Download ST120 Blood

Artery
White blood cells
Platelets
Red blood cells
• Deliver O2
• Remove metabolic wastes & CO2
• Maintain temperature, pH, and fluid volume
• Protection from blood loss- platelets
• Prevent infection- antibodies and WBC
• Transport hormones
• Wound-healing activies
Plasma-60%
Buffy coat-<1%
Formed
elements-40%
92% Water
8% Solutes:
• Proteins
Albumin (60 %)
Alpha and Beta Globulins
Gamma Globulins
fibrinogens
• Gas
• Electrolytes
• Organic Nutrients
Carbohydrates
Amino Acids
Lipids
Vitamins
• Hormones
• Metabolic waste
CO2
Urea
• Leukocytes
• Platelets
• Erythrocytes (red blood cells)
• Leukocytes (white blood cells)
• Platelets (thrombocytes)
Erythrocytes
Erythrocyte7.5m in dia
 Anucleate- so can't reproduce; however, repro
in red bone marrow
 Hematopoiesis- production of RBC
 Function- transport respiratory gases
 Hemoglobin
 Lack mitochondria. Why?
 1 RBC contains 280 million hemoglobin
molecules
 Men- 4.3 to 5.9 million cells/mm3
 Women- 3.5 to 5 million cells/mm3
 Life span 100-120 days and then destroyed in
spleen (RBC graveyard)
(reticuloendothelial system)
Hematopoiesis
• Hematopoiesis (hemopoiesis):
blood cell formation
–Occurs in red bone marrow of
axial skeleton, girdles and
proximal epiphyses of humerus
and femur
Hematopoiesis
• Hemocytoblasts (hematopoietic stem
cells)
– Give rise to all formed elements
– Hormones and growth factors push the cell
toward a specific pathway of blood cell
development
• New blood cells enter blood sinusoids
Erythropoiesis
• Erythropoiesis: red blood cell
production
– A hemocytoblast is transformed into
a proerythroblast
– Proerythroblasts develop into early
erythroblasts
Erythropoiesis
– Phases in development
1. Ribosome synthesis
2. Hemoglobin accumulation
3. Ejection of the nucleus and
formation of reticulocytes
– Reticulocytes then become
mature erythrocytes
Stem cell
Hemocytoblast
Committed
cell
Developmental pathway
Proerythroblast
Early
Late
erythroblast erythroblast
Phase 1
Ribosome
synthesis
Phase 2
Hemoglobin
accumulation
Phase 3
Ejection of
nucleus
Normoblast
Reticulo- Erythrocyte
cyte
Figure 17.5
Regulation of Erythropoiesis
• Too few RBCs leads to tissue hypoxia
• Too many RBCs increases blood
viscosity
• Balance between RBC production and
destruction depends on
– Hormonal controls
– Adequate supplies of iron, amino acids,
and B vitamins
Hormonal Control of
Erythropoiesis
• Erythropoietin (EPO)
–Direct stimulus for erythropoiesis
–Released by the kidneys in
response to hypoxia
Hormonal Control of
Erythropoiesis
• Causes of hypoxia
– Hemorrhage or increased RBC destruction
reduces RBC numbers
– Insufficient hemoglobin (e.g., iron
deficiency)
– Reduced availability of O2 (e.g., high
altitudes)
Hormonal Control of
Erythropoiesis
• Effects of EPO
– More rapid maturation of committed bone
marrow cells
– Increased circulating reticulocyte count in
1–2 days
• Testosterone also enhances EPO
production, resulting in higher RBC
counts in males
Formation & Destruction of RBCs
Anemia- when blood has low O2 carrying
capacity; insufficient RBC or iron deficiency.
Factors that can cause anemia- exercise, B12
deficiency
Polycythemia- excess of erythrocytes, 
viscosity of blood;
8-11 million cells/mm3
Usually caused by cancer, tissue hypoxia,
dehydration; however, naturally occurs at high
elevations
Sickle-cell anemiaHbS results from a change in just one of
the 287 amino acids in the  chain in the
globin molecule.
Found in 1 out of 400 African Americans.
Abnormal hemoglobin crystalizes when
O2 content of blood is low, causing RBCs
to become sickle-shaped.
5,000-10,000 cells/mm 3
Never let monkeys eat bananas
Granulocytes
Neutrophils- 50-70%
Eosinophils- 1-3%
Basophils- 0.25-0.5%
Agranulocytes
Monocytes- 2-6%
Lymphocytes- 25-40%
Basophil
Eosinophil
Lymphocyte
platelet
Neutrophil
Monocyte
eosinophil
neutrophil
monocyte
RBC
neutrophil
monocyte
lymphocyte
basophil
lymphocyte
ID WBC’s
•
Leukopenia
•
•
Abnormally low WBC count—drug induced
Leukemias
•
Cancerous conditions involving WBCs
• Mononucleosis
•
highly contagious viral disease caused by
Epstein-Barr virus; excessive # of
agranulocytes; fatigue, sore throat, recover
in a few weeks
Platelets
• Small fragments of megakaryocytes
• Formation is regulated by
thrombopoietin
Stem cell
Developmental pathway
Hemocytoblast
Promegakaryocyte
Megakaryoblast
Megakaryocyte
Platelets
Figure 17.12
Hemostasis- stoppage of bleeding
Platelets: 250,000-450,000 cells/mm3
Tissue Damage
Platelet Plug
Clotting Factors
Hemostasis:
1. Vessel injury
2. Vascular spasm
3. Platelet plug formation
4. Coagulation
Hemostasis
(+ feedback)
Clotting Factors
thromboplastin
Prothrombin
Thrombin
Fibrinogen
Fibrin
Traps RBC & platelets
Platelets release thromboplastin
Blood
Clot
RBC
Platelet
Fibrin thread
Disorders of Hemostasis
• Thromboembolytic disorders:
undesirable clot formation
• Bleeding disorders: abnormalities that
prevent normal clot formation
Thromboembolytic Conditions
• Thrombus: clot that develops and persists in
an unbroken blood vessel
– May block circulation, leading to tissue death
• Embolus: a thrombus freely floating in the
blood stream
– Pulmonary emboli impair the ability of the body to
obtain oxygen
– Cerebral emboli can cause strokes
Thromboembolytic Conditions
• Prevented by
– Aspirin
• inhibits thromboxane A2
– Heparin
• Anticoagulant used clinically for pre- and
postoperative cardiac care
– Warfarin
• Used for those prone to atrial fibrillation
Thrombocytosis- too many platelets due to
inflammation, infection, or cancer
Thrombocytopenia- too few platelets
• causes spontaneous bleeding
• due to suppression or destruction of bone
marrow (e.g., malignancy, radiation)
– Platelet count <50,000/mm3 is diagnostic
– Treated with transfusion of concentrated
platelets
• Impaired liver function
– Inability to synthesize procoagulants
– Causes include vitamin K deficiency,
hepatitis, and cirrhosis
– Liver disease can also prevent the
liver from producing bile, impairing fat
and vitamin K absorption
Bleeding Disorders
• Hemophilias include several similar
hereditary bleeding disorders
• Symptoms include prolonged
bleeding, especially into joint
cavities
• Treated with plasma transfusions
and injection of missing factors
Hemophiliac- a sex-linked recessive trait, primarily
carried by males (x chromosome)
Type A
Type B
Type AB
Type O
Blood type is based on the presence of 2 major antigens in
RBC membranes-- A and B
Blood type
Antigen
Antibody
A
A
anti-B
B
B
anti-A
A&B
AB
no anti body
Neither A or B
O
anti-A and anti-B
Antigen- protein on the surface of a RBC membrane
Antibody- proteins made by lymphocytes in plasma which are
made in response to the presence of antigens.
They attack foreign antigens, which result in clumping
(agglutination)
ABO Blood Types
b
b
b
b
b
b
Type
A
Produces
anti-B
antibodies
b
b
ABO Blood Types
a
a
a
a
a
a
Type
B
Produces
anti-A
antibodies
a
a
a
a
ABO Blood Types
Type
AB
Produces
neither
anti-A nor
anti-B
antibodies
ABO Blood Types
b
a
b
a
a
b
a
b
a
a
b
a
b
Type
O
Produces
both anti-A
and anti-B
antibodies
b
a
a
a
b
Rh Factor and Pregnancy
RH+ indicates protein
RH- indicates no protein
Rh Factor
and
Pregnancy
Rh+ mother w/Rh- baby– no problem
Rh- mother w/Rh+ baby– problem
Rh- mother w/Rh- father– no problem
Rh- mother w/Rh- baby-- no problem
RhoGAM used @ 28 weeks
Type AB- universal recipients
Type O- universal donor
Rh factor:
Rh+ 85% dominant in pop
Rh- 15% recessive
Blood Type
Clumping
Antibody
A
antigen A
anti-A serum
antibody anti-b
B
antigen B
anti-B serum
antibody anti-a
AB
antigen A & B
anti A & B serum
O
neither A or B
no clumping w/ either anti A or B anti-a, anti-b
-
Blood Type & Rh
How Many Have It
O
O
A
A
B
B
AB
AB
1 person in 3
1 person in 15
1 person in 3
1 person in 16
1 person in 12
1 person in 67
1 person in 29
1 person in 167
Rh Positive
Rh Negative
Rh Positive
Rh Negative
Rh Positive
Rh Negative
Rh Positive
Rh Negative
Frequency
37.4%
6.6%
35.7%
6.3%
8.5%
1.5%
3.4%
.6%
1.
2.
3.
4.
5.
6.
7.
8.
INQUIRY
What is an erythrocyte, leukocyte, and thrombocyte?
What 2 things do red cells lack compared to white
cells?
What dietary component is needed for the production
of red blood cells?
The largest cells in the blood that leave the
bloodstream to become macrophages are ____.
In an acute infection, the white cell count would show
as ______.
Erythroblastosis fetalis , also known as hemolytic
newborn disease, occurs in ____ mothers carrying
____ fetuses.
What antigens and antibodies found on AB red cells?
In a transfusion, what type blood can you give a type
O person?