Blood VHS211

Define whole blood versus peripheral blood.

Whole Blood = blood in cardiovascular system & Peripheral Blood = blood in blood vessels

What is the percentage breakdown of whole blood?

55% Plasma (91% H2O, 7% proteins, 2% other solutes) + 45% Formed Elements (platelets, leukocytes, erythrocytes)

What percentage of body weight does blood account for?

7% of an animals body weight is blood

What is the percentage by volume of the components of blood?

Blood is 55% Plasma and 45% Formed Elements

What are the components of plasma in percentage by weight?

Plasma is 7% Proteins, 91% H2O, and 2% solutes.

How many formed elements are there per cubic mm?

200–500 thous. Platelets, 6–17 thous. Leukocytes, and 5.5–8.5 mil. Erythrocytes

Functions of the blood?

Transportation, Regulation, and Defense

Describe the transportation function of blood.

Erythrocytes contain hemoglobin, which carries O2 to body tissues. Plasma carries nutrients and other essentials dissolved into it. Platelets are transported to injury sites to begin clotting.

What does blood do when dehydration occurs?

The blood leaves circulation and enters other tissues to compensate for water losses.

Define hematopoesis

Production of all the blood cells that occur as a continuous process throughout an animals life

Where does fetal hematopoiesis mostly take place?

The liver and the spleen. Transitions to mostly via red marrow once born.

What are all blood cells derived from?

A single primitive cell type called a pluripotential or multipotential stem cell. Become committed to 1 cell line and develop into unipotential stem cells (only become 1 type of blood cell)

What is erythropoesis?

The process of creating RBC. uni cells differentiated into Proerythroblasts, where they divide and reach a stage where they lose nuclei and begin to produce hemoglobin.

How long is the erythropoesis process in dogs, cows, and birds?

1 week in dogs, 4-5 days in cows, and 36hrs in birds

What hormone controls the erythropoesis process?

Erythropoietin (regulated by blood oxygen levels in the kidney)

Define thrombopoesis

The production of platelets (thrombocytes); uni cells differentiate into Megakaryocytes (large multinucleate cells that live in the marrow—never leave). Release cytoplasm chunks into PR blood as thrombocytes

How long does thrombopoesis take?

Approx. 7 days

Define leukopoesis

The formation of leukocytes (WBC), making Neutrophils, Eosinophils, or Basophils.

What is the sub-process of leukopoesis called? What WBC types does it form?

Granulopoesis; pluripotential cells differentiate into 1 of 3 granulocytes (contain granules): Neutrophils, Eosinophils, and Basophils

What are agranulocytes? What are the 2 types?

They are cells that lack granules; there are Lymphocytes and Monocytes, produced by Lymphopoesis and Monopoesis respectively

How to identify erythrocytes?

They are anucleate, and lack both mitochondria and ribosomes. DO contain hemoglobin and H2O/other elements. They are biconcave, and are red from the hemoglobin.

What animal has the most prominent central pallor and largest RBCs?

The dog

How many O2 molecules can one hemoglobin carry?

4 O2 molecules; 1 O2 per heme group (4 groups)

What are hemoglobin bound and unbound Oxygen molecules called?

Bound = oxyhemoglobin; Unbound = deoxyhemoglobin

Why are RBC biconcave?

To provide more membrane surface area for diffusion of O2 and CO2 and shorten diffusion distance

What is the average lifespan of an Erythrocyte/RBC in different animal species?

Dogs: 120 days, Cats: 68 days, Horses/Sheep: 150 days, Cows: 160 days

What is RBC aging called?

Senescence

What is extravascular hemolysis?

The process of destroying senescent RBC outside the cardiovascular system. 90% of RBC destroyed this way, occurs mainly in Spleen

Where does the degraded AA, Fe+, and heme go after extravascular hemolysis?

The AA goes to the Liver, the Fe+ goes to the Marrow, and the Heme is farther broken down and expelled in the urine/feces.

What is intravascular hemolysis?

The destruction of senescent RBC inside the cardiovascular system. If severe, the uncoagulated bilirubin appears in the plasma, giving it a pink, red, or brown color.

Define hemastasis

The process of blood being prevented from leaking out of damaged vessels. When there is a break collagen, fibronectin, and von Willebrand factor attract platelets to the site in a process called Platelet Adhesion.

What does the blood vessel endothelium lining produce to make platelets change shape?

Thrombin; makes platelets change shape and intertwine to aggregate. To form a Hemostatic Plug, converts fibroginogin to fibrin and cement platelets