Blood- “The River of Life” Specialized connective tissue “ Blood is a priceless commodity.”

Functions of Blood Transports dissolved gases, nutrients, hormones and wastes Regulates pH/ electrolytes thru body Prevents blood loss/ clots Defense (antibodies) against toxins/ bacteria

Basic Physical Characteristics 38 degrees C (100.4 degrees F) 5 times more viscous than H2O; sticky/ cohesive pH = 7.35- 7.45 is slightly alkaline Volume = 5-6L Male; 4-5L Female (7% of body weight)

Composition of Blood Plasma= liquid portion of blood Formed Elements= cells and fragments RBC’s -carry 02 WBC’s –body’s defense Platelets-clotting

Types of Blood Cells

Types of White Blood Cells… How White Blood Cells are Formed

Types of Blood Cells RBC’s-- erythrocytes– biconcave shape that carries hemoglobin which carries the Oxygen EPO-- erythropoietin– hormone that controls the rate of RBC production by negative feedback WBC’s -- leukocytes protect against disease Neutrophils -- have enzymes which break down bacteria Eosinophils-- kill parasites and help control allergic reactions Basophils-- prevents inappropriate blood clotting Monocytes-- largest, destroys damaged RBC’s Lymphocytes-- immune response cells

The Role of White Blood Cells http://www.youtube.com/watch?v=0TvTyj5FAaQv

Hemostasis = “blood standing still”  clotting  Clotting Steps a. platelets “stick” to damaged site, more pile up creating a plug = white thrombus b. serotonin released vessel spasms which decrease blood flow c. thromboplastin creates clotting “cascade” d. reacts with Ca+2  thrombin e. it changes fibrinogen to fibrin (a mesh-like trap), within 1 hr. vessel starts to heal **Normal blood clots in 2 – 6 min. ** Sterile gauze &/ or pressure speeds up process (something to cling to and local thromboplastin released)

Hemostasis--- Video https://www.youtube.com/watch?v=xNZEERMSeyM

Clotting and Bleeding Disorders thrombus = clot inside an unbroken vessel ex. heart attack, legs embolus = if it breaks away and moves ex. stroke (moved to brain) thrombocytopenia = not enough clotting proteins, Vit. K needed by the liver to make proteins  liver damage = blood transfusion Hemophilia = “bleeders disease”; Even small cuts are dangerous, need transfusions of plasma and proteins

Blood Banks and Blood Types Loss of 15-30% of blood = weakness > 30% = shock Blood banks collect blood and put in an anticoagulent and refrigerate. RBC’s have antigens on them so that they recognize “self” If someone gets blood that’s not their type, body thinks it’s disease, RBC’s burst  O2 failure and kidney failure

Blood types A, B, AB, O AB =universal recipient (can get A,B,AB, or O ) O = universal donor (anyone can get) Rh factors Discovered in Rhesus monkeys, Most people are Rh + carry the Rh antigen Rh- women carrying Rh+ babies, baby rejects Mother’s blood … have to take Rhogam, if not, baby is anemic or  brain damage

Blood typing Mix blood with 2 types of Serum antiA / B, Clumping occurs under microscope Cross matching = test donor’s blood with recipient’s and vice versa to be certain! Developmental aspects Blood circulating in fetus at 28 days = 4 WEEKS! Increase in age = more leukemia, anemias, and clotting

Artificial Blood Substitutes… Can stretch blood supply Flusol = related to nonstick cook-ware, glides easier, store donor organs in it Chm. Altered Hemoglobin increases O2 capacity at low temps./ But constricts vessels Neohemocytes = artifical RBC’s 1/12th the size, 6 month shelf life