Blood
Erythrocytes (RBC), Leukocytes (WBC),
Platelets, & Plasma
Blood
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Function
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Components
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Transport nutrients, wastes, body
heat, etc thru bv
55% Plasma – fluid matrix
45% Erythrocytes (rbc) – O2
transport
>1% Leukocytes (wbc) – protect
body
>1% Platelets – cell fragments used
for clotting
Fun Facts
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4-6 liters of blood per person
7% of body weight
Temp 38oC
pH between 7.35 – 7.45
Salty-metallic taste
5x thicker than water
Blood Plasma
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90% water
Distributes body heat through out body
Contains dissolved nutrients, salts, resp.
gases, hormones, plasma proteins, wastes,
and products of cell metabolism
Plasma Proteins
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Albumin – maintains osmotic pressure of blood
Clotting Proteins – prevents blood loss from injured
bv
Antibodies – protect body from pathogens
Erythrocytes (rbc)
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Biconcave disc shape (large s.a. to volume)
Anucleate - lacks a nucleus
Lack cellular organelles including mitochondria (so do
not use O2 themselves)
Hemoglobin (Hb) – Fe carries 4 molecules O2
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1rbc carries 1 billion molecules O2
Avg male 13-18g Hb/100ml blood
Avg female 12-16g Hb/100ml blood
Anemia – low rbc or low Hb
Polycythemia – high rbc (high alt or bone marrow
cancer)
Last 120 days – broken down by liver and spleen
Leukocytes (wbc)
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Live days, months, or even years
About 4,000-11,000 wbc/mm3 blood
Can move in and out of bv
Respond to chems sent out from damaged cells
When in action – body doubles #wbc w/in hrs
Leukocytosis
 >11,000 wbc indicates bacterial or viral infection
Leukopenia
 Decrease in wbc
 Typically due to corticosteroids or anticancer drugs
Leukemia
 Cancer of bone marrow
 Too many immature wbc to defend off pathogens
Types of Leukocytes
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Granulocytes – granule containing wbc w/lobed nuclei
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Neutrophils – phagocytes at site of infection
Eosinophils – increases w/allergies and infections by parasitic
worms
Basophils – histamine (chem incr. wbc to site) containing
granules
Agranulocytes – lack cytolasmic granules
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Lymphocytes – in lymphatic tissue (T cells and B cells)
Monocytes – largest wbc
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Become macrophages when enter tissues
Fight off chronic infections
Platelets & Hemostasis
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Platelets – irregularly shaped,
needed for clotting process
Hemostasis – local stoppage of
blood flow
Platelet Plug Forms
Platelets become sticky and cling
to damaged site
Release clotting factors to
increase platelets to site to
create plug
Vascular Spasms Occur
Serotonin is released to cause bv
to spasm and narrow to
decrease blood loss
Coagulation
Injured tissue releases “Tissue
Factor” (TF)
TF combines with Ca+2, vitamin
K, and PF3  prothrombin
Prothrombin converted to
thrombin
Thrombin + fibrinogen  Fibrin
Fibrin traps rbc to start clot and
pulls ruptured bv closer together
Hematopoiesis – Blood Cell Formation
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Hemocytoblast
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stem cell in rbm takes 3-5 days to form
rbc
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Rbc divides and synthesizes Hb
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Incr. Hb ejects nucleus and most
organelles
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Enters bloodstream
Rbc falls apart in 100-120 days
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Eliminated by phagocytes, spleen, and
liver
Erythropoietin
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hormone controls rate of rbc production
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Produced by kidneys and targets bone
marrow
Thrombopoietin – increases production of
platelets
Interleukins and colony stimulating factors
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increase production of wbc from bone
marrow
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Released in response to inflam chems,
bacteria, or toxins
Blood Types & Transfusions
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Phlebotomist – hs degree +
training + exam
ABO Blood Groups
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Rh Blood Groups
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Based on 2 antigens A&B
Antibodies formed in infancy
Determined by anti-A, and antiB serums
Once Rh- contacts Rh+
produces antibodies
Pregnant Rh- mom carrying
Rh+ baby
RhoGAM prevents moms
antibodies from attacking fetus
Hemolysis – rupture of rbc
Fetal Hb vs. Adult Hb
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By day 28 of fetal
development – embryonic
blood cells circulate in
blood vessels
Fetal Hb (HbF) differs from
adult HbA
HbF has a greater ability to
pick up O2 b/c fetal blood
less O2 rich than mothers
If fetal rbc destroyed so
quick that liver cannot rid of
bile fast enough  causes
infant jaundice