Blood and Myeloid Tissue Flashcards
A specialized type of connective tissue and, like all connective tissues it has relatively few cells and a relatively large amount of intercellular material
Blood
Blood is 38-45%
Cells
This cell number is called the
Hematocrit
RBC + WBC + platelets =
Formed elements
Plasma has proteins that form fibers (in the form of inactive fibrinogen) which will be activated in the formation of a
Blood clot
They function inside the cardiovascular system to carry oxygen to and carbon dioxide away from the cells of the body
Erythrocytes (RBCs)
Derangements in hemoglobin chemistry can also lead to abnormally shaped erythrocytes. An example of this is seen in
Sickle cells
Perform much of their work outside the circulatory system
Leukocytes (WBCs)
In response to chemical signals WBCs migrate through the walls of blood vessels by a process known as
Diapedesis (extravasation)
Leukocytes are classified as
Granulocytes or agranulocytes
Contain 2 types of lysosomes known as primary granules and secondary or specific granules
Granulocytes
Contain only small primary granules
Agranulocytes
A second way to classify leukocytes often used by hematologists is whether they are
Phagocytes or immunocytes
What are the three grnaulocytes?
Neutrophils, eosinophils, and basophils
The granulocytes (neutrophils, eosinophils, basophils) and monocytes are
Phagocytes
The other agranulocytes (lymphocytes) are
Immunocytes
The “first responders” of inflammation.
-The most common WBC in the circulation
Neutrophils (AKA PMNs)
Nucleus is very dense with 3-5 lobes, may show a Barr body (“drumstick”) in females
Neutrophils
Contain two types of granules in their cytoplasm, azureophilic (primary) and specific (secondary), both contain lysosomal enzymes
Neutrophils
Function in phagocytosis and killing of bacteria
Neutrophils
Neutrophils are short-lived cells. They live for only a few
Hours to days
Have a nucleus with 2-3 lobes
-Large, red-orange (specific) granules fill the cytoplasm
Eosinophils
The granules of Eosinophils contain
Peroxidases
Are increased in parasitic infections, asthma, allergic rhinitis, transplant rejection
Eosinophils
The least common of the granulocytes
Basophils
Function in allergic and hypersensitive reactions
-similar to mast cells
Basophils
Agranulocyte, primary granules (lysosomes) in the cytoplasm. The largest of the WBC
Monocytes
Leave the circulation to become macrophages in connective tissue throughout the body
Monocytes
As macrophages they function in phagocytosis of bacteria, cellular and foreign debris. The second wave in the inflammatory response
Monocytes
Monocytes present antigen to
Lymphocytes
Agranulocyte. Small lymphocytes are just a bit larger than an RBC
Lymphocytes
Broadly classified as B,T or NK cells but staining with specific marker is necessary to identify each type
Lymphocytes
With appropriate stimulation B lymphocytes become
Plasma cells
Red cells are larger than a small lymphocyte in
Macrocytic anemia (folate/B12 deficiency)
Small fragments derived from a megakaryocyte, a very large bone marrow cell
Thrombocytes (platelets)
Contain dense vesicles, glycogen, mitochondria, RER, Glogi, lysosomes and invaginations of its membrane, the open canilicular system
Thrombocytes (platelets)
Thrombocytes function in
Thrombogenesis
Stimulates mitosis of vascular smooth muscle for repair
Platelet Derived Growth Factor (PDGF)
Injury → platelets adhere to the exposed subendothelial
CT
Then platelets aggregate, thrombin acts on fibrinogen → fibrin monomers added to form a
Hemostatic Plug
The intercellular material of blood
-Makes up ~55-60% of blood volume
Plasma
Contains salts (Na+, K+), ions (Cl-, HCO3-) clotting factors, lipids, albumin and other proteins such as antibodies, growth factors, hormones, etc
Plasma
If plasma is allowed to form a clot, the remaining liquid is
-Fibrinogen-free plasma
Serum
All blood cells are produced by hemopoiesis in
Myeloid Tissue
What is the location of myeloid tissue for the following?
- ) Fetus 0-2 months
- ) 2-7 months
- ) 5-9 months
- Infants
- ) Adults
- ) Yolk sac
- ) Liver and spleen
- ) Bone marrow
- ) Bone marrow
- ) Bone marrow
Defined as hematopoiesis occurring in organs outside of the bone marrow
Extramedullary hematopoiesis (EH)
Occurs in diverse conditions, including fetal development, normal immune responses, and pathological circumstances
Extramedullary hematopoiesis (EH)
The two niches for hematopoiesis in bone marrow are
Osteoblastic and vascular
The production of RBC is under the control of the hormone
Erythropoietin (EPO)
Erythropoietin is primarily produced by fibroblasts in the cortex of the kidney in response to
Low oxygen tension
Slightly immature RBC that still contain some free ribosomes
-normally 1-2% of circulating RBC
Reticulocytes
The production of leukocytes (white blood cells), the various types of granulocytes and monocytes
Leukopoiesis
Leukopoiesis is controlled by a
-specific for each cell line
Colony Stimulating Factor (CSF)
Each line of development is known as a
Colony Forming Unit (CFU)
A system of antigen presenting cells, derived from monocytes, that function to initiate several different types of immune response
Dendritic Cells
Engulf antigens, digest them into smaller fragments, migrate to lymph nodes and present antigen fragments to T-lymphocytes
Dendritic Cells
The production of thrombocytes (blood platelets) from cytoplasmic fragments of megakaryocytes, a very large, polyploid cells of bone marrow
Thrombopoiesis
Thrombopoiesis is controlled by
Thrombopoietin
