1. Chapter 14 Blood

2. Structure & Function Blood is a type of connective tissue (consists of cells in a matrix) Function – transports O 2 & nutrients, maintains homeostasis, protection from blood loss & infection pH – 7.35-7.45 Volume – 5L (in avg. adult male) Temp. – 100.4 º F. Accounts for 8% of body weight Color varies from scarlet (O 2 rich) to dark red (O 2 poor)

3. Structure Composition – composed of 3 types of cells (called solid portion): 1. RBCs – erythrocytes 2. WBCs – leukocytes 3. platelets - thrombocytes

4. Structure The solid portion makes up 45% of a blood sample Called the hematocrit (HCT) or packed cell volume (PCV) Matrix (liquid portion) – plasma; clear, straw-colored Makes up remaining 55% of sample; mostly H 2 O, nutrients, etc.

5. Hematopoiesis – Production of blood cells (RBCs, WBCs & platelets)

6. Hematopoiesis Video

7. Erythrocytes (RBCs) Structure: 1. biconcave disks three advantages: A. increase SA B. no point within the cytoplasm is far from the surface; ideal for gas exchange C. flexible; can squeeze thru tiny b.v.

8. Erythrocytes Structure: 2. Contain hemoglobin (Hb); allows them to carry resp. gases more efficiently 3. Mature RBCs lack nuclei; allows more room for Hb (each RBC is 1/3 Hb by volume) Normal RBC count: 4-6 million/mm³ of blood (in avg. adult) (slight incr. after meals or exercise; decr. from anemia, leukemia, or hemorrhage)

9. Hemoglobin Hb consists of the protein globin→ Each has 4 polypeptide chains & 4 heme groups (pigment) where O 2 binds Hb combines easily w/O 2 – called affinity ( or attraction) for O 2 Produces oxyhemoglobin; makes blood bright red When O 2 is released from the RBC, deoxyhemoglobin is produced; makes blood dark bluish-red Erythropoietin – hormone that stimulates erythrocyte formation. High altitudes and blood loss stimulate process.

10. Hemoglobin Normal Hb levels – 14-18 gm/100 ml of blood (in avg. adult male) Cyanosis – occurs when O 2 is deficient (hypoxia) & levels of deoxyhemoglobin incr. Symptoms – bluish lips & nail beds, dizziness, fainting, fatigue, muscle weakness

11. Destruction RBC RBC break down from wear and become ruptured when travelling through the kidney and spleen. Live 100-120 days. Macrophages break down RBC and their contents. Hemoglobin breaks down into 4 globin groups and heme groups Heme breaks down into biliverdin (green pigment)

12. Destruction of RBC cont. Biliverdin breaks down into bilirubin (orange) The iron gets reused to make more hemoglobin or is stored in the liver as ferritin.

13. White Blood Cell in Action white blood cell chasing bacteria

14. Immune System Video Immune System Crash Course

15. Leukocytes- WCBs 2 main classes: Granulocytes – have a grainy cytoplasm Agranulocytes – have a clear cytoplasm

16. Types There are 5 types of white blood cells: Granulocytes Neutrophils 40-75% Eosinophils 5% Basophils0.5% Agranulocytes Lymphocytes20-50% Monocytes1-5% The range is because the requirement for different types of WBCs vary from time to time.

17. Neutrophils Structure: Multilobed nucleus Inconspicuous granules Amount: 3-7,000/mm³ Functions: Engulfing bacteria & viruses (phagocytosis) Life Span: hours → days

18. Eosinophils Structure: Bilobed nucleus Large, red granules Amount: 100-400/mm³ Functions: phagocytosis Protects against parasitic infections Neutralize histamines (their amts. incr. during hay fever & allergy attacks) Life Span – hours → days

19. Basophils Structure: Lobed nucleus Large granules, but fewer Amount: 20-50/mm³ Functions: Become mast cells when they leave b.v. & produce histamines Respond to allergens rapidly (anaphylactic shock) Produce heparin (anticoagulant) Life Span – hours → days

20. Monocytes Structure: Largest WBC U-shaped nucleus Grayish blue cytoplasm Amount: 100-700/mm³ Functions: Phagocytosis Become macrophages & remove dead cells Life Span – weeks → months

21. Lymphocytes Structure: Most numerous in children; 2 nd most in adults Spherical nucleus Small “ring”of cytoplasm; pale blue Amount: 1500-3000/mm³ Functions: T cells – attack foreign antigens directly B cells – produce antibodies for immunity Life Span – months → lifetime

22. White Blood Cell Count Normal adult has 5,000-10,000 cells/mm 3 Leukocytosis- WBC count above 10,000 cells/mm 3 –Can be a sign of acute infection –Occurs during times of stress and vigorous exercise. Leukopenia- WBC below 5,000 cells/mm 3 –Can be a sign of virus such as influenza, measles, mumps and HIV

23. Thrombocytes- Platelets Fragments of giant cells (megakaryocytes) (each produces b/t 5-10,000 platelets) Pieces break off these cells in bone marrow Enter circulation – live for approx. 1 wk.; destroyed by spleen & liver Disk-shaped, w/o nucleus ½ the size of an RBC Release serotonin to contract blood vessel walls.

24. Function Normal platelet count – 130,000-360,000/mm³ Stem blood flow (hemo- stasis) 2 ways: 1. Form a platelet plug 2. Initiate the clotting process

25. Platelet Plug Formation 1. B.V.damaged 2. Some blood escapes 3. Platelets adhere to each other & rough surfaces 4. When platelets come in contact w/collagen from connective tissue, they develop spiny projections; helps them adhere -Serotonin is released to cause vasoconstriction 5. Eventually platelet plug is formed & bleeding stops

26. Hemostasis Blood Clotting video

27. Blood Clots Thrombus – blood clot that forms in a b.v. abnormally Embolus – blood clot or fragment of one that dislodges & travels to major organ

28. Plasma Clear, straw-colored fluid; matrix of blood 92% water Functions: 1. transport 2. maintain fluid balance 3. maintain pH

29. Contents of Plasma Contains 3 plasma proteins (all produced in the liver): 1.Albumin – accounts for 60% of all plasma proteins - maintains osmotic pressure (keeps concentration of H 2 O & solutes in plasma stable - example – a decrease in albumin causes cells to lose H 2 O; it collects in interstitial spaces (b/t cells) & causes edema

30. Plasma Proteins 2.Globulins – Accounts for 36% of all plasma proteins - transports lipids & vitamins 3.Fibrinogen – Accounts for 4% of all plasma proteins - responsible for blood clotting

31. Other Substances Plasma also contains: nonprotein nitrogenous substances – amino acids, urea, uric acid electrolytes – release ions when dissolved in H 2 O; maintain osmotic pressure & pH; include Na, K, Cl, Ca Mg, bicarbonate, PO 4 & SO 4 ions

32. Blood Types Antigen – protein on surface of RBC’s Determined by genes Determines blood type Possible antigens – A or B Antibody – protein in plasma Possible antibodies – A or B

33. Human Blood Types

34. Intrinsic Clotting (Agglutination) Occurs when antigen comes in contact with foreign antibody (example – b.t. A receiving a transfusion of b.t. B) Effects – RBC’s burst, hemoglobin released Symptoms – anxiety, difficulty breathing, chest pain, pain in neck & lumbar area

35. Rh Blood Group 85% of humans have an additional protein on their RBCs; called the Rh factor Named after the species of monkey it was discovered in (Rhesus) Termed Rh+ Remaining 15% of humans don’t have this protein Termed Rh- Rh- individuals cannot receive Rh+ blood

36. Erythroblastosis Fetalis

37. 85% of people are rH positive and they are not affected by erythroblastosis fetalis. If a rH negative mother has an rH positive child the mother will build up antibodies against the rH positive blood. If the mother has another rH positive child the mother’s antibodies will attack the developing baby’s RBCs. Can be easily treated with Rhogam.