Laboratory 12 - The Circulatory System I

What does the circulatory system consist of?

Blood, blood vessels, and the heart.

Blood is primarily what?

A transport medium for nutrients and wastes to be supplied and removed from body tissue.

What are the five main types of vessels?

- Arteries
- Arterioles
- Capillaries
- Venules
- Veins

The puming action of the heart provides what?

The force required to send blood to body cells.

What does the term "cardiovascular" refer to?

The heart and blood vessels.

Blood is considered what type of tissue?

A specialized connective tissue.

What does blood consist of?

Cells, cell fragments, ground substance, and dissolved protein fibres.

What does blood do? (3)

- Blood is a transport medium (transporting things like oxygen, carbon dioxide, nutrients, hormones, wastes).
- Circulating blood also help in maintaining homeostasis (regulating pH, adjusting body temperature, maintaining osmotic pressure of cells).
- Blood can clot to prevent excessive loss from the cardiovascular system and blood helps protect the body against disease.

Is circulating blood viscous?

Yes, it is rather sticky.

Depending on the amount of oxygen blood is carrying, it can range from what colours?

Bright scarlet red to dull purplish red.

What is the average volume of blood in a adult male body?

5-6 L

What is the average volume of blood in a adult female body?

4-5 L

What are the two components of blood?

Formed elements (cell and cell fragments) and plasma.

What do formed elements of blood consist of?

Erythrocytes (RBC), leukocytes (WBC), and platelets.

What is the most numerous cell of blood?

RBC

What is the approximate ratio of RBC to WBC?

700:1

Describe RBC.

Biconcave, no nucleus or mitochondria. They are ~7-8 micrometers in diameter, and they carry around hemoglobin.

What is hemoglobin?

An oxygen-carrying protein/pigment.

WBC comes in 2 groups. What are they?

Granulocytes and agranulocytes.

What WBC are granulocytes? (3)

- Neutrophils
- Eosinophils
- Basophils

Describe neutrophils (nucleus, size, cytoplasm, and % of total leukocytes).

- Multi-lobed nucleus
- 10-12 micrometers
- Inconspicuous, pale purple granules in cytoplasm
- 60-70%

What do neutrophils do?

They phagocyte foreign materials.

Describe eosinophils (nucleus, size, cytoplasm, % of total leukocytes).

- Bilobed nucleus
- 10-12 micrometers
- Many large red granules in cytoplasm
- 2-4%

What do eosinophils do?

Play a role in the control of local responses associated with allergic reactions.

Describe basophils (nucleus, size, cytoplasm, % of total leukocytes).

- S-shaped nucleus
- Many large purple granules in cytoplasm
- 0.5-1%

What do basophils do?

Release histamine and heparin during inflammation and allergic reactions.

What WBC are agranulocytes? (2)

- Lymphocytes
- Monocytes

Describe lymphocytes (nucleus, size, cytoplasm, % of total leukocytes).

- Large and round
- Small (6-9 micrometers); Large (10-14 micrometers)
- No visible granules, thin rim of blue cytoplasm
- 20-26%

What do lymphocytes do?

Produce antibodies and other agents involved in the immune response.

Describe monocytes (nucleus, size, cytoplasm, % of total leukocytes).

- Large, horse shoe shaped
- 12-20 micrometers
- No visible granules, abundant pale blue cytoplasm
- 3-8%

Blood contain cell fragments called what?

Platelets.

How many platelets are found per cubic milimeter of blood?

150 000 - 400 000.

Describe platelets.

- Disc shaped
- 2-4 micrometers
- Contain granules, but no nucleus.

What do platelets do?

They help to stop blood loss from damaged vessels by forming a platelet plug and also help promote blood clotting.

What is blood analysis?

A type of tests doctors perform to ensure that the blood indicates the individual is healthy.

What types of things are looked at in a blood analysis?

Percentage of all cell fragments to know if the individual has enough of RBC, WBC, and platelets.

Why is it important to count cell fragments, especially WBC in blood?

Because it can help indicate if you have any diseases.

What is leukemia?

A cancer of white blood cells/leukocytes. It is characterized by an uncontrollable increase of WBC.

Are there different types of leukemia?

Yes. Leukemia can be granulocytic, lymohocytic, or monocytic.

What are the symptoms of leukemia?

Fever, weight loss bleeding problems, and a compromised immune system.

A high neutrophil percentage may indicate what?

Bacterial infection or poison.

A low neutrophil percentage may indicate what?

A toxic reaction to a certain drug.

A high eosinophil percentage may indicate what?

An allergy or parasitic infection.

Some conditions associated with a high lymphocyte count include what?

Infectious mononucleosis, measles, mumps, and tuberculosis.

Increased numbers of monocytes indicate what possible conditions?

Tuberculosis, a protozoan infection, Hodgkin's disease, or infectious mononuleosis.

What is hematocrit?

The percentage of blood volume taken up by RBCs.

Hematocrit is determined by what?

Centrifuging a sample of heparinized blood.

In males, what is the normal value for hematocrit?

40-54%.

In females, what is the normal value for hematocrit?

38-46%.

Leukocytes and platelets contribute to what percentage of blood?

Less than 1%.

Plasma makes up what percentage of blood?

55%

RBCs make up what percentage of blood?

45%

The concentration of hemoglobin in the red blood cells is an important indicator for what?

The oxygen-carrying capacity of blood.

What is the normal hemoglobin concentration at birth?

14-20 grams per 100 ml of blood.

Hemoglobin increases/decreases in concentration as we age.

Decreases.

In males, the normal hemoglobin concentration is?

13.5-18 g/100 ml.

In females, the normal hemoglobin concentration is?

12-16 g/100 ml.

What is the Tallquist scale?

A scale that uses a series of lithographed colours that illustrate the tints of blood ranging from 10% to 100% hemoglobin concentration.

How does the Tallquist scale work?

A sample of blood is placed on a prepared piece of paper from the booklet. The colour is then matched with the appropriate standard colour scale.

What is a hemoglobinometer?

An instrument that compares a hemolyzed sample of blood with a colour standard by mobing a slide on the side of the instrument back and forth until the two halves of the green field match.

A hemoglobinometer measures hemoglobin concentration in what units?

Grams of Hb/100 ml.

What are the different blood types?

A, B, AB, O

"A" blood has what antigens and what antibodies?

A antigen and anti-B antibody.

"B" blood has what antigens and what antibodies?

B antigen and anti-A antibody.

"AB" blood has what antigens and what antibodies?

Both A and B antigens and no antibodies.

"O" blood has what antigens and what antibodies?

No antigens and both anti-A and anti-B antibodies.

People who have positive blood means what?

They have the Rh factor AKA the D antigen.

People who have negative blood means what?

They do not carry the Rh factor AKA the D antigen.

Do people with negative blood have the anti-D antiobody?

No. They only develop this antigen IF their blood comes in contact with another persons blood that must be positive.

When doing the blood typing test in the lab, if there was clumping in well A, but no clumping in well B and Rh, what blood type is the individual?

A-

What is a transfusion reaction?

If a person receives the wrong blood type, antibodies bind to erythrocytes and cause agglutination.

Can the donors antibodies agglutinate the recipent's RBCs?

Yes, but these antibodies are so diluted that it usually isn't a problem in the recipients circulation.

Type O- is known as what?

The universal donor.

Type AB+ is known as what?

The universal recipient.

What is the transfusion rule?

Recipients antibodies must NOT MATCH donors antigens.

A healthy bloodstream will never contain what?

An antigen and antibody that is of the same type (ie. A antigen and anti-A antibody).

An abnormally low RBC can indicate what?

Anemia.

What is anemia?

It is a condition that signifies a decreased amount of hemoglobin, thus decreasing the amount of oxygen reaching tissues.

How does anemia occur?

When there is a decreased production of RBC.

A decrease in RBC can be caused by what?

Deficiencies in iron of vitamin B12 or if certain types of malignancies were present.

Anemia may also be caused by an increased destruction or malformation of RBC. This can occur due to what?

Severe infections, sickle cell anemia, or incorrect transfusions.

What is the most important tests in the diagnosis of anemia?

Hematocrit and hemoglobin evaluations.

What is polycythemia?

When there is an above normal amount of RBCs.

What is polycythemia caused by?

Living at high altitudes where oxygen is less present or red bone marrow malignancy.

What is malignancy?

Cancerous growth.

What is the normal red cell count in males?

4.5-6.5 million per cubic millimeter.

What is the normal red cell count in females?

3.9-5.6 million per cubic millimeter.

What is a hemacytometer?

A device used for hand counting of cells.

The four large squares at the corners of the counting chamber of a hemacytometer is used in making what cell count?

WBC count.

The large square in the middle of a hemacytometer is used in making what cell count?

RBC count. Specifically, the four small outer corner squares and the middle.

A leukocyte cell count is important as it can be used to indicate what?

Infections.

White blood cell count may be elevated in what situations?

Bacterial infection, appendicitis, leukemia, pregnancy, ulcers, etc.

White blood cell count may drop below normal due to what?

Certain viral diseases like measles, infectious hepatitis, and cirrhoisis of the liver.

Can white blood cells decrease in an individual receiving treatment via radiation or antibiotic therapy?

Yes.

In healthy individuals, what is the normal WBC count?

5000-10 000 cells per cubic millimeter.

A WBC count higher than 10 000 is known as what?

Leukocytosis.

A WBC count lower than 5000 is known as what?

Leukopenia.

Blood clotting time takes how many minutes?

2-6 minutes.

How is blood clotting time measured?

By placing some blood in a capillary tube and seeing how long it takes for a strand of "blood" (fibrin threads) to be present when the tube is broken.

The oxygen and carbon dioxide carrying cell are?

RBCs.