$ECT$ is

You are watching a horror movie and notice that your heart rate increases and your mouth becomes dry. What is the reason for this?

Glucose and oxygen are required by the brain for a constant supply of energy to control the functions of our body organs. What will be the consequences if the brain is deprived of oxygen and glucose?
$I.$ Brain deprived of oxygen for just $5$ minutes will get permanently damaged.
$II.$ Glucose is important in the nerve impulse conduction.
$III.$ One side of the brain is unable to know what the other side is doing when it is deprived of oxygen.
$IV.$ Mental confusion will result if the brain is deprived of glucose.

Briefly describe the structure of the following:
$(a)$ Brain
$(b)$ Eye
$(c)$ Ear

Neural system and computers share certain common features. Comment in five lines.

One of the examples of the action of the autonomous nervous system is