A nurse is teaching adolescent boys about pubertal changes. The first sign of pubertal change seen with boys is

Legg-Calve-Perthes disease, also known as Perthes disease, is a childhood condition that affects the hip joint. It occurs due to a disruption in the blood supply to the femoral head (epiphysis), which can lead to bone death (avascular necrosis) and subsequent deformity of the femoral head.

It is essential for parents to understand that Legg-Calve-Perthes disease is not an acute illness that lasts for a short duration (Option A). It is a chronic condition that typically progresses over a period of months or years.

stating that it is caused by a virus, in (option C) is incorrect. The exact cause of Legg-Calve- Perthes disease is not fully understood, but it is not caused by a viral infection. It is believed to be related to multifactorial factors, including genetic and vascular factors.

stating that it primarily affects adults, in (option D) is incorrect. Legg-Calve-Perthes disease predominantly affects children, typically between the ages of 4 and 8 years old, during the period of rapid growth.

The anatomy of the urinary tract can influence the susceptibility to urinary tract infections (UTIs). In the case of young girls, their urethra is shorter compared to adult females, which increases the likelihood of bacteria reaching the bladder. The shorter urethra provides a shorter distance for bacteria to travel from the outside of the body to the bladder, making it easier for bacteria to enter and cause an infection.

Prostatic secretions in males in (option A) is incorrect because they are not directly related to the increased susceptibility to UTIs. Prostatic secretions can, however, contribute to conditions like prostatitis, which is an inflammation of the prostate gland that can be associated with urinary symptoms and sometimes bacterial infections.

Frequent emptying of the bladder in (option C) is incorrect because it is generally considered a healthy practice as it helps to flush out any potential bacteria in the urinary tract. It does not predispose the urinary tract to infection.

Increased fluid intake in (option D) is incorrect because it is generally encouraged to maintain proper hydration and urinary tract health. It can help to flush out bacteria from the urinary system, reducing the risk of infection.

While these factors may have implications for urinary tract health, the specific factor that predisposes the urinary tract to infection, particularly in young girls, is the short urethra (B).