Updated: 2/13/2018

Blood Cell Differentiation

0%
Topic
Review Topic
0
0
Topic
Overview
 

This illustration highlights the basic development of various blood cells from hematopoietic stem cells.

 
Introduction
 
Blood Cell Types
Type Description
Erythrocyte
  • Red cell responsible for carrying O2 to tissues, and CO2 to lungs
  • Erythropoietin increases RBC production
  • Glucose uptake not affected by insulin
  • Life span of 120 days
  • Most energy produced is via glycolysis
  • Hexose monophosphate (HMP) shunt to produce NAPDH and ribose 5-phosphate
Platelets
  • Derived from megakaryocytes
  • Plays a role in hemostasis
  • Endothelial damage leads to platelet aggregation via other platelets and fibrinogen
  • Contains granules that are secreted upon platelet activation
    • dense granules – ADP, Ca2+
    • α-granules – vWF, fibrinogen, platelet-derived growth factor (PDGF)
Mast cells
  • Involved in allergic reaction via a type I hypersensitivity mechanism
  • Granules containing substances such as histamine and heparin
  • Receptors (FcεR1) on mast cell can bind to IgE
    • IgE binding → cross-linking → degranulation
Monocytes
  • When in tissues, it differentiates into macrophages
Macrophages
  • Has ability to ingest pathogens, cellular debris, and dead or dying cells
  • Interferon-γ is an important activator of macrophages
  • Antigen presenting abilities via MHC II
  • Involved in granuloma formation (i.e., tuberculosis)
Dendritic cell
  • Antigen presenting cell via MHC II
  • Acting as a link between the innate and adaptive immune system
White blood cell differential
  • Neutrophils (54 – 62%)
    • if ↑, think bacterial infection
    • ↑ myeloid proliferation due to conditions such as bacterial infections would ↑ band cells
      • Band cell = immature neutrophils
    • C5a, IL-8, LTB4 are some molecules that promote chemotaxis in neutrophils to infection or inflammation sites
    • hypersegmented in vitamin B12 or folate deficiency
  • Lymphocytes (25 – 33%)
    • B-cell
      • matures in marrow
      • differentiates into antibody producing cells (plasma cells) when encountering antigen
      • antigen presenting ability via MHC II
    • T-cell
      • matures in thymus
      • cytotoxic T-cell: CD8+ recognize MHC I
      • helpter T-cell: CD4+ recognize MHC II
      • T-cells are activated with CD28 costimulation
  • Monocytes (3 – 7%)
  • Eosinophils (1 – 3%)
    • ↑ in conditions such as helminthic infection, neoplasia, Addison disease, and so forth
  • Basophils (0 – 0.75%)
    • involved in allergic reactions
    • granules contain heparin and histamine
    • can be ↑ in chronic myelogenous leukemia (CML)
      • can be helpful in differentiating from leukemoid reaction

Please rate topic.

Average 3.6 of 26 Ratings

EXPERT COMMENTS (6)
Private Note