Question

write a few lines on pinna (external ears)​

Answer 1

Answer:

1. It is external projection behind the ear pores.

2. It helps to capture a wide range of sound.

3. In animals it helps to detect the direction of sound by providing sufficient movement of pinna.

Answer 2

Answer:

1. The external ear (pinna) is derived from mesenchymal tissue of the first and second pharyngeal arches that flank the first (hyomandibular) pharyngeal cleft.
2. During the second month, three nodular masses of mesenchyme (auricular hillocks) take shape along each side of the first pharyngeal cleft.
3. The auricular hillocks enlarge asymmetrically and ultimately coalesce to form a recognizable external ear.
4. During its formation, the pinna shifts from the base of the neck to its normal adult location on the side of the head.