Final answer:
Eosinophils' highest numbers in circulation typically occur during the night and early morning. They are important in the immune response, particularly in combating parasitic infections and allergic reactions. Their numbers can fluctuate daily due to various immunological triggers.
Step-by-step explanation:
Eosinophils have a well-documented daily fluctuation; the quantity of circulating eosinophils tends to be highest during the night and early morning hours. Eosinophils are a type of white blood cell that make up 2-4 percent of the total leukocyte count and play a crucial role in the body's immune response, particularly in fighting parasitic infections and in allergic reactions. They are characterized by their bilobed nucleus and granules that stain well with an acidic dye called eosin, giving them a distinct red to orange color.The role of eosinophils in the immune system is diverse; they contain granules with antihistamine molecules to counteract the effects of histamines in allergic reactions. Additionally, some granules carry molecules that are toxic to parasitic worms, which highlights their importance in defending against these organisms that can enter the body through contaminated food.
Additional functions of eosinophils include phagocytosis and the release of inflammatory compounds triggered by specific immune responses. High counts of eosinophils are commonly seen in conditions such as allergies, asthma, and parasitic infections, while low counts may be indicative of drug toxicity or stress. The presence and activity of eosinophils are regulated by various immunological signals, which can lead to the observed diurnal variation in their numbers within the bloodstream.