Cyanosis a. refers to a bluish coloring of the skin caused by hypoxemia. b. refers to a yellow coloring of the skin caused by elevated blood levels of bilirubin. c. is caused by abnormal and spotty deposition of melanin. d. is a hardening of the skin due to keratin.
The correct answer and explanation is:
The correct answer is a. refers to a bluish coloring of the skin caused by hypoxemia.
Explanation:
Cyanosis is a physical condition characterized by a bluish or purplish color of the skin, mucous membranes, and/or nail beds. It occurs when there is a lack of oxygen in the blood, a condition known as hypoxemia. The bluish hue arises because deoxygenated hemoglobin (hemoglobin that is not carrying oxygen) absorbs light differently from oxygenated hemoglobin, giving tissues a blue appearance.
Cyanosis can be either central or peripheral:
- Central cyanosis refers to the bluish discoloration of the central parts of the body, like the lips, tongue, and face. It is typically a sign of a serious underlying condition such as heart failure, chronic lung diseases (like COPD), or congenital heart defects, which affect the oxygenation of blood.
- Peripheral cyanosis, on the other hand, occurs in the extremities, like the hands and feet. It is often related to poor circulation or cold temperatures, rather than an issue with oxygen levels in the blood.
While cyanosis is a direct sign of oxygen deficiency, other conditions mentioned in the options are not correct:
- Option b refers to jaundice, which is a yellowish discoloration of the skin and eyes caused by elevated bilirubin levels, often due to liver disease or bile duct obstruction.
- Option c describes a condition where melanin, the pigment responsible for skin color, is unevenly deposited, leading to skin discoloration, but this does not cause cyanosis.
- Option d describes scleroderma, a skin condition characterized by the hardening of the skin due to an overproduction of collagen, which is not related to cyanosis.
Cyanosis serves as a vital clinical sign that healthcare providers use to help diagnose and treat respiratory or circulatory issues that may compromise oxygen delivery throughout the body.