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.
There are a number of indicators of biological sex, including sex chromosomes, gonads, internal reproductive organs, and external genitalia. Gender refers to the attitudes, feelings, and behaviors that a given culture associates with a personâs biological sex.Behavior that is compatible with cultural expectations is referred to as gender-normative; behaviors that are viewed as incompatible with these expectations constitute gender non-conformity.ender identity refers to âoneâs sense of oneself as male, female, or transgenderâ (American Psychological Association, 2006). When oneâs gender identity and biological sex are not congruent, the individual may identify as transsexual or as another transgender category (cf. Gainor, 2000).