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=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

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 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:

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

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