Oxygen moves from the lungs into the blood via:

A. Rhythmic variation in breathing refers to breathing patterns such as Cheyne-Stokes respiration, not orthopnea.
B. Orthopnea is defined as difficulty breathing when lying flat, which is relieved by sitting or standing upright. It is often seen in patients with heart failure or other conditions causing fluid buildup in the lungs.
C. Difficult or labored breathing is called dyspnea, not orthopnea. While orthopnea is a type of dyspnea, the key feature of orthopnea is its positional nature.
D. Cessation of breathing is known as apnea, not orthopnea.

A. The glottis refers to the opening between the vocal cords in the larynx and is not involved in the formation of the Adam's apple.
B. The hyoid bone is a U-shaped bone in the neck that supports the tongue and is not responsible for the Adam's apple.
C. The cricoid cartilage is a ring-shaped cartilage located just below the thyroid cartilage, but it does not form the Adam's apple.
D. The thyroid cartilage is the largest cartilage of the larynx and forms the prominent structure known as the Adam's apple. It is more prominent in males due to hormonal differences during puberty.