An instructor is reviewing the physiology of the female reproductive system with a group of students. In discussing the uterine anatomy, the instructor emphasizes the role of the myometrium. Which statement accurately reflects a function of the uterine myometrium?

A. Urea: Urea is a normal nitrogenous waste product excreted in urine; its presence alone is not indicative of diabetes (it reflects protein metabolism/kidney function).
B. Creatinine: Creatinine is a normal urinary waste product used to assess kidney function; its presence alone is not diagnostic of diabetes.
C. Glucose: Glucosuria (significant glucose in urine) suggests hyperglycemia and impaired glucose handling (common in diabetes) -indicative of a diabetic problem if present in large amounts.
D. Ketones: Ketonuria (significant ketones in urine) indicates fat breakdown/ketosis and is a sign of uncontrolled diabetes (e.g., diabetic ketoacidosis) -indicative of diabetic metabolic disturbance.

A. Produce surfactant for the alveoli: Surfactant is produced by type II pneumocytes in the alveoli, not by tracheal cartilage.
B. Move mucus towards the alveoli using their cilia: Mucus is moved by ciliated epithelium (mucociliary escalator), not by cartilage rings.
C. Perform external respiration between air and blood: Gas exchange (external respiration) occurs in alveoli, not at the trachea.
D. Allow the trachea to always remain open for passage of air: The C-shaped cartilage rings provide rigid structural support and prevent tracheal collapse while allowing the posterior tracheal wall to flex -this maintains an open airway.