E2 Flashcards
What hormones does the thyroid gland produce and what is their function?
Thyroxine (T4) and triiodothyronine (T3), which increase metabolism.
What is hyperthyroidism?
A condition of high thyroid secretion leading to a faster metabolism and symptoms like weight loss and increased heart rate.
What is hypothyroidism?
A condition of low thyroid secretion, resulting in slower metabolism, weight gain, and potential heart problems.
What is goiter and how does it form?
Enlargement of the thyroid due to low iodine, leading to overstimulation of the thyroid by TSH.
What is the role of human growth hormone (hGH)?
It promotes growth of bones, muscle, and metabolism by stimulating the liver to produce growth factors.
What happens with excess secretion of hGH during childhood and adulthood?
In childhood, it leads to gigantism, and in adulthood, it leads to acromegaly.
What is the relationship between calcitonin and parathyroid hormone (PTH)?
They are antagonistic hormones regulating calcium levels; calcitonin lowers blood calcium, while PTH raises it.
What is the feedback loop for thyroid hormone regulation?
The hypothalamus releases a hormone that signals the pituitary to release TSH, which then stimulates the thyroid to release T3 and T4. High levels of T3 and T4 inhibit TSH production, completing the feedback loop.
What are the symptoms of hyperthyroidism?
Symptoms include sleeplessness, heat intolerance, weight loss, increased heart rate, and excessive sweating.
What are the symptoms of hypothyroidism?
Symptoms include fatigue, weight gain, slower metabolism, and in severe cases, heart problems and elevated cholesterol.
How does low iodine intake lead to goiter formation?
Without enough iodine, the thyroid cannot produce T3 and T4, leading to continuous stimulation by TSH, which causes the thyroid to enlarge (goiter).
What happens in gigantism?
Excessive secretion of hGH during childhood, before growth plates close, leads to abnormal growth of bones and overall size.
What is acromegaly?
A condition caused by excess hGH in adulthood, resulting in abnormal bone growth in the hands, feet, and face.
What does the parathyroid gland do?
It releases parathyroid hormone (PTH), which raises blood calcium levels by releasing calcium from bones and increasing calcium absorption in the kidneys and intestines.
What is the relationship between calcitonin and parathyroid hormone?
Calcitonin lowers blood calcium levels by promoting calcium storage in bones, while PTH raises blood calcium by stimulating calcium release from bones.
