Blood

Function of Blood Transports gases (O2 and CO2), 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 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 O2 and CO2 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 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 O2 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 Platelets contact edges of broken blood vessel Platelet surface becomes sticky Platelets cluster around wound Platelets release clotting factors Thromboplastin converts prothrombin to thrombin 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)