Blood Function of Blood 1 Transports gases O
Blood
Function of Blood 1. Transports gases (O 2 and CO 2), nutrients and waste products 2. Regulates body’s internal environment (i. e. body temp. ) 3. Blood components fight infection 4. Form clots to repair damaged blood vessels
What is Blood? Type of connective tissue Blood is made up of cellular material in a fluid called plasma Makes up 6 -8% of total body mass (4 -6 liters) 45% = Cellular material 55% = Plasma
What is Blood Plasma? 90% water 10% dissolved gases, salts, nutrients, enzymes, hormones, waste products, and plasma proteins
Cells in the Blood is a circulating tissue consisting of three types of cells. Red blood cells Erythrocytes White blood cells Leukocytes Platelets Thrombocytes
Red Blood Cells • • • Most numerous Formed in the bone marrow No nucleus Life span - 120 days Transports O 2 and CO 2 Red color comes from hemoglobin
Hemoglobin Iron containing protein Binds to oxygen in lungs Transports oxygen to tissues throughout body
White Blood Cells • Few (1 WBC for every 1000 RBC) • Produced in the bone marrow • Primary cells of the immune system • Life span - 24 hr to 2 years • Also called Leukocytes
White Blood Cells “Army” of Circulatory System • Guard against infection • Attack foreign material (bacteria, fungi, parasites) • Produce antibodies
Platelets & Blood Clotting • Platelets are cell fragments found in blood • Formed in bone marrow • Life span - 5 -9 days • Role in blood clotting
Blood Type Blood type is a classification of blood based on the presence or absence of inherited surface antigens Blood types: A, B, AB, O
Blood Type Blood types are inherited from both parents. A and B alleles - dominant, O allele - recessive
Blood Disorder: Hemophilia = genetic disorder Clotting process does not work Single base mutation
Blood Disorder Sickle Cell Anemia • Red blood cells are sickle shaped • Can’t carry as much O 2 • Block blood flow in vessels • Genetic disorder
Blood Disorder: Leukemia • Form of cancer in which the bone marrow makes too many white blood cells Normal Leukemia
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Plasma Proteins Albumin, Globulin, Fibrinogen Albumin & Globulin - Transport substances Albumin - Regulates osmotic pressure and blood volume Fibrinogen - important for blood clotting
Steps of Blood Clotting 1. Platelets contact edges of broken blood vessel 2. Platelet surface becomes sticky 3. Platelets cluster around wound 4. Platelets release clotting factors 5. Thromboplastin converts prothrombin to thrombin 6. Thrombin converts fibrinogen into fibers, which form a clot
Lymphatic System Network of vessels, nodes and organs Collects fluid (lymph) lost by blood and returns it back to circulatory system
Lymph Fluid lost by blood into surrounding tissue Ducts collect lymph and return it to circulatory system Lymph moves by osmotic pressure and skeletal muscle contractions Lymph vessels near intestines absorb fats & fat soluble vitamins Carries it from digestive tract to blood Edema = swelling of tissues due to accumulation of excess fluid
Lymph Nodes Filters that trap bacteria and other microorganisms Becomes enlarged when trapping many microorganisms (when you are sick)
Thymus Lymphocyte = white blood cells T-cell (type of lymphocyte) made in thymus T-cells recognize foreign invaders
Spleen Cleans blood Removes damaged blood cells Harbors phagocytes (cells that engulf and destroy pathogens)
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