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Histology - Blood
Med’11 Histology Blood
Question | Answer |
---|---|
What is blood? | It is a specialized unique type of connective tissue composed of blood cells and plasma (extracellular matrix) |
What are the functions of blood? | Provide tissues & cells w/nutrients & O2 Carry waste products such as CO2 Transport hormones Carry drugs, elements & cells that protects the body from infections & foreign bodies. Homeostatic role based on thermoregulatory & buffering |
What are the types of blood cells? | RBCs WBCs Platelets |
Describe the shape of RBCs. | The normal shape is rounded non nucleated biconcave discs. Its size is between 7 and 8 micrometers |
What is the name of abnormally shaped RBCs? | Poikilocytosis |
What is anisocytosis? | Anisocytosis is a medical term meaning that a patient's red blood cells are of unequal size. |
What is the normal number of RBCs? | In males: 5 − 5.5 million/millimeters cubed In females: 4.5 − 5 million/millimeters cubed |
What is an increase in RBCs called? a decrease? | Increase in number of RBCs is called polycythemia Decrease in number of RBCs is called anemia |
What is the function of RBCs? | Gas exchange |
What is the Rouleaux formation? | It is the sticking together of RBCs side by side like a pile of coins |
How is the shape of RBCs suitable to its functions? | *Biconcave surf of RBC inc surf area for gas exchange *Cell membr is v. selective&v. elastic held Hb in RBC in colloidal form & allows cell to change shape&squeeze in small capillaries *Absence of nucleus & organoids allow more space for more Hb in cel |
Based on presence of specific granules, WBCs are divided into _____ and _____. | Granulocytes and Agranulocytes |
What is the total leukocytic count? | The total number of leukocytes/cubic mm |
What is the average total leukocytic count? | 4,000-11,000/mm3 |
What is the distinctive structure of a neutrophil? | 3-4 lobed nucleus connected by thin threads of chromatin. In females, the neutrophils are characterized by the presence of the Barr body. It is one of the two X chromosomes in an inactive state. |
What is the size of a neutrophil and the average % found in blood? | Size: 9-12 micrometers Avg %: 60-70% |
Describe the types of granules present in neutrophils. | Specific:contain lysozyme (bactericidal) e.g. collagenase, lactoferrin&alkaline phosphatase enz Nonspecific(azurophilic):are primary lysosomes containing hydrolytic enz (hydrolase, myeloperoxidase) Tertiary:contain gelatinase, cathepsin&glycoprotein. |
What are the functions of neutrophils? | *Phagocytosis of bacteria&foreign bodies *Synth of leukotriens that promotes migration of more neutro. to site of infection Chemoattractant for eosino.&monocytes for site of infection Neutro. release chem mediators tht stim. bone marrow to prod neutro |
What is the size of a basophil and the average % found in blood? | Size: 12-15 micrometers |
What is the distinctive structure of a basophil? | S shaped nucleus (bilobed) Small Golgi, few mitochondria and many rER. |
Describe the types of granules present in basophils | Specific granules: stain metachromatically reddish violet with basic dyes SRS of anaphylaxis, glycosaminoglycans, histamine and heparin. Azurophilic granules: small granules containing hydrolytic enzymes |
What is basophilia? | Condition where the basophil quantity is abnormally elevated |
What is the function of basophils? | Mediate inflammatory response. They bind to immunoglobulin E (IgE) in allergic reaction and leads to release of its vasoactive substance. Play a role in hypersensitivity (anaphylactic shock) (i.e. vasodilatation and smooth muscle contraction) |
What is the percentage of B-Lymphocytes in the blood? | 25% of lymphocytes |
Where do B-Lymphocytes develop and mature? What is their life span? | Develop: bone marrow Mature: bone marrow Life span: 3 months |
What is the function of B-Lymphocytes? | Humeral immunity |
What does the B-Lymphocyte have in its plasma membrane? | Fe receptors & antibodies |
What is the percentage of T-Lymphocytes in the blood? | 75% of lymphocytes |
What does the T-Lymphocyte have in its plasma membrane? | T-cell receptors |
Where do T-Lymphocytes develop and mature? What is their life span? | Develop: bone marrow Mature: cortex and medulla of the thymus Life span: years |
What is the function of T-Lymphocytes? | Cell mediated immunity |
What is the percentage of monocytes in the blood? | 3-8% leukocytes |
What is the function of a monocyte? | They are highly phagocytic cells. They are transformed to macrophages at the site of inflammmation. They concentrate the antigens and present them to the lymphocytes. |
What is the distinctive structure of a monocyte? | 9-15 micrometers Nucleus is large eccentric, indented and kidney shaped Cytoplasm is bluish-grey and has small number of azurophilic granules, with occasional vacuole like space EM: show glycogen granules |
What is monocytosis? | Increase in number of monocytes (more than 1%) They increases in infectious mononucleosis and chronic inflammaton. |
What is the origin of platelets? What is their size? | They are derived from megakaryocyte Size: 2-4 mm. |
What is the average number of platelets found in blood? What is the life span of platelets? | Number: 250-400 thousands/mm3 Life span is less than 14 days |
How do platelets appear under the light microscope? electron microscope? | LM: Appear as rounded or oval cell fragments derived from singly/in clumps EM: a. Peripheral clear region called hyalomere b. Denser granular center called the granulomere It show few mitochondria and mictotubules with actin and myosin. |