Transcript AH chp 12 ppx

Circulatory System
Chapter 12
Structure & Function
• Includes both lymph & blood
• Both work to maintain
homeostasis
• Give the body immunity
Blood
• Hematology-study of blood
• 5-6 liters of blood
• More than 60,000 miles of vessels
carry blood in the body
• Makes up about 8% of body weight
Formed Elements
• Red blood cells
• White blood cells
• Platelets
(thrombocytes)
• Each drop of blood
contains the following:
– 5 million RBC’s
– 10,000 WBC’s
– 250,000 platelets
Red Blood Cells
• AKA-erythrocytes
• 25 trillion RBC’s circulate
• Each RBC lives 90-120 days
• New cells made by red
marrow or myeloid tissue in
bones
• Hemopoiesis is the process
of making new red cells
which a few million are
made each second
• Liver and spleen remove
dead RBC’s and reuse the
material
Hemoglobin
• Provides the RBC’s with red pigment
• Heme-iron compound
• Globin-protein molecule
• Carry oxygen to the tissue
• Single blood cell contains several
molecules of hemoglobin
White Blood Cells
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AKA-leukocyte
Fights disease & infections
Larger than RBC’s
Live about 9 days
Can move out of blood vessels
Types of WBC’s
• Neutrophils-engulf & digest bacteria
• Basophils-create anti-inflammatory response
• Eosinophils-defend from allergic reactions
• Lymphocytes-help produce antibodies
• Monocytes-help remove foreign materials &
bacteria
Platelets
• AKA-thrombocytes
• Smallest blood cell
• Promotes clotting to prevent blood
loss
• Live only 5-9 days
Plasma
• Pale yellow liquid left
after formed elements
removed from blood
• Whole blood is 55%
plasma
• Contains 90% water &
10% proteins
• Contains nutrients,
electrolytes, oxygen,
enzymes, hormones, &
wastes
• Helps fight infection &
assist with clotting
• Inherited characteristic
Blood Typing
• Type is determined by
looking at specific
antigens found on
surface of RBC
• Clumping of
incompatible cells
blocks the blood vessels
and may cause death
Blood Typing
Group
Antigen
Marker
Antibody
Compatible
Donor
A
A
Anti-B
A, O
B
B
Anti-A
B, O
AB
A, B
None
A, B, AB,
O
O
None
Anti-A
Anti-B
O
• Four Types
RH factor
• Rh factor
– Antigen
– Found in the red blood cells
– 85% of North Americans are Rhpositive
RH-Factor
• Giving Rh-positive blood to
a person with Rh-negative
blood can be fatal
• Considered a foreign
particle to the Rh
person’s blood and tries
to combat it by forming
antibodies
• Rh factor also important in
Rh-negative mother having
a second Rh-positive baby
Blood Type
O positive
O negative
A positive
A negative
B positive
B negative
AB positive
AB negative
Prevalence
38%
7%
34%
6%
9%
2%
3%
1%
Lymph System Functions
• Maintain body
fluid balance
• Helps with
immunity
Lymph System
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Lymph is a watery substance formed from fluid that filters
into the body tissue or interstitially
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Works independently of circulatory system
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Lymph tissue is more porous than capillaries which allows fats,
proteins, & some cancer cells to be transported.
•
Lymph fluid only travels one direction which is toward the
heart
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Fluid is moved to the capillaries where is drained from
lymphatic ducts into the blood
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Circulates very slowly depends on muscle movement to
circulate
Lymphatic Tissues
• consist of:
– Tonsils
• Found in back of throat
– Thymus
• Disintegrates after puberty
– Spleen
• Can store 1 pint of blood
• Filters bacteria &foreign substances
• Makes lymphocytes & monocytes
– Nodes
• Biological filters that remove bacteria & cancerous cells
– Lymph vessels
Immunity
• Immune response takes on two
forms:
– Non-specific
• As a barrier of the skin, mucous
membranes, tears, and the leukocytes
• In leukocytes, antibodies are formed in
response to antigens or foreign materials
that enter the body
– May be a localized or systemic
reaction
Immunity
• Specific Response
– Acquired
• Natural
– Exposure to agent unintentionally
» Babies being breastfed
• Artificial
– Exposure intentionally
» vaccines
– Inherited immunity
• Developed before birth
• Genetic trait
Assessment
• Hemoglobin (Hgb) test measures
the amount of oxygen-carrying
ability of the blood
• Hematocrit (Hct) measures the
volume of erythrocytes in the
blood
Assessment continued
• Red blood cell (RBC) counts
determine the number of
circulating red blood cells in 1
mm3 of blood
• Platelet count measure the
number of platelets in 1 mm3 of
blood to determine clotting
ability
Disorders
• Acquired immunodeficiency syndrome
– Dysfunction of the immune system caused by
a virus
• Allergy
– Hypersensitive response by the immune
system to an outside substance
• Anemia
– The blood has an inadequate amount of
hemoglobin, red blood cells, or both
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Iron deficiency
Pernicious
Aplastic anemia
Sickle cell anemia
Disorders
• Aneurysm
– Weakening of vessel wall
• Autoimmune
– Conditions in which the immune
system of the body turns against itself
• Erythroblastosis fetalis
– A condition in an unborn baby in
which the mother forms antibodies
against the antigens in the baby’s
blood
• Hemophilia
– A rare sex-linked genetic blood
disease in which the blood is
missing a clotting factor
• Hepatitis
– A viral infection of the blood
• Hodgkin’s disease
– A malignant cancer of the lymph
system
• Leukemia
– Also called blood cancer, is an
abnormal malignant increase in the
number and longevity of white
blood cells
• Phlebitis
– Inflammation of the vein
• Most often caused by a formation of a
clot
• Polycythemia
– An abnormal increase in the
number of blood cells, making the
blood thicker and slower flowing
• Septicemia
– Called blood poisoning, is an
infection that occurs when
pathogens enter the blood
• Sickle cell anemia
– A genetic condition that results in
malformed red blood cells
• Splenomegaly
– An enlargement of the spleen
caused by an acute infection such
as mononucleosis or anemia
• Thrombocytopenia
– A decrease in the number of
platelets in the blood
• Thrombosis
– A condition in which a blood clot,
called a thrombus, forms in the
blood vessels