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27 Cards in this Set
- Front
- Back
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Blood |
The only fluid tissue in the human body Classified as a connective tissue
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Living cells =___________ |
Living cells = formed elements |
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Non living matrix = ______ |
Non living matrix = plasma |
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A blood sample is spun in a __________ to separate its components |
A blood sample is spun in a centrifuge to separate its components |
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Hematocrit |
- the percent of a blood sample that’s composed of red blood cells - also referred to as the Packed Cell Volume - should be ~ 45% |
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Buffy Coat |
A thin, whitish-tan layer on top of the red blood cell fraction - contains white blood cells The liquid portion of a blood sample is called plasma - should be approx 55% |
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Color Range of Red Blood Cells |
Oxygen-rich blood is scarlet (bright) red Oxygen-poor blood is dull (dark) red pH levels must remain 7.35 - 7.45 Body temperature is slightly higher than body temperature |
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Blood Plasma |
- Composed of approximately 90% water Includes many dissolved substances: - nutrients - salts (metal ions) - respiratory gases - hormones - proteins - ex. Clotting, anti-bodies - waste products |
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Formed Blood Elements |
Erythrocytes = red blood cells Leukocytes = white blood cells Thrombocytes (platelets) = cell fragments |
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erythrocytes (red blood cells) |
- The main function is to carry oxygen Anatomy of Circulating Erythrocytes: - Biconcave discs - Essentially bags of hemoglobin - Anucleate (no nucleus) - Contain very few organellles - Outnumber white blood cells 1000:1 |
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Hemoglobin |
- iron - containing protein - Binds strongly, but reversibly, to oxygen - Each hemoglobin molecule has four binding sites - each erythrocyte has 250 million hemoglobin molecules |
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Red Blood Cell Disorders |
anemia - low levels of hemoglobin levels in the blood or low number of red blood cells polycythemia - increased number of red blood cells |
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Lymphocytes |
- Nucleus fills most of cell - Play an important role in the immune repose |
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Monocytes |
Largest of the white blood cells Function as macrophages Important in fighting chronic infection |
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Platelets |
Derived from ruptured multi nuclear cells (megakaryocytes) Needed for the clotting process Normal platelet count = 300,000/mm3 |
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Bleeding Disorders |
Thrombocytopenia - Platelet deficiency - Even normal movements can cause bleeding from small blood vessels that require platelets for clotting Hemophilia - Hereditary bleeding disorder - Normal clotting factors are missing |
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Fate of Erythrocytes |
Unable to divide, grow, synthesize proteins Wear out in 100 to 120 days When worn out, are eliminated by phagocytes in the spleen or liver Lost cells are replaced by division of hemocytoblasts |
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Leukocytes (white blood cells) |
- crucial in the body’s defense against disease - These are complete cells, with a nucleus and organelles - Able to move into and out of blood vessels (diapedesis) - can move by ameboid motion - can respond to chemicals released by damaged tissue (chemotaxis) |
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Leukocyte Levels in the Blood |
- Normal levels are between 4,000 - 11,000 cells per millimeter - Abnormal leukocyte |
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Leukocytosis |
- Above 11,000 leukocytes (m) - Generally indicates an infection |
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Leukopenia |
- Abnormally low leukocyte levels - Commonly caused by certain drugs |
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Types of Leukocytes |
Granulocytes &Agranulocytes |
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Neutrophils |
Multi-lobed nucleus with 5 granules Act as phagocytes at active sites of infection |
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Eosinophils |
- Large brick-red cytoplasmic granules - Found in response to allergies and parasitic worms |
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Basophils |
- Have histamine-containing granules - Initiate inflammation |
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Agranulocytes |
Lack visible cytoplasmic granules
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Control of Erythrocytes Production |
- Rate is controlled by a hormone called erythropoietin - (EPO) - Kidneys produce most erythropoietin as a response to reduced oxygen levels in the blood - Homeostasis is maintained by negative feedback from blood oxygen levels |
