Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Session 2 CM endo2
CM- Endo -2- Thyroid lect 5-6
| Question | Answer |
|---|---|
| Where in embrylogical development does the thyroid develop from | Between 1st and 2nd pharyngeal pouches |
| How does the thyroid get to where it is in the adult | decends anterior to the hyoid bone through the thyroglossal duct, which becomes solid and atrophies |
| What problem can present anywhere along this path where the thyroid descended | you can find thyroglossal cysts anywhere along the migration path from tongue to sternum |
| What is the adult thyroid like, Size shpae | made of 2 lateral lobes connected by an isthmus that overlies the anterior 2nd and 3rd tracheal rings |
| How much does a normal thryoid gland weigh | 15-20 grams |
| what are the follicles of the thyroid gland | functional unit of the thyroid that stores thyroid hormone in a viscous gel called colloid |
| What type of cell lines the colloid lumen | colloid lumen is lined by single layer of epithelial cells |
| what do the epithelial cells that line the lumen of the colloid do | they synthesis the thyroid hormone |
| What do para follicular cells do in the thyroid | also called C-Cells they synthesis calcitonin which inhibits bone reabsorption |
| What is calcitonin | hormone secreted by parafollicular cells that inhibits bone reabsorption |
| How do we get Iodine into the body | it is absorbed from the dietary intake in the GI tract |
| HOw does thyroid get into the thyroid | it is actively transported into the thyroid |
| What is thryoglobulin | a large glycoprotein in the follicular colloid |
| How is thyroid hormone T3 and T4 made | 1st- 1 or 2 iodine are added to tyrosine attached to thyroglobulin to make either monoiodotyrosine (MIT) or diodotyrosine (DIT) 2nd- 1mit + 1DIT= T3 triiodothyronine or 2 dit = t4 thyroxine |
| How is hormone secretion from the thyroid controlled | controlled by hypothalamic secretion of TRH which stimulates pituitary to secrete TSH which stimulate thyroid to secrete and produce more T3 and T4 |
| What blood proteins bind T3 and T4 | thyroid binding globulin TBG 70% and albumin 30% bind T4 and T3 for transport to periphereal tissues |
| Which hormone T4 or T3 is biologically active | T3 |
| What happens to T4 in peripheral tissue | it is converted to more bioactive hormone T3 |
| What does T3 generally do | promotes growth and development of musculoskeletal and neural brain systems |
| When do you see rT3 (reverse T3) which is biologically inactive isomere of T3 | you see more in starvation, severe illness, trauma, liver and kidney disease |
| What thyroid hormone is responsible for negative feedback on the hypothalmus and pituitary | T3 |
| Where are thyroid hormones deactivated and broken down | broken down in the liver and kidney are recycled back to the thyroid |
| What can happen if the mother has low hormone levels of T3 and T4 and the fetus doesn't make enough | Cretinism- growth delay and mental retardation will develop |
| What is cretinism | growth delay and mental retardation often from lack of thyroid hormones during fetal development |
| Does thyroid hormone cross the placenta | yes it is lipid soluble |
| what development in the fetus relies critically on thyroid hormone | development of the musculoskeletal and CNS systems |
| What does thyroid hormone do to the following oxygen consumption heat production glucose absorption in gut lipid breakdown cholesterol synthesis and breakdown protein synthesis and breakdown | Increases oxygen consumption causes heat production promotes glucose absorption in the gut promotes lipid breakdown promotes cholesterol synthesis and breakdown increases protein synthesis and breakdown |
| What is the action of thyroid hormone on cardiovasculature | influences heart rate and contractility |
| What does thryoid hormone do to respiratory systems | influences hypoxic/hypercapnic drive |
| What does thyroid hormone do to GI system | influences gastric motility |
| What does thyroid hormone do to the skeletal system | stimulates bone turnover increases bone formation and resorption |
| What does thyroid hormone do to the muscular system | increased muscle relaxation as measured by deep tendon reflex |
| If you do a tendon reflex on some one and it is slow and relaxed (delayed) what flag should that send up in your brain | this person may be hypothryoid |
| What does thyroid hormone effect hematologically | increases erythropoiesis due to increased use of oxygen by tissues |
| When does thyroid binding globulin increase | increases in pregnancy, newborns, oral contraceptives, hepatitis, drugs: phenothiazides, clofibrate, heroin |
| When does Thyroid binding globulin decrease | nephrotic syndrome malnutrition severe illness drugs: alcohol, phenytoin, steroids |
| What does the thyroid function test for TSH do | evaluates pituitary function elevated in primary thryoid gland failur low in overactive thyroid gland |
| What does the thyroid fucntion test for total T4 do and show | measures bound and free T4 does not reflect metabloic state: an increase in TBG will increase TT4 |
| What does free T4 measure | measures active hormone |
| What does free thyroxin index show | FTI takes into account binding protein FTI=TT4xT3u/100 |
| What does Thryoid resin uptake show T3u | radiolabeled T3* is added to the patients serum. The T3 will fill any empty binding spaces in TBG the remaining *T3 unbound is measured this gives measurement of binding potential not hormone levels |
| What does total T3 show you | measures bound and active T3 may be useful to diagnose hyperthyroidism |
| What does free T3 measure | measures bioactive T3 |
| What can thyroglobulin be used for in regards to cancer | can be a marker when treating thyroid cancer after thyroidectomy you measure thyroglobulin to see there is any residual thyroid tissue |
| What does Thyroid peroxidase antibody show | shows auto immune disease to thyroid these antibodies attack thyroid gland |
| What is TSH receptor antibody and what disease is 90% for TSC receptor antibody | TSHrAb is an antibody to TSH receptor 90% positive in graves disease |
| What is normal thyroid function called | euthyroid TSH/FT4/FTI/FT3 are all in normal range |
| What will you see in hypothyroid | elevated TSH low FT4 FT3 FTI |
| What will you see in hyperthyroid condition | suppressed TSH level, high FT4, FTI and FT3 |
| When should you do a thyroid test | all newborns be screened dementia history of fatigue cardiac arrythmia workup family history of thyroid disease patients with known thyroid disease |
| A clinical syndrome resulting from deficiency in thyroid hormone which in turn results in a generalized slowing of metabolic process | hypothyroidism |
| What is the most common cause world wide of hypothyroidism | iodine deficiency |
| What is the most common cause of hypothyroid in the US | Autoimmune disorders like hashimoto's |
| Apart from iodine deficiency and autoimmune disorders how else can hypothyroidism be caused | thyroidectomy(duh), radioactibe ablation of thyroid, medications such as lithium amiodarone post partum and pituitary hypothalamic tumors |
| What are the s/sx of hypothyroidism | fatigue/lethargy weight gain constipation cold intolerant heavy menstrual flow/ amenorrhea/ infertility dry skin/diffuse hair loss bradycardia difficulty concentrating/ memory loss delayed relaxation phase deep tendon reflex growth delays in kid |
| What will you see in a primary hypothyroid | elevated TSH with low to normal FT4 |
| What can help you determine the cause of primary hypothyroid | antibodies |
| What will you see in a secondary (central) hypothyroid | dcreased TSH with Decreased FT4 |
| What will you see in sub-clinical hypothyroid | patient has no cinical s/sx but has elevated TSH with normal FT4/FT3 |
| Circulating anitbodies attack the thyroid gland. Thyroid peroxidase antibody (also called thyroid microsomal antibody, anti-thyroglobulin antibody) | Hashimoto's thyroiditis |
| What other autoimmune diseases besides hashimoto's may cause hypothyroid | lupus, Type I daibetes, rheumatoid arthritis, pernicous anemia. |
| What does the gland show histologically in hashimotos | gland shows diffuse lymphocyte infiltration, lymphoid follicles with germinal centers |
| what is the treatment for hypothyroid | hormone replacement therapy, levothyroxine, synthroid, levoxyl, unithroid or levothroid |
| what is average replacement dose of thyroid | 1.7mcg/kg/day |
| How do you dose elderly people and cardiac patients with thyroid replacement | go low go slow titrate up slowly |
| How does calcium, iron, cholestyramine, aluminum affect thyroid replacement therapy | they all decrease absorption along with malabsorption |
| A complication of severe untreated long standing hypothyroidism life threatening with high mortality rate. usually precipitated by illness(heart failure, pneumonia, stroke, sedative or narcotics) | Myxedema Coma |
| What are the clinical s/sx of myxedema coma | hypothermia, hypoventilation, hyponatremia, stupor-coma |
| What is the treatment for myxedema coma | icu/ventilation support slowly warm body IV levothyroxine 300-400mcg loading dose followed by 50-100mcg/day |
| a clinical syndrome that results when tissues are exposed to high levels of circulating thyroid hormones | hyperthyroid disease |
| What is the autoimmune cause of hyperthyroid | grave's disease |
| what are other hyperthyroid disease besides graves disease | toxic multinodular goiter toxic nodular plummer's disease factitious: ingestion of levothyroxine painful/ painless thyroiditis struma ovarii: teratoma thyroid storm secondary hyperthyroidism:TSH secreting tumor |
| What are the clinical s/sx of hyperthyroid | palpitations/tachchardia/dyspnea tremors/hyperkinesis mood swings increased appetite w/o weight gain heat intolerance increased bowel movements goiter with thyroid thrill stare/lid lag proximal muscle weakness/brisk deep tendn rflx |
| Autoimmune disease caused by circulating antibodies against the TSH receptor the antibody binds the TSH receptor stimulating thyroid hormone synthesis and release | Grave's disease |
| What is grave's disease associated with | autoimmune opthalmopathy, infiltration of eye muscles and connective tissue, proptosis bulging eyes measured by hertel exophthalmometer Associated with autoimmune dermopathy pink skin colored form nodules and plaques usually pretibial:lower extremitie |
| what is the Tx for graves disease | beta blockers- Help control tachycardia anti-thyroid medications- inhibit hormone synthesis and release radioactive iodine- destroys thryoid |
| when wouldn't you give radioactive iodine | to a pregnant women |
| Enlarged asymmetric thyroid gland, often in elderly usually with gradual onset, no opthalmopathy, precipitated by kelp, lithium, amiodarone | Toxic Multinodular Goiter |
| What are the s/s of toxic multinodular goiter | dysphagia, hoarseness, pemberton's sign, airway obstruction with arms raised over head |
| what is pemberton's sign can indicate what | airway obstruction with arms raised over head may indicate toxic multinodular goiter |
| What is the Tx for toxic multinodular goiter | thyroidectomy for obstructive disease |
| A single hyper-functioning nodule the rest of the thyroid gland is suppressed and is generally benign | toxic nodule |
| Tx for toxic nodule | depends on symptoms; gen anti thyroid medication or radioactive iodine |
| What is factitious hyperthyroid | intentional or unintentional ingestion of thyroid hormone. Tx is having person stop or lower dose of thyroid hormone |
| caused by viral infection that destroys thyroid tissue causing release of stored hormone (leaky gland) generally resolves followed by hypothyroidism | Painful Thyroiditis |
| What is the Tx for painful thyroiditis | anti inflammatories or steroids if painful |
| ovarian teratoma with endogenous synthesis and secretion of thyroid hormone from ectopic tissue this suprresses normal thyroid tissue | struma ovarii |
| what is the Tx for struma ovarii | surgical resection of ectopic tissue |
| also called thyrotoxic crisis is extreme tissue responsivness to excess thyroid hormone | Thyroid Storm |
| what are the s/s of thyroid storm | fever, tachycardia, atrial fibrilation, heart failure, agitation, delirium, and diarrhea |
| what can cause thyroid storm | often follows stressful events such as surgery, trauma, infection myocardial infarction, catecholamines plus excess hormone exacerbate symptoms |
| what is the treatment for thyroid storm | Propylthiouracil beta blockers corticosteroids supportive care and antipyretics |
| suppressed TSH, high T3/T4 would indicate what | primary hyperthyroidism |
| In primary hyperthyroidism presence of what may help determine the cause of the condition | presence of thyroglobulin antibodies |
| High TSH and High T3/T4 would indicate what | secondary hyperthyroid |
| these hyperthyroid conditions show low TSH, with High T3/T4 with an increase in radio-iodine uptake | Grave's, Toxic multinodular goiter, toxic nodule |
| These hyperthyroid conditions show low TSH with high T3/T4 but a decrease in radio-iodine uptake one has thyroglobulin the other doesn't | Thyroiditis- has the thyroglobulin Factitious- doesn't have thyroglobulin |
| a discrete enlargement on part of the thyroid with the remaining gland normal | thryoid nodule |
| What can cause a thyroid nodule | thyroid carcinoma dominant toxic nodule of multinodular disease benign adenoma thyroglossal duct cyst focal thyroiditis- hashimotos |
| What do you want to check when you have a thyroid nodule | check TSH if low do a thyroid scan thyroid ultrasound shows cystic or solid fine needle aspiration to determine malignancy |
| What will you see in a thyroid scan for a cold vs hot nodule | cold nodule will NOT uptake tracer hot nodule take up tracer and appear bright on scan |
| How often will a cold nodule be malignant and how often will a hot nodule be malignant | a cold nodule is malignant 10% of the time a hot nodul is NEVER malignant |
| What do you do if you find a cold nodule on a thyroid scan | fine needle aspiration to check for malignancy |
| What are the five types of thyroid cancer | papillary carcinoma follicular medullary anaplastic lymphoma |
| how does a thyroid carcinoma typically present | presents as a solitary or dominant nodule it is firm to rock hard on physical exams cervical adenophathy may also be present |
| most common form of thyroid cancer | papillary carcinoma with papillae of carinoma cells |
| types of thyroid cancer that arises from parafollicular cells in the thyroid and produce calcitonin associated with MEN II syndrome | Medullary thyroid cancer |
| rapidly growing thyroid mass that can cause airway obstruction and esophageal obstruction rapidly fatal | anaplastic thyroid cancer |
| over 50% of this thyroid cancer is associated with hashimoto's syndrome | lymphoma thyroid cancer |
| what are the Tx for thyroid cancer | surgery partial or total thyroidectomy Radioactive iodine suppression therapy chemotherapy external beam radiation palliative care |
| when do you use chemotherapy or external beam radiation for thyroid cancer | used on anaplastic medullary and lymphoma cancers |
| why do you need palliative care for thyroid cancers | you may need a feeding tube or endotracheal tube for anaplastic tumors to keep patient a live while treating the tumor |
Created by:
smaxsmith
Popular Science sets