Jennifer has just moved out of her family home to live with friends in a rental flat. At home and alone one night, Jennifer hears gun shots and screams coming from the flat next door. Jennifer is terrified. She quickly turns off the lights and hides in her wardrobe. Apply your knowledge of the Autonomic Nervous System (ANS) to answer the following questions. (25 marks in total)
a) Activation of the sympathetic division of the ANS, and the release of hormones from the adrenal medulla, set in motion a series of physiological responses collectively called the ‘fight-flight’ response. How do the physiological changes that occur in Jennifer’s body help to prepare her to deal with the potentially threatening situation occurring in the flat next door.
Jennifer stays in the wardrobe until her flat mates get home a short time later. They inform her that they have been in the flat next door watching a horror movie. Jennifer realised that the gun shots and screams must have been from that movie.
b) The physiological effects that helped prepare Jennifer for the threat are now subsiding and she feels calmer. Her body is returning to its resting state. The parasympathetic division of the ANS is responsible for returning Jennifer’s body to the resting state? Explain why it is also called an energy conservation / restoration system?
c) Autonomic reflexes are responses that occur when nerve impulses pass through an autonomic reflex arc. By outlining the components of an autonomic reflex arc, explain how a reflex is produced.
d) The body is able to respond quickly to certain stimuli because of rapid conduction of impulses along neurons. How does the structure of an axon enhance the speed of conduction? How else does this axonal structure participate in homeostasis?