Family Nurse Practitioner Exam

At which Tanner stage does an adolescent male's penis primarily grow in length rather than width?

1. Tanner Stage II

2. Tanner Stage III

3. Tanner Stage IV

4. Tanner Stage V

The correct answer is: Tanner Stage III

During Tanner Stage III of male sexual maturation, significant development occurs in the growth of the penis, primarily in length rather than width. This stage typically signifies a rapid growth phase, where the testes have already enlarged, and pubic hair begins to show increased density and curliness. The penis becomes noticeably longer, which is a key indicator of progress in this stage of development. In comparison to Tanner Stage II, where initial growth of the penis begins but is more focused on width and overall size rather than just length, Tanner Stage III marks a transition to lengthening as the primary growth focus. Tanner Stage IV continues to show growth and increased size of the penis, but it might also involve width changes as the adolescent approaches full maturity. Tanner Stage V represents full maturity, where the genitalia reach adult size and characteristics. Therefore, Tanner Stage III is the correct stage to identify the phase of lengthening growth in the penis for adolescent males.