NEET 2012 Biology question

A person entering an empty room suddenly finds a snake right in front on opening the door. Which one of the following is likely to happen in his neuro-hormonal control system ?

(1)Sympathetic nervous system is activated releasing epinephrine and norepinephrine from adrenal cortex
(2)Sympathetic nervous system is activated releasing epinephrine and norepinephrine from adrenal medullaCorrect
(3)Neurotransmitters diffuse rapidly across the cleft and transmit a nerve impulse
(4)Hypothalamus activates the parasympathetic division of brain

Answer: (2)

Solution

In a sudden fear/emergency (fight-or-flight) situation the hypothalamus activates the sympathetic nervous system. Sympathetic nerves stimulate the adrenal medulla, which secretes epinephrine (adrenaline) and norepinephrine (noradrenaline); these raise heart rate, blood pressure, blood glucose and alertness. (1) is

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Question ID VK-091203