Thyroid/Parathyroid 1 Flashcards
Feedback loops: (+)
Increase in one action triggers an increase in target
Feedback loops: (-)
Response in a target is opposite to the perturbation
Example of a positive feedback loop (oxytocin)
Childbirth contractions trigger oxytocin, which in turn amplifies the contractions
T3 =
Triiodothyronine
T4 =
Throxine
What are the thyroid hormones?
T3
T4
Calcitonin
Overall, what do T3 and T4 do?
- Regulate metabolic rate of body
- Increase protein synthesis
T3 and T4: How do they work in the cell and how does this account for the genetic component in thyroid disease?
- Enter cell and bind with receptors in nucleus
- DNA stimulated for gene expression (this is why there’s a genetic component in thyroid disease)
T3 and T4 are necessary for
normal growth and development
- esp brain and bone!
T3 and T4 stimulate and enhance the effects of ____, accounting for impacts on brain and bone development
GH
Thyroid hormones: calcitonin has a weak effect on:
calcium-phosphorus balance
Thyroid function is regulated by:
- hypothalamus and pituitary feedback controls
- SOME intrinsic regulation by the gland itself
How does thyroid function impact metabolism, growth, and development?
- increased thermogenesis
- cardiovascular effects
- metabolic effects
How does thyroid function impact thermogenesis
affects BMR and heat production
How does thyroid function impact the cardiovascular system?
- increases HR and contractility
- possibly by enhancing effect of epi and norepi
