Final answer:
The statement in question is false. Leukocytosis refers to a high leukocyte count, not erythrocytes, while leukopenia indicates a low leukocyte count.
Step-by-step explanation:
The statement that leukocytosis refers to an increase in erythrocytes above 10,000/microliters and leukopenia refers to a level of leukocytes below 5000/microliters is false.
Leukocytosis is the condition where there is an excessive proliferation of leukocytes, not erythrocytes. Typically, leukocyte counts in a healthy individual range from 5,000 to 10,000 per µL. When these counts are significantly higher, it is known as leukocytosis, which can indicate an increased risk for disease because the leukocytes may be nonfunctional. On the other hand, leukopenia is characterized by a below-normal production of leukocytes, leading to counts lower than 5,000 per µL and can leave an individual susceptible to infections.
Leukocytes and erythrocytes are both formed from hematopoietic stem cells in the bone marrow but serve different functions within the body. Leukocytes play crucial roles in the immune system, while erythrocytes are primarily responsible for oxygen transport in the blood.