Final answer:
Within 24 hours of quitting smoking, circulation improves and the chance of a heart attack decreases, although the regrowth of cilia and reduction in coughing and shortness of breath will take longer to manifest.
Step-by-step explanation:
Health Benefits Within 24 Hours of Quitting Smoking
Upon quitting smoking, several immediate health benefits begin to take effect. Significant improvements can occur in circulation, and the chance of a heart attack decreases. Smoking contributes to cardiovascular risks by increasing heart rate, blood pressure, and the formation of blood clots, as well as releasing carbon monoxide which binds to hemoglobin, impairing oxygen transport. Within the first 24 hours of cessation, these adverse effects begin to reverse, returning towards normal physiological conditions and reducing the risk of a cardiac event.
While it takes a few months for the cilia in the lungs to regrow after they have been damaged by substances in tobacco smoke, the cessation of smoking allows these processes to commence. The recovery of ciliary function helps in the removal of mucus and foreign particles, reducing the severity of coughing and shortness of breath over time.
Therefore, one of the correct statements regarding what occurs within 24 hours of quitting smoking is that circulation improves and the chance of a heart attack decreases. The regrowth of cilia and the decrease in coughing and shortness of breath, however, typically take longer to be noticeable after smoking cessation.