endocrine Flashcards

Question

negative feedback system

Answer 1

Increased hormone effects on target organs can inhibit further hormone release

Answer 2

triggered by: Endocrine gland stimuli (ions or hormones) * Nervous system modulation (sympathetic nervous system)

Answer 3

Changing blood levels of ions and nutrients directly stimulate secretion of hormones – Example: Ca2+ in blood: * LOW or declining blood Ca2+ concentration stimulates parathyroid glands to secrete PTH (parathyroid hormone) * PTH goes to bone and causes blood Ca2+ concentrations to rise, and stimulus is removed

Answer 4

water soluble hormones

Answer 5

lipid soluble hormones

Answer 6

found on nearly all cells of the body

Answer 7

found only in certain cells in adrenal cortex

Answer 8

releases hormones stimulate release of most anterior pituitary hormones is connected to pituitary gland via stalk called infundibulum Posterior lobe is neural tissue derived from a downgrowth of brain and maintains neural connection to hypothalamus Neurons of hypothalamus make and secrete two neurohormones (oxytocin– PVN and ADH – supraoptic nucleus)

Answer 9

hormones stimulate other target cells to secrete still more hormones consists of glandular tissue Anterior lobe, called the adenohypoph

Answer 10

Hormones from final target organs ultimately inhibit release of anterior pituitary hormones

Answer 11

(tropic hormones) stimulate other endocrine organs to release their hormones

Answer 12

hypothalamus- pituitary – thyroid gland FN: Metabolic function

Answer 13

hypothalamus – pituitary – adrenal gland FN: Central stress response system

Answer 14

hypothalamus – pituitary – gonads FN: Regulate reproductive function

Answer 15

involved in glucose metabolism

Answer 16

the number of receptors increases in response to lowered hormone or antagonist drug levels, making the cell more sensitive to the hormone or drug and allowing for more cellular activity/stronger response

Answer 17

response to rising hormone or agonist drug levels, making the cell less sensitive to the hormone or drug and cellular activity demonstrate a reduced/diminished response

Answer 18

long term medication use or elevated hormone levels

Answer 19

long term blocker or lowered hormone levels

Answer 20

Chronic increased levels of glucose lead to increased production of insulin * It occurs due to constant or repeated or long-term administration of an agonist (med) or hormone (in this example: insulin) * Over time, insulin receptors down regulate making the individual less sensitive (less responsive) to insulin * Also referred to as insulin resistance = low insulin sensitivity * Body is stuck in a loop of high insulin levels that leads to ineffective blood sugar regulation

Answer 21

secretes 8 major hormones

Answer 22

composed of neural tissue that secretes neurohormones Posterior lobe, along with infundibulum make up the neurohypophysis Hormones are stored in axon terminals in posterior pituitary and are released into blood when neurons fire consists of axon terminals of neurons originating from the hypothalamus: – Oxytocin produced in paraventricular neurons (PVN) – ADH produced in supraoptic neurons produce antidiuretic hormone (ADH)

Answer 23

– Each composed of nine amino acids – Almost identical – differ in two amino acids

Answer 24

Strong stimulant of uterine contractions released during childbirth – Also acts as hormonal trigger for milk ejection – Both are positive feedback mechanisms – Acts as neurotransmitter in brain: “cuddle hormone” – Important role in maternal behavior

Answer 25

Hypothalamus contains osmoreceptors that monitor solute concentrations – If solute concentration too high, posterior pituitary triggered to secrete ADH – FN: Targets kidney tubules to reabsorb more water which will inhibit or prevent urine formation – “Concentrates your urine” – Release also triggered by pain, low blood pressure, and drugs Action is inhibited: use of alcohol – Clinically: ADH release is inhibited or halted – body told not to hold onto water – increases water loss – Result: water loss increase unchecked

Answer 26

Inability to suppress the secretion (excess secretion) of ADH = fluid retention * Impaired (reduced) water excretion (associated relative hyponatremia) * Many causes: CNS disturbances, pulmonary diseases (pneumonia), small cell CA of lung, medications (seizure, bipolar meds) * Treatment: 1. Treat the underlying cause 2. Fluid restriction

Answer 27

glucophage (metformin)-> GI symps.

Answer 28

concentrated due to retention of water throughout the night from increased ADH secretion

Answer 29

All six hormones are amino acid (peptide) hormones All but growth hormone (GH) activate target cells via cAMP second-messenger system All but two are tropic hormones: they regulate the secretion of other hormones – 1. Growth hormone (GH) – 2. Thyroid-stimulating hormone (TSH) (tropic) – 3. Adrenocorticotropic hormone (ACTH) (tropic) – 4. Follicle-stimulating hormone (FSH) (tropic) – 5. Luteinizing hormone (LH) (tropic) – 6. Prolactin (PRL)

Answer 30

Also called somatotropin as it is produced by somatotropic cells – Has direct actions on metabolism and indirect on growth – Actions on metabolism and growth: * 1,) Glucose-sparing actions decrease rate of cellular glucose uptake and metabolism (anti-insulin effects) * 2.) Triggers liver to break down glycogen into glucose * 3.) Increases blood levels of fatty acids for use as fuel and encourages cellular protein synthesis * 4.) Stimulates most cells to enlarge and divide; major targets bone and skeletal muscle = growth and repair

Answer 31

usually caused by anterior pituitary tumor – In children results in gigantism * Can reach heights of 8 feet – In adults results in acromegaly * Overgrowth of hands, feet, and face

Answer 32

In children results in pituitary dwarfism * May reach height of only 4 feet – In adults usually causes no problems

Answer 33

Tropic hormone that is also called thyrotropin as it is produced by thyrotropic cells – Stimulates normal development and secretory activity of thyroid gland – Release triggered by thyrotropin-releasing hormone (TRH) from hypothalamus (responding to low levels of T3 + T4 = TH) – Inhibited by rising blood levels of thyroid hormones that act on both pituitary and hypothalamus

Answer 34

Butterfly-shaped gland in anterior neck on the trachea, just inferior to larynx, that consists of: * Isthmus: median mass connecting two lateral lobes * Follicles: hollow sphere of epithelial follicular cells responsible for the production of thyroglobulin * Thyroglobulin: inactive thyroid hormone Colloid: fluid of follicular cell (follicle) lumen containing thyroglobulin plus iodine and is precursor to thyroid hormone – FN: body’s major metabolic hormone * Also have parafollicular cells: produce hormone calcitonin – FN: decrease blood calcium levels

Answer 35

Body’s major metabolic hormone * Found in two forms: – T4 (thyroxine): major form that consists of two tyrosine molecules with four bound iodine atoms – T3 (triiodothyronine): form that has two tyrosines with three bound iodine atoms – speeds up cellular processes * T4 must be converted to T3 at tissue level * Both are iodine-containing amine hormones

Answer 36

TH affects virtually every cell in body * Enters target cell and binds to intracellular receptors within nucleus – Triggers transcription of various metabolic genes * Effects of thyroid hormone include: – Increases basal metabolic rate and heat production ▪ Referred to as calorigenic effect

Answer 37

Hypersecretion of TH: most common type is Graves’ disease – Autoimmune disease: body makes ABNORMAL antibodies directed against thyroid follicular cells (that make active TH) – MOA: Antibodies mimic TSH, stimulating TH release – Symptoms include elevated metabolic rate, sweating, rapid and irregular heartbeats, nervousness, and weight loss (despite adequate food) * Exophthalmos may be a result: eyes protrude as tissue behind eyes becomes edematous and fibrous – Treatments include surgical removal of thyroid or radioactive iodine to destroy active thyroid cells – Thyroid: only gland in the body that takes up/uses iodine

Answer 38

Produced by parafollicular (C) cells of thyroid gland and released in response to high blood Ca2+ levels (helps the body store calcium in bone) – functions to decrease/lower blood Ca2+ levels * Antagonist to parathyroid hormone (PTH) - functions to increase blood Ca2+ levels * No known physiological role in humans at normal physiological levels, but at higher-than-normal doses: – Inhibits release of Ca2+ from bone matrix – Stimulates Ca2+ uptake and incorporation into bone matrix

Answer 39

Four to eight tiny yellow-brown glands embedded in posterior aspect of thyroid gland * Contain oxyphil cells (function not clear) and parathyroid cells that secrete parathyroid hormone (PTH) * Produces PTH: the most important hormone in Ca2+ homeostasis – Triggered by: secreted in response to low blood levels of Ca2+ – Inhibited by: rising levels of Ca2+ * Target organs are skeleton, kidneys, and intestine

Answer 40

Paired, pyramid-shaped organs atop kidneys – Also referred to as suprarenal glands * Is structurally and functionally: two glands in one: – Adrenal cortex – outer portion: three layers of glandular tissue each that synthesize and secrete several different hormones – Adrenal medulla – inner portion: considered nervous tissue that is part of sympathetic nervous system (think norepinephrine)

Answer 41

Aldosterone: – MOA: regulate electrolyte concentrations (primarily Na+ and K+) in ECF: * Importance of Na+ : affects ECF volume, blood volume, blood pressure, and levels of other ions (K+ , H+, HCO3- and Cl-) * Importance of K+ : sets resting membrane potential of cells – Most potent mineralocorticoid * FN: Stimulates Na+ reabsorption (K+ loss) and secondarily water reabsorption by kidneys – Results in increased blood volume and increase blood pressure (STIMULATES: K+ elimination by kidneys) * Rule: when body reabsorbs 1 Na+ it secretes 1 K+

Answer 42

1. Decreased blood pressure and blood volume stimulates special cells in kidneys called granular cells 2. These cells release renin into blood 3. Renin cleaves off part of plasma protein, angiotensinogen, that triggers enzyme cascade, resulting in conversion to angiotensin II 4. Angiotensin II is a potent stimulator of aldosterone release: – Result: vasoconstriction and increased BP

Answer 43

stress hormone – Influence metabolism of most cells and help us resist stressors – Keep blood glucose levels relatively constant – Maintain blood pressure by increasing action of vasoconstrictors – Only glucocorticoid in significant amounts in humans

Answer 44

* Release of cortisol causes increase in blood levels of glucose, fatty acids, and amino acids (think stress response = “stress hormone”) * Prime metabolic effect is gluconeogenesis, formation of glucose from fats and proteins (or new sources of glucose that are not carbohydrates) – Encourages cells to use fatty acids for fuel so glucose is “saved” for brain (glucose-sparing affect) * Other function is to enhance vasoconstriction – Causes rise in blood pressure to quickly distribute nutrients to cells

Answer 45

* Medullary chromaffin cells synthesize catecholamines epinephrine (80%) and norepinephrine (20%) * Major affects of catecholamines EPI and NE and (corresponding adrenergic receptors): – Vasoconstriction (A1 – blood vessel smooth muscle) – Increased blood glucose levels (A2 – pancreas) – Increased heart rate (B1 – heart) – Bronchodilation (B2 – lungs) – Lipolysis (B3 – adipose tissue) – When released: blood diverted to brain, heart, and skeletal muscle

Answer 46

Triangular gland located posterior to the stomach * Has BOTH exocrine and endocrine cells: – EXO: Acinar cells (exocrine) produce enzyme-rich juice for digestion – ENDO: Pancreatic islets (islets of Langerhans) contain 2 types of endocrine cells that produce hormones: * Alpha () cells produce glucagon (elevates blood sugar levels) * Beta () cells produce insulin (lowers blood sugar levels)

Answer 47

Extremely potent hyperglycemic agent = elevates blood sugar levels * 3 triggers: decreased blood glucose levels, rising amino acid levels, or sympathetic nervous system – Raises blood glucose levels by targeting liver to: 1. Break down glycogen into glucose – Glycogenolysis 2. Synthesize new glucose from lactic acid and other noncarbohydrates (lipids and proteins) – Gluconeogenesis 3. Release glucose into blood stored in the liver

Answer 48

Secreted when blood glucose levels increase = elevated blood sugar – Synthesized as proinsulin that is then modified – Insulin lowers blood glucose levels in three ways: * 1.) Enhances membrane transport of glucose into fat and muscle cells * 2.) Inhibits breakdown of glycogen to glucose * 3.) Inhibits conversion of amino acids or fats (non-carbohydrates) to glucose

Answer 49

Diabetes mellitus (DM) can be due to: – Hyposecretion of insulin: Type 1 – Hypoactivity of insulin: Type 2 * Three cardinal signs of DM: – Polyuria: huge urine output * Glucose acts as osmotic diuretic = promotes water loss * Polydipsia: excessive thirst * From water loss due to polyuria * Polyphagia: excessive hunger and food consumption * Cells cannot take up glucose and are “starving”

Answer 50

Small gland hanging from roof of third ventricle, secretes melatonin * Receives input from CN II (optic nerve - at the optic chiasm) * Pinealocytes secrete melatonin, which is derived from serotonin

Answer 51

Modulates Melatonin Synthesis an autocrine neurotransmitter of the pineal gland

Answer 52

Gonads (ovaries and testes) produce same steroid sex hormones (androgens) as those of adrenal cortex, just lesser amounts

Answer 53

produced by the testes Initiates maturation of male reproductive organs – Causes appearance of male secondary sexual characteristics and sex drive – Necessary for normal sperm production – Maintains reproductive organs in functional state

Answer 54

temporarily secretes estrogens, progesterone, and human chorionic gonadotropin (hCG)

Answer 55

* Ovaries produce estrogens and progesterone: * Estrogen: maturation of reproductive organs * Appearance of secondary sexual characteristics * With progesterone, cause breast development and cyclic changes in uterine mucosa * Progesterone: endometrial thickening for implantation of the fertilized egg (“propregnancy”)

Answer 56

releases leptin->appetite control; stimulates increased energy expenditure and energy use

Answer 57

Enteroendocrine cells secrete these 4 hormones: * Gastrin: hormone from stomach and pancreas stimulates release of HCl * Ghrelin from stomach stimulates food intake; increases appetite; energy seeking hormone * Secretin stimulates liver and pancreas * Cholecystokinin (CCK) activates pancreas, gallbladder, and hepatopancreatic sphincter

Answer 58

Erythropoietin signals production of red blood cells – Renin (enzyme) – initiates the renin-angiotensin-aldosterone mechanism

Answer 59

ANP = atrial natriuretic hormone signals the kidney to secrete Na+, and thus secrete water, which both result in: – decreased blood volume – decreased BP

Answer 60

May affect: -Timing of sexual maturation and puberty – Day/night cycles (sleep/awake cycle) – Physiological processes that show rhythmic variations (body temperature, sleep/awake cycle, appetite) – Production of antioxidant and detoxification molecules in cells

Answer 61

more important than calcitonin digestive, urinary, and skeletal system has affect on Ca2+ levels

Answer 62

STUDY DIAGRAM

Answer 63

absorbs Ca2+ in intestines

Answer 64

hypoglycemic hormone

Answer 65

hyperglycemic hormone

Answer 66

stored as glycogen in liver and skeletal muscles

Answer 67

binds to rat pinealocyte and signals production of melatonin to assist in sleep

Answer 68

FSH and LH

Answer 69

produces an egg

Answer 70

mature egg is ready now->signals ovulation

Answer 71

increases progesterone levels waits for mature egg to get fertilized via sperm

Answer 72

stimulate spermatogenesis testosterone secretion via testes

Answer 73

testosterone and inhibin inhibit the secretion of GnRH by the hypothalamus and LH and FSH via the pituitary

Answer 74

from 1 of the anterior pituitary cell types * Adults: 35 – 60 years of age * Patients asymptomatic, or present with S/S of hyper/hyposecretion of hormone and/or a mass * Classic visual field findings: visual deficit secondary to compression of optic chiasm is called bitemporal hemianopsia = loss of vision in outer half of both visual fields (>10 cm)

Answer 75

a minimally invasive surgical procedure used to remove tumors from the pituitary gland through the nasal passages and the sphenoid sinus

Answer 76

A condition in which the thyroid gland doesn't produce enough thyroid hormone the deficiency of thyroid hormones can disrupt such things as heart rate, body temperature, and all aspects of metabolism most prevalent in older women (diagnosed younger) * Major symptoms include fatigue, cold sensitivity, constipation, dry skin, and unexplained weight gain * Diagnosis: elevated TSH and low TH * Treatment consists of thyroid hormone replacement, levothyroxine

Answer 77

The overproduction of thyroid hormone by the butterfly-shaped gland in the neck (thyroid) can increase metabolism * Symptoms include unexpected weight loss, rapid or irregular heartbeat, sweating, and irritability, although the elderly often experience no symptoms * Treatments include radioactive iodine, antithyroid medications, and sometimes surgery * Why radioactive iodine for hyperthyroid and certain cancers: specifically destroys thyroid tissue

Answer 78

A lifelong condition where the pancreas makes little or no insulin, which leads to high blood sugar levels: * It's not clear what causes type 1 diabetes. The body's immune system, certain viruses and genes seem to play roles

Answer 79

Type II DM happens because your pancreas doesn’t make enough insulin (a hormone), your body doesn’t use insulin properly, or both * This is different from Type 1 diabetes, which happens when an autoimmune attack on your pancreas results in a total lack of insulin production

Answer 80

produce glucagon

Answer 81

produce insulin

Answer 82

produce digestive enzymes exocrine

Answer 83

* People with insulin resistance, also known as impaired insulin sensitivity, have built up a tolerance to insulin, making the hormone less effective (is a down-regulation of receptors) * As a result, more insulin is needed to persuade fat and muscle cells to take up glucose and for the liver to continue to store it = body cells now resistant to insulin effects or insulin resistant * In response to the body's insulin resistance, the pancreas deploys more of the hormone to keep cells energized and manage blood glucose levels in a healthy range Over time, though, insulin resistance tends to get worse, and the pancreatic beta cells that make insulin wear out * Eventually, the pancreas no longer produces enough insulin to overcome the cells' resistance * The result is higher blood glucose levels, and ultimately prediabetes or Type II diabetes

Answer 84

a blood sugar level that is higher than what's considered healthy, but not high enough to be type 2 diabetes Most often, prediabetes doesn't have any symptoms * But it may cause skin to darken on the neck (acanthosis nigricans), armpits or groin. Some symptoms may be clues that prediabetes has become Type II diabetes * These symptoms include more thirst and hunger, frequent urination, tiredness, blurred vision, and numb or tingling hands or feet

Answer 85

measures your average blood sugar levels over the past 3 months (key: your red blood cells regenerate roughly every 3 months) When sugar enters your bloodstream, it attaches to hemoglobin, a protein in your red blood cells Everybody has some sugar attached to their hemoglobin, but people with higher blood sugar levels have more measures the percentage of your red blood cells that have sugar-coated hemoglobin Normal: below 5.7% Prediabetes: 5.7% to 6.4% Diabetes: 6.5% or above For most people with diabetes, the A1C goal is 7% or less Higher A1C levels are linked to health complications, so reaching and maintaining your goal is key to living well with diabetes

Answer 86

measures your blood sugar after an overnight fast or not eating – usually a 12-hour fast (per CDC): Normal: 99 mg/dL or below Prediabetes: 100–125 mg/dL Diabetes: 126 mg/dL or above

Answer 87

this measures your blood sugar before and after you drink a liquid that contains glucose Steps: 1. You'll fast (not eat) overnight before the test and have your blood drawn to measure your fasting blood sugar level 2. Then you'll drink the liquid and have your blood sugar level checked at intervals 3. These checks usually happen at 1 hour, 2 hours, and possibly 3 hours afterward At 2 hours: Normal: 140mg/dL or below Prediabetes: 140–199 mg/dL Diabetes: 200 mg/dL or above

Answer 88

Make and eat healthy food * Be active most days and get your sleep * Test your blood sugar often: varies but first thing and last thing each day, before and 2 hours after every meal * Take medicines as prescribed (be compliant), even if you feel good * Learn ways to manage stress in your regular life * Cope with the emotional side of diabetes and learn to manage stress related to the diagnosis of diabetes * Go to regular checkups

endocrine Flashcards

(114 cards)