Physiology

Question 1

What 2 hormones are produced by the thyroid gland?

Answer 1

1. Thyroxine (T4) (90% of thyroid hormones secreted)

2. Triiodothyronine (T3) (10%, but ~4x more potent than T4)

Question 2

Give examples of steroid hormones

Answer 2

Cortisol & testosterone

Question 3

Give examples of amine/peptide/protein hormones

Answer 3

Eg. Oxytocin, insulin

Question 4

What are the 3 classes of hormones?

Answer 4

1. Steroid hormones
2. amine/peptide/protein hormones
3. Tyrosine & tryptophan derivates

Question 5

What are the distinctive cells of the thyroid?

Answer 5

Follicular cells

Question 6

What element is taken up by the follicular cells of the thyroid to make T3 & T4?

Answer 6

Iodine

Question 7

What hormone is released by the hypothalamus in the production of thyroid hormones?

Answer 7

Thyrotrophin releasing hormone (TRH) is released by the hypothalamus. It stimulates the release of:

1. Thyroid stimulating hormone (TSH) by the anterior pituitary. It stimulates the release of:
2. T3 and T4 from thyroid gland. This has a negative feedback effect on TRH and TSH

Question 8

What hormone is released by the anterior pituitary in the production of thyroid hormones?

Answer 8

Thyroid stimulating hormone (TSH) by the anterior pituitary. It stimulates the release of T3 and T4 from thyroid gland. This has a negative feedback effect on TRH and TSH

Question 9

Where is TSH released from?

Answer 9

Anterior pituitary

Question 10

Where is TRH released from?

Answer 10

Hypothalamus

Question 11

Which of the two thyroid hormones is most potent?

Answer 11

T3 - shorter half-life

Question 12

What changes does the release of ADH in the body cause?

Answer 12

Water reabsorption

Increased ADH levels, cause a correlative increase in urine concentration (because water remains in the body)

Question 13

What hormones are released from the anterior pituitary gland?

Answer 13

1. Growth hormone
2. TSH
3. LH/FSH
4. ACTH
5. Prolactin

Question 14

What hormones are released by the Posterior pituitary gland?

Answer 14

ADH

Oxytocin

Question 15

Where is calcitonin produced?

Answer 15

Thyroid gland

Question 16

What is the role of calcitonin?

Answer 16

Inhibits the activity of the osteoclasts, the cells that break down bone.

When the osteoclasts break down bone tissue, the calcium enters the bloodstream.

Question 17

What is the role of PTH?

Answer 17

1. Release of calcium by bones into the bloodstream (increased serum calcium)
2. Absorption of calcium from food by intestines.
3. Renal phosphate excretion
4. . Conservation of calcium by kidneys.