follicles 3. Iodide is oxidized to iodine by thyroid peroxidase; diffuses to follicle lumen 4. Iodine atoms are covalently attached to tyrosine residues on thyroglobulin, forming MIT or DIT 5. Two DIT molecules join to form T4, or one MIT and one DIT join to form T3 6. Follicular cells take up iodinated thyroglobulin by endocytosis. Within endosomes, proteolytic enzymes release thyroxine from TG 7. Thyroxine is released into blood bound to proteins (ex: TBG or albumin) |
front 96 Anatomy of the parathyroid gland | back 96 - Four parathyroid glands (2 embedded in each thyroid gland) - Densely-packed with chief and oxyphil cells - Mainly secrete parathyroid hormone (PTH) |
front 97 Effects of parathyroid hormone throughout the body | back 97 - Bone: increased resorption - Kidney: increased calcitriol - Intestine: increased calcium reabsorption |
front 98 Anatomy of the adrenal glands | back 98 - Embedded in adipose tissue in the superior regions of the kidney - Composed of endocrine and nervous tissue - Organized into zones which are structurally and functionally distinct |
front 99 Hormones by the adrenal gland | back 99 - Mineralocorticoids (aldosterone) - Glucocorticoids - Androgen precursors |
front 100 Mineralocorticoids (aldosterone) | back 100 - Zone glomerulosa - Increases Na+ resorption (urine, sweat glands, salivary glands, colon), increased renal K+ excretion |
front 101 Glucocorticoids | back 101 - Zone fasciculate - Hyperglycemia, immunosuppression, increase lipolysis, decreased glucose uptake into skeletal muscle, increased gluconeogenesis, increased protein degradation |
front 102 Androgen precursors | back 102 - Zona reticularis - Converted to androgens; direct effects on testes and ovaries, bone-protective effects, increased neuron survival |
front 103 Anatomy of adipose tissue | back 103 - Found under skin, around organs, in bone marrow, within muscle and breast tissue - Composed predominantly of adipocytes along with fibroblasts, macrophages and endothelial cells - Releases hormones (leptin (hormone that makes you feel full), adiponectin (modulates insulin response), resistin - Main hormone functions: regulating body metabolism, weight, reproductive function and inflammation |
front 104 Anatomy of the pancreas | back 104 - Lies beneath the greater curvature of the stomach and small intestine - Bulk of mass is exocrine tissue/ducts - Produces pancreatic juice and secretes it into the small intestine for digestion - Clusters of endocrine cells are scattered throughout; produce insulin and glucagon |
front 105 Types of endocrine cells in the islets of Langerhans | back 105 - a cells (20%): secrete glucagon - b cells (70%): secrete insulin and amylin - delta cells (3-10%): secrete somatostatin - PP cells (3-5%): secrete pancreatic polypeptide - E cells (1%): secrete ghrelin |
front 106 Insulin structure | back 106 A and b chains held together by disulfide bonds |
front 107 Insulin functions | back 107 - Secreted in response to increased blood glucose concentrations - Insulin facilitates glucose entry into muscle, adipose and other tissues, through GLUT4 - Increases glucose in liver through multiple mechanisms |
front 108 Structure of glucagon | back 108 - Synthesized as pro-glucagon in pancreatic a cells - Proteolytically processed to yield glucagon |
front 109 Functions of glucagon | back 109 - Secreted in response to low blood glucose concentrations - Mainly affects the liver to increase blood glucose levels - Stimulates breakdown of liver glycogen and stimulates gluconeogenesis |
front 110 Decrease in GH release | back 110 Decrease in body mass |
front 111 Decrease in TSH and the T3/T4 ratio | back 111 Loss of TSH regulated functions |
front 112 Over-secretion of PTH | back 112 Loss of bone mass |
front 113 Decrease in renal renin release | back 113 Decreased ability to regulate arterial blood pressure |
front 114 Decrease in reproductive hormones | back 114 Reduced production of sperm, menopause |
front 115 Decrease in thymus cytokines | back 115 Fewer mature, functional lymphocytes |