Melatonin is the hormone that regulates wakefulness. Which of the following does not correctly characterize melatonin?
1. It is secreted by the pineal gland, the gland located in the roof of the third ventricle.
2. Its secretion is highest in children aged one to five and decreases thereafter.
3. It may have an important role in the onset of puberty.
4. More is secreted in the daytime than at night.

The human placenta has endocrine functions that does not secrete:
1. prolactin
2. estrogens
3. progesterones
4. human chorionic gonadotropin (HCG)

Cortisol, estrogen, progesterone, androgens and aldosterone:

Identify the non steroidal hormones that are nonpolar and can be administered orally:
1. prostaglandins
2. estrogen and progesterone
3. insulin and glucagon
4. thyroid hormones (T₃ and T₄)

All the following regarding regulation of a physiological function by either a neurotransmitter or a hormone are true except:

1. Target cells must have specific receptor proteins with which these molecules combine.
2. When these molecules bind to target cells, specific sequences of changes must occur.
3. There must be an "off-switch" that will stop the induced changes.
4. Second messengers will always be involved in the response of the target cell.

Synergism between hormones can be best described as:
1. Two or more hormones working together to produce a particular result.
2. One hormone is needed to enhance the responsiveness of an organ to a second hormone.
3. Either of the hormones does not act alone.
4. The effects of the two hormones are opposite to each other.

What would not be true for steroid hormones like corticosteroids?

1. Steroids are lipids with complex ring structures.
2. Steroids can pass through their target cell membrane and interact with receptors in the nucleus.
3. Steroids employ first and second messengers that amplify the cellular response.
4. The estrogens and testosterone are examples of steroid hormones.

Modified fatty acids, prostaglandins, act as localized hormones that regulate neighboring cells. Such a regulation is called as:
1. endocrine
2. paracrine
3. eccrine
4. glycoprotein

Which of the following correctly describes the role of cAMP and the hormones employing it?
1. binding site; nonsteroid
2. membrane receptor; steroid
3. activity site; G protein
4. second messenger; nonsteroid

Oxytocin and ADH are synthesized:
1. in neurosecretory cells that originate in the hypothalamus
2. in the posterior pituitary
3. in the hypothalamic-hypophyseal portal system
4. in the pineal