Second messengers are activated in response to a. steroid hormones. b. thyroxine. c. hydrophilic hormones. d. All of the choices are correct.

The sympathetic postganglionic neurons release only norepinephrine while the adrenal medulla secretes mainly epinephrine (80%) and a small amount of norepinephrine (20%). The sympathetic postganglionic neurons do not secrete epinephrine because; Group of answer choices a. Epinephrine is not as widely used in the nervous system as norepinephrine b. Phenylethanolamine-N-methyltransferase (PNMT) which converts norepinephrine to epinephrine is present in the adrenal medulla, but not in sympathetic postganglionic adrenergic neurons c. Acetylcholine which stimulates the secretion of epinephrine does not act on postganglionic neurons d. Dopamine beta hydroxylase in hyperactive in the adrenal medulla

If a cell were to express both alpha-1 and beta adrenergic receptors what would the expected response to epinephrine/ adrenaline be ?  a. Only cAMP would be released b. Both ca2+ and cAMP would be released c. The receptors would cancel each other and nothing would happen d. Only ca2+ would be released would be released.

Melatonin is a hormone made by the pineal gland, a small gland in the brain. Melatonin helps control your sleep and wake cycles. Evaluate each statement below and select the statement that best describes the pathway. Select one: a. Light on the retina stimulates the hypothalamus to send a signal to the pineal gland to stop producing melatonin, signalling the body to go to sleep. b. Light on the retina stimulates the hypothalamus to send a signal to the pineal gland to increase the production of melatonin, signalling the body to go to sleep. c. Light on the retina stimulates the hypothalamus to send a signal to the pineal gland to stop producing melatonin, signalling the body to wake up. d. Light on the retina stimulates the hypothalamus to send a signal to the pineal gland to increase the production of melatonin, signalling the body to wake up.

Which of the following hormones are NOT released in response to releasing hormones secreted by the hypothalamus? a. FSH and LH b. ADH and prostaglandin c. Oxytocin and thyroxine d. hGH and calcitonin

17. Steroid hormones are... a. polar hormones exert their effects via a second messenger system b. polar hormones exert their effects via an intracellular receptor C. nonpolar hormones exert their effects via an extracellular membrane receptor dnonpolar hormones exert their effects via a cytoplasmic or nuclear receptor e. nonexistent in the body

Naloxone works because it blocks receptors that usually bind with a. Endogenous opioids b. Heroine c. Opium d. Morphine e. All of these f. None of these

Overexpression of this receptor in the cells of the adrenal gland causes Cushing's syndrome, a disease caused by the overproduction of cortisol. One strategy that scientists have employed to treat this disease is the use of small molecules that bind to, but do not activate, MC2R. This type of molecule is generically referred to as an antagonist. How can an antagonist bind to the same receptor as ACTH but not activate it? O a. The antagonist can bind covalently while ACTH binds non-covalently O b. The antagonist is only partially complimentary to the binding pocket of MC2R O The antagonist binds to ACTH and blocks it from binding to the receptor properly O d. The antagonist is the exact same structure as ACTH but since it is synthetic it doesn't work One cause of Cushing's syndrome is the inappropriate production of GPCRS in the adrenal gland that are not normally present in those cells. When these receptors are activated they result in the production of cortisol. Which statement about…

what happens to a water souble hormone after it binds to a receptor on the target cell? select all that apply A. the hormone unbinds the receptor or pops back off B. the hormone is broken down by an enzyme C. the hormone is transported into the cell where it is destroyed by enzymes d. the hormones is transported into the cell where it promotes transcription.

Overdose by thyroid hormones in elderly patients most commonly leads to:A. Increased irritabilityB. Atrial fibrilationC. AggressionD. PsychosisE. Psychomotor excitation