a. If you had a severe infection, would you expect your WBC count to be closest to 5000, 10,000, or 15,000/μl? b. What is this condition called?

Video transcript

Welcome back everyone. We've got statement A which reads that neutropenia refers to a decrease in the number of neutrophils, A type of white blood cell. And then statement B which reads that leucocytosis refers to a decrease in the total white blood cell count below the normal range. We need to select the appropriate choice between choices A through D which decide whether statements A and B are correct or not. So let's start by considering white blood cell count. Recall that the normal range for white blood cell count is going to be approximately to 11,000 and that is 11,000 white blood cells. And out of this range we have in the denominator microliter of blood. So 4500 to 11,000 white blood cells per microliter of blood is the normal range at an approximation of white blood cells. And then when we have a count of white blood cells, that is above the normal range. Recall that this refers to leucocytosis, which again defines, defines an increase in white blood cell counts above the normal range. And to an opposite definition, we then can have a white blood cell count that is below the normal range, which is defined by a decrease in white blood cells known as neutropenia. And in this case, those white blood cells that will be decreased and count would be known as neutrophils. So recall that neutropenia can be caused by several different factors. So, an individual's white blood cell count could fall below the normal range based on maybe a viral bacterial or fungal infection that can lead to neutropenia, which can lead to an increased destruction of neutrophils to inhibit the production in bone marrow. Or we can observe neutropenia occurring where the white blood cell count is below the normal range due to an autoimmune disorder where neutrophils will be destroyed by the body's immune system. So let's write that out infection, autoimmune disorders. And then a third case of neutropenia could possibly be due to medications because some medications like antibiotics or antivirals and even chemotherapy drugs can cause a temporary decrease in neutrophil count as a side effect. So, neutropenia is a side effect of certain medications. Now, the cases where we would observe an increase in white blood cell count above the normal range being leucocytosis, which can be triggered in response to inflammation where inflammatory signals like cytokines and chemokines would be released at the site of infection. And that would stimulate the bone marrow to release more white blood cells into the bloodstream, re allowing that count of white blood cells to range above the normal range or fall above the normal range. And in the same way, infection where infections can also stimulate the bone marrow to increase the production of white blood cells. And a third reason that leucocytosis would occur would be due to my sorry mylo proliferative disorders. And such disorders could cause leucocytosis due to an overproduction of blood cells which would increase the count of white blood cells above the normal range. And then another factor that comes to mind is actually chronic stress or even acute stress. And that is because that can stimulate the release of stress hormones such as cortisol and that would cause an increase in white blood cell count via leucocytosis. So, with all of this outlined, based on our given statements, statement A which identifies neutropenia as a decrease in the number of neutrophils. A type of white blood cell would actually be a false statement since as we outlined or sorry, that would be a true statement because as we outline, neutropenia does correlate to a decrease in white blood cells. However, statement B says that leucocytosis refers to a decrease in the total white blood cell count and we would correct that to say an increase. So it is choice B or statement B rather that is false because leucocytosis increases white blood cell count above the normal range. And so based on our answer choices, we would rule out choice A because it states that statement B is correct when we determined that statement B was false. We would also rule out choices C and D because D states that both A and B are incorrect statements where we determined that statement A was correct. And C we rule out for the same reason because it determines that both statements are correct, which was false. So that leaves us with choice B as the final answer. That statement A is correct and statement B is incorrect. And so statement A is true being that neutropenia refers to a decrease in the number of neutrophils. A type of white blood cell. And statement B is given falsely which stating which states that leucocytosis refers to a decrease in the total white blood cell count below the normal range. So that is why choice B is our final answer. I hope that this made sense and let us know if you have any questions.