Thyroid, Parathyroid A&P Pathophysiology (incomplete)

Question 1

what increased iodide uptake

Answer 1

thyroid stimulating hormone

Question 2

what helps to inhibit the production of TSH in a negative feedback loop

Answer 2

somatostatin

Question 3

what is the middle portion of the thyroid gland that connects the two lobes called

Answer 3

isthmus

Question 4

what is the blood supply to the thyroid gland

Answer 4

superior thyroid artery - off external carotid
also from inferior thyroid after (off of the thyrocervical trunk from the suprascauplar artery)

Question 5

what innervates the thyroid gland

Answer 5

recurrent laryngeal nerve - branch off the vagus nerve (CN X)

Question 6

how much hormone does the thyroid store

Answer 6

2-3 months worth

Question 7

what is the thyroid gland made up of

Answer 7

follicular cells surrounded by colloid
follicular cells are sites for binding of TSH and trigger release of stored TH
can also be neurally controlled by acetylcholine and catecholamines

Question 8

what is the active form of TH

Answer 8

triodothyronin (T3)

Question 9

what is made within the follicular cell

Answer 9

thyroglobulin - large protein that contains significant amount of tyrosine amino acids - stored in colloid

Question 10

what is able to oxyidize the iodide into active form of iodine

Answer 10

thyroid peroxidase

Question 11

what is the advantaged of T4

Answer 11

longer half life

Question 12

where is iodide aborbed

Answer 12

in the GI tract

Question 13

what is thyroid hormone bound to within the blood stream

Answer 13

thyroxine binding globulin
small amount bound to albumin

Question 14

is thyroid hormone water soluble or lipid soluble

Answer 14

lipid soluble

Question 15

what are the actions of thyroid homrone

Answer 15

changing ion channel regulation
increase protein catabolism
increase number and size of mitochondria
stimulate glucose metabolism which will increase the basal metabolic rate and encourage glucose uptake, glycoysis
increases thermogenesis

Question 16

what is primary hyperthyroidism

Answer 16

elevated thyroid hormone (T3 and T4), low thyroid stimulating hormone (does not need to stimulate the thyroid for the elevated production)

Question 17

what is seen on labs with secondary hyperthyroidism

Answer 17

elevated TH, elevated TSH (excess being production/secreted in the pituitary)

Question 18

what is thyrotoxicosis

Answer 18

symptomatic elevation in circulating thyroid hormone (hyperthyroidism)
Major primary cause of this is Graves disease

Question 19

what is the secondary cause of thyrotoxicosis

Answer 19

(not as common) active TSH pituitary adenoma

Question 20

What is an autoimmune disorder that causes 50-80% of hyperthyroidism

Answer 20

Graves disease

Question 21

what are the ophthalmologic manifestations of graves disease

Answer 21

lid lag (both upper and lower)
exophthalmos: inflammation, edema, too much content in the orbit

Question 22

what is the dermatologic manifestations of Graves disease

Answer 22

pretibial myxedema - aka graves dermopathy

Question 23

what causes pretibial myxedema

Answer 23

thryoid stimulating immunoglobulins causing increased stimulation of T lymphocytes
increased hyaluronic acid production
swelling/induration/erythema to anterior lower extremities

Question 24

when do nodular thyroid diseases occur

Answer 24

during stressor - typically will normalize after stressor

Question 25

what is the presentation of hyperthyroid

Answer 25

heat intolerance sweating weight loss diarrhea weakness psychiatric disorders fatigue but inability to sleep excitable

Question 26

what is the most common disorder of the thyroid

Answer 26

hypothyroidism

Question 27

what is primary disease state of hypothyroidism

Answer 27

low thyroid hormone (T3 and T4), high thyroid stimulating hormone (trying to up regulate to TH)

Question 28

what is secondary disease state of hypothyroidism

Answer 28

low TH, low TSH ( the low TSH is causing the low TH) - associated with trauma, lesions, CVA

Question 29

what is the most common type of hypothyroidism worldwide

Answer 29

deficiency

Question 30

what is Hashimoto disease

Answer 30

an autoimmune thyroiditis - hypothyroidism

Question 31

what does the central cause of hypothyroidism lead to

Answer 31

decreases TRH and/or TSH

Question 32

what is Sheehan syndrome

Answer 32

necrotic pituitary from postpartum syndrome

Question 33

what is the presentation of hypothyroidism

Answer 33

cold intolerance, fatigue, low body temp weight gain, decreased appetite, bradycardia, constipation, fatigue, dry skin, thin nails may lead to goiter

Question 34

what is central hypothyroidism

Answer 34

damage to hypothalamus leading to decrease TRH or damage to the anterior pituitary leading to decreased TSH

Question 35

what are labs indicative of hypothyroidism

Answer 35

low TSH low T3 low T4

Question 36

what is an autoimmune thyroiditis with autoantibodies attaching follicular cells

Answer 36

hashimotos thyroiditis

Question 37

if someone has primary hypothyroidism what are their labs going to show

Answer 37

High TSH Low T3 and T4

Question 38

what can Graves disease develop into

Answer 38

Hashimotos

Question 39

what is Hashitoxicosis

Answer 39

as cells undergo apoptosis it can cause transient hyperthyroidism (so many hormones released all at once)

Question 40

what is myxedema

Answer 40

prolonged significant hypothyroidism - typically near zero TH

Question 41

what is myxedema coma

Answer 41

rare and often fatal condition associated with untreated, longstanding hypothyroidism in which the body has not been able to compensate - no true coma

Question 42

what is the presentation of myxedema coma

Answer 42

AMS HTN dry, cool skin - hypothermia constipation, distension - illeus, impaction, myxedema megacolon hypoventilation arrhythmias, heart block facial changes nonpitting edema acquired von willebrand syndrome

Question 43

what is cretinism

Answer 43

occurs with profoundly low thyroid hormone during development, infancy or early childhood

Question 44

what is cretinism associated with

Answer 44

agenesis or under developed mom will supply some in utero

Question 45

how do you treat cretinism

Answer 45

iodine and T4 - will lead to normal growth

Question 46

what is an abnormal cellular growth of the thyroid

Answer 46

goiter

Question 47

what can thyroid goiters be associated with

Answer 47

inability to trap iodide not enough peroxidase so that iodine can not be oxidized into iodine lack of or defective thyroid peroxidase (unable to go through final steps of TH formation)

Question 48

what does the parathyroid release

Answer 48

parathyroid hormone which regulates calcium concentration

Question 49

what cells are the primary creator of the parathyroid hormone

Answer 49

chief cells

Question 50

is PTH water or lipid soluble

Answer 50

lipid soluble?

Question 51

what triggers the release of PTH

Answer 51

hypocalcemia

Question 52

what does PTH first trigger

Answer 52

inhibition of osteoblasts

Question 53

what does PTH work with

Answer 53

vitamin D to allow for absorption in GI tract

Question 54

what activates vitamin D

Answer 54

kidney and liver

Question 55

when can the parathyroid gland enlarge in live

Answer 55

during pregnancy and breast feeding

Question 56

what are the action of PTH in the kidney

Answer 56

bind to cell within distal collecting duct -- increase in calcium channels to cause respiration of Ca2+ from urine, will cause increased phosphate excretion

Question 57

what are the actions of PTH in the intestine

Answer 57

induces the conversion of Vitamin D to active vitamin D - allows for absorption in GI tract

Question 58

what type of hormone is vitamin D

Answer 58

steroid hormone

Question 59

what secreted calcitonin

Answer 59

thyroid has C cells - to lower calcium levels in blood

Question 60

what is the purpose of calcitonin

Answer 60

decrease circulating Ca2+

Question 61

what is the most common cause of hyperparathyroidism

Answer 61

solitary parathyroid adenoma

Question 62

what is secondary hyperparathyroidism

Answer 62

elevated PTH but b/c of low Ca2+ - typically associated with CKD or vitamin D deficiency

Question 63

what is seen with hyperparathyroidism

Answer 63

elevated PTH hypercalcemia hypophosphatemia (causes increased renal excretion) elevated phosphate in urine elevated calcium in urine

Question 64

what are the signs of hyperparathyroidism

Answer 64

elevated calcium: fatigue, nephrolithiasis, polydipsia, polyuria, N/V/D, abd discomfort, arrhythmia, osteoporosis, neurologic symptoms

Question 65

what is seen with significant hypercalcemia

Answer 65

stones, bones, groans, moans and psychiatric overtones -kidney stones, bone break down, constipation, pancreatitis, fatigue, psychiatric disturbances

Question 66

what is the most common cause of Hypothyroidism

Answer 66

damage to the parathyroid* -accidental removal with thyroidectomy -neck radiation -purposefully removed

Question 67

what can you see with hypocalcemia

Answer 67

muscular tetani Chvostek sign Trousseau sign AMS prolonged QT

Question 68

what is Chvostek sign

Answer 68

tap facial nerve anterior to the ear - causes facial twitch

Question 69

what is Trousseau sign

Answer 69

BP cuff will cause carpal spasm - wrist flexion, MCP flexion, interphalangeal joint extension