Transcript Red blood - cloudfront.net

Cardiovascular System
Blood
19-1
Functions of Blood
• Transport of:
– Gases, nutrients, waste products
– Processed molecules
– Regulatory molecules
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Regulation of pH and osmosis
Maintenance of body temperature
Protection against foreign substances
Clot formation
19-2
Composition of Blood
19-3
Plasma
• Liquid part of blood
– Pale yellow made up of 91% water, 9% other
• Colloid: Liquid containing suspended
substances that don’t settle out
– Albumin: Important in regulation of water
movement between tissues and blood
– Globulins: Immune system or transport
molecules
– Fibrinogen: Responsible for formation of blood
clots
19-4
Formed Elements
• Red blood cells (erythrocytes)
• White blood cells (leukocytes)
– Granulocytes
• Neutrophils
• Eosinophils
• Basophils
– Agranulocytes
• Lymphocytes
• Monocytes
• Platelets (thrombocytes)
19-5
Production of Formed Elements
• Hematopoiesis or hemopoiesis: Process of
blood cell production
• Stem cells: All formed elements derived
from single population
– Proerythroblasts: Develop into red blood cells
– Myeloblasts: Develop into basophils,
neutrophils, eosinophils
– Lymphoblasts: Develop into lymphocytes
– Monoblasts: Develop into monocytes
– Megakaryoblasts: Develop into platelets
19-6
Hematopoiesis
19-7
Erythrocytes
• Structure
– Biconcave, anucleate
• Components
– Hemoglobin
– Lipids, ATP, carbonic
anhydrase
• Function
– Transport oxygen from
lungs to tissues and
carbon dioxide from
tissues to lungs
19-8
Hemoglobin
• Consists of:
– 4 globin molecules: Transport carbon dioxide (carbonic
anhydrase involved), nitric oxide
– 4 heme molecules: Transport oxygen
• Iron is required for oxygen transport
19-9
Erythropoiesis
• Production of red blood cells
– Stem cells
proerythroblasts
early erythroblasts
intermediate
late
reticulocytes
• Erythropoietin: Hormone to stimulate RBC
production
19-10
Hemoglobin Breakdown
19-11
Leukocytes
• Protect body against • Types
– Neutrophils: Most common;
microorganisms and
phagocytic cells destroy bacteria
remove dead cells and
(60%)
debris
– Eosinophils: Detoxify chemicals;
• Movements
reduce inflammation (4%)
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Ameboid
Diapedesis
Chemotaxis
Passive Immunity
Active Immunity
Antigen – Antibody
– Basophils: Alergic reactions;
Release histamine, heparin increase
inflam. response (1%)
– Lymphocytes: Immunity 2 types; b
& t Cell types. IgG-infection, IgMmicrobes, IgA-Resp & GI, IgEAlergy, IgD-immune response
– Monocytes: Become macrophages
19-12
Leukocytes
19-13
Thrombocytes
• Cell fragments
pinched off from
megakaryocytes in red
bone marrow
• Important in
preventing blood loss
– Platelet plugs
– Promoting formation
and contraction of clots
19-14
Hemostasis
• Arrest of bleeding
• Events preventing excessive blood loss
– Vascular spasm: Vasoconstriction of damaged
blood vessels
– Platelet plug formation
– Coagulation or blood clotting
19-15
Platelet Plug Formation
19-16
Coagulation
• Stages
– Activation of
prothrombinase
– Conversion of
prothrombin to
thrombin
– Conversion of
fibrinogen to fibrin
• Pathways
– Extrinsic
– Intrinsic
19-17
Clot Formation
19-18
Fibrinolysis
• Clot dissolved by
activity of plasmin,
an enzyme which
hydrolyzes fibrin
19-19
Blood Grouping
• Determined by antigens (agglutinogens) on
surface of RBCs
• Antibodies (agglutinins) can bind to RBC
antigens, resulting in agglutination
(clumping) or hemolysis (rupture) of RBCs
• Groups
– ABO and Rh
19-20
ABO Blood Groups
19-21
Agglutination Reaction
19-22
Rh Blood Group
• First studied in rhesus monkeys
• Types
– Rh positive: Have these antigens present on
surface of RBCs
– Rh negative: Do not have these antigens present
• Hemolytic disease of the newborn (HDN)
– Mother produces anti-Rh antibodies that cross
placenta and cause agglutination and hemolysis
of fetal RBCs
19-23
Erythroblastosis Fetalis
19-24
Diagnostic Blood Tests
• Type and crossmatch
• Complete blood count
– Red blood count
– Hemoglobin measurement
– Hematocrit measurement
• White blood count
• Differential white blood
count
• Clotting
19-25
Blood Disorders
• Erythrocytosis: RBC
overabundance
• Anemia: Deficiency of
hemoglobin
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Iron-deficiency
Pernicious
Hemorrhagic
Hemolytic
Sickle-cell
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Hemophilia
Thrombocytopenia
Leukemia
Septicemia
Malaria
Infectious
mononucleosis
• Hepatitis
19-26
Anemia cont…
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Pernicious anemia is a type of anemia. The term
"anemia" usually refers to a condition in which the
blood has a lower than normal number of red blood
cells. In pernicious anemia, the body can't make
enough healthy red blood cells because it doesn't
have enough vitamin B12.
Without enough vitamin B12, your red blood cells
don't divide normally and are too large. They may
have trouble getting out of the bone marrow—a
sponge-like tissue inside the bones where blood cells
are made.
Without enough red blood cells to carry oxygen to
your body, you may feel tired and weak. Severe or
long-lasting pernicious anemia can damage the heart,
brain, and other organs in the body.
Pernicious anemia also can cause other problems,
such as nerve damage, neurological problems (such
as memory loss), and digestive tract problems.
People who have pernicious anemia also may be at
higher risk for weakened bone strength and stomach
cancer.
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Hemolytic anemia occurs when the bone
marrow is unable to replace the red blood
cells that are being destroyed
Leukemia:
When you have leukemia, the bone marrow
starts to make a lot of abnormal
whiteblood cells, called leukemia cells. They
don't do the work of normal white blood
cells, they grow faster than normal cells, and
they don't stop growing when they should.
Over time, leukemia cells can crowd out the
normal blood cells. This can lead to serious
problems such as anemia, bleeding, and
infections. Leukemia cells can also spread to
the lymph nodes or other organs and cause
swelling or pain.
19-27
Blood disorders
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Sepsis is an extreme immunesystem response
to an infection that has spread throughout the
blood and tissues
19-28