Thyroid Flashcards
1
Q
2 thyroid hormones?
A
T3 - Triiodothyronine
T4 - Thyroxine
2
Q
2 cell types in thyroid?
A
C cells - secrete calcitonin
Follicular cells - thyroid hormone synthesis
3
Q
structure of thyroid follicles?
A
spherical structures who’s walls are made of follicular cells and centre filled with colloid a sticky glycoprotein metric - contains 2/3mths supply of TH
4
Q
half-life of T3 and T4?
A
T3 = 1 day T4 = 6 days
5
Q
What has a high affinity for T4 and releases it slowly?
A
Thryoxine binding globulin (TBG)
6
Q
T3 vs. T4?
A
there is more T4 than T3 (50 times more) but TH receptor has a much higher affinity for T3
7
Q
Thyroid hormone function?
A
raises metabolic rate and thermogenesis net increase in proteolysis net increase in lipolysis critical for growth essential for brain development in utero (by mother)
8
Q
Hyperthyroidism?
A
Graves disease
- autoantibodies that mimic TSH and continually activate the thyroid
- TSH very low in plasma
9
Q
symptoms in Grave’s disease?
A
exophthalmos weight loss muscle weakness hyper excitable reflexes elevated cardio function
10
Q
Hypothyroidism?
A
Hashimoto’s disease
- autoimmune destruction of the thyroid gland
11
Q
Hashimoto’s disease symptoms?
A
weight gain cold intolerance brittle nails, thin skin slow speech and reflexes reduces cardio function
