Lab 2 Anatomy of the Heart Exercise 30 Activity 1: Using the Heart Model to Study Heart Anatomy. Use Lab Exam Sheet as guide. Activity 2: Tracing the Path of Blood Through the Heart Activity 4: (Activity 3 in 8th Edition) Examining Cardiac Muscle Tissue Anatomy, 3. Dissection of the Sheep Heart. Follow instructions in this handout to do the dissection. Use the Lab Exam 1 Review Sheet as a guide. Blood Flow Through the Heart Watch the movie on the heart in Canvas under the Video link.
Transcript
Lab 2
Anatomy of the Heart Exercise 30
Activity 1: Using the Heart Model to Study Heart Anatomy.Use Lab Exam Sheet as guide.
Activity 2: Tracing the Path of Blood Through the Heart
Dissection of the Sheep Heart. Follow instructions in this handout to do the dissection. Use the Lab Exam 1 Review Sheet as a guide.
Blood Flow Through the Heart
Watch the movie on the heart in Canvas under the Video link.
Dissection of the Sheep Heart
Getting Ready
1. Clear off the lab bench except for a copy of the dissection directions.
2. Obtain goggles and gloves, dissection tools, a dissection pan and a sheep heart.
a. The tools you will need are several blunt probes, scissors, a scalpel and forceps
b. Put on the goggles and the gloves. Everyone must wear goggles, gloves are only necessary if you plan to touch the dissection.
3. Wait for the instructor before beginning the dissection.
External Anatomy
1. The sheep heart is encased in the pericardial sac. Notice that the outer layer, the parietal pericardium, is filled with fat and quite thick. It has an outer fibrous pericardial layer and a thin inner serous pericardial layer.
a. Using scissors, cut into the parietal pericardium and remove it from the heart. You will see that it is attached at the base of the heart.
b. Examine the shiny inner serous pericardial layer.c. Using a blunt probe, isolate the thin visceral pericardium
from the surface of the heart itself. Your instructor will demonstrate how to do this.
2. Locate the anterior surface of the heart. Place the heart so that the auricles (flaps attached to the right and left atria) are facing you.
a. The large blood vessels are attached to the heart at the base.
b. The apex is the pointed inferior tip of the heart.c. Locate the anterior interventricular sulcus, a groove
between the ventricles.d. Squeeze the ventricles to identify the thicker-walled left
ventricle.a. Note that the right ventricle makes up most of the
posterior of the heart.
e. Note that the right ventricle makes up most of the posterior of the heart.
f. Note blood vessels on the surface of the heart. Look at the preserved specimens with injected vessels for a clearer view of the blood vessels.
g. Identify the aorta and the pulmonary trunk. h. Put a blunt probe into the pulmonary trunk and note that it
enters the right ventricle. Leave the probe in the pulmonary trunk as a marker.
i. The aorta may have a large branch, the brachiocephalic artery, attached to it.
j. Find the superior vena cava close to the right auricle. Put a blunt probe through it to locate the inferior vena cava on the other side of the right atrium. The probe will extend through the superior vena cava, the right atrium and the inferior vena cava.
k. The pulmonary veins have probably been removed from your specimen. If present, they enter the left atrium on the posterior side of the heart. If they are not present, view them on the preserved heart at the front of the room.
Internal Anatomy
1. Locate the aorta at the base of the heart.2. Cut a frontal section passing through the aorta. Use Figure
35.10 as a reference. You may use the scalpel or a large knife from the lab bench.
3. Examine the two sides of the heart.a. Identify the right and left atria.b. Identify the right and left ventricles.c. Identify the interventricular septum.d. Compare the myocardium of the right ventricle with that
of the left ventricle. Which is thicker? _______________ .4. Identify the columnar pectinate muscles in the right atrium.5. Identify the trabeculae carneae folds in the ventricles.6. Locate the tricuspid (right heart) and bicuspid (left heart)
valves.7. Identify the chordae tendineae and papillary muscles.8. Locate the aortic semilunar valves at the base of the aorta
and the pulmonary semilunar valves at the base of the pulmonary trunk.
9. Locate the opening of the coronary sinus just above the tricuspid valve in the right atrium.
Cleaning Up
1. Dispose of any dissection materials in the gray container in the prep room.
2. If you are keeping your heart for review, put it in a plastic bag and use a marker to label it with your name. Leave the bag on the designated tray at the front of the lab.
3. Wash the dissection tools in soapy water, rinse, dry them and return them to the tray.
4. Wash and rinse the dissection pan and leave it upside down to dry at the sink.
5. Throw away gloves and paper towels in the regular trash.6. Return goggles to the sterilizing cabinet correctly.7. Wash the lab bench with disinfectant.
8. Wash your hands before you leave the lab.
Name ____________________________ Section _________________
Turn in at the end of lab or at the next regular class.
Sheep Heart Dissection
1. Contrast the thickness of the fused fibrous pericardium and serous layer of the parietal pericardium to the thickness of the visceral layer of the serous pericardium. (Sometimes just called parietal and visceral pericardia.)
2. a. Which ventricle has a thicker myocardium?
b. How does this relate to its function?
3. a. What is the role of the semilunar valves?
4. a. What is the role of the atrioventricular valves?
Activity
Use arrows drawn with colored pencils to trace the paths of blood into, out of and through the heart and all the vessels and chambers shown on the figure. Use red for well-oxygenated blood and blue for poorly oxygenated blood. Points will be deducted for other colors.
Label: pulmonary and aortic semilunar valves and the tricuspid and bicuspid valves. Print the labels in the margins.
7. Trace a drop of blood through the heart. Start with the right atrium and end with the aorta. List all chambers, valves and vessels in the pathway.
Right atrium
____________________________________
____________________________________
____________________________________
____________________________________
____________________________________
Lung capillaries
____________________________________
____________________________________
____________________________________
____________________________________
____________________________________
Aorta
Preparing for Lab 3 – the ECG
Next week in lab we are going to run experiments on the effect of exercise on the lengths of ventricular systole and diastole. The data will be used to prepare a modified lab report. As a part of your preparation for the lab, please do the following:
1. Read over the experiment in Lab 3 so that you have an idea of what we will be doing during lab.
2. There are instructions writing a lab report attached to lab 3. I have copied the section on the Introduction below. Please read this over carefully.
3. Prepare the Introduction for the lab exercise following the directions, and turn it in with Lab 2 for comments. Please staple it to the Lab 2 sheets. It must be typed or word-processed. The Introduction is worth 20 points in the lab report, so take some time to do it well. You will have one chance to redo it after reading the comments.
IntroductionThe purpose of an introduction is to give readers and idea of what you plan to do, why you plan to do it , and what you think will happen. Please number these and include in this order. This is just for the first draft.
1. What is your objective? (What do you plan to test?)
2. Why is this study of scientific interest?
3. It is important to read other papers to help explain why the current study is of
scientific interest. One study can be accessed through Canvas, or directly from
the web at h ttp://www.cardiovascularultrasound.com/content/6/1/15 . We will only
look at a small part of the study. Follow the directions below.
I have selected a set of graphs from the cardiovascular study I gave you to read. We will concentrate on just these graphs for the introduction to the lab report. You should use the same information for the citation as described below.
These graphs show the results of exercise on the lengths of systole and diastole in normal subjects and subjects with various heart conditions. This is what the abbreviations on the graphs stand for
NL- normal heartCHD – chronic heart diseaseVALV – valve diseaseDC – Dilated Cardiomyopathy ( problems with the heart)HYP – arterial hypertension (vasoconstriction0COPD – chronic obstructive pulmonary disease
4. Try to connect the pieces in the lab report. Your observations should lead to the
hypothesis. The hypothesis should come from observations and reading (the
graphs from the study in this case).
5. Citations in the text and in Literature Cited
a. It is important to cite sources in the introduction section of your paper as
evidence of the claims you are making. Use the (author’s last name, date
of publication) method of in text citations. For example (Marieb, 2010).
For web sites use (URL). Note that articles by one or two authors are
always cited in the text using their last names. However, if there are more
than two authors, the last name of the 1st author is given followed by the
abbreviation et al., which is Latin for "and others".
b. Make sure you give a full citation in the Literature Cited section for all
sources mentioned in the text.
6. Define pulse, systole, diastole and the cardiac cycle. Describe the length of time
the heart is in ventricular systole, and the length of time the ventricles are in
diastole. Use a 0.8s cardiac cycle for your example. Describe an ECG and
explain how the lengths of systole and diastole can be estimated from an ECG.
Information about this is included with Lab 3.
7. Describe personal observations about your heartbeat during exercise.
8. Describe which part of the cycle is most affected by an increased heart rate, and
why.
9. The last sentences of the introduction should be a statement of your
hypotheses. Use “I think” , not “I believe.” It should have 3 parts; systole,
diastole and pulse.
For the Lab Exam
Heart Identify on figures and models of the human heart:
o aortao apexo right and left atriao baseo bicuspid valveo chordae tendineaeo coronary sinuso endocardiumo epicardiumo inferior vena cavao interatrial septum
o interventricular septumo myocardiumo papillary muscleso pulmonary arterieso pulmonary trunko pulmonary veinso semilunar valveso superior vena cavao tricuspid valveo right and left ventricles
Identify on the sheep heart (or pig heart): o aortao aortic semilunar valves o apex o atriao auricleso baseo brachiocephalic arteryo chordae tendineaeo coronary sinuso inferior vena cavao left atrioventricular valveo left ventricleo myocardium
o papillary muscleso parietal pericardium,
fibrous and serous layerso pectinate muscleo pulmonary semilunar
valveo pulmonary trunko right atrioventricular
valveo right ventricleo superior vena cavao trabeculae carneaeo visceral pericardium
