Hematology Flashcards
Plasma is __% water and __% solutes
90% and 10%
Composition of blood
Plasma, water, plasma proteins, electrolytes, gases, nutrients, waste, hormones
Main plasma proteins
1) Albumin (large, carrier molecules responsible for oncotic pressure)
2) Globulins
3) Clotting factors (fibrinogen)
Types of globulins
1) Alpha and Beta globulins (transport lipids and lipid soluble vitamins)
2) Gamma globulins (made by lymphocytes in the lymph node and are part of the immune response. Most significant of the gamma globulins are the immunoglobulins)
RBC description
Non-nucleated cytoplasmic disl of hemoglobin. It’s biconcavity allows for gas diffusion and reversible deformity so that it can squeeze through capillaries. RBCs have the longest average life-span of the blood cells at 120 days.
Examples of granular phagocytes
BENM
Basophils, eosinophils, neutrophils, mast cells
Examples of agranular phagocytes
Monocytes and macrophages
What is the diference between a leukocyte and a lymphocyte?
Leukocyte is a general term for a WBC
Lymphocyte refers to B, T, plasma cells, and NK cells
Are NK cells granulocytes?
Yes
What are granulocytes?
WBCs with membrane-bound granules that may contain digestive enzymes or biochemical mediators. These cells kill microorganisms, catabolize debris and have inflammatory / immune functions. They also exhibit diapedesis to pass through vessel walls.
Neutrophils
PMN- polymorphonuclear neutrophil First responder to injury! Acts as a phagocyte of cellular debris in early inflammation 55% of WBCs Reaches maturity in the bone marrow Lifespan of about 4 days
Eosinophils
Ingest antigen-antibody complexes
Involved in the recovery phase of the inflammatory process
1-4% of WBCs
Basophils
Least common of the WBCs (<1%)
Contain vasoactive amines (histamine and seratonin)
Contain anticoagulant (heparin)
Mast cells
Found in vascularized connective tissue
Involved in acute and chronic inflammation, fibrotic disorders, and wound healing
Releases histamine, chemotactic factors, and cytokines
Causes rapid BV permeability
Lymphocytes
B, T, plasma cells, and NK cells Mononuclear 25-33% of WBCs Do NOT contain digestive vacuoles NK cells, however, are granular
Monocytes and Macrophages
Agranulocytes
Are larger and have fewer digestive vacuoles than granulocytes
What cells make up the Mononuclear Phagocyte System (MPS)
Referring to MONOcytes (MONOcytes and MONOnuclear!)
From the bone marrow > monoblasts > promonocytes > monocytes (circulating)> macrophage (once in tissue)
What are the functions of the MPS?
1) Ingest and destroy microorganisms and foreign material, debris, and defective/dead cells
2) Cleanse the blood in the liver and spleen
Have a life-span of months to years!
Description of platelets
They are not cells in the classical sense (they are disk-shaped fragments of megakaryocytes) Contain secretory vesicles Responsible for blood coagulation Reserves are located in the spleen Lifespan around 10 days
Lymphoid system
Site for residence, proliferation, differentiation, or function of lymphocytes / MPS
Primary lymphoid organs
Thymus and BM
Secondary lymphoid organs
Spleen, tonsils, adenoids, Peyer’s patches, and lymph nodes
This is the largest secondary lymphoid organ
Spleen
Red splenic pulp
This is the main site of filtration. Results in filtration and phagocytosis of old, damaged, and dead blood cells (mostly RBCs). Also filters antigen, microorganisms, and other debris. Site of Hb catabolism (makes sense because it’s red!)
White splenic pulp
Masses of lymphoid tissue containing macrophages and lymphocytes. Here, the mononuclear phagocytes cleanse and filter the blood, while the lymphocytes initiate the immune response and convert lymphoid follicles into germinal centers.
What is the spleen?
Masses of lymphoid tissue with red and white pulp. Has venous sinuses for blood storage (it acts as a reservoir for blood)
Lymph nodes
Provide filtration to the lymph during it’s journey through the lymphatics, towards the SVC. Lymph nodes are the primary site for the first encounter between antigen and lymphocytes. In the germinal centers, B cells respond to antigenic stimulation by undergoing proliferation and further differentiation, including class-switch, into memory cells and plasma cells. Results in antibody formation.
What is hematopoiesis?
The production of blood cells. Includes proliferation and differentiation.
Where does hematopoiesis occur?
Embryo: liver and spleen
Adults: bone marrow
Diseased states: extramedullary sites (outside the BM)
Marrow biopsy can tell you
How much hematopoiesis is occurring depending on the ratio of red:yellow marrow
What causes a higher rate of hematopoiesis, chronic disease or acute hemorrhage?
Chronic disease
What is the origin of all peripheral blood cells?
Pluripotent hematopoietic stem cells. Found primarily in BM. These cells are uncommitted and multiple possibly indefinitely.
Leukocytosis
WBC count above normal
Causes of cytosis and penia
Problems with bone marrow (over or underproduction) or premature destruction of cells
Is leukocytosis normal?
It is the normal protective physiologic response to physiologic stressors
What is infectious mononucleosis?
1) Acute, self-limiting infection of B cells.
2) Often caused by the Epstein-Barr virus.
- Cells have an EBV receptor site
3) Transmitted via saliva and personal contact
4) Symptoms: fever, sore throat, swollen cervical lymph nodes, increased lymphocyte count, atypical (activated lymphocytes). At least 10% atypical lymphocytes
Difference between leukemia and lymphoma
Leukemia: bloodstream
Lymphoma: lymph
What is anaplasia?
Lack of differentiation (reversal from further committed to less committed cells). Variable in size and shape, multiple atypical mitoses, lack of structure.
Difference between benign and malignant
Benign: Well differentiated cells. Features of parent cells are preserved (like hormone release). Tumor is usually well demarcated. No local invasion of distant metastases.
Malignant: Anaplasia (lack of differentiation). Invasive and metastatic.
Sites in the body where cell proliferation is normal
BM (myeloblasts), immune cells, epidermal cells, epithelial cells, and regenerating tissues
6 features of cancer cells
1) Self-sufficiency of growth hormones
2) Insensitivity to growth inhibition signals (loss of contact inhibition)
3) Sustained angiogenesis
4) Limitless replicative potential
5) Ability to invade and metastasize
6) Evasion of host immune response
Tumors are kind of like ______. They are complex tissues containing ______.
Unorganized organs.
Contain tumor cells, fibroblasts, immune cells (in there trying to get rid of it), blood vessels, and lymphatic vessels.
What causes cancer?
Direct damage to the DNA. Damage may be caused by diet, hormones, genotoxic carcinogens (cause DNA mutations and replication errors), non-genotoxic carcinogens (change the expression of genes involved in DNA repair, methylation, cell signaling, and proliferation), UV, and x-rays. The extent that these will cause damage often relies on the person’s heredity.
Genotoxic carcinogens
cause DNA mutations and replication errors
Non-genotoxic carcinogens
change the expression of genes involved in DNA repair, DNA methylation, cell signaling, and proliferation
Genomic instability and cancer
Related to dysfunction of p53. There is now no longer regulation of DNA replication. There are no more cell cycle checkpoints or DNA repair and the mutated cell avoids apoptosis.
Non-specific signs of cancer
Fatigue, fever, unexplained weight loss, pain, skin changes.
Difference between BM biopsy vs. BM aspiration
Biopsy removes bone and marrow.
Aspiration removes only marrow.
What is immunocytochemistry?
Detects tumor cells by using antibodies against tumor-specific antigens
Long-term effects of chemo
Infertility, secondary cancers, osteoporosis, and growth abnormalities
Cell deviations vary greatly
Between different types of cancers, between patients with the same type of cancer, and between subclones of cells within the same tumor
The genetic instability of cancer cells allows them to adapt to the new conditions, and may acquire drug resistance or develop into a more malignant phenotype. If one cell becomes resistant, the other cells die, but this one proliferates (and at a rapid rate cause that’s what cancer does!)
When is chemo strictly contraindicated?
Pregnancy. Remember that chemo targets rapidly dividing cells!