Blood

Blood Volume and Composition

- average adult :

- males slightly more

- varies with size

- varies with various conditions, including pregnancy

- abnormal high blood volume (enlarged heart) push extra blood through body (GIANTS)

Blood is:

plasma –

hematocrit -

Hemopoiesis - blood cell formation

embryo - liver, spleen, thymus, and bone marrow

adults - red bone marrow is site of hemopoiesis

Red Blood Cells (erthrocytes)

Hypoxeia - prolonged oxygen deficiency, cyanotic (blue)

Cold temperatures - blood vessels constricted, body removes maximum amount of oxygen - cyanotic

RBC - donut with indentation instead of hole - facilitates movement and oxygen carryingg capacity

Wear and Tear with No Repair

•

RBCs constantly being produced and entering blood stream

old cells die and are phagocytzed and recycled or rupture (hemolyze) and are removed from the body

ƒ RBCs = endurance

„ RBCs = fatigue

Substances that aid in RBC formation:

RBC Disorders:

White Blood Cells - leukocytes (WBCs)

•

WBCs -

•

Inflammation

• body’s reaction to injury

• histimine which dialtes smaller blood vessels making them “leaky”

• more blood flow, tissues redden, fluids leak into interstitial spaces (edema - swelling)

• swelling delays spread of microbes to other areas

• damaged cells release WBC attracting chemicals

• WBCs move into damaged area

pus - bacteria, WBCs, damaged cells

leukocytosis - too many WBCs; indictes infection

leukopenia - too few; indicates viral infection

Platelets - thrombopcytes

Hemostasis - process that stops bleeding

A chain reaction involving the following:

1. Blood Vessel Spasm - when cut, blood vessel triggers smooth muscle contraction within its wall which slows bleeding and may actually close cut

2. Platelet Plug Formation - platelets stick to broken ends of vessells and each other forming plug to further slow or stop bleeding

3. Blood Coagulation - formation of blood clot

May be Intrinsic or Extrinsic

Extrinsic - damaged vessels - cut

Intrinsic - when blood comes in contact with some other surface besides the smooth muscle of vessel walls (ex. bone fragments)

flowing blood normally produces anticoagulants: antithrombin, heparin

flowing blood also does not allow thrombin to accumulate

thrombus -

embolus -

embolism-

infarction -

pulmonary embolism -

anticoagulant drugs

- heparin -

- coumadin -

Medical leeches

- hivudin -

hirulog-

Blood Types

antigens -

antibodies –

ABO group

Rh factor

PLASMA