The platysma is a superficial muscle that overlaps the sternocleidomastoid. It is a broad sheet arising from the fascia covering the upper parts of the pectoralis major and deltoid; its fibers cross the clavicle, and proceed obliquely upward and medially along the side of the neck.
For example genetic differences, females inherit X chromosomes from their father giving them a genetic make-up of XX, while males inherit a Y chromosome from their father, thus giving them a genetic make-up of XY.
1 Bisexual identity more so establishes attraction to both genders, whereas pansexual identity more so recognizes the existence of other genders (third genders) and the capacity to be sexually attracted to individuals identifying as these various genders.