Blood

Functions Carries O2, hormones, and nutrients to the body tissues Helps to remove CO2 and other wastes from the body helps to regulate and distribute body heat Helps protect against infection Clotting to prevent excessive bleeding from the wound

Composition Plasma (55%) Erythrocytes (RBC’s) Leukocytes (WBC’s) Thrombocytes (platelets)

Erythrocyte Red blood cell (35 trillion) Primary function to carry oxygen to all of the cells. RBC formation (erythropoiesis) in adults takes place in the bone marrow Average life span 120 days As they become fragile they are removed by macrophages in the liver, spleen and bone marrow.

Leukocyte White blood cell (lifespan 9 days) Primary effector cells against fighting infection and tissue damage. Neutralize and destroy organisms act as scavengers clean up damaged cells by phagocytosis to initiate the repair process Normal WBC count 5,000 to10,000/mm3 Differential count: measures % of each type of WBC

Thrombocytes Platelets 130,000 to 400,000 mm3 Play an important role in blood coagulation, hemostasis, and blood thrombus formation when a small vessel is injured, platelets adhere to each other and form a clot Can be beneficial or harmful (ex. Includes coronary occlusion)

Plasma Liquid part of lymph and blood consists of serum, protein and chemical substances like electrolytes, glucose, and proteins Serves as a medium for transporting these substances to various structures and at the same time transporting waste products to various sites of clearance thin and colorless

Types A- 40% B- 11% AB-4% Universal Recipient O- 45% Universal donor

Reasons for blood transfusions To replace blood lost through hemorrhage to treat anemia To treat shock To exchange blood in certain disorders To aid recovery as a preoperative or postoperative procedure

BLOOD TYPEDONATE TORECEIVE FROM AA or ABA or O BB or ABB or O AB A, B, AB, O O O

Rh Factor Red Blood Cell Protein 85% of population have protein and are + 15% are Negative When Rh = blood given to a neg blood antibodies are formed and positive blood is destroyed. Negative blood can be given to positive

Rh Factor and Pregnancy An Rh negative mother may become sensitized by proteins from an RH positive baby (inherited from the father) During pregnancies following the sensitization, the mother’s antibodies may pass into the blood of the unborn infant and cause erythroblastosis, a destruction of RBC’s

Innovations in Blood Transfusion Autologous transfusion – collection and transfusion of a person’s own blood Interoperative salvage – collecting and returning a person’s own blood Apheresis – donated blood is separated into parts using a centrifuge. (before apheresis, platelets for one transfusion required 5-10 donors)

Functions of Lymph and Lymphatic Tissue Maintains fluid balance Immunity

What is lymph? A watery substance formed from fluids that filters into the body tissues or interstitially. The fluid is returned to the body through the lymph vessels Lymph capillaries are more porous than blood capillaries, allowing fluid in the tissues to collect and be returned to the circulatory system

What are the lymphatic tissues Tonsils Thymus Spleen Nodes Lymph vessels

IMMUNITY Non-specific or innate Specific –Acquired –Inherited

Non-Specific or Innate Immune Response Includes the barrier of the skin, mucous membranes, tears and leukocytes Types of non-specific defense –Localized Inflammatory Response –Systemic Inflammatory Response

Specific Immunity Inherited –Genetic trait (e.g., humans can’t get some diseases that affect dogs) Acquired –Natural: caused by exposure to the agent unintentionally (maternal antibodies transmitted via breast milk) –Artificial – obtained intentionally (e.g., vaccination)

Common Assessment techniques Direct Examination Chemical Tests Coagulation Studies

Direct Examination Hemoglobin test (Hgb) Hematocrit (Hct) Sedimentation Reticulocyte studies Platelet or Thrombocyte count Aspiration biopsy cytology

Chemical Tests Use spectrophotometry – calculates the concentration of substances in solution by measuring the amt of light it absorbs Examples: Complete Blood Count (CBC) and Sequential Multiple Analysis (SMA)

Coagulation Studies Bleeding Time – amt of time an incision takes to clot Prothrombin time (PT) uses an anticoagulant to measure the blood sample’s clotting time