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16 Cards in this Set
- Front
- Back
- 3rd side (hint)
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Name 2 thryoid hormones
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thyroxine (T4) and triidothyronin (T3)
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Why is the thyroid gland highly vascularised?
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So that hormones can easily be secreted into the blood
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What is the precursor for thyroid hormones?
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thyroglobulin
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The thyroid gland is composed of?
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Thyroid follicles surrounded by follicular cells
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T4 and T3 regulate what in the body?
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Metabolic processes - eg. growth and energy expenditure
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What type of receptors do T3 and T4 act on?
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Nuclear receptors
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TSH regulates what activities?
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- Iodine uptake
- Thyrogolbulin synthesis/secretion - Secretion of T3 and T4 - Iodination of Tyr |
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What happens if a person has a low iodide intake? (In terms of TSH production)
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TSH production increases, which causes hypertrophy and hypervascularity of the gland
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Causes of hypothyroidism?
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- iodide deficiency --> low T3/T4 production
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Leads to goitre
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Symptoms of hypothyroidism?
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- Lethargy
- Goitre - Feel cold - weight gain |
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Causes of hyperthyroidism?
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Too much T3 and T4, Graves' disease (over stimulation of thyroid gland)
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Symptoms of hyperthyroidism?
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- Weight loss
- bulging eyes - sweating - rapid pulse |
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What are the main steps in T3/T4 production?
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-Uptake of plasma iodide by follicle cells
- oxidation of iodide - iodination of tyr residues of thyroglobulin - secretion of T3 and T4 |
uptake of iodide is an energy requiring process
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MIT + DIT forms
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T3
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DIT +DIT forms?
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T4
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Name a drug which decreases the production of thyroid hormones
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Thioureylenes - reduces iodination of TG
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