Biology 11A #13
Blood and Heart Dissection
BRING YOUR TEXT TO LAB
Prelab Use diagram 27.7 from your text and label at least 10 of the 1-15 structures.
1._________________
2. ________________
3. ________________
4. _______________
5. ________________
6._________________
7._________________
8._________________
9._________________
10.________________
11 ________________
12. _______________
13. _______________
14. ________________
15. ________________
1
sPart 1: Heart Dissection
Each pair of students should obtain a sheep heart and place it on a tray. Use six wooden sticks
and with tape label them with the names of the six following arteries. When you find the vessel
you are looking for, insert the labeled wooden stick in the correct opening. Check with me to see
if you are correct!
Find the following three vessels on the anterior (ventral) side:
1. Pulmonary trunk
2. Aorta
3. Brachiocephalic artery
Find the following six vessels on the posterior (dorsal) side:
4. Superior Vena Cava
5. Inferior Vena Cava
6. Pulmonary Veins
Next we will cut the heart open. DANGER! SCALPELS ARE VERY SHARP!!!!!!
Did I mention the scalpels were sharp? Well they are!
Ask for help as to the trajectory you should follow when opening the heart. The right side of the
heart needs a cut that swirls around from the anterior part of the heart to the posterior part. Wait
until you get specific directions from me before cutting. Also, the blade is sharp, so be careful.
Once inside the heart, you need to find the heart valves. They are listed below.
1. Tricuspid Valve
2. Bicuspid Valve
3. Pulmonary Semilunar Valve
Part 2: Blood Typing
The membranes of human red blood cells (RBCs) contain a variety of cell surface
proteins called blood group antigens. The most important and best known of these are the A
and B antigens, also called the ABO blood group, and the Rh antigen. When blood is transfused
between a donor and a recipient, blood group
antigens must be identified in order to ensure
that their blood is compatible.
Blood group antigens are found only
on RBCs and their presence is determined by
2
an individual's genetics. An individual who does NOT inherit a particular blood group antigen
will produce an antibody that recognizes that antigen as foreign. Most commonly, an antibody is
produced after an antigen is introduced into the body, as with the Rh system. The ABO blood
group is unusual in that an individual lacking a blood group antigen will automatically produce
an antibody against the lacking antigen, even if that antigen has never been introduced into the
recipient. (Fig 1)
An antibody will specifically bind to the antigen it recognizes in an attempt to eliminate
the antigen. This binding reaction is called agglutination (Fig. 2). Agglutination of blood group
antigens causes large clumps of RBCs and antibody to form, which can block and damage the
small capillaries, especially in the kidneys. The resulting damage is called a transfusion
reaction and can cause permanent kidney damage or even kill the recipient.
Figure 2 Blood types and agglutination reactions when tested with antibodies.
So how are these blood group antigens identified before a transfusion is made? A sample
of blood is removed from the recipient and mixed in a dish with purified antibodies that are
known to recognize a specific blood group antigen. If the purified antibodies cause the blood
sample to agglutinate, then the RBCs in the blood sample carry the protein recognized by the
antibody. See Fig. 2 for examples of agglutination.
A person with Type A blood has RBC's that carry the A antigen. Antibodies that
recognize the A antigen are called anti-A antibodies or anti-A serum. If Type A blood is mixed
with anti-A antibodies, the RBCs will agglutinate. If Type A blood is mixed with anti-B
antibodies, the RBCs will NOT agglutinate because the B antigen is not present. Conversely, if a
3
blood sample agglutinates with anti-B antibodies but not with anti-A antibodies, then the blood
sample contains Type B blood.
Where do these antibodies come from? They are naturally found in the blood of the
opposite blood type. Remember that individuals with A antigen on their RBCs will carry anti-B
antibodies and individuals with B antigen will carry anti-A antibodies. See Table 1 for
clarification of which type of antigen and antibody is found in a given blood type. Type O blood
contains neither A nor B antigen, and so can produce both Anti-A and Anti-B antibodies. Type
AB blood contains both A and B antigen, and so will produce neither Anti-A nor Anti-B
antibodies.
At one time, Type O blood was considered a universal donor since it contained neither A
nor B antigens and would therefore not react with any blood group antibodies produced by the
recipient. Today, it is recognized that Anti-A and Anti-B antibodies found in the plasma of Type
O blood have the potential to produce a transfusion reaction with a Type A or Type B recipient
and so is no longer given to recipients with other blood types.
The Rh factor is separate from the ABO blood group. An individual carrying the Rh
antigen is said to be Rh + while an individual without the Rh antigen is said to be Rh –. The + or
– is added to the ABO blood type. For example, a person with Type A+ blood carries the A
antigen, the Rh antigen, but not the B antigen.
Individuals who are Rh – will not produce Anti-Rh antibodies unless the Rh antigen has
been introduced into their bodies. It becomes a problem when an Rh negative Mom is pregnant
carrying an Rh positive child. Fetal RBCs carrying the Rh factor are too
big
to cross the placenta, so the mother is not exposed to the Rh factor until
the
baby is delivered. During delivery, or any break in the placenta, fetal
blood can mix with the mother's blood and the mother can begin to
produce Anti-Rh antibodies. When the mother becomes pregnant a
second time and is carrying an Rh+ baby a second time, these antibody
proteins are small enough to cross the placenta and attack the Rh+ fetus,
causing damage to fetus and possible miscarriage. This is referred to as
erythroblastosis fetalis.
Getting Started
Materials:
•
one plastic petri dish
•
12 toothpicks
•
4 unknown blood samples:
Donors #1, #2, #3 and #4
•
Anti-A Antiserum (Blue)
•
Anti B Antiserum (Yellow)
•
Anti-Rh Antiserum (Transparent)
4
Procedure
1.
Label four petridishes by drawing three circles on each dish with
pencil.
a wax
2.
Place one drop of donor # one’s blood in a dish within each of the
circles.
3.
Do the same for donors 2, 3 and 4. Be sure to label them!
4.
Place 1 drop of Anti-A antiserum in one circle over the blood drop.
5.
Place 1 drop of Anti-B antiserum in another circle over the blood drop.
6.
Place 1 drop of Anti-Rh antiserum in the third circle. over the blood drop.
7.
Use a separate clean toothpick to stir each well for 30 seconds.
8.
Record the occurrence of agglutination in Table 2. If the sample appears grainy or opaque,
assume agglutination has occurred. Determine the blood type based on your agglutination
results.
9.
When finished, throw away all toothpicks and trays in the BIOHAZARD.
three
Table 2. Blood Typing Observations
Anti-A Antiserum
Anti-B Antiserum
Anti-Rh Antiserum
Donor #1:
Donor #2:
Donor #3:
Donor #4:
Table 3. Blood Typing Results
Antigens present
Antibodies present
Blood Type
Donor #1
Donor #2
Donor #3
Donor #4
5
Questions:
Name _______________
1. Explain Table 3 in your own words. Include your reasoning behind the
deduction of which antigen and which antibody is present when you see
agglutination in a well. Include how concluded which blood type you were
testing.
2. For each donor, determine what blood type(s) could be used if an emergency
transfusion were needed. It is understood that he/she should receive only
his/her own blood type under optimal conditions, but assume that he/she was
in an emergency situation, out of reach of a hospital, but close to a partially
equipped clinic with some blood in its coolers.
3. At what age or time in life does an individual acquire antibodies against ABO
blood types other than their own?
4. At what age or time in life does an individual acquire antibodies against Rh
positive blood if their own blood type is Rh negative?
5. Does the vial labeled anti-A antiserum contain whole blood? Explain. What
about the vials labeled anti-B and anti-Rh antiserum?
6. What blood type must the mother, father and child be, in order for
erythroblastosis fetalis to occur ?
Lab Report for next week:
1. Hand in Table 3 filled in (BY HAND IS OK)
2. Hand in the answers to questions 1-6 on Blood Typing, typed, in complete sentences.
3. Hand in Blood Flow diagram filled in with red and blue arrows.
6
Heart Labeling (lnternal)
Name
Heart Labeling
1.
9.
SHOWING2.BLOOD
3.
No
4.
NJO
10.
FLOW THROUGH THE HEART
11.
12.
tr'.J O
Show blood flow through the heart with arrows. Use blue
arrows to show flow to the lungs, use
6.
14.
red arrows to show blood flow to the rest of the body.
5.
13.
7.
15.
NO
8.
16. . Use arrows to trace the blood flow in the human heart.
http: / / blologycorner.com/worksheets/hean_inte
rnal. html
7