Download Document

Blood is made up of about 60%
liquid (plasma) and 40% formed
elements which consist of
erythrocytes (red blood cells)
leukocytes (white blood cells) and
thrombocytes (platelets)
Blood :
*transports oxygen from the lungs
*collects waste products and
delivers it to the excretory organs
for disposal
*carries hormones from ductles
glands
*maintains fluid content of the
tissue
*regulates temperature
Blood is about 5 times as viscous
as water and the color varies
from bright red to dark purple
depending on the oxygen
content.
Plasma:
This liquid portion of the blood is
straw colored and is
approximately 90% water and
10% solutes. Protein makes up
the majority of the solutes. One
of these proteins is fibrinogen
which is important for blood
clotting
If the clotting factors are
removed the resulting liquid is
called serum
Blood cells:
all blood cells begin as stem cells,
which are undifferentiated cells.
In young animals blood cells are
produced in all bone marrow. In
adults blood cells are produced in
red bone marrow
Proerythrocytes=erythrocytes
myeloblasts=granulocytes
lymphoblasts=lymphocytes
monoblasts=monocytes
megakaryoblasts=thrombocytes
Erythrocytes are non-nucleated
biconcave disks that carry hemoglobin.
This iron containing pigment combines
with oxygen and gives blood the red
color. Hemoglobin not only combines
with oxygen in the lungs to carry it
throughout the body but also combines
with carbon dioxide and carries it to the
lungs for disposal
The average life span of
erythrocytes is 120 days but can
vary. If iron is lacking then the
hemoglobin is reduced as well as
the total number of erythrocytes
resulting in a decreased ability to
carry oxygen and waste
Leukocytes:
Everybody say “yeah for
leukocytes!!!!!!”
There are five types of leukocytes
and they are divided into two
groups:
Granulocytes
Agranulocytes
Granulocytes: these originate in
the bone marrow and contain
fine granules. These are further
classified based on staining
characteristics.
Segmented neutrophils:
These cells are the first line of defense and
phagocytize invaders as well as build a wall against
invaders
Eosinophils:
These detoxify foreign proteins from allergens or
parasitic infections.
Basophils:
These have purple to blue staining granules. There
function isn’t clear but they may prevent coagulation
in blood vessels
Agranulocytes:
“yeah agranulocyte, it’s your
birthday, !!!!!!!”
These cells originate in the lymph
system and have a round or
horseshoe shaped nucleus
Lymphocyte:
These have a rounded nucleus and function in
phagocytosis and immune response.
Monocytes:
these have a horseshoe shaped nucleus and function
primarily as phagocytes
Platelets (thrombocytes)
these cells originate in the bone
marrow and function in the
clotting mechanism. Clotting is
a result of a chemical reaction.
Platelets attach to an injured
blood vessel and release
substances that contract blood
vessels.
Blood is grouped into types
named for the antigens found on
the cell membranes. The
purpose of matching is to find a
match before giving blood
transfusions.
Rh factor:
in some animals there is a
reaction of antibodies from the
dam. These animals exhibit
destruction of erythrocytes.
Blood pressure:
his is the force exerted by the heart in
pumping the blood through the blood
vessels.
Systolic pressure is produced by the
blood pressing against the walls of the
arteries during contraction of the
ventricles and diastolic is pressure is
produced against the artery walls during
ventricular relaxation
The difference between the systolic and
diastolic pressure is called the pulse
pressure. Diastolic is considered more
important medically because it shows
the least amount of pressure to the
artery walls. An elevation in blood
pressure is called hypertension and a
low blood pressure is called
hypotension
The pulse:
This is produced by the blood
pumping out of the heart and into
the aorta. This increases and
decreases the pressure on the
walls of the aorta which expands
as blood enters and relaxes as it
leaves.
Circulation:
systemic circulation:
blood circulating from the left
ventricle to aorta, arteries,
arterioles, capillaries, vemules,
veins and returning to the right
atrium
Portal circulation:
The circuit through the
abdominal digestive organs.
Blood from veins and organs is
carried to the liver via the portal
vein. The hepatic veins carry
the blood to the caudle vena
cava, back to the right atrium
Pulmonary circulation:
blood enters the right atrium to
right ventricle to pulmonary
artery which has two branches,
one branch for each lung. Blood
is oxygenated and returned to the
left atrium and ventricle via the
pulmonary vein.
It takes about one minute for the
blood to make a complete cycle.
The aorta is the largest artery in
the body. The aorta branches
into other arteries that supply
blood to all of the systems
Right and left common carotid
arteries.
These supply the right and left
side of the head
The external iliac arteries branch
to the femoral arteries. These
supply blood to the hind legs and
are used for taking an animal’s
pulse
Superficial veins include the
internal and external jugular
veins. The external jugular vein
is commonly used for
venapuncture
The saphenous vein drains into
the femoral vein and returns
blood from the hindlegs. The
saphenous vein is commonly
used for venapuncture in felines
The lyphatic system:
This system is made of fluid
called lymph. Lymph is rich in
white blood cells and is
circulated through the body by
the lymphatic system.
The lymph glands are enclosed
fibrous capsules. They are
identified by their location.
Superficial nodes are palpable
(submandibular, axillary,
popliteal, inguinal)
The lymph nodes act as filters to
remove bacteria and other foreign
bodies, including malignant cells. They
are seen or felt when they are inflamed
or swollen by ingested bacteria.
If they are swollen and painful: an acute
reaction is indicated
If they swollen, lobulated and not
painful:
a chronic reaction is indicated
Another important function of the
lymph glands is to manufacture
lymphocytes and monocytes..
The lymphatic system is very
important for the body’s defense
against infection
The Spleen:
The spleen is a large, flattened
glandlike organ located on the
left side of the abdominal cavity.
It is the largest structure in the
lymphoid system. It’s primary
functions are:
Hemopoiesis:
The formation of lymphocytes,
monocytes and plasma cells.
Phagocytosis:
The removal and destruction of
microorganisms, faulty platelets,
and old erythrocytes. It also
salvages the contents of
destroyed erythrocytes to reuse.
The Tonsils:
These are three pairs of small round masses
of lymphoid tissue that filter out foreign
bacteria and play a part in forming
lymphocytes.
The palatine: located in the back of the
throat
The lingual: located at the root of the
tongue
The pharyngeal: located at the back of the
roof of the pharynx
The Thymus:
This is a structure of lymph tissue located
cranial to the heart. It plays an important role
in the immune system by producing cells that
destroy foreign substances and forming
lymphocytes. It’s maximum development is in
young animals. It then begins to atrophy and
has almost disappeared by extreme old age