A&P - Chapter 26 (Part 4) Flashcards
Which thyroid gland hormone is more abundant? How much more?
- T4
- 20x more abundant
- but not as potent
What does T4 contain?
4 iodine atoms
What is the main role of T4?
That it is the precursor to T3
How must adequate amounts of T4 be produced?
Your diet must contain sufficient iodine
Which thyroid hormone is most potent?
T3
What is T3 considered to be?
The principle thyroid hormone
What does it mean when you have Goiter?
An enlarged thyroid
How do you get Goiter?
It is due to lack of iodine in the diet and they thyroid cant produce enough T3 and T4
What does Goiter lead to?
An increased amount of TSH being released
- makes more hypothyroidism
What is another word for hyperthyroidism?
Graves disease
Hyperthyroidism
Increased levels of thyroid hormones
What type of disease is Graves disease?
Autoimmune disease
Graves disease
The immune system attacks the thyroid causing it to over produce hormones and the tissues around the eyes
- may be affected by the excess hormones
- autoimmune disease
What does calcitonin do? (2)
- Decrease the blood calcium concentration by increasing osteoblast activity and inhibiting osteoclast activity
- Maintains homeostasis of blood calcium by preventing hypercalcemia
Where is the parathyroid gland located?
4 or 5 glands found on the back of the thyroid
What does the parathyroid hormone do (PTH)?
It increases blood calcium concentration by increasing the breakdown of bone and releases the calcium into the blood
What kind of effect does PTH compared to calcitonin?
An opposite effect
Where are adrenal glands located?
On top of the kidneys
What 2 glands make up the adrenal glands?
- Adrenal cortex
- outer part - Adrenal medulla
- inner part
What is the adrenal cortex composed of?
Endocrine tissue
What does the adrenal cortex do?
Secretes corticoids
What is the adrenal medulla composed of?
Neurosecretory tissue
What does the adrenal medulla do?
Secretes stress hormones
What stress hormones does the adrenal medulla secrete? (2)
- Adrenaline
2. Noradrenaline
What do all the layers of the adrenal cortex do?
They secretes hormones
What are all steroids known as?
Corticosteroids
What does the outer layer secrete?
Mineralocorticoids
What does the middle layer secrete?
Glucocorticoids
What does the inner layer secrete?
Gonadocorticoids
