blood is made up of about 60% liquid (plasma) and 40% formed elements which consist of erythrocytes...
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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
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=erythrocytesmyeloblasts=granulocytes
lymphoblasts=lymphocytesmonoblasts=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
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
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
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
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 indicatedIf 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:
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
throatThe lingual: located at the root of the
tongueThe 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