Thyroid/Parathyroid 1 Flashcards Preview

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Flashcards in Thyroid/Parathyroid 1 Deck (18)
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1
Q

Feedback loops: (+)

A

Increase in one action triggers an increase in target

2
Q

Feedback loops: (-)

A

Response in a target is opposite to the perturbation

3
Q

Example of a positive feedback loop (oxytocin)

A

Childbirth contractions trigger oxytocin, which in turn amplifies the contractions

4
Q

T3 =

A

Triiodothyronine

5
Q

T4 =

A

Throxine

6
Q

What are the thyroid hormones?

A

T3
T4
Calcitonin

7
Q

Overall, what do T3 and T4 do?

A
  • Regulate metabolic rate of body

- Increase protein synthesis

8
Q

T3 and T4: How do they work in the cell and how does this account for the genetic component in thyroid disease?

A
  • Enter cell and bind with receptors in nucleus

- DNA stimulated for gene expression (this is why there’s a genetic component in thyroid disease)

9
Q

T3 and T4 are necessary for

A

normal growth and development

  • esp brain and bone!
10
Q

T3 and T4 stimulate and enhance the effects of ____, accounting for impacts on brain and bone development

A

GH

11
Q

Thyroid hormones: calcitonin has a weak effect on:

A

calcium-phosphorus balance

12
Q

Thyroid function is regulated by:

A
  • hypothalamus and pituitary feedback controls

- SOME intrinsic regulation by the gland itself

13
Q

How does thyroid function impact metabolism, growth, and development?

A
  • increased thermogenesis
  • cardiovascular effects
  • metabolic effects
14
Q

How does thyroid function impact thermogenesis

A

affects BMR and heat production

15
Q

How does thyroid function impact the cardiovascular system?

A
  • increases HR and contractility

- possibly by enhancing effect of epi and norepi

16
Q

How does thyroid function impact metabolism?

A

energy substrate utilization

  • Glucose absorption and enzyme enhancement
  • Lipolysis and lipolytic hormone use
17
Q

When the thyroid gland is stimulated, where do the hormones go and what do they do?

A
  • travel from thyroid via bloodstream to nearly all body tissues
  • Activate genes that regulate body functions
18
Q

Negative feedback loop control of thyroid function

A
  • When hypothalamus senses that circulating levels have dropped, it signals the pituitary gland
  • Pituitary sends TSH to the thyroid to trigger release of thyroid hormones