7) Blood Histology Flashcards
What is blood classified as, and why?
Blood is classified as a connective tissue because it has a matrix, specifically plasma, and it contains cells such as red blood cells (erythrocytes) and white blood cells (leukocytes).
What are the functions of blood?
Transports nutrients, gases, and waste
Regulates pH, temperature, and water content of cells
Provides immune function (antibodies, phagocytic WBCs)
Coagulation (blood clotting)
Hematopoiesis (blood cell formation)
What makes up blood plasma?
Blood plasma consists of 90% water, 7% plasma proteins (albumin, fibrinogen, globulins), 0.9% inorganic salts, and other organic molecules like vitamins, amino acids, lipids, and hormones.
What is the difference between plasma and serum?
Plasma is the liquid part of blood that contains clotting factors, while serum is plasma without fibrinogen (clotting factor), which is removed during clotting.
What are the main components of blood?
The main components of blood are red blood cells (erythrocytes), white blood cells (leukocytes), and platelets.
What are the main functions of erythrocytes (RBCs)?
RBCs transport oxygen, help in CO2 transport, regulate pH, and deliver nutrients throughout the body.
Describe the morphology and function of RBCs.
RBCs are biconcave disks, anucleate, and contain hemoglobin. They transport oxygen when oxygenated (bright red) and CO2 when deoxygenated (blue/purple).
What clinical significance do RBCs have?
Abnormal RBC morphology can indicate diseases like anemia, sickle cell disease, and conditions like hemolysis or hypoxia.
What are the main types of white blood cells (WBCs)?
WBCs are classified as granular (neutrophils, eosinophils, basophils) and non-granular (lymphocytes, monocytes).
What are neutrophils and their function?
APPEARANCE: Most common, multi-lobed nucleus, purple-staining cytoplasm.
Neutrophils are the most abundant WBCs (60-70% of total WBCs) and are involved in phagocytosis of microorganisms, especially bacteria.
What are lymphocytes and their function?
APPEARANCE: Round nucleus, thin cytoplasm, large relative size.
Lymphocytes make up 20-50% of WBCs and are crucial for immune responses, with T-cells involved in cell-mediated immunity and B-cells in antibody production.
What is the role of monocytes?
APPEARANCE: Largest, kidney-shaped nucleus.
Monocytes are the largest WBCs, accounting for 3-8% of the total. They become macrophages in tissues and are involved in phagocytosis of microorganisms and debris.
What is the role of eosinophils?
APPEARANCE: Bi-lobed nucleus, red-staining granules.
Eosinophils (1-3% of WBCs) are involved in allergic reactions and parasitic infections. They contain refractile granules that stain bright pink or orange.
What is the role of basophils?
APPEARANCE: Rare, large blue-black granules in cytoplasm.
Basophils (0.5-1% of WBCs) release vasoactive substances in hypersensitivity reactions and can bind IgE antibodies, though they are not phagocytic.
On a hematology test (Blood smear), what is appropriate for scanning?
a) head
b) body
c) tail
c) tail
Specifically, within the monolayer region near the tail, where cells are evenly distributed and not overlapping, making it easier to evaluate morphology.
The head of the smear should be avoided as the cell density is twice that seen at the tail.
