thyroid hormone effects

treatment of myxedema

-T4 levothyroxine -immediate emergency care -many weeks of intensive care

diagnosis of primary cause hypothyroidism

-TH low, TSH high (no feedbakc to pituitary)

diagnosis of secondary cause hypothyroidism

-TH low, TSH low

conditions associated with hashimotos

-addisons -type 1 diabetes -celiac disease -pernicious anemia

most common cause of hypothyroidism

-autoimmune destruction of thyroid gland (Hashimoto's thyroiditis)

diagnosis of hashimotos

-blood test to check for thyroperoxidase antibodies most people have increased levels in the blood

grave's disease symptoms

-bulging eyes (exopthalmosis) -red/swollen inflamed eyes -sensitivity to light -blurred or double vision -thinning of hair -loose bowels -weight loss -fatigue -infertility

symptoms of hypothyroidism in infants/children/teens

-choking (infant) -protruding tongue -puffy face -poor growth -delay of permanent teeth -delay of puberty -poor mental development

congenital hypothyroidism

-congenital - prior to birth or 2 yrs old -myxedema -hashimoto's thyroiditis

hypothyroidism & peripheral neuropathy

-damage to peripheral nerves -pain -numbness -muscle weakness

symptoms of hypothyroidism

-decreased metabolic rate -weight gain without increased food intake -decreased heat production and cold intolerance -decreased heart rate -slowing movement, slurred speech, slowed mental activity, lethargy -periorbital puffiness -constipation -hair loss -menstrual dysfunction

how does autoimmune cause destruction of the thyroid galnd

-detroy gland to block thyroid horme syntehsis

in advanced cases of hashimoto's

-extreme puffiness around eyes, face -slowing of heart rate -decrease in body temp -heart failure -myxedma coma

symptoms of hasimoto's

-fatigue -depression -weight gain -cold intolerance -excessive sleepiness -dry, coarse hair -constipation -muscle cramps -increased cholesterol levels -vague aches -swelling in legs

hypothyroidism symptoms in adults

-fatigue -sensitivity to cold -dry skin -weight gain -puffy face -hoarseness of voice -muscle aches -pain and stiffness -thinning hair -slow heart rate

incidence of hashimotos

-females 40-60 -8x more common in females -fluctuating hormones -5-100 ratio have it

malignant thyroid neoplasm

-giant cell -- eats through surrounding cells - very aggressive -medullary carcinoma

myxedema

-happens in severe hypothyroidism -increased filtratiofn of fluid out of the capillaries -resulting in edema-pitting -usually starting in lower tibia -accumulation of osmotically active gycosaminoglycans in intestines

causes of myxedma

-hypothyroidism untreated -surgical removal of thyroid -some cancer treatments -iodine deficiency or excess -sudden illness or infection

symptoms of preeclampsia

-increase BP -persistent headache -edema -protein in urine -blurred vision -nausea or vomitting -upper abdominal pain -changes in vision

diagonsis of primary hyperthyroidism

-increased levels of T3 and T4 (lower TSH) -unbound thyroid hormones will be high

hashimoto's disease

-inflammation of thyroid gland -immune system attacking thyroid tissue -can lead to hypothyroidism -not all cases of hypothyroidism are from hashimotos

hypothyroidism and myxedema

-intense cold intolerance -drowsiness -unconsciousness -medical emergency

thyrotoxic crisis and hyperthyroidism

-intensification of symptoms -fever -rapid pulse -delirium

thyroid hormone effects on ANS

-interacts with the sympathetic system (not fully understood) -many effects of thyroid hormones on BMR, heat production, HR, and SV are similar to those produced by B-adrenergic receptors -effects and catecholamines on heat production, cardiac output, lipolysis, and GnG appear to be synergistic -significance of this synergism is illustrated by the effectiveness of B-adrenergic blocking agents in treating many of the symptoms of hyperthyroidism

other cuases of hypothyroidism

-iodine deficiency, surgical removal of thyroid as treatment for hyperthyroidism -hypothalamic or pituitary failure and medication -result of target tissue resistance caused by down regulation

symptoms of a thyroid storm

-irritable -high systolic BP (low diastolic) -nausea, vomiting, diarrhea -shock/delirium -feeling confused or sleepy -yellowing of skin -breathing problems -coma/heart failure/death

anaplastic thyroid cancers

-least common ->60 years old -affects follicular cells -aggressive form -hard to control -poor prognosis -cells of the thyroid are abnormal and do not resemble the original

fetal complications

-low birth weight -APGAR scar <7 at 5 mins -intrauterine growth retardation -still birth -neonatal death -jaundice -fetal hypothyroidism

symptoms of thyroid cancers

-lumps or nodules -enlarge lymph nodes -cough -discomfort in neck -swallowing issues -hoarseness

papillary thyroid cancers

-most common (in young individuals--women) -solid, irregular or cystic mass -grows slowly -most can be cured -accounts for more than 2/3 of all thyroid cancers

other symptoms of hyperthyroidism

-nervousness -moody, weak, tired -shakiness -fast heartbeat -sweaty and warm, moist itchy skin -fine hair, losing abnormal amounts of hair -losing unexplained weight

medullary thyroid cancers

-not common -in the parafollicular cells (C cells) --produce calcitonin -abnormal high levels of calcitonin -slow growth -gene change - medullary cancer

once thyroid hormone levels are found to be high in diagnosing hyperthyroidism, what test can be done to determine the cause?

-radioactive iodine uptake test and thyroid scan

other tests for testing thyroid gland function

-scinitgraphy - radioactive detector to detect metabolism -ultrasound - enlargement of the thyroid can be pictured -needle aspiration - cancers

maternal outcomes of thyroid problmes

-threaten abortion -preeclampsia -preterm labor -placental abruption -hemorrhage

other causes of hyperthyroidism

-thyroid damage or inflammation -jod-basedow syndrome - idoine-induced thyrotoxicosis -neonatal hyperthyroidism

Treatment of hypothyroidism

-thyroid hormone replacement therapy, usually T4 -levothyroxine measure monthly untile TSH stable ---if TSH inc (dose = too low) ---if TSH dec (dose = too high)

thyroid hormone and growth (generally)

-thyroid hormones required for growth -act synergistically with growth hormone and somatomedins to promote bone formation -promote ossification and fusion of bone plates and bone maturation

hyperthroid treatment

-varies based on cause -include administration of drugs such as beta blockers and popylthioruacil -inhibit synthesis of thyroid hormones -surgical removal of the gland -radioactive ablation of the thyroid gland followed by hormone replacement

autoimmune diseases associated with grave's disease

-vitiligo (destroys skin color) -RA -Addison's (adrenal disease) -Type 1 diabetes (high blood sugar levels) -pernicious anemia (decrease in absorption of B12) -lupus (damages joints, skin, bv, and organs)

treatment of hashimotos

-watch and wait -diet: avoid soy, tofu, tempeh, lectins, beans, nighshades, peanuts -increase in damge to thyroid - thyroid hormone replacement -levothyroxine -armour

symptoms of hyperthyroidism

-weight loss with increased food intake due to increased metabolic rate -excessive heat production and sweating secondary to increased oxygen consumption -rapid heart rate (due to up-regulation of beta1 receptors in heart -breathlessness on exertion -tremor, nervousness, and weakness due to CNS effects of thyroid hormones -increased activity of the thyroid gland causes it to enlarge

thyroid disease increase?

-wide range of substances thought to cause endocrine disruption -including pharmaceuticals, dioxin, polychorinated biphenyls, DDT, other pesticides and plasticizers -may be greatest risk at prenatal/postnatal developmnet -genetic/epigenetic changes induced by bisphenol A

hypothyroidism risk factors

-women 60+ -autoimmune -relative with autoimmune -radioactive iodine treatment -radiation of upper body -thyroidectomy (partial) -pregnancy and delivery of baby past 6mo

six primary causes of hyperthyroidism

1) graves disease 2) toxic nodular goiter 3) hyperfunctioning thyroid adenoma 4) thyroid damage or inflammation 5) jod-basedow syndrome 6) neonatal hyperthyroidism

thyroxine binding globulin test

TBG binds thyroid hormone in circulation

what is the most powerful thyroxine releaser and most important in measuring levels of thyroxine?

TSH

thyroid neoplasms

benign or malignant

thyroid functional tests

blood tests can measure thyroid function -FT4 and FT3 (unbound/free are active and have effect) ---low levels - hypothyroidism ---high levels - hyperthyroidism -total T4 and T3 (rarely performed, bound in blood by proteins) --TSH most powerful thyroxine releaser -- most important in measuring levels of thyroxine

thyroid hormones increase oxygen consumption in all tissues except

brain, gonads, spleen by inducing synthesis and increasing activity of the NA+K+ ATPase (NA+K+ ATPase is responsible for primary active transport of Na+ and K+ in all cells, activity is highly correlated with and accounts for large percentage of total oxygen consumption and heat production in the body)

bone complications with hyperthyroidism

brittle bones osteoporosis decrease of calcium in bones

cretinism

can be caused by hypothyroidism in the perinatal period left untreated, causes irreversible form of growth and mental retardation

most common form of hyperthyroidism

caused by graves disease -B cells produce antibodies against thyroid proteins -increased circulating levels of thyroid-stimulating immunoglobulins -bind to TSH receptors on thyroid follicular cells and imitate TSH -antibodies intensely stimulate the thyroid gland and result in increased secretion of thyroid hormones and hypertrophy of the gland

metabolic effects occur because thyroid hormones induce the synthesis of metabolic enzymes including

cytochrome oxidase, NADPH cytochrome C reductase, alpha glycerophosphate dehydrogenase, malic enzyme and proteolytic enzymes

Diagnosis of hypothyroidism

decreased levels of T3 and T4

catabolic effect of thyroid hormons on muscle mass

decreases

TSH levels are level or high -- diagnosing hyperthyroidism

due to pituitary tumor - confirm by injection of thyrotropin-releasing hormone -secondary cause of hyperthyroidism

thyroid hormone effects on CNS

effects are age dependent

thyroid hormone effects on CNS in perinatal period

essential for normal maturation of the CNS -hypothyroidism in the perinatal period causes irreversible mental retardation

hyperthyroidism can cause ___ problems

eye problems (bulging eyes)

how does hyper-functioning thyroid adenoma cause hyperthyroidsim

follicular cells grow uncontrollably, forming a benign tumor that produces an excessive amount of exogenous thyroid hormone

what causes grave's disease?

gender -- sex hormones stress (emotional or trauma) pregnancy infections

thyroid hormones increase the effects of other hormones on

gluconeogenesis, lipolysis, and proteolysis

enlarge thyroid gland aka

goiter -may compress esophagus and cause difficulty in swallowing

when cause of hypothyroidism is a defect of the thyroid, what develops

goiter - unrelenting high circulations of TSH

myxedema may develop in

hypothyroidism - increased filtration of fluid out of the capillaries and edema

thyroid hormone effects on CNS in adults

hypothyroidism: causes lack of energy, spirit, interest, slowed movement, sleepy, impaired memory and decreased mental capacity hyperthyroidism: causes hyperexcitability, hyperreflexia, irritability

thyroid hormones _________ glucose absorption from the GI tract

increase

thyroid hormones cause basal metabolic rate to

increase -increased oxygen consumption and body temperature

thyroid hormones __________ both protein synthesis and degradation, their effect is _________

increase ; catabolic

thyroid binding globulin increases due to

increase in estrogen and human chorionic gonadotropin hormone (can lead to decreased iodine to placenta due to renal globerular filtration rate)

what does increased oxygen consumption depend on

increased availability of substrates for oxidative metabolism

hypothyroidism can cause (fertility)

infertility (interferes with ovulation) birth defects

neonatal hyperthyroidism

newborns with moms who have graves disease generate too much TH -response to thyroid-stimulating immunoglobulins crossing the placenta

jod-basedow effect

overproduction of thyroid hormone in presence of high iodine in people who fail to exhibit the wolff-chaikoff effect

since thyroid hormones increase NaK ATPase activity, they also increase

oxygen consumption, BMR, and heat production

hypothyroidism can cause

peripheral neuropathy and myxedema

thyroid crisis - thyroid storm

person has too much thyroxine

Wolff-Chaikoff effect

protective downregulation of thyroid hormone in the presence of large amounts of iodine

heart complications with hyperthyroidism

rapid heart rate atrial fibrillation congestive heart failure

hyperthyroism & skin

red swollen skin -grave's dermopathy

Follicular thyroid cancer

second most common, usually in women over 50. -in follicular cells -grows slowly -more aggressive than papillary cancer

myxedema is

serverely advanced hypothyroidism

constitutees one of the major endocrine problems in pregnancy

thyroid disorders

how does toxic nodular goiter cause hyperthyroidism

thyroid follicles start to generate a lot of thyroid hormone

hypothyroidism

too little thyroid hormone and a hypometabolic state

hyperthyroidism

too much thyroid hormone and a hypermetabolic state

thyroid storm

too much thyroid hormone int he body and all normal symptoms become exaggerated medical emergency - medical emergency - severe state of hypermetabolism -multiple organ dysfunction

causes of hashimotos

virus -overwhelm immune system -inc. lymphocytes -build up in thyroid gland genetic -inc. risk if family member has it

when does thyroid storm occur?

when the patient stops treatment, develops and infection, or has surgery