Answer:
Circadian rhythms.
Step-by-step explanation:
After spending 36 hours in the emergency room, Dr. Alli has trouble sleeping well when he finally gets home late in the afternoon. The next day, he is irritable and cannot concentrate at work. Dr. Alli's problems are likely due to disruption in his Circadian rhythms.
Circadian rhythms are physical and mental and behavioral changes that follow a daily cycle.
They respond to light and darkness in organism's environment. Sleeping at night and being awake in day time.