HS1 – Section 4 Blood/Heart/Circulation

Part 1 - Blood

Blood Facts

• Average adult = 8-10 pints of blood• Hematology = Study of Blood

Functions of Blood

• Transports nutrients, O2, cellular waste products, & hormones

• Aids in distribution of heat• Regulates acid-base balance• Helps protect against infection

Components of Blood

What is Blood made up of?1. Plasma

2. Erythrocytes (RBC’s)3. Leukocytes (WBC’s)

4. Thrombocytes

Plasma liquid portion of blood, transports• Straw colored – contains:

• Water (90%)• Blood proteins• Plasma proteins

FIBRONOGEN – needed for blood clotting, synthesized in the liverALBUMIN – from the liver, helps maintain blood’s osmotic

pressure and volumePROTHROMBIN – a globulin which helps blood coagulate. Vitamin K necessary for prothrombin

synthesis.

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

Erythrocytes Erythro = Red Cyte = Cell

• Shape = biconcave discs

• Carries O2

• Erythropoiesis = Manufacture of red blood cells-Occurs in bone marrow-Red cells live 120 days-Old cells broken down by the spleen and liver

• Hemolysis = rupture or bursting of erythrocyte, can be from a blood transfusion or disease.

Erythrocytes Cont… Hemoglobin

gives red color, heme is iron and globin is protein

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 redVenous blood – lots of CO2 = dark crimson

Leukocytes Leuko=White Cyte=Cell

• Larger than erythrocytes• Normal leukocyte count = 3,200 – 9,800• Group of cell that fights infections• 2 Main Types -Granulocytes (formed in bone marrow)

-Neutrophils (performs phagocytosis)-Eosinophils (involved in parasitic infections)-Basophils (secretes heparin (anticoagulant) )

-Agranulocytes (formed in bone marrow, lymph glands, & spleen)-Lymphocytes (produces antibodies)-Monocytes

Leukocytes Cont…

• PHAGOCYTOSIS – process when wbc’s surround, engulf, and digest harmful bacteria.

• DIAPEDESIS – when wbc’s move through capillary wall into neighboring tissue.

Leukocytes Cont… Inflammation

Body’s reaction to chemical or physical trauma

Cause: disease producing organisms• Sx: redness, local heat, swelling and pain

• Why? Bacterial toxins, increased blood flow, collection of plasma in tissues (edema)

Leukocytes Cont… Inflammation Cont…• HISTAMINE increases the blood flow to the injured area

• PUS produced – a combination of dead tissue, dead and living bacteria, dead leukocytes and plasma

• ABSCESS – pus-filled cavity below the epidermis

Leukocytes Cont… Inflammation Cont…

• PYREXIA – increase in body temp 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• Necessary for the initiation of the blood clotting process “coagulation”

Thrombocytes Cont…

• ANTICOAGULANTS – prevent blood clotting

• HEPARIN = antiprothrombin

• PROTHROMBIN – dependent on Vitamin K

Blood Types

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

Blood Types Cont… Antibodies

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

• Type A blood has b antibodies• Type B blood has a antibodies• Type AB blood has no antibodies• Type O blood has a and b antibodies

• UNIVERSAL DONOR O• UNIVERSAL RECIPIENT AB

Blood Types Cont… RH Factor

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

• Negatives may only receive negatives• Positives can receive negative or positive

• Problem will result with pregnancies and their infant as well as possible hemolysis or transfusion reaction

Donating & Receiving Blood Products

Possible Blood Types of a Child

Parent 1 AB AB AB AB B A A O O O

Parent 2 AB B A O B B A B A O

O X X X X X X

A X X X X X X X

B X X X X X X X

AB X X X X