Hematology Flashcards
Plasma
55% of blood.
7% proteins, 91% water, 2% other solutions (nutrients, waste products, gases, regulatory substance.)
Buffy Coat
Platelets and Leukocytes
Formed Elements
Suspended in plasma
Finite lifespan
Originate from stem cells
Erythrocytes (RBCs)
Leucocytes (WBCs)-Granular and Agranular
Thrombocytes (Plts)
Serum
refers to blood which has been allowed to clot and then spun to remove clotting factors that may interfere with tests.
Plasma proteins
ALBUMIN-Vascular, transport, and metabolic
GLOBULINS-3 types (alpha, beta,
and gamma)
FIBRINOGEN- clotting
Hematopoiesis
Begins to form about 5th week of gestation in spleen/liver and then moves to the bone marrow
Starts with pluripotent stem cells (parent cells) then differentiates
Cytokines control proliferation, differentiation and functional activity
Production is regulated by Colony stimulating factors (CSFs):
Erythropoietin (RBCs)
GM-CSF (granulocytes & monocytes)
G-CSF (neutrophils)
M-CSF ( macrophage )
Thrombopoietin (platelets)
Erythropoiesis
Synthesis of RBCs, formed in bone marrow.
All RBCs begin as a pluripotent stem cell in the bone marrow that is stimulated to become an erythroid precursor cell.
The precursor goes through a series of changes until it becomes a mature erythrocyte released by the bone marrow.
Erythrocytes
Most abundant, Make up about 1/2 of the blood volume
Tissue oxygenation
Contains hemoglobin (Gases, Electrolytes,
Regulate diffusion through the cell membrane)
Has no nucleus, or cytoplasmic organelles (no protein synthesis)
Life span of 120 days
Types of Hemoglobin
Hb A - adult (Oxygen carrying protein)
Hb F – fetal
Hb S – sickle cell
Hb A1C - glycosylated
Nutritional requirements for adequate synthesis of healthy RBCs include
Protein
Iron-the main nutritional element needed for hemoglobin synthesis
Vitamin B12
Folic acid.
Hypoxia
Low oxygen in blood
Reticulocyte Count
The number of reticulocytes is a good indicator of bone marrow activity, because it represents recent production of RBCs.
A high reticulocyte count indicates that the bone marrow is working hard to keep up with RBC loss.
Examples of causes: anemia and cancer
Role of the Spleen
Is a highly vascular organ, considered tobe the “graveyard of RBCs”.
Also is an organ of immunity.
The spleen removes aged, lysed, and dead RBCs from circulation.
In the spleen, RBCs are broken down into their component parts, which are recycled to make new RBCs.
It sequesters abnormally shaped and hemolyzed RBCs and destroys them.
Splenomegaly
occurs when there is a large amount of RBC breakdown occurring in the body.
Leukocytes
Normal count = 5 to 10,000
Types:
Granulocytes
Neutrophils
Eosinophils
Basophils
Agranulocytes
Lymphocytes
Monocytes
Function – to combat inflammation and infection
Leukocyte Development Stages
Begins with pluripotent stem cells that differentiate into either MYELOID or LYMPHOID cells in the bone marrow.
BLAST CELLS are the immature precursor cells for each line
Granulocytic precursor cells called MYELOBLASTS (have delicate chromatin and blue gray cytoplasm)
PROMYELOCYTES have the same nuclei, and now the cytoplasm has granules.
BANDS are immature cells
Granulocytes
Are round and distinctive multi-lobar nuclei
All can be phagocytic because of the cytoplasmic granules
Specific granules : bind neutral, basic or acidic dye components
Azurophilic: lysosomes
Neutrophils
AKA: Polymorphonuclear leukocytes (Polys)
Segmented (Segs): Mature
Blasts: Immature
Responsible for host defense against invaders
Account for 60 -70% of total WBC
Only live 2-5 days
Major role: phagocytosis
Die 1-2 days after migrating to site of injury/inflammation
Eosinophils
1-3% of total WBC count
Primary role: Ingest antigen-antibody complex
Mediate vascular effects of histamine and serotonin in allergic reactions
Thought to help by releasing chemicals which detoxify the agents causing the reaction
Also work in parasitic reactions by attaching themselves to the parasite and then release hydrolytic enzymes to kill it
Basophils
Lowest number of basophils (2%)
Granules contain:
Heparin
Histamine
Other inflammatory mediators
Structurally similar to mast cells
ALLERGIC AND HYPERSENSITIVTY
Agranulocytes
No cytoplasmic granules
Types:
Lymphocytes
Monocytes
