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
Growth hormone is secreted by the:
1. mammatropes
2. gonadotropes
3. corticotropes
4. somatotropes
Under stress, the human body shows an increased secretion of:
1. thyroid-stimulating hormone
2. adrenocorticotropic hormone
3. luteinizing hormone
4. prolactin
It is not advised to consume alcoholic beverages on hot days because alcohol inhibits the release of:
1. antidiuretic hormone
2. oxytocin
3. thyroxine
4. triiodothyronine
The peptide thyroid hormone that lowers calcium and phosphate ion concentration in the blood is:
1. thyroxine | 2. triiodothyronine |
3. calcitonin | 4. thyroid-stimulating hormone |