Blood

1. Blood Honors Anatomy & Physiology

2. Do Now: WHAT DO THE RED AND WHITE STRIPES OF A BARBERSHOP POLE REPRESENT? • Barbers and surgeons were the early bloodletters, and the pole advertised their trade. The barbershop pole is striped red and white. Red represents blood, white represents the tourniquet, and the pole itself represents the stick that the patient squeezed to dilate the veins for easy puncturing. Fortunately, today’s barbers cut hair and not your jugulars.

3. Components

4. Erythrocytes (RBC) • Small biconcave discs (7.5 µm) • Anucleatew/no organelles • Advantage of no mitochondria? • 97% Hemoglobin (Hb) – binds reversibly w/O2 • 4 polypeptide chains • w/4 Fe Heme pigments (binds 4 O2) • Ea/cell 250 million Hb (over 1 billion O2 molecules) • Oxyhemoglobin (oxidation) vs. deoxyhemoglobin (reduction) • Amino acids binds to 20% of CO2 produced making carbaminohemoglobin

5. Blood Plasma • Straw colored sticky fluid • 90% Water • Homeostasis maintains composition • Dissolved solutes • Glucose, fatty acids, amino acids • Ions , hormones, gasses • Plasma proteins • Albumin – maintains osmotic pressure w/ions

6. Hematopoiesis: Blood Cell Formation • 100 billion new blood cells ea/day!!! • Maintains RBC count • Formed in red bone marrow & migrate to blood stream • Hemocytoblast stem cell differentiates into a proerythroblast, as hemoglobin accumulates, organelles degenerate, causing indentation ( SA) forming reticulocyte (15 days) • Released into blood stream, mature in 2 days • Regulated by hormone erthropoiten (EPO) secreted by kidneys triggered by blood O2 levels

7. Destruction of Erythrocytes • Cannot grow, divide or synthesize new proteins. Why? • Hb degenerates • 100-120 day lifespan • Spleen traps dying rbc where engulfed by macrophages • Fe salvaged and stored • Heme degraded into bilirubin (yellow pigment) travels to liver where used to make bile, released in feces

8. Fetal Hb vs. Adult Hb • By day 28 of fetal development – embryonic blood cells circulate in blood vessels • Fetal Hb (HbF) differs from adult HbA • HbF has a greater ability to pick up O2 b/c fetal blood less O2 rich than mothers • If fetal rbc destroyed so quick that liver cannot rid of bile fast enough  causes infant jaundice

9. Leukocytes (WBC) • Diapedesis – able to leave by ameoboid motion to area of infection • WBC count double w/in a few hours if infected • 2 types: • Granulocytes • Contain cytoplasmic granules • Large cells w/lobed nuclei • Shorter life than RBC • Phagocytic • Agranulocytes • Lack granules • Spherical or kidney shaped nuclei

10. In order of abundance:Never Let Monkeys Eat Bananas Granulocytes Agranulocytes • Neutrophils (50-70%) • Phagocytes kill bacteria and some fungi • Hydrolytic enzyme granules • Inflammation sites • Basophils (0.5-1%) • Histamine (vasodialator) granules • U or S shaped nucleus • Eosinophils (2-4%) • Bilobed nucleus • Digestive enzyme granules • Attack parasitic worms to large for phagocytosis • Lymphocytes (25%) • Nucleus is most of cell • Mostly in lymph tissue • T cells & B cells • Monocytes (3-8%) • Largest leukocytes • Differentiate into mobile macrophages

11. Platelets • Derived from hemocytoplast stem cell in bone marrow • Cytoplasmic fragments last 10 days if not in clot • Form temporary plug ‘clot’ in ruptured bv • Once upon a time platelets: • http://www.youtube.com/watch?feature=fvwp&NR=1&v=vEmsaXA-go0 • http://www.youtube.com/watch?v=9QVTHDM90io&feature=related

12. Hemostasis: Stoppage of bleeding • Vascular Spasms (20-30 mins) • Constriction of damaged bv to restrict blood loss • Platelet Plug formation (1 minute) • Platelets swell, form spiked processes, and become sticky adhering to collagen fibers at site of damage • Platelets release seratonin (enhance spasms), ADP (attract more platelets) . Type of feedback? • Coagulation (blood clotting) • Fibrinogen (soluble) triggered to insoluble fibrin fomring a mesh to trap blood cells sealing damaged site until repaired

13. WHY WAS HEMOPHILIA CALLED THE “ROYAL DISEASE”? • Hemophilia is a bleeding disorder caused by the deficiency of a clotting factor called factor VII, or the hemophilia factor. Hemophilia was common in the royal families of Europe; hence it was called the “royal disease.” Why was hemophilia so prevalent in the royal families? Hemophilia is genetically transmitted. Because of the tendency of the royals to intermarry (e.g. cousin marrying cousin), the gene carrying hemophilia was kept in the family and expressed frequently in the royal offspring. Queen Victoria of England carried the gene for hemophilia. Victoria, being both prolific and politically astute, placed a descendent on every throne in Europe. As each descendent married and intermarried, the incidence of hemophilia increased.

14. Blood types & Transfusions

15. A TOE WAS ACCIDENTALLY SEVERED FROM ITS OWNER. IN REATTACHING THE TOE, THE SURGEON APPLIED LEACHES TO THE GRAFT SITE. • The surgeon recognized that the toe graft would be successful only if the blood supply to the toe was good. Frequently after surgery of this type, blood clots develop at the graft site, resulting in a decrease in blood flow. Leeches, or bloodsuckers, may be applied to the site of the graft. As the leech attaches to the skin to feed, it injects a potent anticoagulant. The leech and anticoagulant prevents blood clots at the graft site, thereby maintaining a good blood flow and improving the chances for successful grafting.