A hiker falls on a sharp limb and suffers a puncture wound that causes profuse bleeding. As he loses blood and his blood volume begins to drop, how does the autonomic nervous system respond?
The sympathetic, or "flight-or-fight" portion of the autonomic nervous system will respond in cases where the body in under stress, such as here with significant blood loss. The SNS will release norepinephrine from the adrenal glands that will cause vasoconstriction of the arterioles, increasing blood pressure and preventing it from dropping further. It will also act on the beta 1 receptors of the heart to increase contractility and rate to maintain normal cardiac output since blood volume and therefore stroke volume have decreased.
A mid-systolic click best heard on auscultation at the apex is most likely indicated what heart condition?
This is the finding for mitral valve prolapse.
How is the release of prolactin controlled in the anterior pituitary gland?
Prolactin release is tonically inhibited by dopamine, which is released from the hypothalamus.