Blood
Overview of Blood




Blood is a fluid
connective tissue.
Its total volume is
about 5 liters.
It has many
functions.
Blood is made of
two parts: blood
cells and plasma.
Main Functions





Transport of nutrients and oxygen to cells.
Transport of wastes and carbon dioxide away
from cells.
Delivery of hormones and other regulatory
substances to and from cells and tissues.
Maintenance of homeostasis.
Transport of humoral agent and cells of the
immune system.
Blood is made of two parts:
blood cells and plasma.
Plasma



Its main component is water.
plasma proteins (albumin, globulins，
fibrinogen)
A variety of solutes ,including dissolved
gases (oxygen, carbon dioxide) ,
electrolytes (Na, Mg ,Ca), nutrients
(glucose, lipids) , regulatory substances
(hormones, enzymes) and waste
materials (drugs，urea).
What do blood cells include?



Erythrocytes
neutrophils
granulocytes eosinophils
Leukocytes
basophils
agranulocytes lymphocytes
monocytes
Platelets
Erythrocytes





Anucleate, biconcave
disks.
Quite flexible.
Packed with protein
hemoglobin.
Main function is O2
and co2 transporting
Few reticulocytes.
Leukocytes-granulocytes



Possess two types of granules: specific
granules and azurophilic granules.
Granulocytes have nuclei with two or
more lobes.
Include the neutrophils, eosinophils,
and basophils.
Neutrophils





make up 60-70% of blood leukocytes
Spherical, with a nucleus consisting of
two to five lobes.
cytoplasm is lightly eosinophilic
contain specific granules(including
bactericidal enzymes) and azurophilic
granules
The active phagocytes of bacteria and
other foreign agents.
Eosinophils




make up 1-4% of blood
leukocytes
Nuclei are bilobed.
Large and highly refractile
acidophilic specific
granules.
Associated with allergic
reactions, parasitic
infections.
Eosinophils


Specific granules: major basic protein (MBP),
eosinophil cationic protein(ECP), eosinophil
peroxidase(EPO) and eosinophil-derived
neurotoxin (EDN);
----destruct parasites.
histaminase, arylsulfatase, collagenase.
----attenuate allergic reactions.
Azurophilic granules: acid hydrolases.
----attenuate allergic reactions.
Basophils



Nucleus is divided into
irregular lobes.
Basophilic specific granules fill
the cytoplasm.Specific
granules contain heparan
sulfate, histamine, and slowreacting substance of allergic
reactions.
Participate in allergic reactions
, anticoagulation.
Leukocytes-agranulocytes



Do not have specific granules, but
contain azurophilic granules.
The nucleus is round or indented.
Includes lymphocytes and monocytes.
Lymphocytes




make up 20-40% of blood
leukocytes
The spherical cell has a
densely stained nucleus and a
thin rim of blue-gray cytoplasm.
T cells differentiate and
mature in the thymus;B cells
develop in bone marrow.
main immune cells.
Monocytes





make up make up 3-10% of
blood leukocytes
The largest cells of the
leukocytes.
The nucleus is oval, horseshoe
or kidney shaped and is
eccentrically placed.
The cytoplasm is basophilic
Precursors of the cells of the
mononuclear phagocytotic
system.
Platelets（thrombocytes）


Nonnucleated,
cytoplasmic fragments
derived from
megakaryocytes.
Promote blood clotting
and help repair gaps in
the walls of blood
vessels.
Summary



What is plasma?
What do blood cells include?
What is the characteristics of each kind
of blood cells?
Homework

Review the characteristics of blood cells.