BloodFunctions of Blood•Transports – O2, CO2, nutrients and hormones

• Regulates – pH, temperature, and osmotic pressure

• Protects – Blood clotting (stops excess loss)

White Blood Cells – phagocytosis

- antibodies

Components of Whole Blood

pH of 7.35 – 7.45

temperature ~ 38°C

8% of total body weight

◦ Avg. Male – 5-6 liters = 1.5 gal

◦ Avg. Female – 4-5 liters = 1.2 gal

Blood Composition

Plasma – 55%

A. Proteins

Albumins

54% - maintain osmotic pressure

Globulins

38% - immune response

Fibrinogen

7% - forms blood clots

B. Other solutes

Electrolytes, nutrients, gases,

enzymes, hormones, vitamins &

waste products

Blood Composition

Formed Elements

1. Red Blood Cells (RBCs)

◦ Erythrocytes

◦ Biconcave Discs

Greater surface to volume

ratio

“Hematocrit”

Less than 45% -Anemia!

The formed elements are composed of

Red Blood Cells or Erythrocytes

These are biconcave discs that carry

Oxygen to the entire body

Blood Composition11. White Blood Cells (WBCs)

◦ Less numerous than red(700:1)

◦ Nuclei

◦ Life span of a few days (some B and T cells remain for years)

A. Granular leukocytes Neutrophils – most abundant

Respond first to bacterial invasion

Radiation, chemotherapy and stress can reduce #

Eosinophils

Cytotoxic – release contents on invader

Basophils

Allergic responses – cause secretion of histamine

#’s increase during infection

Blood CompositionB. Agranular leukocytes

Lymphocytes

B cells – make antibodies

T cells – destroy tumor cells

Bone marrow is source of

lymphocytes but T cells

mature in Thymus gland

Monocytes – become

macrophages

III. Platelets◦ No nucleus

◦ Fragments of a Megakaryocyte

◦ Essential role in blood clotting

Hematopoiesis – process by which the

formed elements of blood develop

Red bone marrow in axial skeleton,

pectoral, pelvic girdles and proximal

epiphyses of humerus and femur.

Pluripotent stem cell – have capacity to

develop into several different types of

cells “hematopoietic stem cell.

RBC’s

• Women average 4.8 million rbc’s/mm3

• Men average 5.4 million rbc’s/mm3

• Stimulated by hormones according to need

▪ EPO – Erythropoietin (RBC’s)

▪ TPO – Thrombopoietin (platelets)

• Terminally differentiated – never divide

• Ex. Peruvians living at 18000 feet have as many as

8.3 x 106

• Live about 120 days

Production of Erythrocytes

Erythropoiesis

Production of Platelets

Genesis of Platelets

Production Of WBCs

HUMAN BLOOD GROUPS

ABO Blood Groups

First discovered by Karl

Landsteiner in 1900

ABO Blood Groups

The ABO blood groups consists of:

◦ Two antigens (A and B) on the surface of the

RBCs

◦ Two antibodies in the plasma (anti-A and anti-

B)

Agglutinogens and their corresponding

antibodies cannot be mixed without

serious hemolytic reactions

ABO Blood Groups

These antigens are:

◦ Unique to the individual

◦ Recognized as foreign if transfused into another individual

◦ Promoters of agglutination and are referred to as agglutinogens

Presence or absence of these antigens is used to classify blood groups

Agglutinogen = Antigen = name tag

Agglutinins = Antibodies

ABO Blood Groups

RBC membranes have glycoprotein antigens on their external surfaces

The Blood Typing Game

Nobel Prize.org

◦ Type into your browser “Blood typing game”

◦ Once on the website, click on the “Quick

Game” random patients tab

◦ Write down the blood type of your three

patients and what blood types you game them

for transfusion.

◦ Happy blood typing!

Now we are going to find out….what is

your blood type?