Medical assisting Administrative and clinical procedures (5e) Chapter 27 The blood

After studying this chapter you will be able to: Describe the components of blood, giving the function of each component listed; explain how bleeding is controlled; explain the differences among blood types A, B, AB, and O, including in the discussion which blood types are compatible;...

The Blood

Learning Outcomes (cont.)

27.1 Describe the components of blood, giving the

function of each component listed

27.2 Explain how bleeding is controlled

27.3 Explain the differences among blood types A, B,

AB, and O; including in the discussion which blood

types are compatible

Learning Outcomes (cont.)

27.4 Explain the difference between Rh- positive

blood and Rh-negative blood

27.5 Describe the causes, signs and symptoms, and

treatments of various diseases and disorders of the

blood

• Blood

– 4-6 liters per adult ~ 8% of body weight

– Essential functions

• Carries oxygen and nutrients

• Removes carbon dioxide and wastes

• Transport mechanism for hormones

• Regulation of body temperature

Blood Components (cont.)

Blood Components (cont.)

• Hemoglobin

– Oxyhemoglobin carries oxygen

– Deoxyhemoglobin ~ carries carbon dioxide

• RBC count

– Normally between 4 million and 6.5 million RBC/ml

– Anemia

Blood Components (cont.)

• RBCs

– Produced in the red

bone marrow – Life span ~ 120 days

– Erythropoietin

• Produced by kidneys

• Stimulates bone marrow

• Released when oxygen concentrations are low

Blood Components (cont.)

– Biliverdin released and converted to bilirubin

by the liver

White Blood Cells

White Blood Cells

White Blood Cells (cont.)

Blood Platelets

• Also called thrombocytes

• Fragments of cells

• Needed for the clotting process

• Normal count – 130,000 to 360,000 platelets per cubic

millimeter of blood

Blood Plasma

• Water

• Proteins

– Albumins ~ help to maintain blood pressure

– Globulins ~ transport lipids and fat-soluble vitamins

– Fibrinogen ~ needed for blood clotting

• Serum

Blood Plasma (cont.)

Blood Plasma (cont.)

• Electrolytes

• Non-protein nitrogenous substances

• Waste products

Apply Your Knowledge

True or False:

Hematocrit is the percentage of WBCs in the blood.

Neutrophils destroy bacteria, viruses, and toxins in the

bloodstream

Platelets are important to the clotting process.

Albumin is a small plasma protein that pushes water out of the

Bleeding Control

• Hemostasis – the control of bleeding

• Three processes of hemostasis

– Blood vessel spasm

– Platelet plug formation

– Blood coagulation

Bleeding Control (cont.)

Bleeding Control (cont.)

• Coagulation

– Fibrinogen converts to fibrin

– Fibrin sticks to damaged area

– Fibrin meshwork traps blood cells and platelets

– Blood clot stops bleeding

Bleeding Control (cont.)

• Thrombus – clot in a vessel with no known injury

• Embolus

– Thrombus that breaks off and moves through blood stream

– Danger of blocking artery

• Pulmonary embolism

• Myocardial infarction

• CVA

Apply Your Knowledge

ARTERIES: Hemostasis occurs to control bleeding First

the blood vessel spasms, then a platelet plug forms, and

lastly, the blood coagulates forming a blood clot.

Explain what happens when a blood vessel is

injured?

ABO Blood Types

• Blood types are distinguished by antigens

Blood Types (cont.)

Blood Types (cont.)

Blood Type Antigen

on RBC in Plasma Antibody Blood That Can Be Received

Apply Your Knowledge

Identify the blood type: ANSWER:

1

4 3

2

– Match for Rh factor

– 1 st unmatched transfusion ~ antibodies develop

– 2 nd time ~ agglutination

Rh Factor

• Erythroblastosis fetalis

– Mother developed antibodies to the Rh antigen in prior

pregnancy – Antibodies attack fetus’ blood

– Infant ~ severe anemia

Rh Factor (cont.)

Apply Your Knowledge

ANSWER: Rh-positive blood contains the Rh antigen

while negative blood does not If a person with negative blood receives a transfusion of Rh-positive

Rh-blood, he will develop antibodies to the Rh antigen If

he receives any subsequent transfusions of

Rh-positive, agglutination will occur.

What is the difference between Rh-positive and

Rh-negative blood and why is it important to know

whether a person is RH-positive or negative before transfusing blood?

Bravo!

Diseases and Disorders of the Blood

System

Disease Description

Anemia The blood does not have enough

RBCs or hemoglobin to carry an adequate amount of oxygen to the body’s cells

Leukemia Bone marrow produces a large

number of abnormal WBCs Sickle cell

anemia Abnormal hemoglobin causes RBCs to change to a sickle shape; abnormal

cells stick in capillaries

Diseases and Disorders of the Blood

System (cont.)

Disease Description

Polycythemia

vera Disease of the bone marrow that results in an abnormally high

number of blood cells, especially RBCs, causing the blood to thicken

Thalassemia Inherited form of anemia; defective

hemoglobin chain causes, small, pale, and short-lived RBCs

Apply Your Knowledge

ANSWER: Anemia is a condition in which a person does not have enough red blood cells or hemoglobin in the

blood to carry an adequate amount of oxygen to body

cells

The doctor has told your patient she has anemia

How would you explain this to her?

Way to

go!

In Summary

27.1 The formed elements in blood include: red blood

cells that are responsible for oxygen and carbon dioxide transport; white blood cells that are

responsible for working with the immune system by

fighting infection; and platelets, which assist in blood

clotting

The liquid component of blood is called plasma and when all clotting factors and formed elements are spun out of plasma, the remaining liquid is called serum

In Summary (cont.)

27.2 Hemostasis refers to the control of bleeding Three

basic processes occur during hemostasis:

1 blood vessel spasm;

2 platelet plug formation; and

3 blood coagulation

Clot formation is coagulation It involves fibrinogen

converting to fibrin, which sticks to the damaged area of the blood vessel, creating a meshwork that entraps blood cells and platelets

In Summary (cont.)

27.3 The four blood types are: A, B, AB and O

The antibodies attached to each type (except AB, which has no antibodies) require that each blood type receive only its specific antigen type during transfusions

So, A receives A or O; B receives B or O; AB as the universal receiver can receive any blood type; and

O, although the universal donor, may receive only type O blood

(Rh-also during pregnancy if the mother is Rh- negative

but the fetus received the Rh-positive antigen from the

father

The effect on the first fetus will be little, but unless treated, any subsequent Rh-positive fetus will suffer effects of erythroblastosis fetalis, as the mother’s blood developed antibodies against the Rh-positive factor during the initial pregnancy

In Summary (cont.)

27.5 There are many different types of blood diseases

described within this chapter

The signs, symptoms, and treatments are as varied

as the diseases themselves

The Common Diseases and Disorders for the Blood System section of this chapter outlines the most

common of these diseases, their signs and symptoms, as well as their treatments

End of Chapter 27

The bond that links

your true family is not

one of blood, but of

respect and joy in

each other’s life

~ Richard Bach