Define the location and function of the following structures:
$(1)$ Epiglottis
$(2)$ Intercostal muscles

(N/A) $(1)$ Epiglottis:
Location: It is a thin,leaf-like flap composed of elastic cartilage,attached to the entrance of the larynx.
Function: It remains open during normal breathing but closes the glottis during the process of swallowing to prevent food from entering the trachea.
$(2)$ Intercostal muscles:
Location: These muscles are situated between the ribs.
Function: They play a crucial role in the mechanics of breathing by creating pressure differences between the lungs and the atmosphere,facilitating inspiration and expiration.