What type of pump is the iodide pump?
2: 1 sodium:iodide symporter.
- sodium potassium ATPase pump
Where is iodide more highly concentrated?
in the cell (colloid gland). 30-250x that in the plasma
What is used to transport the iodide across the apical membrane?
pendrin: choride-iodide counter transporter
How does the thyroid hormone form?
- thyroglobulin from the thyroid binds up 70 Tyr with iodine to form thyroid hormones
Which form of iodide is able to bind with tyrosine directly?
nascent form binds directly (oxidized form)
What is the major hormonal product of teh thyroid?
thyroxine
What combinations will produce thyroxine?
- 2 diiodotyrosine joining
2. monoiodotyrosine and dioodotyrosine to form triiodothyronine (T3)
Explain the process of how thyroid hormones are released.
- apical surface pinches off to form the pinocytosic vesicles
- lysosome fuse with vesicels, digest thyroblogulin molecules, releases thyroxine and triiodothyronine
- thyroid diffuse into blood
What is the majority of thyroid hormone that is released?
- thyroxine, which slowly deiodinated to form triiodothyronine
What is the purpose of the deiodinase enzyme?
- helps to recycle the majority of iodinated tyrosine in the thyroglobulin during a recycling process
What plasma component has a high affinity for the thyroid hormones?
plasma proteins which maintains a high level in the blood and slow diffusion into tissues
How does thyroid hormone affect the cardiovascular system?
- increase blood flow and cardiac output
- increase heart rate
- normal arterial pressure (no change)
- increased respiration
How does thyroid hormone affect the nervous and muscular systems?
- increases excitation of CNS leading to muscle tremors
Does thyroid hormone affect the GI?
- yes, it will lead to increased GI motility
How will thyroid affect the metabolic system?
- initiate carbohydrate metabolism
- initiate fat metabolism
- requires increased vitamin in take
- increase BMR and decrease body weight
What type of signaling molecule is thyroid hormone?
- intracellular; lipophilic signaling. Both T3,T4 can cross membrane. T4 requires iodinase to enter into the nucleus
What compounds regulate thyroid secretions?
TSH, cAMP, TRH, cold(immune response), Thyroid hormone feedback
Causes of hyperthyroidism?
- Grave’s disease
2. Adenoma (benign glandular tumor)
What are common effects of hyperthyroidism?
- fatigue
- inability to sleep
- tremors
- exopthalmos (anterior bulging of the eye)
- psychic disorder
What are common causes of hypothyroidism?
- Hasimoto disease (autoimmune)
- Endemic goiter
- Cretinism
Cause: myxedema, atherosclerosis
What does thiocyanate ions Rx do?
inhibit iodine uptake by blocking the I, Na cotransporter
What is used to block the I, Na cotransporter system?
thiocyanate ion
What drug is used to inhibit peroxidase?
propylthiouracil
What is the effect of propylthiouracil?
inhibiting peroxidase uptake
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Skeletal Muscle Contraction34
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Lecture 19, acid bases39
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Ventilatory system89
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CNS and Brain Development123
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Brain Function Lecture 0315
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Brain Function Lecture 0326
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General Sensory Mechanisms-422
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Lecture 5, General Sensory Information39
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Lecture 6. General Sensory34
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Lecture 10: Control Of Motor Function41
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Lecture 7: vision I86
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25.3 Male Reproductive50
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Lecture 9: auditory conduction system24
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11. spinal cord, brainstem, cortex control of motor function II25
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12. contributions of cerebellum and basal nuclei to motor function56
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13. cerebellum and basal nuclei motor function20
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14. temperature regulation54
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15. GI Tract Introduction42
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16. Energy Balance and metabolism43
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21.3 Thyroid hormones41
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22.3 Adrenal Hormones46
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20.3 endocrine31
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23.3 Calcium Balance45
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24.3 Autonomic nervous system67
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The final51
