BLOOD

Physical Characteristics

Color depends on oxygen content

8% of body weight 4 - 5 L in females, 5 - 6 L in

males pH – slightly alkaline

(7.35 – 7.45) About 100.4° F

With O2

Without O2

What Is It?

What Is It?

55% plasma Plasma is 90% water – solvent, heat

absorber Plasma proteins

Albumin – osmotic balance, pH buffering

Fibrinogen – blood clotting Globulins – defense (antibodies), lipid

transport Salts (electrolytes) – osmotic

balance, pH buffering

What Is It?

45% formed elements (living cells) Buffy coat = less than 1%

Leukocytes (white blood cells) Platelets

Erythrocytes (red blood cells) More than 99% Percentage of total blood volume =

hematocrit

Erythrocytes

Transport oxygen to cells Tiny - 4-6 million /mm3 of blood Produced in bone marrow Life span is 100-120 days Biconcave (Why?) Anucleate No organelles (How do they get

energy?)

Erythrocytes

97% of solid material is hemoglobin Anemia – reduced oxygen levels

low # of erythrocytes low amounts of hemoglobin

Sickle-cell anemia Mutation in hemoglobin gene Reduced malaria risk

Normal vs. Iron Deficiency Anemia

Normal vs. Sickle Cell Anemia

Leukocytes

Defend against disease Produced in bone marrow Perform diapedesis

Types of Leukocytes

Granulocytes – contain granules Neutrophils

Most numerous WBC (~60%) Multi-lobed nucleus & pale granules Kill bacteria

Eosinophils Bi-lobed nucleus, reddish granules Kill parasitic worms

Basophils Bluish granules Inflammatory response

Types of Leukocytes

Agranulocytes – lack granules Lymphocytes

About 30% WBC One large nucleus

2 Types T-Lymphocytes (T-Cells) – control immune response B-Lymphocytes (B-Cells) – secrete antibodies

Monocytes Largest WBC with pale U-shaped nucleus Become macrophages – “cell eaters”

Normal vs. Leukemia

Platelets

Small cell fragments Responsible for blood clotting

Sketch & Label

Hemostasis – 3 Phases

Phase One: Platelet plug formation

Damage to a blood vessel

Exposes collagen fibers

Platelets stick to collagen and

release chemicals

Chemicals attract more

platelets

Hemostasis – 3 Phases

Phase Two: Vascular spasms Platelets release serotonin, causing the blood

vessel to spasm and narrow.

How is this helpful?

Hemostasis – 3 Phases

Phase Three: CoagulationA “clotting cascade” is triggered:Damaged tissues release TF (tissue factor)TF combines with vitamins, ions and clotting factors in the plasma and platelet plug to form prothrombin activatorProthrombin activator converts prothrombin in plasma to thrombinThrombin joins together soluble fibrinogen proteins into long insoluble molecules of fibrin

Tissue Damage

(TF)

Platelet Plug(PF3)

Factors in blood(clotting proteins,

Vitamin K, calcium)

Prothrombin Activator

Prothrombin Thrombin

Fibrinogen(soluble)

Fibrin(insoluble)

Clotting Cascade (continued)

Fibrin traps red blood cells & contracts, squeezing out plasma & sealing blood vessels

Question to consider…

When you have an open wound, why should you apply gauze and pressure?

Disorders of Hemostasis

Hemophilia

Disorders of Hemostasis

Thrombus Embolus

Blood Typing - Antigens

Blood Typing - Antibodies

To clarify…

Blood Typing - Agglutination

Blood Typing

Hematopoiesis

Blood cell formation In red bone marrow

Axial skeleton Pelvic and pectoral girdles Humerus & femur

Hemocytoblasts

Stem cells that make all formed elements

Erythropoiesis

Red blood cell production 3 phases:

1. Ribosome synthesis – used to produce hemoglobin

2. Hemoglobin accumulates

3. Nucleus and organelles are ejected

Erythropoietin

Hormone that stimulates erythropoiesis; increases RBC production

Produced by the kidneys Release controlled by negative feedback

The balance between RBC production and destruction is very important!! Why?

Events causing release of erythropoietin…

1. Decreased RBC count

2. Decreased availability of oxygen

3. Increased tissue demands for oxygen

What is the variable that is being monitored?

The Spleen

Graveyard for RBC’s Dying erythrocytes are

engulfed and destroyed by macrophages

Hemoglobin gets reused

Why do erythrocytes

die of old age?

Questions for thought…

How would spending time on the upper slopes of K2 (at right) affect your body’s erythropoietin levels?

How would it affect your blood viscosity?

Questions for thought…

What changes would you expect to see in an athlete who trains at high altitudes?

Do you think these are a benefit or detriment to sea-level performance?

Questions for thought…

Blood-DopingBlood-Doping – illegally boosting the number of RBCs in circulation in order to enhance athletic performance

Do you think this should be illegal?

How does it differ from high altitude training?