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Blood. Anatomy Ch. 12. Average adult has 5L of blood Cells form mostly in bone marrow Fig 12.1 http://videos.howstuffworks.com/hsw/5953-blood-a-comparison-of-blood-cells-video.htm. Blood composition. A sample is 45% cells: Mostly red blood cells Some white bc and platelets
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Blood Anatomy Ch. 12
Average adult has 5L of blood • Cells form mostly in bone marrow • Fig 12.1 • http://videos.howstuffworks.com/hsw/5953-blood-a-comparison-of-blood-cells-video.htm
Blood composition • A sample is 45% cells: • Mostly red blood cells • Some white bc and platelets • 55% is plasma, a clearish liquid • Complex mixture of water, amino acids, proteins, carbs, electrolytes and wastes
Erythrocytes • The shape (biconcave disks) increases surface area where gases can diffuse • Each rbc is 1/3 hemoglobin (by volume) • Do not have nuclei, so they can’t divide or make proteins; gives them more space for hemoglobin.
Blood color • Color comes from hemoglobin (iron) • When it combines with O2, it turns bright red, and when it releases it, turns darker.
# of rbc determines oxygen-carrying capacity • Athletes have higher levels • Men- ~5.5 million per mm3 • Women- ~5 million per mm3
RBCs • Avg lifespan is 4 months • In high altitudes, more rbcs are formed • Fig. 12.3 • Vitamin B12 and folic acid influence rbc production
Anemia • Too little hemoglobin or rbc’s • Appear pale • and lack • energy
Leukocytes • Protects against disease and infections • white blood cells - Google Video
5 types of wbc (Table 12.1) • 1. Neutrophils: eats small particles • 2. Eosinophils: kills parasites, controls inflammation • 3. Basophils: releases heparin and histamine
Wbc’s cont. • 4. Monocyte: eats larger particles • 5. Lymphocyte: provides immunity
WBC counts • Usu. 5000-10,000 per cubic mL • Changes in response to infection/sickness
Functions of WBC • Make antibodies that destroy or disable foreign particles • Can leave blood stream to fight infections
Leukemia • Too many WBCs and too few RBCs • Cancer of the blood • Different types of leukemia • With treatment, 50-80% of patients enter remission
Platelets • Thrombocytes • Fragments of large blood cells in red bone marrow • Lack nuclei
Platelets • They help close breaks in vessels • Help form scabs and initiate clots
Blood Plasma • About 92% water, straw colored liquid • Has 3 main proteins: albumin, globulin, and fibrinogin • Table 12.2
Hemostasis-stopping bleeding • Platelets adhere to any rough surface, collagen, and each other • This forms a plug to stop small breaks • Larger breaks may require a clot (Fig. 12.12)
Coagulation • Causes a blood to clot • Anticoagulants-keep it from clotting • Most clots disappear with time (will dissolve in moving blood)
Surface molecules-antigens • Proteins-antibodies • Everyone has either A, B, AB, or O blood
ABO blood group • Based on 2 major antigens: A and B, on rbc membranes • Type A person has only A antigen • AB person has both antigens • O person has neither antigen
Table 12.4 • Blood type Antigen Antibody • A A Anti-B • B B Anti-B • AB A and B Neither anti-A nor anti-B • O Neither Both
Therefore: • An antibody of one type will react with an antigen of the same type, and clump, which is bad • This is why someone w/ type A blood can’t receive type B or AB blood
Giving blood (Table 12.5) • Since type AB lacks both antibodies, they can receive any blood type • AB people are universal recipients • Type O lacks antigens A and B, so it can be transferred to anyone. • Type O people are universal donors
Rh factor • Rh antigens named after rhesus monkey (1st studied in them) • It is an antigen • + if it has it • - if not
Hemophilia • Blood doesn’t clot normally (missing a protein) • Is genetic, and usually only occurs in males