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Chapter 10
Blood
• Blood transports nutrients, wastes
and body heat from one part of the
body to another.
Composition of Blood
• Blood is a fluid tissue (complex
connective tissue). It has solid and
liquid components.
Physical Characteristics
of Blood
•
•
•
•
Opaque, sticky
Metallic taste
Salty
Scarlet (lots of oxygen), Dull Red
(low oxygen)
• Viscous (5 X water)
• Alkaline pH 7.35-7.45
• Temperature 38 C or 100.4 F
• 8% of body weight
• Volume in males is 5 to 6 liters
Components of Blood
1.
2.
Plasma – non-living fluid matrix
Formed elements – living blood
cells
Percent Composition
of Blood
• 45% Erythrocytes or Red Blood Cells
• < 1% Leukocytes or WBC and Platelets
• 55% Plasma
Plasma
• The liquid part of the blood
• Straw colored fluid
• 100’s of substances are dissolved
in it (nutrients, metal ions, salts,
respiratory gases, hormones,
plasma proteins, various wastes
and products of cell metabolism)
The Three Plasma
Proteins
1.
2.
3.
Albumin – contributes to the
osmotic pressure of blood, keeps
water in the blood stream
Clotting Proteins – cut down on
blood loss
Antibodies – protection from
pathogens
- The composition of blood is kept
constant by homeostatic
mechanisms
Formed Elements – Three
Kinds – Blood Cells
1. Erythrocytes (Red
Blood Cells) or RBC’s
• Bring oxygen to all body cells
• Flattened discs with depressed centers,
increases surface area
• Outnumber white blood cells 1000 to 1
• Make blood viscous
• Contain hemoglobin – an iron containing
protein that transports oxygen
Anemia
• Occurs when there is a decrease in
the oxygen carrying ability of blood
• Decrease in RBC or RBC’s with
deficient hemoglobin content
Sickle Cell Anemia
• Red blood cells are sickle shaped and clog up in
small blood vessels
• Decrease in oxygen delivery
• Causes pain
• Caused by one change in an amino acid
• Offers a resistance to malaria
Polycythemia
• Abnormal increase in RBC
• Causes: bone marrow cancer, high
attitudes
• Problem: blood to viscous –
impairs circulation
2. Leukocytes or White
Blood Cells or WBC’s
• Crucial to the bodies defense against
disease
• Protective moveable army that helps
defend the body against damage by
bacteria, parasites, viruses and tumor
cells
• Move by ameboid movement
There are two types
of WBC
Groups based on visible granules or
not
Granulocytes
a.
b.
c.
Neutrophils
Eosinophils
Basophils
Agranulocytes
a.
b.
Lymphocytes
Monocytes
Leukemia
• When the bone marrow becomes
cancerous and makes lots of WBC
• The WBC do not develop and do
not prey on disease good
3. Platelets
• Needed for clotting
Hematopoiesis
• The process of blood cell formation
occurs in: Red Bone Marrow (flat
bones of skull, pelvis, ribs,
sternum, humerus, femur)
• All of the formed elements arise
from a common type of stem cell
called a hemocytoblast, which is in
the red bone marrow
Hemocytoblast
Lymphoid Stem Cell
Lymphocytes (WBC)
Myeloid Stem Cell
other WBC’s
RBC’s
Platletes
Erythoproteins
• Control the rate of production and
which types of cells are produced.
Hemostasis
• Stoppage of blood flow or clotting
Blood Clots in 3
Stages:
1.
2.
3.
When a blood vessel is damaged
platelets and RBC spill into the
damaged tissues
Platelets increase in number and
begin to attach to damaged
surfaces. Strands of a protein
called fibrin are formed.
Blood cells, platelets and strands
of fibrin become enmeshed in a
fibrous tangle called a clot.
Disorders of
Hemostasis
1.
Undesirable Clotting – forms in
intact blood vessels especially
the legs
Thrombus – clot that develops and
persists in an unbroken blood
vessel
Thrombus Types
a.
b.
Coronary thrombosis – forms in
the blood vessels serving the
heart muscle and a fatal heart
attack
Embolus – thrombus that breaks
away from the vessel wall and
floats freely into the blood stream
2. Bleeding Disorders
a.
b.
Thrombocytopenia – insufficient
number of circulating platelets –
normal movements can cause
spontaneous bleeding
Hemophilia – genetic – caused by
a lack of any of the factors
needed for clotting – blood does
not clot
Blood Groups and
Transfusions
• Loss of 15-30% leads to pallor and
weakness.
• 30% or more causes severe shock
and can be fatal
Human Blood Groups
• Cell membrane of a RBC has
genetically determined proteins
(antigens) which ID a person.
• Antigen – substances that the body
recognizes as foreign – stimulates
an immune response
• Antibodies – recognize antigens as foreign
Agglutination
•
•
•
•
Binding of antibodies to antigens
Causes RBC to clump
Clogs blood vessels
RBC’s lyse and release their
hemoglobin (no oxygen)
• Results – kidney failure, fever,
chills. Nausea, vomiting
• There are 30 common RBC
antigens.
• The main ones: Antigens of A, B, O
and Rh
ABO Blood Groups
• Table 10.2 pg 306
• If you have type A blood your body
forms Anti B antibodies
• If you have type B blood your body
forms Anti-A antibodies.
• If you have type O blood your body
forms Anti- A and Anti-B
antibodies.
• Type O – Universal donor
• If you have type AB blood your
body forms no antibodies
• Type AB universal recipient
Rh Blood Groups
• People are either Rh+ and have the
Rh anitgen or they are Rh- and then
they do not have the Rh antigen.
• 85% of people are Rh+
• Antibodies are formed when the
wrong blood is added.
• Rh antibodies are produced by Rhpeople who come in contact with
Rh+ blood. RBC’s that are Rh+ are
attacked and destroyed.
Rh Factor and
Pregnancy
• Rh- female pregnant with an Rh+
kid
• Baby is born healthy but mom
begins to make Anti-Rh+ antibodies
• 2nd Rh+ kid – her antibodies will go
through the placenta and destroy
the babies RBC’s
Hemolytic Disease of
the Newborn
• Babies RBC’s are destroyed – baby
is anemic and hypoxic
• Brain damage and death results if
the baby does not get transfusions.
Blood Typing
• Blood is tested by mixing it with
two different types of immune
serums – Anti A and Anti B.
Agglutination
happens when:
• Type A is mixed with Anti-A but not
Anti-B
• Type B is mixed with Anti-B but not
Anti-A
• Figure 10.7 pg 308
The End