Leukopoiesis and Leukocyte Types

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Questions and Answers

What is leukopoiesis?

Production of white blood cells.

What is leukopenia?

Decrease in white blood cell production.

What is leukocytosis?

Increase in white blood cell production.

Leukocytes are less numerous than red blood cells.

True Signup and view all the answers

What are the functions of leukocytes?

Major defense against foreign invaders, phagocytosis, inflammation, immune response. Signup and view all the answers

Leukocytes are divided into?

Granulocytes and Agranulocytes. Signup and view all the answers

PMN is?

Polymorphonuclear. Signup and view all the answers

Granulocytes are what?

PMN- Polymorphonuclear. Signup and view all the answers

What are the types of granulocytes?

Neutrophils, Eosinophils, Basophils. Signup and view all the answers

Agranulocytes are called?

Mononuclear. Signup and view all the answers

What are the types of agranulocytes?

Monocytes, Macrophages, Lymphocytes, Plasma cells. Signup and view all the answers

What is granulopoiesis?

Production of granulocytes. Signup and view all the answers

What is the first stage of a granulocyte?

Myeloblast. Signup and view all the answers

Describe a myeloblast nucleus.

Round/oval, 3/4 of the cell, fine chromatin pattern, contains nucleoli. Signup and view all the answers

Describe a myeloblast cytoplasm.

Basophilic, takes up purple stain, no granules unless very immature. Signup and view all the answers

What is the 2nd stage of a granulocyte?

Promyelocyte. Signup and view all the answers

What is a banded cell?

A type of neutrophil. Signup and view all the answers

What is neutrophilia?

An increase in neutrophils. Signup and view all the answers

What are some causes of neutrophilia?

Epinephrine, corticosteroids, stress, inflammation, infection/sepsis, anemias. Signup and view all the answers

What is neutropenia?

A decrease in neutrophils. Signup and view all the answers

What causes neutropenia?

Long-term steroids, stress, infection, viral infections. Signup and view all the answers

A band cell is immature and comes right before a mature cell.

True Signup and view all the answers

What is left shift?

When the number of immature neutrophils exceeds the reference range. Signup and view all the answers

What is an increase in eosinophils called?

Eosinophilia. Signup and view all the answers

What causes eosinophilia?

Allergic reactions, parasites, mast cell tumors. Signup and view all the answers

What is a decrease in eosinophils called?

Eosinopenia. Signup and view all the answers

What is lymphocytosis?

An increase of lymphocytes. Signup and view all the answers

What causes lymphocytes to increase?

Viral infection, excitement, antigenic stimulation, hypoadrenocorticism, lymphosarcoma, lymphocytic leukemia. Signup and view all the answers

What causes lymphopenia?

Steroid response, Cushing's disease, chronic inflammation. Signup and view all the answers

What is monocytosis?

An increase in monocytes. Signup and view all the answers

What causes monocytosis?

Inflammation, chronic infection, stress. Signup and view all the answers

What is a macrophage?

Monocyte in tissue. Signup and view all the answers

What is a toxic neutrophil?

Neutrophil with abnormalities due to shortened maturation. Signup and view all the answers

What do toxic neutrophils: diffuse cytoplasmic basophilia indicate?

Blue-grey color of cytoplasm. Signup and view all the answers

What do toxic neutrophils: foamy vacuolation of cytoplasm indicate?

Irregular clearing of cytoplasm. Signup and view all the answers

What are Dohle bodies?

Irregular basophilic cytoplasmic inclusions. Signup and view all the answers

What is the primary defense of a neutrophil?

Phagocytosis and antimicrobial action. Signup and view all the answers

Functions of platelets?

Aid in clotting. Signup and view all the answers

True or False: A smudge cell is significant if numerous.

true Signup and view all the answers

What causes a stress leukogram?

Corticosteroid release or administration. Signup and view all the answers

Study Notes

Leukopoiesis Overview

Definition: Process of producing white blood cells (leukocytes) that play a crucial role in the immune system.
Related terms:
- Leukopenia: A decrease in white blood cell production.
- Leukocytosis: An increase in white blood cell production.

Leukocyte Characteristics

Leukocytes are less numerous than red blood cells.
Functions:
- Defense against foreign invaders.
- Involvement in phagocytosis (cellular ingestion of microbes).
- Participation in inflammatory responses and immune defense.

Types of Leukocytes

Divided into two main categories:
- Granulocytes: Contain granules in their cytoplasm.
  - Types include:
    - Neutrophils
    - Eosinophils
    - Basophils
- Agranulocytes: Lack visible granules.
  - Types include:
    - Monocytes
    - Macrophages (tissue-resident monocytes)
    - Lymphocytes
    - Plasma cells (activated lymphocytes)

Granulocyte Development

Granulopoiesis: Production of granulocytes.
Stages:
- Myeloblast: Most immature form, large, rarely seen in peripheral blood.
- Promyelocyte: Second stage, lighter blue cytoplasm with non-specific granules.
- Myelocyte: Third stage, smaller, more specific granules begin to appear.
- Metamyelocyte: Fourth stage, no further cell division occurs.

Neutrophils

Most common type of white blood cell in dogs and cats, primarily involved in fighting infections.
Neutrophilia: Increase in neutrophils; can be caused by factors like stress, inflammation, and infections.
Neutropenia: Decrease in neutrophils; can result from long-term steroid use or viral infections.
Banded Neutrophils: Immature form with a horseshoe-shaped nucleus.

Eosinophils

Characterized by pink/orange granules; involved in allergic reactions and defense against parasites.
Eosinophilia: Increase in eosinophils commonly associated with allergies or parasitic infections.
Eosinopenia: Decrease in eosinophils due to increased corticosteroids.

Basophils

Contain purple granules and are involved in allergic reactions.
Rare in circulation; thought to be tied to mast cells in tissues.
Basophilia: Increase in basophils often in relation to allergies.

Lymphocytes

Major producers of antibodies and main type of white blood cell in ruminants.
Types:
- B-lymphocytes: Mature in bone marrow; develop specific receptors and can become plasma cells.
- T-lymphocytes: Mature in thymus; important for cellular immunity and activating B-cells.
Lymphocytosis: Increase in lymphocytes due to infections or excitement.
Lymphopenia: Decrease often caused by steroid response or Cushing's disease.

Monocytes and Macrophages

Monocytes are larger than granulocytes, with a kidney bean-shaped nucleus.
Functions include phagocytosis and antigen processing.
In tissues, they differentiate into macrophages.

Smudge Cells

Result from excessive pressure during blood film preparation or fragile cells.
Appear as pale nuclear remnants; few are benign, many indicate cell fragility.

White Blood Cell Response to Infections

Bacterial Infections: Typically show leukocytosis with neutrophilia followed by potential left shift.
Viral Infections: Initial leukocytosis transitioning to leukocytopenia.

Leukogram Evaluation

Stress Leukogram: Characterized by neutrophilia and lymphopenia.
Inflammatory Leukogram: Shows neutrophilia with left shift.
Excitement Leukogram: Caused by epinephrine release, showing lymphocytosis and neutrophilia without left shift.

Platelets

Function in clotting; classified as cellular fragments from megakaryocytes, aiding hemostasis.

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Description

Explore the intricacies of leukopoiesis, the process responsible for the production of white blood cells. This quiz covers the different types of leukocytes, their characteristics, and their essential roles in the immune system, including granulocyte development and classifications.