Leukocytes: Structure, Function, and Classification
21 Questions
1 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to Lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the function of leukocytes in the immune response?

  • Secrete antibodies
  • Transport oxygen
  • Produce red blood cells
  • Recognize self from non-self antigens (correct)

Which type of stem cell gives rise to granulocytes and monocytes?

  • Granulocyte-monocyte progenitor
  • Common lymphoid progenitor
  • Multipotent hematopoietic stem cell
  • Common myeloid progenitor (correct)

What is the typical range for adult white blood cell (WBC) count?

  • $15 - 20$ x $10^9$/L
  • $4 - 10$ x $10^9$/L (correct)
  • $30 - 40$ x $10^9$/L
  • $1 - 5$ x $10^9$/L

Which of the following is NOT a determinant of the number of circulating leukocytes?

<p>Nutritional intake (A)</p> Signup and view all the answers

During leukopoiesis, which pool involves division and maturation of precursor cells?

<p>Proliferation pool (B)</p> Signup and view all the answers

How long does it take for a myeloblast to develop into a myelocyte?

<p>3 to 6 days (D)</p> Signup and view all the answers

What is the average lifespan of neutrophils in the peripheral blood?

<p>6 to 10 hours (A)</p> Signup and view all the answers

Which cytokines are responsible for the growth and differentiation of neutrophils?

<p>GM-CSF, IL-3, G-CSF (B)</p> Signup and view all the answers

Where is the storage pool of mature neutrophils located?

<p>Bone marrow (D)</p> Signup and view all the answers

Which of the following is NOT a stage in neutrophil development?

<p>Basophil (D)</p> Signup and view all the answers

What is the last step in the process of neutrophil phagocytosis and killing of a microbe?

<p>Granule releases its contents into the vacuole (D)</p> Signup and view all the answers

What is the main function of neutrophils in relation to undigested vacuole contents?

<p>Exocytosis (C)</p> Signup and view all the answers

Which type of granules in neutrophils contains proteins like myeloperoxidase, lysozyme, and collagenase?

<p>Primary (azurophilic) (D)</p> Signup and view all the answers

What is the main function of monocytes in immunity?

<p>Phagocytosis (B)</p> Signup and view all the answers

Eosinophils release histaminase to:

<p>Destroy parasites (B)</p> Signup and view all the answers

What is the main similarity between basophils and mast cells?

<p>Contain histamine (D)</p> Signup and view all the answers

Where do lymphocytes develop from?

<p>Common lymphoid progenitor (A)</p> Signup and view all the answers

Which type of lymphocyte plays a key role in generating antigenic specificity?

<p>T-cells (C)</p> Signup and view all the answers

What is a likely cause of leukocytosis (>10.0 x 10^9/L)?

<p>Infection (A)</p> Signup and view all the answers

What is a qualitative abnormality that can affect leukocytes?

<p>Cytoplasmic abnormalities (D)</p> Signup and view all the answers

Which disorder can impact leukocyte structure and function?

<p>Chediak-Higashi Syndrome (C)</p> Signup and view all the answers

Study Notes

Leukocytes

  • Developed from hematopoietic stem cells in the bone marrow (BM)
  • Go through differentiation and maturation before entering the circulation
  • Classified based on morphology: polymorphonuclear (PMN) and mononuclear (MN)

Functions of Leukocytes

  • Innate immunity: defend against infectious agents and foreign substances
  • Adaptive immunity: participate in specific immune responses

Granulocytes

  • Derived from granulocyte-monocyte progenitor (GMP) in BM
  • Cytokines responsible for growth and differentiation: GM-CSF, IL-3, and G-CSF
  • Stages of development: myeloblast, promyelocyte, myelocyte, metamyelocyte, band, and segmented neutrophil
  • Average lifespan: 6-10 hours in peripheral blood, several days in tissues

Neutrophils

  • First line of defense against foreign substances and microorganisms
  • Functions:
    • Adhesion
    • Diapedesis
    • Migration
    • Phagocytosis
    • Killing and digestion
  • Granules: primary, secondary, and tertiary
  • Primary granules: contain myeloperoxidase (MPO), lysozyme, and bacterial permeability-increasing protein (BPI)
  • Secondary granules: contain lactoferrin, lysozyme, and collagenase
  • Tertiary granules: contain lysozyme and collagenase

Monocytes

  • Derived from granulocyte-monocyte progenitor (GMP) in BM
  • Cytokines responsible for growth and differentiation: GM-CSF, IL-3, and M-CSF
  • Stages of development: monoblast, promonocyte, and monocyte
  • Average lifespan: 20-40 hours in peripheral blood, then mature into macrophages in tissues
  • Functions:
    • Innate immunity: phagocytosis and cytokine production
    • Adaptive immunity: antigen presentation to T-lymphocytes

Eosinophils

  • Derived from eosinophil-basophil progenitor (EBP) in BM
  • Cytokines responsible for growth and differentiation: GM-CSF, IL-3, and IL-5
  • Average lifespan: 18 hours in circulation, 2-5 days in tissues
  • Functions:
    • Parasitic infections: release histaminase to slow down hypersensitivity reaction
    • Antigen presentation: promote proliferation of effector T cells

Basophils

  • Derived from eosinophil-basophil progenitor (EBP) in BM
  • Cytokines responsible for growth and differentiation: GM-CSF, IL-3, and IL-5
  • Average lifespan: 4 days in circulation
  • Functions:
    • Allergic reactions: release histamine and other mediators
    • Inflammation: involved in innate immunity

Lymphocytes

  • Derived from common lymphoid progenitor (CLP) in BM
  • Participate in adaptive immunity
  • Two types of adaptive immune response: humoral immunity and cell-mediated immunity
  • Subtypes: T-lymphocytes, B-lymphocytes, and natural killer (NK)-cells
  • Functions:
    • T-lymphocytes: helper and cytotoxic
    • B-lymphocytes: antibody production and antigen presentation
    • NK-cells: innate immunity and tumor surveillance

Benign Leukocytes Disorders

  • Quantitative Abnormalities:
    • Leukocytosis: >10.0 x 10^9/L in adults
    • Leukopenia: <4.0 x 10^9/L in adults
  • Qualitative Abnormalities:
    • Nuclear abnormalities: Pelger-Huët Anomaly
    • Cytoplasmic abnormalities: toxic granulation and toxic vacuolization
    • Adhesion defect: leukocyte adhesion deficiency
    • Toxic changes: Döhle bodies and May-Hegglin Anomaly

Cytochemistry

  • Diagnosis and classification of acute leukemia
  • Study of chemical elements in cells: enzymatically or nonenzymatically
  • Stains:
    • Myeloperoxidase (MPO)
    • Sudan black B (SBB)
    • Chloroacetate esterase (CAE)
    • Nonspecific esterase (NSE)
    • Periodic acid Schiff (PAS)
    • Neutrophil alkaline phosphatase (NAP)
    • Acid phosphatase (AP) and tartrate-resistant acid phosphatase (TRAP)

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Quiz Team

Description

Learn about the structure, function, and classification of leukocytes, the white blood cells that protect the body from infectious agents. Explore how leukocytes develop from hematopoietic stem cells and the different types based on morphology and function.

More Like This

Use Quizgecko on...
Browser
Browser