LEC 1 Peripheral Blood & Cytomorphology Flashcards
Dr. Jesus Delgado-Calle To define the formed elements of blood. Learn the characteristic morphologic features of erythrocytes, neutrophils, lymphocytes, plasma cells, monocytes, eosinophil, basophils, macrophages, platelets and their precursors. Be able to provide a brief introduction of cellular function for each blood cell.
Where are blood cells formed in the embryo?
Yolk sac
Slide 3
As development progresses, where in the body does blood formation occur?
Spleen, Liver, & Lymph Nodes
Slide 3
Once developed, what assumes the task of forming the blood cells for the entire organism?
Bone Marrow
Slide 3
Once developed, what assumes the task of forming the blood cells for the entire organism?
Bone Marrow
Slide 3
Where does hematopoesis occur in children?
What bones?
marrow of the long bones such as femur and tibia
Slide 3
Where does hematopoeisis occur in adults?
What bones?
Pelvis, Cranium, Vertebrae, and Sternum
Slide 3
Where does maturation, activation, and growth of lymphoid cells occur?
Spleen, Thymus, and Lymph Nodes
Slide 3
What is the common precursor cell for all blood cells?
Multipotent Hematopoeitic Stem Cell
Slide 3
What percentage of the blood is plasma?
55%
Slide 5
What percentage of the blood is made up of erythrocytes?
45%
Slide 5
What is the buffy coat and where is it located?
Leukocytes; Located between the plasma and erythrocytes of a centrifuged specimen
Slide 5
In a hematological analyzer, the small aperture serves what role?
determines platelet number and size
Slide 6
In a hematological analyzer, the large aperture serves what role?
determines RBC number and size
Slide 6
Explain the concept of electrical impedance as it relates to hematological analyzers.
- Whole blood is passed between two electrodes through an aperture so narrow that only one cell can pass through at a time
- The impedance changes as a cell passes through
- The change in impedance is proportional to cell volume, resulting in a cell count and measure of volume.
Slide 6
How does flow cytometry function as it relates to a hematological analyzer?
- A single-cell stream passes through a laser beam
- The absorbance is measured, and the scattered light is measured at multiple angles to determine the cell’s granularity, diameter, and inner complexity
Slide 6
What information does flow cytometry tell us about the blood cells?
Morphology
Slide 6
What suffix means decreased?
-enia
Slide 8
What suffix means increased?
-cytosis
Slide 8
What is the purpose of fluorescence light in flow cytometry?
Enables the detection of surface proteins using specific antibodies
Slide 10
In flow cytometry, where is the forward scatter located and what does it measure?
- Located in line with the laser intercept
- Considered a measure of the relative cell size
Slide 10
In flow cytometry, where is the side scatter located and what does it measure?
- Located perpendicular to the laser beam intercept
- used to measure the relative complexity of the cell (granularity)
Slide 10
What 2 dyes are used in H&E staining?
Haemotoxylin & Eosin
Slide 15
How does eosin work?
- acidic dye
- stains basic structures red or pink
Slide 15
How does Hematoxylin work?
- basic dye
- stains the nucleus (nucleic acids) and other parts of the cytoplasm that have RNA purple
- the rest of the cytoplasm stains pink
Slide 15
What is another name for a platelet?
Thrombocyte
Slide 17
What is the precursor cell of thrombocytes?
Megakaryocyte
Slide 17
What is the function of platelets?
- Help control blood loss from broken vessels
- Begin clotting process to prevent bleeding
Slide 17
How and where does thrombopoeisis occur?
- In the bone marrow
- Megakaryocyte’s membrane projections break up into smaller fragments
Slide 17
What is the average lifespan of platelets?
7-10 days
Slide 17
What are the components of a thrombocyte?
- Open canalicular system: internal membrane structure connected to cell surface
- Granules: dense, alpha, and lysosomal. Contain proteins & factors necessary for several steps of the coagulation cascade
- Microtubules: preserve the elliptic shape of resting platelets & play a critical role in cytoskeleton reorganization during platelet activation
Slide 17
Do thrombocytes have a nucleus?
NO
They are also the smallest blood cell
Slide 17
What is the precursor of an erythrocyte?
Proerythroblast
Slide 19
What is the fuction of erythrocytes?
transport oxygen and carbon dioxide between the lungs and tissues
Slide 19
How does formation of erythrocytes occur?
Formation starts in the bone marrow and ends in the blood stream when reticulocytes complete their maturation.
Slide 19