6. Anatomy
Myeloid Lineage
Erythrocytes (RBCs): Shape,
Sites of production: Yolk sac,Placenta, Liver,
Spleen, Bone marrow
They lose most of their cell contents. Why?
Life span is about 120 days.
Reticulocytes: Immature RBC with reticular
network of rRNA.
7. Myeloid Lineage
Leukocytes
Highest percentage to lowest: Neutrophils,
Lymphocytes, Monocytes, Eosinophils, Basophils
Neutrophils: Polymorphonuclear neutrophils
(PMNs); 50% to 80%
first responders in the acute phase of inflammation
Nonsegmented (band) neutrophils
Segmented – 3 to 5 nuclear lobes
Hypersegmented?
8.
9.
Monocytes
Kidney-shaped nucleus
2% to 10%
Act to clean up circulating debris, microorganisms,
senescent RBCs, and damaged cells.
Monocytes in blood; macrophages in tissues
Kupffer cells
Alveolar Macrophages
Oligodendrocytes
Glial Cells
Macrophages – Function as APCs – Antigen
Presenting cells via MHC II.
11.
Eosinophils
Bilobed nuclei and have prominent eosinophilic
(reddish-orange) granules
1% to 6%
Major Basic Protein (MBP)
Mnemonic for the causes of Eosinophilia (NAACP)
Neoplasia Asthma Allergies Collagen vascular
disease Parasites
12.
13.
Basophils
Bilobed nuclei but have granules
Inflammatory reactions that cause allergic
symptoms.
Express Immunoglobulin E (IgE) receptors
Release chemokines
Mast cells in tissues
Platelets/Thrombocytes
Originate from megakaryotes
Anucleate
Lifespan – 7 to 10 days (First 2 days spent in the
spleen)
150,000 – 400,000/mm³
14.
15. Lymphoid Lineage
Lymphocytes are also leukocytes
Originate from CLP cells
25% to 33%
T cells
B cells
Plasma cells
Natural killer (NK) cells.
16.
17.
T-Lymphocytes
mediate the cellular immune response
Made in the bone marrow
Mature in the thymus
Reside in lymphoid tissues
CD 4 & CD 8 T-cells
18.
CD 4 T-cells
Helper cells
Bind to MHC II – MHC II is present on the surface
of APCs
CD 8 T-cells
Eliminate T cells, viral cells, virus-infected cells
Bind to MHC I – MHC I is expressed by all cells in
the body except platelets & RBCs
NK cells – tumor cells & viral-infected cells
perforin and granzyme
B-lymphocytes
Humoral immune system
Create Antibodies
20. Hematology
Physiology
Blood groups A, B, AB, O
Blood Groups: ABO and Rh Systems
Presence of surface antigen(s) on RBCs.
Presence of plasma antibodies (Ab) against
antigen(s) not present on RBCs
Presence or absence of Rh factor
21.
Rh system
D, C, c, E, e on the RBC
D antigen – most immunogenic
Rh-negative people do not produce the D antigen
Do not produce anti-Rh Abs.
Rh-negative individuals can become sensitized
Blood transfusion
Pregnancy: Rh immunoglobulin (RhoGAM)
RhoGAM at 28 weeks of pregnancy
within 72 hours after delivery
22. USMLE Step 1 question
A 28year old woman gravida 2, para 1, at 27
weeks gestation presents to the clinic for
antenatal. She denies any complaints except
for back pain. Blood investigations reveal she is
blood group B negative. The father of the fetus
is A positive. Which of the following precautions
must be ensured?