4610 - LAB 10 - leukocytes and immunology

p. 136 - 144

calculate the amount of white blood cells in a diluted blood sample

normal WBC count for males and females

adults in general = 4 to 11,000 cells / microliter

males = 5 to 10k

females = 4.5 to 11k

What is leukopenia, and what conditions might it cause?

leukopenia = condition characterized by lower than normal number of white blood cells (leukocytes) in the blood, under 4k cells per microliter.

causes

• weakened immune system leading to frequent severe long lasting infections. increased susceptibility to illnesses like pneumonia, sepsis, abscesses, mouth sores

Does emotional or physical stress affect white blood cell counts?

both affect WBC count.

impact:

• increased WBC count - stress triggers release of cortisol and adrenaline prompting increase in inflammatory leukocytes specifically neutrophils

• reduced lymphocytes - chronic stress leads to decrease in lymphocytes (WBC that fights infection), because long term stress can make immune cells less sensitive to cortisol

What happens to WBC count when a person develops leukemia? why

WBC count becomes extremely high 100k to 400k per microliter, because the bone marrow produces large amounts of abnormal, immature, dysfunctional WBC called blast cells.

some leukemia types have very low WBC count because dysfunctional cells crowd out the bone marrow preventing healthy cells from entering blood and being counted

treatment for leukemia

chemotherapy, targeted therapies, stem cell transplants

normal levels of each leukocyte type in whole blood

• Neutrophils: 55% to 70% (1,500–8,000 cells)

• Lymphocytes: 20% to 40% (1,000–4,800 cells)

• Monocytes: 2% to 8% (200–800 cells)

• Eosinophils: 1% to 4% (0–500 cells)

• Basophils: 0.5% to 1% (0–100 cells)

everything above is WBC count per microliter

differential blood cell count of a patient reveals that the eosinophil count is abnormally high. why?

indicates the immune system is reacting to a specific threat, usually parasitic infections, allergy, or drug reactions.

how does HIV affect WBC count? which specific leukocytes are targeted?

HIV destroys immune system by targeting, kiling helper T cells aka CD4+ T lymphocytes (who coordinate immune response)

HIV usually leads to

• less, destroyed CD4 cells

• leukopenia (low total WBC count)

• neutropenia (decrease in neutrophils)

• lymphopenia (decrease in lymphocytes)

treatments available for HIV

daily pills, long acting injections

WBC

WBC aka leukocytes are immune system’s primary defense, produced in bone marrow found in blood/lymph tissue. 5 types categorized as granulocytes (containing granules) or agranulocytes (lacking granules)

• neutrophils, lymphocytes, monocytes, eosinophils, basophils

neutrophils

• Definition: The most common type of WBC and the first to respond to infection, often forming the main component of pus.

• Function: Act as fast-acting phagocytes, engulfing and destroying bacteria and fungi.

lymphocytes

• Definition: Key cells in the adaptive immune system, comprising T cells, B cells, and Natural Killer (NK) cells.

• Function: Responsible for producing antibodies (B cells), destroying infected or cancerous cells (T cells/NK cells), and creating immune memory.

monocytes

• Definition: The largest type of WBC, which migrate from the bloodstream into tissues to become macrophages.

• Function: Defend against infection by clearing up dead cells, debris, and bacteria

eosinophils

• Definition: Granulocytes that target parasites and play a major role in allergic responses.

• Function: Destroy parasites and cancer cells, and help modulate inflammation

basophils

• Definition: The least common WBC, which releases chemical signals during allergic reactions.

• Function: Produce histamine (initiating inflammation) and heparin (preventing blood clotting)

granulocytes

fight pathogens through innate immunity (rapid, non specific)

Neutrophils, Eosinophils, Basophils

agranulocytes

for adaptive immunity (slow, specific)

Lymphocytes, Monocytes

how to identify each of the leukocytes on the microscope

Neutrophil: 3–5 nuclear lobes | Pale pink cytoplasm | Fine granules.

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Lymphocyte: Huge round nucleus | Thin blue halo of cytoplasm | Smallest size.

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Monocyte: Kidney/U-shaped nucleus | Gray-blue cytoplasm | Largest size.

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Eosinophil: 2 nuclear lobes | Bright red/orange granules | Medium size.

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Basophils: Obscured nucleus | Dark purple/black granules | Medium size.