White Blood Cells Overview

Questions and Answers

Which type of granulocyte contains granules that stain with both acidic and basic dyes?

Basophils

Neutrophils (correct)

Eosinophils

Monocytes

What is the typical total leukocyte count (TLC) range for a healthy adult?

1000–4000/mm3

11,000–20,000/mm3

25,000–50,000/mm3

4000–11,000/mm3 (correct)

In which age group is the total leukocyte count at its highest, reaching between 10,000–25,000/mm3?

Adults

Children, 4–7 years

Infants up to 1 year

Newborns, full-term (correct)

Which type of agranulocyte is primarily involved in the immune response?

Lymphocytes Signup and view all the answers

What physiological variation is observed when there is an increase in the percentage of neutrophils?

Lymphocytopenia Signup and view all the answers

What is a key distinguishing feature of basophils compared to other granulocytes?

They are involved primarily in allergic reactions. Signup and view all the answers

Which of the following statements regarding WBCs is inaccurate?

Monocytes can be classified as granulocytes. Signup and view all the answers

What does a differential count measure in the context of WBCs?

Unique types and proportions of WBCs. Signup and view all the answers

What is the significance of DLC in blood tests?

It is never performed in isolation and is part of full blood counts. Signup and view all the answers

Which characteristic is NOT associated with mature neutrophils?

Contains a single, spherical nucleus Signup and view all the answers

What is the primary role of neutrophils in the immune response?

They are involved in the phagocytosis of pathogens. Signup and view all the answers

What happens to neutrophils after they have completed their defensive role?

They are destroyed during phagocytosis or die after senescence. Signup and view all the answers

What types of substances do neutrophils release during inflammation?

Histamines and leukotrienes Signup and view all the answers

Which statement accurately describes the lifespan of neutrophils?

Their lifespan may shorten drastically during severe infections. Signup and view all the answers

Which of the following is NOT a function of neutrophils?

Producing antibodies against foreign substances. Signup and view all the answers

What is the primary role of eosinophils in the immune system?

Providing mucosal immunity Signup and view all the answers

Which of the following accurately describes the granules of eosinophils?

Stain bright pink and contain basic protein Signup and view all the answers

Neutrophil granules are best described by what feature?

They contain enzymes and can take both acidic and basic stains. Signup and view all the answers

What characterizes the nucleus of basophils?

Irregular shape that may be bilobed or trilobed Signup and view all the answers

What is the main component of the eosinophil's granules known for its larvicidal properties?

Major basic protein Signup and view all the answers

How do eosinophils respond during allergic reactions?

By responding with mild phagocytic activity Signup and view all the answers

Which feature distinguishes neutrophils' febrile response from other white blood cells?

Presence of endogenous pyrogen Signup and view all the answers

What is true about the morphological features of eosinophils?

Nucleus is bilobed in 85% of cells Signup and view all the answers

Which condition is not typically associated with eosinophil activity?

Bacterial infections Signup and view all the answers

What primary role do mast cells play in the body?

Participating in allergic reactions Signup and view all the answers

Which substance is released by mast cells during an allergic reaction that contributes to local vascular changes?

Histamine Signup and view all the answers

Which of the following statements correctly describes the interaction of mast cells with allergens?

Mast cells degranulate when allergens bind with IgG. Signup and view all the answers

What is the key function of eosinophils in the context of allergic reactions?

Phagocytosing and destroying antigen-antibody complexes Signup and view all the answers

What does the presence of a large round nucleus in lymphocytes indicate?

The cell is associated with immune response Signup and view all the answers

What substance do mast cells release that plays a role in preventing blood coagulation?

Heparin Signup and view all the answers

The primary location of mast cells in the body includes which of the following?

In bone marrow and tissue outside capillaries Signup and view all the answers

Which of the following lies at the center of the humoral immunity process?

B lymphocytes Signup and view all the answers

What primary role do T lymphocytes play in the immune system?

They provide cellular immunity. Signup and view all the answers

What happens to monocytes after they are released from the bone marrow?

They develop into macrophages in extravascular tissues. Signup and view all the answers

Which of the following accurately describes the cytoplasm of monocytes?

It is clear and pale blue, often with purple granules. Signup and view all the answers

What is a significant function of monocytes in the immune response?

Engaging in phagocytosis. Signup and view all the answers

Natural killer (NK) cells are primarily associated with which type of immunity?

Innate immunity by targeting all foreign cells. Signup and view all the answers

Study Notes

White Blood Cells (WBCs) Overview

WBCs or leukocytes are colorless, nucleated cells vital for the body's defense mechanisms.
Divided into two main categories: Granulocytes (contain granules) and Agranulocytes (lack granules).

Types of Granulocytes

Neutrophils:
- Multilobed nucleus (2-6 lobes) linked by chromatin.
- Cytoplasm has fine granules, staining violet-pink, containing lysosomal enzymes.
- Lifespan: Circulate for 8-10 hours; tissue presence up to 5 days.
- Functions:
  - Phagocytosis of pathogens.
  - Release inflammatory mediators (leukotrienes, prostaglandins).
  - Involved in febrile response.
Eosinophils:
- Bilobed nucleus, cytoplasm bright pink with coarse red-staining granules.
- Functions:
  - Mild phagocytosis.
  - Responses in allergic conditions and parasitic infestations.
  - Release toxic proteins like Major Basic Protein (MBP) for defense against larger parasites.
Basophils:
- Irregular nucleus, numerous coarse granules staining purple/blue.
- Functions:
  - Mild phagocytosis and significant role in allergic reactions.
  - Release inflammatory mediators including histamine and heparin to prevent clotting.

Agranulocytes

Lymphocytes:
- Large round nucleus, scant cytoplasm with no visible granules.
- Types:
  - B lymphocytes (humoral immunity, antibody production).
  - T lymphocytes (cellular immunity).
  - Natural Killer (NK) cells (innate immunity through non-specific killing).
Monocytes:
- Large, horseshoe-shaped nucleus, abundant pale blue cytoplasm.
- Lifespan: Circulate for 10-20 hours before maturing into macrophages in tissues.
- Functions:
  - Phagocytosis and clearance of dead cells and debris.
  - Synthesize biologically important substances and participate in tumor immunity.

White Blood Cell Counts

Total Leukocyte Count (TLC) varies by age:
- Adults: 4000-11,000/mm³
- At birth: 10,000-25,000/mm³
- Infants (up to 1 year): 6000-16,000/mm³
- Children (4-7 years): 5000-15,000/mm³
- Children (8-12 years): 4500-13,500/mm³
Clinical significance of differential and absolute counts helps diagnose diseases by evaluating changes in specific WBC types.

Morphology of WBCs

Neutrophils: Multilobed nucleus, pale bluish cytoplasm with pinpoint granules.
Eosinophils: Bilobed nucleus, bright pink cytoplasm with coarse granules containing basic proteins.
Basophils: Irregular nucleus overcrowded with granules, functions predominantly in allergic responses.
Lymphocytes: Prominent nucleus with minimal cytoplasm, crucial for immune defense.
Monocytes: Large nucleus, abundant cytoplasm, role in phagocytosis and tissue immunity.

Summary of Functions

Neutrophils: First line of defense, inflammation, and fever response.
Eosinophils: Mediators of allergic responses, defense against parasitic infections.
Basophils: Release mediators that contribute to allergic reaction, prevent clotting.
Lymphocytes: Essential for specific immune responses through antibodies and cellular actions.
Monocytes: Major role in phagocytosis and tumor immunity, long lifespan in tissues.

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Description

Explore the fascinating world of white blood cells (WBCs) and their crucial roles in the immune system. This quiz covers the two main categories of WBCs: granulocytes and agranulocytes, along with detailed descriptions of neutrophils, eosinophils, and basophils. Test your knowledge on their functions, lifespan, and involvement in immune responses.