How Emotions influence the size of Pupil
Pupil When you're tired and suddenly become excited, it can trigger changes in your autonomic nervous system. The autonomic nervous system consists of the sympathetic and parasympathetic divisions, which regulate various bodily functions, including the size of your pupils. When you experience excitement, the sympathetic division of the autonomic nervous system becomes active. This triggers the release of adrenaline (also known as epinephrine) from the adrenal glands. Adrenaline acts as a neurotransmitter and hormone, and it has various effects on different parts of the body. One of the effects of adrenaline is the dilation of the pupils. Adrenaline binds to alpha-adrenergic receptors in the muscles of the iris, specifically the dilator pupillae muscles. Activation of these receptors causes the radial muscles of the iris to contract, which leads to pupil dilation. Howeve...