Ch. 17 Blood

• Leukocytes - White blood cells (fight infection and disease)

  Erythrocytes - Red blood cells (circulate oxygen and carbon dioxide throughout the body)
• Myeloma - a type of cancer that affects the plasma cells in the bone marrow

  Plasma Cells produce antibodies
• Leukocytes

  • Make up <1% of total blood volume
  • Leukocytosis: WBC count over 11,000/mm3
  • Normal response to infection
• A hematopoietic stem cell will give rise to erythrocytes, leukocytes, and platelets.
• Types of WBCs:

  Granulocytes - Neutrophils, Eosinophils, Basophils,

  Agranulocytes - Lymphocytes, Monocytes
• Platelets:

  • Helps create blood clots and repair injuries
  • Normal = 150,000-400,000 platelets/ml of blood
• Granulocytes - Larger amd shorter-lived then RBCs

  Neutrophils - Most numerous WBCs

  Eosinophils - release enzymes to digest parasitic worms (role in allergies, asthma, and modulating immune response)

  Basophils - Rarest WBCs (similar to mast cells)

  Lymphocytes - Second most numerous WBC
• Histamine: inflammatory chemical that acts as vasodilator to attract WBCs to inflamed sites
• thrombus = blood clot (forms in a undamaged blood vessel abnormal)

  embolus = freely moving

  DVT = Deep Venous thrombosus
• Lymphocytes:

  • T lymphocytes(T cells) act against virus-infected cells and tumor cells
  • B lymphocytes (B cells) give rise to plasma cells, which produce antibodies
• A megakaryocyte is the progenitor (origin) of platelets.
• • Thrombus: clot that develops and persists in unbroken blood vessel
  • Embolus: thrombus freely floating in the bloodstream
  • Embolism embolus obstructing a vessel
• Human Blood Groups:

  • RBC membranes bear 30 types of glycoprotein antigens
  • Presence or absence of each antigen is used to classify blood cells into different groups
• Blood types:

  A, B, AB, and O
• • Plasma – non-living fluid matrix
  • Formed elements – living blood "cells" suspended in plasma
• Body Composition

  • Plasma on top (~55%)
  • Erythrocytes on bottom (~45%)
  • WBCs and platelets in Buffy coat (< 1%)
  • Hematocrit - Percent of blood volume that is RBCs (about 45%)
• Blood Characteristics

  • Sticky, opaque fluid with metallic taste
  • Color varies with O2 content
  • High O2 - scarlet; Low O2 - dark red
  • pH 7.35–7.45
  • ~8% of body weight
  • Average volume
  • 5–6 L for males; 4–5 L for females
• Functions of blood

  • Distributing substances
  • Regulating blood levels of substances
  • Protection
• • Plasma: 90% water, 10% dissolved substances
  • Plasma Proteins made up 60% Albumin, 36% golubins, 4% fibrinogen
• Albumin

  • 60% of plasma protein
  • Functions
  • Substance carrier
  • Blood buffer
  • Major contributor of plasma osmotic pressure
• Erythrocytes

  • >97% hemoglobin (not counting water)
  • No mitochondria; ATP production anaerobic; do not consume O2 they transport
• • RBCs dedicated to respiratory gas transport
  • Hemoglobin binds reversibly with oxygen
  • Normal values
  • Males - 13–18g/100ml; Females - 12–16 g/100ml
• Hemoglobin Structure

  • Globin composed of 4 polypeptide chains
  • Two alpha and two beta chains
  • Heme pigment bonded to each globin chain
  • Gives blood red color
  • Each heme's central iron atom binds one O2
  • Each Hb molecule can transport four O2
  • Each RBC contains 250 million Hb molecules
• Hematopoiesis - Blood cell formation in red bone marrow

  • Composed of reticular connective tissue and blood sinusoids

  Leukopoiesis - Production of WBCs
• Hematopoietic stem cells (Hemocytoblasts)

  • Give rise to all formed elements
  • Hormones and growth factors push cell toward specific pathway of blood cell development
  • Committed cells cannot change
• • Leukopenia: Abnormally low WBC count—drug induced
  • Leukemia - Cancerous leukocytes fill red bone marrow
• Multiple Myeloma

  • Cancer of the plasma cells
  • Plasma cells produce antibodies
• Platelets - Cytoplasmic fragments of megakaryocytes

  • Normal = 150,000 – 400,000 platelets /ml of blood