Blood

Chapter 10

Features of Blood

pH between 7.35 – 7.45 (slightly alkaline) Sticky Opaque – not translucent Has metallic taste

Plasma

Makes up 55% of the blood Approximately 90% water Dissolved substances

Nutrients Salts Respiratory gases (O2 and CO2) Hormones Plasma proteins Waste

Plasma (cont.)

Formed Elements

Makes up 45% of the blood Three types of formed elements (cells)

Erythrocytes (RBCs) Leukocytes (WBCs) Platelets

Formed Elements (cont.)

Erythrocytes Transport oxygen in blood Anucleated (without nucleus) Doughnut shaped Life span: 100 to 120 days 4-6 million RBCs in the body

RBC outnumber WBC 1,000 to 1 Hemoglobin – an iron-containing protein that oxygen

attach to for transportation Iron – The element that gives erythrocytes their red color

Formed Elements (cont.)

Erythrocyte disorders Anemia – a decrease in the oxygen-carrying

ability of the blood May result from:

A lower than normal number of RBCs Deficient hemoglobin content in the RBCs

Sickle-cell anemia – deformed (crescent shaped) RBCs rupture easily and can cause blood clots

Formed Elements (cont.)

Leukocytes 4,000-11,000 WBCs in the body

Less than 1% of total blood volume Nucleated Can move by amoeboid motion WBCs defend the body against damage by

bacteria, viruses, parasites, and tumor cells When infection occurs, WBCs double in number

within hours

Formed Elements (cont.) Types of Leukocytes

Granulocytes – WBCs that have grains (or dots) Neutrophils – Fight acute bacterial infections

Most common WBC - 40% to 60%

Eosinophils – Kill parasitic worms; increase during allergy attacks 1% to 4%

Basophils – Produces histamine Least common WBC - 0.5% to 1%

Formed Elements (cont.)

Types of Leukocytes (cont.) Agranulocytes – WBCs that do not have grains

Lympocytes – Fight viral infections, fungal infections, and cancer cells

20% to 40%

Monocytes – Fight chronic bacterial infections; makes up long-term “clean-up team”

2% to 8%

Note: Granulocytes end in –phils and agranulocytes end in –cytes

Formed Elements (cont.)

List of the WBCs from most to least abundant Neutrophils Lymphocytes Monocytes Eosinophils Basophils

Easy way to remember this list Never Let Monkeys Eat Bananas

Formed Elements (cont.)

Abnormal leukocyte activity Leukocytosis – a total WBC count above 11,000

cells/mm3 Leukocytosis indicates a bacterial or viral infection is

present in the body Leukopenia – an abnormally low WBC count

Caused by certain drugs such as corticosteroids and anticancer agents

Leukemia – cancer of the blood cells that starts in the bone marrow

Formed Elements (cont.)

Platelets – Fragments of cells that are used in the clotting process

Hemostasis

Hemostasis – stoppage of blood flow Blood usually clots within 3 to 6 minutes Hemostasis has four phases:

Platelets fill the cut Clotting proteins activate Fibrin forms RBCs and WBCs coagulate with other coagulated

components http://www.youtube.com/watch?v=--bZUeb83uU

Hemostasis (cont.)

Disorders of Hemostasis Undesirable Clotting

Thrombus – A clot that develops and persists in an unbroken blood vessel

Embolus – A thrombus breaks away from the vessel wall and floats freely in the bloodstream For example, a cerebral embolus may cause a stroke

Bleeding Disorder Hemophilia – a lack of any of the factors needed for

clotting

Blood Groups

Antigen (or agglutinogen) – a sugar or protein that is attached to the surface of erythrocytes Antigens are sugars in ABO blood groups Antigens are proteins in the Rh blood group

Antibody (or agglutinin) – a protein produced by the body's immune system

Blood Groups

Blood Groups (cont.)

Blood Group Frequency for White Americans

Frequency for Black Americans

Frequency for Asian Americans

Blood that can be received

AB 4 4 5 A, B, AB, O (universal recipient)

B 11 20 27 B, O

A 40 27 28 A, O

O 45 49 40 O (universal DOnOr)

Blood Groups (cont.)

Rh Blood Groups Originated from rhesus monkeys Rh+ - RBCs carry the Rh antigen Rh- - RBCs that do not carry the Rh antigen

Anti- Rh+ antibodies are not automatically present in the blood of Rh- individuals.

If an Rh- person receives mismatch blood (Rh+), their immune system becomes sensitized and begins producing anti- Rh+ antibodies against the foreign blood.

Blood Groups (cont.)

Rh Blood Groups Pregnant women

The same concept occurs in pregnant Rh- women that carry Rh+ babies.

The first pregnancy will result in a healthy baby. The mother is now sensitized by Rh+ antigen. The doctor will treat her with RhoGAM (an immune serum

that prevents this sensitization) during the second pregnancy. Serum – plasma without clotting proteins If mother is not treated, the baby can become anemic, have

brain damage, or die.