Which statement best describes how smoking affects tissue healing?

Prepare for the Tissue Injury, Healing, and Pain Test. Utilize flashcards and multiple-choice questions with hints and explanations. Ensure you're ready for the exam!

Smoking impairs tissue healing mainly by reducing oxygen delivery to tissues and causing vasoconstriction. Nicotine triggers sympathetic stimulation and release of vasoconstrictors, narrowing blood vessels and lowering blood flow to the wound. Carbon monoxide from smoke binds hemoglobin with high affinity, forming carboxyhemoglobin and reducing the amount of oxygen carried to tissues. Both effects drop the oxygen tension at the injury site, which is crucial for energy production, collagen synthesis, fibroblast activity, and new blood vessel formation—all key steps in healing. The result is slower closure and remodeling of wounds.

Increased oxygen delivery isn’t correct because smoking actually lowers it; improved neutrophil function isn’t accurate because smoking tends to impair neutrophil activity; and decreased oxidative stress isn’t correct because smoking increases oxidative stress through more free radicals.