Saturday, February 28, 2015

BLOOD & LYMPHATIC SYSTEM LAB (Online)

The circulatory system, lymphatic system, and microorganisms are intimately related. In this exercise, we will explore these relationships along with details on the structure and functions of each. This laboratory exercise offers you the opportunity to explore structure and function of the lymphatic system and the world of microorganisms.



Objectives

1.       Visualize and determine the differences between erythrocytes, and leukocytes, and platelets.
2.       Distinguish the different types of leukocytes
3.       Identify sickled erythrocytes and the implications for sickle cell disease
4.       Explain the difference between the terms antigen and antibody.
5.       Describe the ABO blood typing system and the implications for donation and transfusion.
6.       View and identify organs of the lymphatic system and their microscopic components
7.       Relate the circulatory system and lymphatic system in terms of their structure and function
8.       Compare and contrast the first, second, and third line of defense and the cells and chemicals involved in each
9.       Differentiate between active and passive immunization

Part 1. Blood

Erythrocytes and Leukocytes



1.       Click here to visit the Histology Index. Go to “Erythrocytes” near the bottom.
2.       Choose “Unlabel” to see the slide in color and then go back to the labeled view. Sketch and label what you see.

3.       From the same page, choose 2 leukocytes.
4.       Choose “Unlabel” to see the slide in color and then go back to the labeled view. Sketch and label what you see.


5.       Make an alphabetical list of every type of leukocyte and state the function of each. Use your text or other resources.
1. Basophil: Basophils contain histamine a chemical that initiates the inflammatory response.
2. Eosinophils: Eosinophils defend the body against the large parasites such as worms.
3. Lymphocyte: Lymphocytes are found in the blood stream, tonsils, spleen and lymph nodes. There are two classified types. B cells increase to plasma cells to produce antibodies that defend against micro organisms and the T cells that target and destroy bacteria, viruses and cancer cells.

4. Monocyte: Monocytes filter out of the blood stream where they differentiate into the macrophages that engulf invaders.

5. Neutrophil: Neutrophils are the first white blood cell to combat infection.

6.       Fun tutorial and quiz at http://bcs.whfreeman.com/thelifewire/content/chp18/1802001.html


Sickle Cell Disease



Sickle cell disease is an inherited blood disorder that affects red blood cells. People with sickle cell disease make hemoglobin S or C. Red blood cells containing mostly hemoglobin S do not live as long as normal red blood cells (normally about 16 days). They also become stiff, distorted in shape and have difficulty passing through the body’s small blood vessels. When sickle-shaped cells block small blood vessels, less blood can reach that part of the body. Tissue that does not receive a normal blood flow eventually becomes damaged. This is what causes the complications of sickle cell disease. There is currently no universal cure for sickle cell disease.

The video you may have watched last week, Natural Selection of Humans, has more about sickle cell disease and its genetics. Watch again, if you haven’t to answer this question.

What is the connection between protection from malaria and being a carrier of the sickle cell gene?

The connection between protection from malaria and being a carrier of the sickle cell gene is that if a person  has a sickle cell trait as in they have one hemoglobin S gene and one Hemoglobin A gene they are more likely to survive malaria. The downside to being immune to malaria means that they will develop sickle cell.

Blood Typing


The most well-known and medically important blood types are in the ABO group. Karl Landsteiner discovered them in 1900 at the University of Vienna. All humans and many other primates can be typed for the ABO blood group. There are four principal types: A, B, AB, and O. There are two antigens and two antibodies that are mostly responsible for the ABO types. The specific combination of these four components determines an individual's type in most cases.

It is easy to determine an individual's ABO type from a few drops of blood. A serum containing antibody A (anti-A) is mixed with some of the blood. Another serum with antibody B (anti-B) is mixed with another sample. Whether or not agglutination occurs in either sample indicates the blood type. For instance, if an individual's blood sample is agglutinated by antibody A, but not antibody B, it means that the A antigen is present but not the B antigen. Therefore, the blood type is A.

Rh factor is another red blood cell surface protein. A person can have two copies of Rh+, two copies of Rh- (meaning no antigen is made), or one copy of each. When an Rh- individual makes contact with the Rh+ factor (as is the case with an Rh- fetus carried by an Rh- mother), the Rh factor is recognized as foreign, and an immune response begins and small amounts of Rh antibodies and lymphocytes are made. Keep in mind that the fetus’s blood and the mother’s blood do not mix during the gestation, but they do during the birthing process, so a future contact with the antigen signals circulating antibodies to create an intense and effective attack against the Rh+ factor.

O positive is the most common blood type. Not all ethnic groups have the same mix of these blood types. Hispanic people, for example, have a relatively high number of O’s, while Asian people have a relatively high number of B’s. The mix of the different blood types in the U.S. population is:


Caucasians
African American
Hispanic
Asian
O +
37%
47%
53%
39%
O -
8%
4%
4%
1%
A +
33%
24%
29%
27%
A -
7%
2%
2%
0.5%
B +
9%
18%
9%
25%
B -
2%
1%
1%
0.4%
AB +
3%
4%
2%
7%
AB -
1%
0.3%
0.2%
0.1%

Some patients require a closer blood match than that provided by the ABO positive/negative blood typing. For example, sometimes if the donor and recipient are from the same ethnic background the chance of a reaction can be reduced. That’s why an African-American blood donation may be the best hope for the needs of patients with sickle cell disease, 98 percent of whom are of African-American descent.

It’s inherited. Like eye color, blood type is passed genetically from your parents. Whether your blood group is type A, B, AB or O is based on the blood types of your mother and father.

1.       Click here to play the Blood Typing Game.
2.       Choose the Quick Game.
a.       Play the Blood Typing part.
b.       How did you do? The first time I played the blood typing game I did mess up once.
c.       Did you get it right the first time? I played two times and got it right the second game I played.
d.      Go on to Transfusion. Be sure to scroll through all the choices of blood bags. How did you do? The first time I played the game I probably killed the first patient but the second time I got it right.
3.       Describe how a particular blood antigen composition would respond to receiving a non-compatible blood type (the transfusion reaction).  
If someone were to receive a non-compatible transfusion their bodies would see the donor cells as foreign invaders and their immune system would attack the donor cells. Not only could it render the transfusion useless but it could also result in death.

4.       Define the terms antigen and antibody.
An antigen is a toxic or foreign substance that induces an immune response in the body, especially the production of antibodies. An antibody is a blood protein produced in response to and counteracting a specific antigen.

5.       Explain, in your own words, what occurs when an Rh negative woman is carrying an Rh positive child for the second time. Refer to text.
During the second the pregnancy the mother has at this time built up immunity the RH antibodies, because of this immunity both the mothers blood and the blood of the fetus start attacking each other. When this happens it starts to breakdown the red blood cells it can be dangerous to both. In severe cases it can lead to death of the fetus.


Part 2. Lymphatic System


1.       Click here to visit the Histology Index. Go to “Lymphoid Tissues and Organs” and choose Tonsil.
2.       Choose “Unlabel” to see the slide in color and then go back to the labeled view. Sketch and label what you see.


3.       Explain how the lymphatic system is physiologically and anatomically related to the cardiovascular system.
The lymphatic system is related to the cardiovascular system as the lymphatic system helps maintain the blood volume and interstitial fluid volume in the cardiovascular system.

Part 3. Nonspecific Body Defenses


1.       Name and explain three ways the integumentary system provides the first line of defense.
The first line of defense is our skin as it is the most important barrier against pathogens. The outermost layer of the skin’s epidermis consist of dead, dried out epithelial cells called keratin. Keratin helps form a tough, dry elastic barrier to organisms. Second the skin is always shedding old cells and when this happens any pathogens deposited on the surface are shed along with the dead cells. The third defense, healthy skin has a low pH because of the sweat produced which makes it a hostile environment for many microorganisms. Sweat glands also produce a natural antibiotic that can kill a range of harmful bacteria.

2.       Explain the protective role of cilia.  From what primary tissue type do cilia arise?
The role of cilia is to move materials along the surface of cells. The cilia is located in the respiratory tract and enables us to be able to cough when something foreign like dust or particles are inhaled.
3.       Define and sketch the process of phagocytosis.


4.       Name and sketch two cell types that perform phagocytosis.



5.       Describe the process involved in the inflammatory response. Include all chemicals and cell types.
The processes involved in the inflammatory response starts when tissues are injured.  The damaged cells release an alarm that release chemicals which stimulate the mast cells which are connective tissue cells to release histamine.  Histamine dilated the blood vessels. This allows phagocytes to squeeze through the capillary walls. Vasodilation brings more blood to the injured area making it red and warm. The increasing temperature increases phagocyte activity. The increased leakiness of capillary walls allows more fluid to seep into tissue spaces causing swelling. The extra fluid dilutes pathogens and toxins and brings in clotting proteins that form a fibrin mesh to wall off the damaged area from healthy tissue. This swollen tissue press against nerve endings that cause pain.


6.       Explain and sketch the mechanism by which complement kills bacteria.




Part 4. Specific Body Defenses



1.       What is the major histocompatibility complex?
Human cells have surface proteins that can act as antigens under the right circumstances. Your cells have a unique set of proteins on their surfaces that your immune system uses to recognize that the cells belong to you. These self markers are known as major histocompatibility.

2.       Describe and sketch the basic structure of an antibody. How many different types of antibodies do you have in your body?


There are 5 classes of antibodies, IgG, IgM, IgA, IgB, Igd and IgE.

3.       Describe and sketch clonal expansion.


Activation occurs when a mature but inactive helper T cell comes in contact with an antigen-presenting cell displaying the appropriate antigen fragment.

4.       How does interferon operate?
       Interferon stimulates the production of proteins that interfere with viral reproduction.
5.       What is the difference between cell mediated and antibody mediated immune response?
The difference is cell mediated immunity, cells directly attack foreign cells that carry antigens and release proteins that help coordinate other aspects of immune response. Antibody medicated immunity B cells produce antibodies-proteins that bind with and neutralize specific antigens.

6.       Name the cells involved in the cell mediated immune response.
The cells involved in cell mediated immune response are T cells.

7.       Name the cells involved in the antibody mediate immune response.
The cells involved in the antibody mediate immune response are B cells.

8.       Explain the difference between passive immunization and active immunization and give an example of each.

Active immunization is the process of activating the body’s immune system in advance. It involves administering an antigen-containing preparation or a vaccine. An example is an oral polio vaccine. Passive immunization is used to fight an existing or even anticipated infection; a person can be given antibodies prepared in advance from a human or animal donor with immunity to that illness. An example would be when someone has been newly infected with Ebola and they take blood from a person who has beaten the disease and they give it to the newly infected person.

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