Final answer:
The Valsalva maneuver involves closing the glottis while trying to exhale. It increases pressure in the thoracic and abdominal cavities, aiding in tasks such as defecation, urination, or childbirth.
Step-by-step explanation:
The Valsalva maneuver involves closing the glottis while trying to exhale. The glottis is the opening between the vocal cords in the larynx. By closing the glottis, it increases the pressure in the thoracic and abdominal cavities, which can aid in tasks such as defecation, urination, or childbirth. The Valsalva maneuver is a voluntary procedure that involves the coordinated contraction of the diaphragm and abdominal wall muscles.