Lesson 5 (CP2)

Question 1

Describe the components of the bloodforming and blood-coagulation systems

Answer 1

the coagulation of blood proceeds through a mechanical phase and a chemical phase. The mechanical phase is initiated when a blood vessel is ruptured or torn. The exposed blood vessel subendothelium is a charged surface, and platelets are attracted to this surface. As platelets congregate at the site, they undergo morphologic and physiologic changes. These changes cause the platelets to adhere to each other as well as to the blood vessel endothelium.

Question 2

Describe various hematological principles

and procedures

Answer 2

The term hematopoiesis refers to the production of blood cells and platelets. Erythropoiesis, Leukopoiesis & Thrombopoiesis.

Question 3

Erythropoiesis

Answer 3

production of red blood cells (RBCs).

Question 4

Leukopoiesis

Answer 4

production of white blood cells.

Question 5

Thrombopoiesis

Answer 5

production of platelets.

Question 6

Describe normal erythrocyte in the peripheral blood of mammalian species

Answer 6

Normal RBCs have a biconcave shape and contain hemoglobin but no nucleus or organelles

Question 7

Describe abnormal erythrocyte in the peripheral blood of mammalian species

Answer 7

Poikilocytosis is usually caused by another medical condition, such as anemia, liver disease, alcoholism, or an inherited blood disorder.

Question 8

Describe normal leukocyte
types in the peripheral blood of
mammalian species

Answer 8

a cellular component of the blood that lacks hemoglobin, has a nucleus, is capable of motility, and defends the body against infection and disease.

Question 9

Describe abnormal leukocyte
types in the peripheral blood of
mammalian species

Answer 9

An abnormal increase in the number of white cells is known as leukocytosis, whereas an abnormal decrease in number is known as leukopenia.

Question 10

Describe various aspects of blood

cell counts

Answer 10

Complete blood count (CBC). Blood is collected by inserting a needle into a vein and allowing the blood to flow into a tube. The blood sample is sent to the laboratory and the red blood cells, white blood cells, and platelets are counted. The CBC is used to test for, diagnose, and monitor many different conditions.

Question 11

Erythrocyte indices and the significance of abnormal test results

Answer 11

Calculated values that use the cell
count, hemoglobin measurement, and PCV. Known as mean corpuscular volume (MCV), mean
corpuscular hemoglobin (MCH), and mean corpuscular hemoglobin concentration (MCHC)…numbers can help diagnose anemia

Question 12

packed cell volume (PCV) and the significance of abnormal test results

Answer 12

The PCV represents the ratio of the height of the column of red blood cells relative to the total volume in the capillary tube. Decreased PCV may indicate anemia

Question 13

Complete blood counts (CBCs) and the significance of abnormal test results

Answer 13

A CBC includes total erythrocyte and
leukocyte counts, packed cell volume, hemoglobin concentration, and red blood cell indices. Specific indications include unexplained nonregenerative anemia, leukopenia, thrombocytopenia, and pancytopenia (i.e., decreased numbers of all cell lines).

Question 14

Discuss the collection and processing
of blood samples for clinical chemistry
evaluations

Answer 14

• What tests are needed = what tubes, which syringe/needle & which site to use to draw the blood.
• Labs should be drawn before any treatment or pharmaceuticals have been given.

Question 15

anemia

Answer 15

Anemia is a condition that involves reduced oxygen-carrying capacity of erythrocytes. It may result from a reduced number of circulating RBCs, reduced packed cell volume (PCV), or a reduced concentration of hemoglobin.

Question 16

leukopenia

Answer 16

a reduction in the number of white cells in the blood, typical of various diseases

Question 17

thrombocytopenia

Answer 17

decrease in the circulating platelet mass

Question 18

pancytopenia

Answer 18

a decrease in the number of all blood cell types.

Question 19

prothrombin time (PT) test

Answer 19

evaluates the extrinsic coagulation
pathway. The test requires a citrated plasma sample to which tissue thromboplastin reagent is added. A reagent designed to recalcify the sample is then added. Under normal conditions, a clot should form within 6 to 20 seconds.

Question 20

clot retraction test

Answer 20

evaluation of platelet number and function as well as the intrinsic and extrinsic coagulation pathways. Blood is drawn into a plain sterile tube and incubated at 37ºC (98.6ºF). The tube is examined at 60 minutes and reexamined periodically over a 24-hour period. A clot should be evident in 60 minutes, retracted (i.e., drawn away from the wall of the blood tube) in approximately 4 hours,
and markedly compact at 24 hours.

Question 21

buccal mucosal test

Answer 21

detects abnormalities in platelet
function. The test requires a spring-loaded lancet, blotting paper, a stopwatch, and a tourniquet. The patient is placed in lateral recumbency. A strip of gauze is used to tie the upper lip back to expose the mucosal surface, and an incision made with the lancet. Blood is wicked away from the incision using the blotting paper every 5 seconds until bleeding has stopped

Question 22

activated clotting time (ACT) test

Answer 22

evaluates every clinically significant clotting factor except for factor VII. The test requires
a pre-incubated Vacutainer tube containing diatomaceous earth (DE). DE serves to activate platelets, initiating the clotting mechanisms

Question 23

platelet count

Answer 23

Although some automated analyzers provide platelets counts, these counts tend to be inaccurate. In most cases a manual platelet count is preferred.