Objectives

Explain the structure of the blood.

Analyze the function of the blood

Discuss characteristics and treatments of common blood disorders

Structure of Blood

Average adult = 8-10 pints of blood

Composition:

• PLASMA – liquid portion of blood without cellular components

• SERUM – plasma after a blood clot is formed

• CELLULAR COMPONENTS – (elements are red cells, white cells and platelets)

PLASMA• Straw colored, contains – • Water• Blood proteins• Plasma proteins

– FIBRONOGEN – necessary for blood clotting, synthesized in the liver

– ALBUMIN – from the liver, helps maintain blood’s osmotic pressure and volume

– PROTHROMBIN – a globulin which helps blood coagulate. Vitamin K necessary for prothrombin synthesis.

• Nutrients• Electrolytes• Hormones, vitamins, enzymes• Metabolic waster products

ERYTHROCYTES

Shape = biconcave disc donut-shaped

HEMOGLOBIN – gives red color, heme is iron and globin is protein.

Function = transports oxygen to tissues and carbon dioxide away from cells

Normal – men =14-18 gm, women = 12-16 gm

Function of Hemoglobin

• Red cells travel through the lungs where

O2 is carried to tissues and released

• CO2 picked up and carried back to lungs for exchange

• Arterial blood – lots of oxygen = bright red

• Venous blood – lots of CO2 = dark crimson What is carbon monoxide poisoning?

What is carbon monoxide poisoning?

ERYTHROPOIESIS Manufacture of red blood cellsOccurs in bone marrow

Red cells live 120 daysOld cells broken down by the spleen and liver

HEMOLYSIS – rupture or bursting of erythrocyte, can be from a blood transfusion or disease.

LEUKOCYTES

White Blood Cells – LEUKOCYTES

• Larger than erythrocytes

• 5 types

• Normal leukocyte count = 3,200 – 9,800

Types of White Cells

• Neutrophils

• Eosinophils

• Basophils

• Lymphocytes

• Monocytes

PHAGOCYTOSIS – process when white cells surround, engulf, and digest harmful bacteria

Basophils produce HEPARIN – an anticoagulant

DIAPEDESIS – when white cells move through capillary wall into neighboring tissue.

Body’s reaction to chemical or physical traumaPATHOGENIC – disease producing microorganisms can cause inflammationSymptoms – redness, local heat, swelling and painWhy? Bacterial toxins, increased blood flow, collection of plasma in tissues (edema)HISTAMINE increases the blood flow to the injured areaPUS produced – a combination of dead tissue, dead and living bacteria, dead leukocytes and plasmaABSCESS – pus-filled cavity below the epidermisPYREXIA – increase in body temperature by the hypothalamus – in response to pathogenic invasion

LEUKOCYTOSIS – increase in the number of white cells in response to infection

LEUKOPENIA – decrease in number of white cells due to chemotherapy or radiation

THROMBOCYTES (Platelets)• Smallest of solid components of blood

• Synthesized in red marrow

• Not cells – fragments of megakaryocytes

• Necessary for the initiation of the blood clotting process COAGULATION

COAGULATION:

Cut or injury platelets and injured tissue release THROMBOPLASTIN act on PROTHROMBIN in plasma + Calcium ions converts to THROMBIN the thrombin acts as an enzyme and changes FIBRINOGEN FIBRIN creating a mesh that traps red blood cells, platelets and plasma creating a blood clot.

ANTICOAGULANTS – prevent blood clottingHEPARIN = antiprothrombinPROTHROMBIN – dependent on Vitamin K

Function of the Blood

Four main functions:

1.Transport oxygen, nutrients, cellular waste products and hormones

2. Aids in distribution of heat

3. Regulates acid-base balance

4. Helps protect against infection

BLOOD TYPES

• Four major types of blood- A, B, AB and O

• Inherited from parents

• Determined by presence or absence of an ANTIGEN on the surface of the red blood cell

ANTIBODY – a protein in the plasma that will inactivate a foreign substance that enters the body.

Someone with type A blood has b antibodies

Someone with type B blood has a antibodies

Someone with type AB blood has no antibodies

Someone with type O blood has a and b antibodies

UNIVERSAL DONOR – OUNIVERSAL RECIPIENT – AB

Red cells also may contain Rh factorIf you have it, you’re Rh +If you don’t, you’re Rh –

DISORDERS OF THE BLOOD

• ANEMIA• IRON-DEFICIENCY ANEMIA • APLASTIC ANEMIA• SICKLE CELL ANEMIA• POLYCYTHEMIA• EMBOLISM• THROMBOSIS• HEMATOMA

DISORDERS OF THE BLOOD

• HEMOPHILIA

• THROMBOCYTOPENIA

• LEUKEMIA

IRON-DEFICIENCY ANEMIA

• Usually in women, children and adolescents

• Deficiency of iron in the diet causing insufficient hemoglobin synthesis

• Treat with iron supplements and green, leafy vegetables

APLASTIC ANEMIA

• Bone marrow does not produce enough red and white blood cells

• Caused by drugs or radiation therapy

SICKLE CELL ANEMIA

• Chronic blood disease inherited from both parents

• Causes the red cells to form in abnormal sickle shape

• Sickle cells break easily and carry less oxygen

• Occurs primarily in blacks

• Treatment – blood transfusions

POLYCYTHEMIA

• Too many red blood cells are formed

• May be a temporary condition that occurs at high altitude

EMBOLISM

• Air, blood clot, cancer cells, fat, etc. that is carried by the bloodstream until it reaches an artery too small for passage

• Also known as a “moving blood clot”

THROMBOSIS

• The formation of a blood clot in a blood vessel

• The blood clot is a THROMBUS

HEMATOMA

• Localized clotted mass of blood found in an organ, tissue or space.

• Caused by an injury that can cause a blood vessel to rupture

HEMOPHILIA

• Hereditary

• Missing clotting factor

• Blood clots slow or abnormally

• Sex-linked – transmitted genetically from mothers to sons

Treatment: with missing clotting factor, avoid trauma

THROMBOCYTOPENIA

• Not enough platelets

• Blood will not clot properly

LEUKEMIA

• Malignant condition

• Overproduction of immature white blood cells

• Hinders synthesis of red cells

• Treatment: Research on cord blood