 Consists

of blood cells & plasma
Blood cells = Erythrocytes (RBC’s), Leukocytes
(WBC’s), & Thrombocytes (Platelets)
 Blood
is 55% plasma & 45% blood cells
 Woman has ≈ 5 liters
 Man has ≈ 6 liters

Transport

Nutrients, waste, hormones, enzymes, O2
& CO2
Regulation of body temp due to high
volume of H2O in plasma
 Helps regulate body pH
 Helps regulate water content of
cells/Osmosis
 Clotting: prevents fluid loss
 Protection against pathogens
(immune response, production of
antibodies, destruction of
bacteria/viruses, removal of cellular
debris & allergic reactions)

 91%
water
 7% proteins:
1.
2.
3.
Albumin: maintains osmotic
pressure & water balance
Globulins: antibodies, complements
(immune response) & transport
molecules
Fibrinogens: important role in
clotting
2% solutes:


Ions, nutrients, waste products,
gases, enzymes & hormones
 95%
of blood cell volume; biconcave disks
 No nucleus, simple structures, don’t divide &
live ≈ 120 days
 Composed of a network of protein called
stroma, cytoplasm, lipids (cholesterol) &
hemoglobin (red pigment ≈ 33% of cell’s
volume)
 Function:

Transport O2 & CO2 →→
Hemoglobin allows this
 Hemoglobin:




Globin = protein
Heme = pigment containing 4 iron
atoms
Iron combines with O2 in the lungs &
releases it in tissues; Bright red in
color
Globin at tissues combines with CO2
& releases it at lungs; Dark red in
color
2
subcategories: Granular & Nongranular
 Have nuclei & no pigment; larger than RBC’s
 General function in immune response:

Combat inflammation & infection
 Can
leave the blood stream & move into tissues via
ameboid movement
 Phagocytosis: “cell eating”
Neutrophils: 60% - 70% of WBC’s
1.




Most active in WBC’s response to tissue destruction by
bacteria
Stay in blood for 12 hours & then move to tissues
where they phagocytize (eat) foreign substances
Secrete enzyme Lysozyme that destroys certain
bacteria
Pus contains dead neutrophils, cell debris & fluids
Eosinophils: 2% - 4% of WBC’s
2.


Combat irritants (pollen, dust, pet dander, etc) that
causes allergies
Produce antihistamines
Basophils: 0.5% - 1% of WBC’s
3.


Involved in allergic reactions
Releases heparin (anticoagulant), histamine (inflammatory
substance) & serotonin (a vasoconstrictor)
Monocytes: 3% - 8% of WBC’s
1.


Phagocytotic: eat bacteria, dead cells
&/or cellular debris
Largest; after they leave blood & enter
tissue, they increase in size & are
called Macrophages
Lymphocytes: 20% - 25% of WBC’s
2.



Production of antibodies & play
important role in immune response
Smallest; several types: B & T
lymphocytes
Control cancer cells, destroy
microorganisms & reject foreign tissues
 Disk-shaped
cellular fragments with a
nucleus
 Prevent fluid loss when blood vessels are
damaged
 When
larger blood vessels are
damaged, clotting mechanism
takes over

3
Cut vessel is rough & irregular shaped
stages to clotting/coagulation
Rough surface of vessel causes
platelets to clump together at the
site of the injury
1.


Tissue releases thromboplastin which
produces prothrombin activator
Requires Ca2+, certain proteins &
phospholipids
Ca2+ & prothrombin activator
converts prothrombin into thrombin
Soluble fibrinogen is converted into
insoluble fibrin
2.
3.
Thrombin catalyzes the reaction
Fibrin forms long threads that act like
a net = CLOT



Clot forms & traps blood cells & platelets
in the fibrin threads & bleeding stops
 Syneresis:
clot retraction; tightening of clot so wound
gets smaller & smaller
 Serum (blood plasma minus clotting factors) surrounds
wound under clot & hemorrhage is stopped
 Blood vessel repairs itself
 Fibronolysis occurs: blood clot dissolves
 Build
up of cholesterol mass
(Plaque) on smooth walls of
UNDAMAGED blood vessels can cause
clot formation




Called Thrombosis & clot is called a
Thrombus
Thrombus may dissolve or a piece can
dislodge & get transported in blood =
Embolus
Embolus can get stuck in a vessel &
cut-off circulation = Embolism
If tissues are killed = Infarction
 Agglutination:
clumping of RBC’s, A.K.A transfusion
reaction
 Caused by reaction between antibodies in plasma &
surface antigens on RBC’s
 Caused by mismatched blood types

Headache, difficulty breathing, face flushed, pain in neck,
chest & lower back, jaundice & kidney failure


Presence or absence of antigens on RBC surface: antigen A &
antigen B
Inherited; 4 possible antigen combinations:
A only: Type A
 B only: Type B
 A & B : Type AB
 Neither A nor B: Type O


Antibodies are formed during infancy against the ABO antigens NOT
present on our own RBC’s
Type A: antibody anti-B
Universal
 Type B: antibody anti-A
Recipient
 Type AB: neither antibody →


Type O: both anti-A & anti-B
Universal
Donor




Inherited; named after Rhesus monkey where antigen 1st
discovered
If antigen D is found on RBC, the blood is Rh positive
If the RBC lacks the antigen, blood is Rh negative
Anti-Rh antibodies only develop after initial exposure to
Rh-positive blood
Rh-negative person receives transfusion from Rh-positive
person = no reaction (1st time) but anti-Rh antibodies form
 If 2nd exposure happens, agglutination occurs
