Great for aspiring doctors, these medical flash cards discuss the thyroid
There are 13 flash cards in this set (3 pages to print.)
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Sample flash cards in this set:
|Where is the thyroid gland located?||Highly vascularized, butterfly shaped gland located below the larynx.|
|Describe the function and control of the thyroid hormones?||Almost every cell in the body has receptors for the thyroid hormones -Generally, the hormones stimulates enzymes associated with glucose oxidation. -They then increase BMR, oxygen utilization, and heat production -They also play a role in nervous system tissue growth, the skeletal system, reproduction, and in blood pressure maintenance -Regulation occurs as the hypothalamus monitors hormone levels and stimulates the anterior pituitary to release TSH as needed.|
|What is the structure of the thyroid gland?||Highly vascularized, butterfly shaped gland -Consists of two lobes connected by an isthmus -There is sometimes a pyramidal lobe which extends superiorly from the isthmus -The majority of the gland is the thyroid follicles and follicular cells around them -These cells produce the glycoprotein, thyroglobulin and the two hormones which together make up the colloid. -Thyroxine(T4)Secreted at the highest levels -Converted in the lungs and the liver to T3(Based on how many iodides are attached) -Triiodothyronine(T3) -Released in lower quantities that T4 but it has 10 times the potency of T4 -Most is converted into T4 at the target cell.|
|What is Calcitonin(CT)?||This is also a thyroid hormone, but it is produced by the parafollicular cells(C cells) -It inhibits the breakdown of bone and it increases the bodies ability to increase the uptake of calcium and phosphate -The net result is that blood calcium and phosphate levels decreased -It decreases bone breakdown by decreasing osteoclastic activity -Although it is not known for sure, it is thought that calcitonin levels are regulated by(-) feedback and that blood calcium levels control calcitonin release with NO pituitary action. -This is more important hormone in children -It is antagonistic to parathyroid hormone(PTH)|
|Describe the synthesis of Hormones in the thyroid?||Follicular cells produce thyroglobulin which is released into the lumen of the follicles as COLLOID which are pigs for Iodide -Iodide(I-) is trapped from the bloodstream and is converted to I2 and secreted into the follicle(Attachment of Iodine to tyrosine to form T1 and T2 occurs in the follicle.|
|Where is the parathyroid glands located?||These are imbedded with the lateral lobes of the thyroid gland, usually superior and inferior fashion on the posterior surface|
|What cells produce parathyroid hormone(PTH)?||Chief cells and Oxyphil cells|
|Where are the adrenal glands located?||located just superiorly to the kidneys -Also called the suprarenal glands|
|Describe Chief cells and oxyphil cells?||Chief cells although smaller, are the most numerous and are the primary synthesizer of parathyroid hormone(PTH) which antagonistic to calcitonin. -Oxyphil cells thought to be a reserve producer of PTH, but are not fully understood.|
|Describe the anatomy of the adrenal glands?||They are highly vascularized -The glands can be divided into an outer cortex and an inner medulla -The adrenal cortex can be divided further into three zone: Zona Glomerulosa, Zona Fasiculata, and Zona Reticularis|
|Describe parathyroid hormone(PTH)?||PTH and calcitonin are antagonistic -Must then also be important in blood calcium and phosphate homeostasis -PTH will increase osteoclastic activity(this increases calcium and phosphate in the blood) -Increase calcium and magnesium reabsorption from the kidneys -Calcium is vitally important for: Blood clotting, muscle contractions, Nerve conduction -Increased calcium absorption from the gut by promoting the formation of the active form of vitamin D(Calcitriol) -Increases urine phosphate excretion -The net effect of PTH is to increase levels of calcium and magnesium and to decrease the levels of phosphate in the blood.|
|What are the three groups of hormones produced by the glomerulosa, fasiculata, and reticularis? Give an example of each||1)Zona Glomerulosa=Mineralcoticoids(Aldosterone) 2)Zona Fasiculata=Glucocorticoids(Cortisone) 3)Zona Reticularis=Gonadocorticoids(Estrogens & Androgens)|
|What is the function of aldosterone and how does it accomplish this function?||Aldosterone acts on the kidney tubule cells to increase sodium reabsorption and to increase the excretion of potassium -It can provide very precise control over these electrolytes as the effects only last ~20 minutes. -H+ loss -Cl- and HCO3 reabsorption -Water reabsorption via osmosis|