Ch 17 - Blood.docx - Nur 0013 Spring 2014 Chapter 17 Blood...

Nur 0013 Spring 2014
Chapter 17: Blood
Learning Objectives
1. Know the composition of blood
 Make sure you know the normal percentages and ranges for each

 Know what other substances are in each portion of blood
 plasma = plasma proteins, nutrients, gases.
2. Know the structure and function of a RBC, and the structure of the
hemoglobin molecule.
3. Know the types of white blood cells, what their normal percentages are and
what an increase of one type would mean clinically.
4. Be sure to go over the production of formed elements.
 What is a reticulocyte? – What is the significance of seeing them in circulation?
 What causes a clot to form?
 Know the effects of thrombin and fibrin on proper clot formation. Does it matter if you
use the extrinsic or intrinsic clotting pathway?
6. Know how the ABO and Rh blood types are determined.
 What are the hazards of cross-matching blood types?
 What is the danger to a newborn of the Rh factor?
7. Clinical significance of Blood tests
 RBC/WBC counts – know the normal ranges and averages for each
 Hematocrit – what does it test, what are the normal percentages?
1

Nur 0013 Spring 2014
I. Components of Blood
A. General Information
 8% of body weight.
 5-6L in adult males, 4-5L in adult females
 Bright red – Oxygen rich
 Dark red – Oxygen poor
 Functions
 Distribution – oxygen delivery, waste transport, hormones
 Regulation – body temp, pH, fluid volume
 Protection – preventing blood loss, immune fxns.
B. Unformed vs. Formed Elements
1. Unformed – Plasma
2. Formed – RBC, WBC, and Platelets.
II. Unformed Elements
A. Plasma = 55% of blood by volume
 Composed mainly of proteins dissolved in serum
 Plasma is about 92% H2O and 8% proteins
 The important proteins are albumins, globulins, fibrinogen
1. Albumins -(~60%) - maintain osmotic pressure in capillaries.
2. Globulins - (~36%) - transport binding proteins, and some antibodies
3. Fibrinogen – (~4%) - forming blood clots
 Others - Glucose, ions, and gases
III. Formed Elements - RBC
A. Erythrocytes (RBC)  45% of blood by volume
 Not technically cells - 4-6 mill/µL
 Small biconcave discs that are anucleated, which allows for increased surface area
for gas exchange.