Blood. Functions Carries O2, hormones, and nutrients to the body tissues Helps to remove CO2 and...
-
Upload
gyles-preston -
Category
Documents
-
view
220 -
download
5
Transcript of Blood. Functions Carries O2, hormones, and nutrients to the body tissues Helps to remove CO2 and...
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 TYPE DONATE TO RECEIVE FROM
A A or AB A or O
B B or AB B or O
AB AB A, B, AB, O
O A, B, AB, 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 InnateImmune 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