Hematopoiesis in a foetus outside of the bone marrow
Hematopoiesis after birth inside of the bone marrow
Small fragments of large cells called Megakaryocytes
Splits into platelets
Forms platelets from Pluripotent stem cells
Too few platelets, leading to bleeding problems and blood loss
Too many platelets, leading to excessive clotting and thrombi/emboli
Hematopoietic system components
Blood (cells and plasma)
Production of RBCs by differentiation of stem cells via the stimulation of bone marrow by Erythropoietin
a hormone formed mainly in the kidneys, but somewhat in the liver.
Destruction of RBCs. Average lifespan is 120 days.
Hematocrit / RBC count / Hemoglobin concentration
Hematocrit: Packed cell volume of RBCs in blood (i.e. the % of RBCs in blood). Usually ≈ 40% - 52%
RBC count: Number of RBCs per cubic mm of blood. Usually ≈ 4.2 - 6.0 million/mm³
Hemoglobin concentration: grams of Hb per decilitre of whole blood | Usually ≈ 12-15 g/dL in ♂ | Usually ≈ 10.5-14 g/dL in♀
White Blood Cells:
Healthy pt will have ≈ 5,000 - 9,000 WBC per microlitre (µL)
Infections can raise this number to >16,000
Large % of total WBCs which attach to blood vessel walls waiting for action.
Marginated leukocytes detach from blood vessle walls
WBCs travel through the lining of a blood vessel
WBCs follow chemical signals to an infection site
WBCs engulf and destroy invaders
Production of WBCs by differentiation of stem cells
Absorb basic stains and have blue granules
Primarily involved in allergic reactions.
Their granules contain Histamines and Heparin
Released in allergic reactions
Break down blood clots
formed from Lymphoblasts
Primary cells involved in immune response
No granules or staining
Highly specialized with surface receptors specific to a single antigen
Have two forms: T- and B-cells
Called that because they mature in the Thymus gland within the mediastinum
Part of the Cell mediated immunity response
Are able to induce apoptosis in body cells displaying foreign antigen on their surface,
Once an antigen activates them, they stimulate the production of other cells called Effector cells (aka plasmocytes) (aka B Cells)
Originate in Bone marrow and migrate to peripheral lymphatic tissue.
Some B cells are maintained in the body after an attack, giving the body a `memory` of the previous infection
Once exposed to an antigen, they produce large volumes of the specific antibodies necessary to defend against the invader, an effect called Humoral immunity
Because protective function of immunization is found in the humor (cell-free bodily fluid/serum)
Absorb acidic stains and have red granules
They can inactivate the chemical mediators of acute allergic reactions, thus modulating the anaphylactic response.
Their granules contain:Major Base Protein (MBP) - A protein released in conjunction to an antibody used against parasitic infections
Major Base Protein (MBP)
A protein released in conjunction to an antibody used against parasitic infections
Contain granules & have 3 forms: Basophils, Eosinophils, and Neutrophils
Dormant form of WBC that can mature when needed into: Macrophages
'Garbage collectors' which engulf foreign invaders, dead neutrophils, and remove damaged or abnormal RBCs
Involved in tissue repair
Secrete growth factors that stimulated production of Granulocytes and RBCs
Some are bound to tissues and form part of the; Reticuloendothelial system
Macrophages, after engulfing foreign bodies or infectious agents, stimulate Lymphocyte production in an immune response
Type of Granulocyte
Absorb neither acidic or base stains, and contain pale blue and pink granules
Primarily used to fight infection by phagocytosis
If the neutrophil count is low then you have Neutropenia
neutrophil count is low
Where the infection may overwhelm and kill the pt.
can be => of bone marrow disorders
the process of programmed cell death
aka an immunoglobulin, is a large Y-shaped protein used by the immune system to identify and neutralize foreign objects such as bacteria and viruses.
The antibody recognizes a unique part of the foreign target, termed an antigen
Each tip of the "Y" of an antibody contains a 'lock' that is specific for one particular antigen 'key'
Using this binding mechanism, an antibody can tag a microbe or an infected cell for attack by other parts of the immune system, or can neutralize its target directly (e.g. by blocking a part of a microbe that is essential for its invasion and survival).
Cell mediated immunity
aka cellular immunity because protective function of immunization is associated with cells
is an immune response that does not involve antibodies, but rather involves the activation of various cells including Macrophages and antigen-specific T cells