The Structure and Function of Blood

Composition of Blood

• Blood is responsible for…..– Transporting gases (oxygen & carbon dioxide)– Transporting waste products – Transporting nutrients– Helping remove toxins from the body

Composition of Blood

• Blood makes up 6–8% of our total body weight.

• Normal adult blood volume is 5 L.

• Blood is made up of cellular material in a fluid called plasma.

Composition of Blood

• Blood is a circulating tissue consisting of three types of cells.1. Red Blood Cells Erythrocytes2. White Blood Cells Leukocytes3. Platelets Thrombocytes

• The cells listed above are suspended in a liquid known as plasma.

Composition of Blood: Red Blood Cells

• Red Blood Cells— AKA: Erythrocytes or RBCs

— Most abundant cell in the blood (4 million – 6 million per microliter of blood)

— Formed in the bone marrow

—Main function is transporting oxygen and carbon dioxide

http://www.giantmicrobes.com/us/products/redbloodcell.html

Composition of Blood: White Blood Cells

• White blood cells — AKA: Leukocytes or WBCs

— Largest sized blood cells

— Lowest numbers in the blood (4,500 – 11,000 per microliter)

— Formed in the bone marrow and some in lymph glands

— Primary cells of the immune system

— Fights disease and foreign invaders

http://www.giantmicrobes.com/us/products/whitebloodcell.html

Composition of Blood: Platelets

• Platelets — Involved in the clotting process

— Seal wounds and prevent blood loss

— Help repair damaged vessels

— 150,000 – 400,000 per microliter of blood

—Platelets stain bluish with reddish or purple granules

Formation of Blood

• Hematopoiesis the formation and development of blood cells

Blood Evidence• Blood spatter – Can be analyzed to determine

patterns that give investigators clues to how a crime might have happened.

• Blood droplets – Can be analyzed to give clues to the location of a crime, movement of a victim, and type of weapon.

• Blood samples – Can be analyzed to determine blood type and DNA, which can be matched to possible suspects.

Microscopic Views

Bird Blood

Cat Blood

Dog Blood

Fish Blood

Frog Blood

Snake BloodHuman Blood

Horse Blood

Blood Typing Definitions• Antibody- a protein that identifies foreign

matter by shape and begins immune response• Antigen- a foreign small molecule that the

body can attack with an antibody• Agglutination- clumping that occurs in blood

when antibodies connect to antigens on different red blood cells forming a meshwork.

ABO blood types

Possible blood types: A, B, AB, and O+ or – for each8 total possibilities

One gene with three possible alleles controls ABOA B or O

A separate gene determines +/-

ABO blood types

http://learn.genetics.utah.edu/units/basics/blood/types.cfm

Blood type describes the proteins called antigens on the surface of the red blood cells.

The letter(s) in the blood type indicate(s) the antigens on the red blood cell

Antibodies and ABO blood types

http://learn.genetics.utah.edu/units/basics/blood/types.cfm

The body makes antibodies to all the antigens not on its own RBC.

Genetics of Blood Types

• Your blood type is established before you are BORN, by specific GENES inherited from your parents.

• You inherit one gene from your MOTHER and one from your FATHER.

• These genes determine your blood type by causing proteins called AGGLUTINOGENS to exist on the surface of all of your red blood cells.

Blood Transfusions

Red Blood Cell Donation or Whole Blood Donation

We transfuse in the red blood cells and antigens of the donor.Universal Donors: TYPE O blood has no antigens

is not recognized as foreign

Universal Recipients: TYPE AB blood has no antibodiesdoes not recognize other blood as foreign

Rh + Can receive + or - Rh - Can only receive -

(plasma transfusion is different)

Rh Factors

A+ A-B+ B-

AB+ AB-O+ O-

http://www.fi.edu/biosci/blood/rh.html

If a person is Rh +/- or +/+ the RBC also have D antigenA person with a positive blood type

can receive blood transfusion from positive or negA person with a negative blood type

can receive blood transfusion from neg only

Rh antigens can cross the placental barrier. Pregnant women who are Rh Neg get a shot to prevent mounting an immune response to a fetus with Rh Pos