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LABORATORY
Week 2
Blood Pathologies
Heart Anatomy
Objectives:
1.
Observe prepared slides of pathologic blood samples (pernicious anemia,
iron deficiency anemia, sickle cell anemia, chronic lymphocytic leukemia and
eosinophilia). Describe the appearance of each smear and indicate how it
deviates from normal.
2.
Human Heart Anatomy
Identify the following structures using charts, diagrams and models available
in the lab:
apex
base
aorta
myocardium
endocardium
bicuspid (mitral) valve
coronary sinus
chordae tendineae
marginal artery
pectinate muscle
epicardium
visceral pericardium
middle cardiac vein
inferior vena cava
atrioventricular sulcus
left common carotid artery
2.1
right atrium
left atrium
right ventricle
left ventricle
pulmonary trunk
pulmonary veins
tricuspid valve
papillary muscles
circumflex artery
fossa ovalis
left subclavian artery
great cardiac vein
superior vena cava
right and left auricles
interatrial septum
left subclavian artery
interventricular septum
ligamentum arteriosum
pulmonary semilunar valve
inferior vena cava
left common carotid artery
aortic semilunar valve
trabeculae carneae
pulmonary arteries
left coronary artery
right coronary artery
anterior interventricular artery
brachiocephalic artery
posterior interventricular artery
posterior interventricular sulcus
anterior interventricular sulcus
3.
Sheep Heart Dissection
Complete a dissection of a sheep heart specimen and identify the following structures:
apex
right ventricle
right atrium
aorta
tricuspid valve
bicuspid (mitral) valve
coronary sinus
brachiocephalic artery
myocardium
fossa ovalis
atrioventricular sulcus
4.
base
parietal pericardium
visceral pericardium
inferior vena cava
pulmonary veins
pectinate muscle
chordae tendineae
aortic semilunar valve
interventricular septum
pulmonary semilunar valve
ligamentum arteriosum
right and left auricles
left ventricle
left atrium
pulmonary trunk
pulmonary arteries
superior vena cava
moderator band
endocardium
anterior interventricular sulcus
posterior interventricular sulcus
fibrous pericardium
Microscopic Anatomy of Cardiac Muscle
Observe prepared slides of cardiac muscle and identify the nucleus, striations, sarcolemma
and intercalated discs.
Introduction:
Hematology involves the scientific study of the anatomy, physiology and pathology of blood
and blood forming tissues. Hematological tests can help diagnose anemias, hemophilia,
blood-clotting disorders, and leukemias. In this lab, you will observe blood smears that
represent common blood disorders.
The heart is located in the thorax, in a region between the lungs known as the mediastinum.
The function of the heart is to collect blood from veins and eject that blood into arteries. In this lab
session, you will examine the gross anatomy of the heart and the pericardium and review the
microscopic anatomy of cardiac muscle.
2.2
Activity 1
Blood Pathologies
Materials:
Per student:
compound microscope
Per pair of students:
colored pencils
lens cleaner
lens paper
immersion oil
box of prepared slides:
pernicious anemia, iron deficiency anemia, sickle cell
anemia, chronic lymphocytic leukemia, eosinophilia
Procedure:
1.
Observe each of the prepared slides using the 40X and/or the 100X
objective.
2.
Prepare sketches of each slide in the spaces provided in the Lab Worksheet.
Tips:
2.3
1.
When viewing the slides of pernicious anemia, iron deficiency anemia and sickle
cell anemia, compare the color, shape and size of the RBCs to that of normal
RBCs.
2.
When viewing the slides of chronic lymphocytic leukemia and eosinophilia,
compare the WBCs to the WBCs seen in a normal blood smear; pay close
attention to the relative numbers of WBCs.
Relevant Background Information:
1. Disorders Associated With Erythrocytes - Anemias:
Anemia refers to a variety of conditions in which there is a reduction in the number of
erythrocytes or in the concentration of normal hemoglobin. Anemias are classified
according to etiology (cause, such as decreased erythropoiesis, accelerated hemolysis,
hemorrhage or biochemical defects) or by the morphology (size, color) of the red blood
cells. Some useful terms for morphological classification are:
Size
Microcytic: small cell
Normocytic: normal sized cell
Macrocytic: large cell
Color
Hypochromic: pale cell
Normochromic: cell with normal color
Hyperchromic: dark cell
Pernicious anemia is an example of a macrocytic, hyperchromic or macrocytic
normochromic anemia. A few microcytes and tear shaped red blood cells may be
present. Basophilic stippling (round, dark blue granules) and nucleated red blood cells
may also be seen. Neutrophils showing hypersegmented nuclei are commonly
encountered and these nuclei may be larger in size that a typical neutrophil.
Pernicious anemia is most commonly diagnosed in people over 60 years of age and is
rarely present in people below 40 years of age. This disease is caused by a deficiency
of vitamin B12, which is often related to the fact that the gastric mucosa does not secrete
the intrinsic factor (IF) needed for vitamin B12 absorption. There is strong evidence that
pernicious anemia is an autoimmune disorder with a genetic predisposition. Clinical
symptoms evolve slowly over a period of several months. Generally, the person
develops weakness, shortness of breath and jaundice. The tongue may become red
and raw or pale, sore and smooth. Gastrointestinal symptoms are usually present in the
form of abdominal pain, diarrhea, nausea and vomiting. Degeneration of the white
matter in parts of the CNS leads to several neurological symptoms, such as numbness
and tingling of the extremities, loss of position sense, muscle weakness and decreased
tendon reflexes. In more advanced cases, the person may become emotionally unstable
or display personality changes.
Iron deficiency anemia is an example of a microcytic, hypochromic anemia. This
disease results when there is insufficient iron for normal hemoglobin synthesis. This can
happen when iron loss or consumption exceeds iron intake, and may be associated with
pregnancy, dietary deficiency or bleeding. The red blood cells are small and of different
sizes, and pale (central pallor > 0.4 m). The reticulocyte count is usually within the
normal range (unless following hemorrhage or iron therapy) and although the platelet
count is normal, the platelets may appear smaller than usual. Patients with iron
deficiency anemia display the typical symptoms of anemia – fatigue, irritability,
breathlessness, palpitations, dizziness and/or headache. Other, less frequently
encountered symptoms include epithelial cell defects involving the tongue, nails, mouth
and stomach. There may be neurologic pain, vasomotor disturbances, numbness or
tingling.
2.4
Sickle cell disease is inherited as an autonomic recessive gene. This mutated gene
encodes abnormal hemoglobin S, in which the amino acid valine replaces a glutamino
acid that is normally found in the beta chain of adult hemoglobin A. When hemoglobin S
is deoxygenated, it crystallizes in the red blood cell; this leads to a distortion in the shape
of the red blood cells, rapid destruction of red blood cells, reduced red blood cell number
and anemia. In addition, masses of sickled red blood cells may block the lumen of small
blood vessels and cause infarcts (areas of cell death) in various tissues; this is believed
to be the cause of the severe pain in the abdomen, bone and joints that characterizes a
clinical crisis.
When a gene for hemoglobin S is inherited from only one parent, the individual is
heterozygous for the condition and has sickle cell trait; these individuals are rarely
severely affected. When the gene for hemoglobin S is inherited from both parents, the
individual is homozygous and suffers from sickle cell anemia. These patients have
profound anemia and recurrent infections. On a stained smear, the red blood cells
appear normochromic and normocytic. Some sickle shaped cells are generally present,
and the reticulocyte count is elevated. The platelet count is usually increased and there
may be moderate neutrophilia.
2.
Disorders Associated With Leukocytes: Leukemia and Eosinophilia
Leukemia is an uncontrolled, abnormal proliferation of one or more of the leukocyte
precursor cells. It is a cancer, then, of blood forming tissues. While the exact cause of
leukemia is unknown, the following risk factors have been identified: aging, chemical
exposure (some solvents (eg, benzene), some pesticides and herbicides), radiation
exposure, genetic predisposition, certain viruses and cigarette smoking. Among the
generalized symptoms that may appear are fatigue, weakness, discomfort, abnormal
bleeding and easy bruising, weight loss, bone or joint pain, infection and fever, and
enlargement of the liver, lymph nodes and spleen
Leukemias are classified according to the rate at which the disease progresses and
according to the type of cell that is malignant. Acute leukemia progresses quickly and
can lead to death in a period of weeks to months. The blood forming cells remain in an
immature state and are not functional. Chronic leukemia moves more slowly, over a
period of years. The leukocytes involved do mature but they are barely functional. If the
abnormal cells are primarily granulocytes or monocytes, the leukemia is called
myelogenous. It the abnormal cells are lymphocyte originating in bone marrow, it is
called lymphocytic (lymphomas are derived from lymphocytes in lymph nodes, the
spleen, and other organs).
Blood smears from patients with chronic lymphocytic leukemia (CLL) contain
abundant small lymphocytes (60-95% out of as many as 20,000 to 200,000
leukocytes/mm3 blood). The lymphocytes present are generally small, mature cells that
contain a nucleus with a small dent or cleft. The lymphocytes are generally fragile than
normal lymphocytes; this may result in the rupture of some cells during preparation of
the smear (smudge cells).
2.5
Eosinophilia is defined as an increase in the number of circulating eosinophils beyond
normal (> 450 eosinophils/l blood). There may also be increased eosinophils in other
body fluids and in tissues. There are several possible causes including malignancy,
connective tissue diseases, parasitic diseases, allergies but in many cases the cause is
unknown. Blood smears characteristically display a larger than normal density of
eosinophils with normal morphology.
Activity 2
Human Heart Anatomy
Materials:
models, charts and diagrams of the human heart
Resources:
Textbook:
Photographic Atlas
pages 658-668
pages 107-110
Procedure
Identify the following structures using charts, models and diagrams available in the lab:
apex
base
aorta
myocardium
endocardium
bicuspid (mitral) valve
coronary sinus
chordae tendineae
marginal artery
pectinate muscle
epicardium
visceral pericardium
middle cardiac vein
inferior vena cava
atrioventricular sulcus
left common carotid artery
2.6
right atrium
left atrium
right ventricle
left ventricle
pulmonary trunk
pulmonary veins
tricuspid valve
papillary muscles
circumflex artery
fossa ovalis
left subclavian artery
great cardiac vein
superior vena cava
right and left auricles
interatrial septum
left subclavian artery
interventricular septum
ligamentum arteriosum
pulmonary semilunar valve
inferior vena cava
left common carotid artery
aortic semilunar valve
trabeculae carneae
pulmonary arteries
left coronary artery
right coronary artery
anterior interventricular artery
brachiocephalic artery
posterior interventricular artery
posterior interventricular sulcus
anterior interventricular sulcus
Tips:
1.
Describe out loud to your lab partner how blood flows through the heart, naming in
order all of the chambers, valves, vessels, etc. Start with the inferior and superior
vena cava and end with the aorta. Point to each structure on a human heart
model. Use this chart to help you:
Circulation of Blood Through The Heart
1. Inferior/Superior Vena Cava
15. Body Systems
14. Aorta
2. Right Atrium
13. Through the Aortic
Semilunar Valve
3. Through the
Tricuspid Valve
12. Left Ventricle
4. Right Ventricle
11. Through the Bicuspid
(Mitral) Valve
5. Through the Pulmonary
Semilunar Valve
6. Pulmonary Trunk
7. Pulmonary Arteries
Activity 3
Materials:
Per pair of students:
Sheep heart specimen
Dissecting pan
Dissecting tools
Pins
Gloves
Goggles (if needed)
Bag for disposal or storage
2.7
10. Left Atrium
8. Lungs
9. Pulmonary Veins
Sheep Heart Dissection
Resources:
Photographic Atlas:
pages 111 and 116
Procedure:
Properly dissect a sheep’s heart and identify the following structures:
apex
right ventricle
right atrium
aorta
tricuspid valve
bicuspid (mitral) valve
coronary sinus
brachiocephalic artery
myocardium
fossa ovalis
atrioventricular sulcus
2.8
base
parietal pericardium
visceral pericardium
inferior vena cava
pulmonary veins
pectinate muscle
chordae tendineae
aortic semilunar valve
interventricular septum
pulmonary semilunar valve
ligamentum arteriosum
right and left auricles
left ventricle
left atrium
pulmonary trunk
pulmonary arteries
superior vena cava
moderator band
endocardium
anterior interventricular sulcus
posterior interventricular sulcus
fibrous pericardium
1.
Observe the pericardial sac (outer sac around the heart) and note how its
attachment to the heart.
2.
Cut open the pericardial sac and remove it carefully from its attachment point.
Identify the layers of the pericardial sac – the outer, fibrous layer and the inner,
serous, parietal pericardium. Then, identify the serous, visceral layer of the
pericardium (also called the epicardium) adherent to the surface of the heart
itself.
3.
Carefully clear the adipose tissue that is on the surface of the heart and around
the great vessels of the heart. The great vessels will appear as gray tubular
structures buried in the fat.
4.
Turn to page 111 and116 of the photographic atlas. Examine the external
surface of the heart. Note the fat filled anterior interventricular sulcus on the
anterior side of the heart surface. This sulcus is positioned obliquely on the
anterior side of the heart and marks the boundary between the right and the left
ventricles. Turn the heart over and examine the posterior surface; note the fat
filled posterior interventricular sulcus which has a more vertical orientation.
5.
Now, identify the apex (tip) and base of the heart. Locate the two ear like
auricles. The auricles are flaps of tissue on the surface of the right and left atrial
chambers. All tissue below the auricles makes up the walls of the right and left
ventricles.
2.9
6.
Compare the right and the left ventricles by compressing each. The wall of the
left ventricle will feel firm and thick; the wall of the right ventricle will feel flabby
and thin. How does the structure of each relate to its function?
7.
Turn the heart over and view the anterior surface. Note that the apex of the heart
is located in the left ventricle.
8.
While viewing the anterior heart, locate the pulmonary trunk and the aorta as
they emerge from the base of the heart. Follow the more anterior pulmonary
trunk until it divides to form the right and left pulmonary arteries (occasionally,
these arteries have been cut off – if that is the case, look at another specimen).
Now, follow the aorta until you locate the brachiocephalic artery. You should be
able to locate the ligamentum arteriosum, a remnant of fetal circulation, that
connects the pulmonary trunk and the aorta. The ligamentum arteriosum may be
buried in fat.
9.
Turn the heart over so that you are again viewing the posterior side. Locate the
openings into the left atrium; these openings were attached to the pulmonary
veins which are usually trimmed away when the specimen is procured. The
openings of the pulmonary veins are usually positioned inferior to the pulmonary
arteries. It may help to insert a probe through these openings into the left atrium.
10.
Next, identify the flat, thin walled superior and inferior vena cavae entering the
right atrium. Connect these two vessels by inserting a blunt probe into the
superior vena cava, through the right atrium and into the inferior vena cava.
11.
Starting at the top of the pulmonary trunk, use scissors to cut inferiorly until you
see the pulmonary semilunar valve. Locate the aortic semilunar valve by cutting
through the wall of the aorta in the same fashion. Try to identify the openings of
the right and left coronary arteries just above the valve leaflets of the aortic
semilunar valve.
12.
You are now ready to examine the internal structures of the heart. For this part
of the dissection. Follow the directions on page 166 of the photographic
atlas for this part of the procedure.
13.
Clean all of the tools and the dissection tray with soap and water, being careful to
remove any fat. Dispose of the heart in the biohazard bag at the front of the
room. Clean and disinfect your lab bench.
Activity 4
Microscopic Anatomy of Cardiac Muscle
Materials
Compound microscope
Colored pencils
Lens paper
Lens cleaner
Immersion oil
Prepared slide of cardiac muscle
Resources:
Textbook:
page 672: Fig 18.12
Procedure
1.
Observe a prepared slide of cardiac muscle and identify the striations, nuclei,
sarcolemma, and intercalated discs.
2.
Make a labeled drawing in the Lab Activities Worksheet.
2.10
Checklist
A.
Blood Pathologies
____
Pernicious anemia
____
Iron deficiency anemia
____
Sickle cell anemia
____
Chronic lymphocytic leukemia
____
Eosinophilia
B.
Human and Sheep Heart Anatomy
Structure
Chambers
Right atrium
Left atrium
Right ventricle
Left ventricle
Valves:
Tricuspid valve
Bicuspid (mitral) valve
Pulmonary semilunar valve
Aortic semilunar valve
Muscle
Pectinate muscle
Papillary muscles
Trabeculae carneae
Moderator band
Tissue Layers of the Heart Wall
Epicardium (visceral pericardium)
Myocardium
Endocardium
Pericardium
Pericardial sac (fibrous layer/parietal serous layer)
Epicardium (visceral pericardium)
2.11
Human Heart
Sheep Heart
Structure
Human Heart
Major Blood Vessels
Aorta
Brachiocephalic artery
Left common carotid artery
Left subclavian artery
Pulmonary trunk
Right and left pulmonary arteries
Superior and inferior vena cava
Right and left pulmonary veins
Sheep Heart
NA
NA
may be absent
may be absent
Remnants of Fetal Circulation
Fossa ovalis
Ligamentum arteriosum
Coronary Circulation
Right coronary artery
Left coronary artery
Anterior interventricular artery
Posterior interventricular artery
Circumflex artery
Marginal artery
Great cardiac vein
Middle cardiac vein
Coronary sinus
Other
Apex
Base
Chordae tendineae
Interventricular septum
Interatrial septum
Right and left auricles
2. Microscopic Anatomy of Cardiac Muscle
____
intercalated discs
____
striations
____
sarcolemma
2.12
NA
NA
NA
Lab 2 Pre-Lab Questions
1. Define the following terms:
Macrocytic:
____________________________________________________________
____________________________________________________________
Normochromic: __________________________________________________________
____________________________________________________________
Etiology:
____________________________________________________________
____________________________________________________________
Anemia
____________________________________________________________
____________________________________________________________
Leukemia
____________________________________________________________
____________________________________________________________
Eosinophilia
____________________________________________________________
____________________________________________________________
Hematology
____________________________________________________________
____________________________________________________________
Hemoglobin S____________________________________________________________
____________________________________________________________
Smudge Cell ___________________________________________________________
____________________________________________________________
Intrinsic factor ___________________________________________________________
____________________________________________________________
2.13
2. Match the term with the appropriate description:
a.
b.
c.
d.
e.
f.
g.
mediastinum
fibrous pericardium
parietal pericardium
superior vena cava
trabeculae carneae
pulmonary veins
papillary muscle
h. pulmonary trunk
i. interventricular septum
j. coronary sinus
k. ventricles
l. inferior vena cava
m. visceral pericardium
n. fossa ovalis
o. chordae tendineae
____
largest artery in the body
____
internal partition that divides the ventricles internally
____
three veins that deliver blood to the right artrium
p. pectinate muscle
q. aorta
r. apex
s. intercalated disc
t. myocardium
u. atria
v. endocardium
w. auricles
____
____
____
lines the internal surface of the fibrous pericardium
____
muscle that plays a role in valve function
____
lies in the left fifth intercostal space; points inferiorly towards the left hip
____
superior heart chambers
____
vessels that deliver blood to the left atrium
____
the medial cavity of the thorax
____
irregular ridges of muscle found in the internal walls of the ventricles
____
small protruding ear like flaps that increase atrial volume to a small degree
____
maintains a smooth surface for blood flow; lines heart chambers and covers heart valves
____
middle heart layer
____
remnant of fetal circulation located in the interatrial septum
____
also known as the epicardium
____
ridged bundles of muscle tissue in the anterior atrial walls
____
inferior chambers of the heart
____
outer, tough dense connective tissue layer of the pericardium
____
collagen cords connected to the AV valves; anchor the valves to papillary muscles
2.14
3. Identify the structures using the terms below:
_____ interventricular septum
_____ superior vena cava
_____ brachiocephalic artery
_____ tricuspid valve
_____ left atrium
_____ endocardium
_____ pulmonary semilunar valve
_____ aortic arch
_____ right pulmonary veins
_____ bicuspid (mitral) valve
_____ right atrium
_____ inferior vena cava
_____ aortic semilunar valve
_____ myocardium
_____ left pulmonary veins
_____ left common carotid artery
_____ left ventricle
_____ right ventricle
_____ left subclavian artery
_____ pulmonary trunk
_____ right pulmonary artery
_____ left pulmonary artery
_____ descending aorta
_____ epicardium
18
19
17
21
23
16
24
2.15
20
22
4. Match the terms below with the descriptions:
a.
b.
c.
d.
e.
right coronary artery
marginal artery
left coronary artery
great cardiac vein
pulmonary semilunar valve
f. tricuspid valve
g. aortic semilunar valve
h. anterior interventricular artery
i. middle cardiac vein
j. posterior interventricular artery
k. bicuspid valve
These two structures prevent the backflow of blood into the atria
_____ _____
These two structures prevent the backflow of blood into the ventricles
_____ _____
These two structures arise from the base of the aorta and supply blood
to coronary circulation
_____ _____
These two vessels supply blood to the interventricular septum
_____ _____
These two structures are tributaries of the coronary sinus
_____ _____
This vessel supplies blood to the right ventricular wall
_____
5. Describe the location and position of the heart in the human body: _________________
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
6. Compare the function of the pulmonary circuit and the systemic circuit
___________
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
2.16
Lab Activities Worksheet
Name:
_____________________
Week 2 Lab
1.
Prepare sketches of each slide indicated below:
Pernicious Anemia
Iron Deficiency Anemia
Macrocytic/Normo-hyperchromic
Microcytic/Hypochromic
Magnification: ______________
Magnification: ____________
Sickle Cell Anemia
Chronic Lymphocytic Leukemia
Normocytic/Normochromic
Magnification ______________
Magnification: ________________
Eosinophilia
Magnification: ___________
2.17
2.
Which chamber of the heart – left or right ventricle – has thicker walls? How does this
difference reflect the functions of these two chambers?
____________________________________________________________________
____________________________________________________________________
____________________________________________________________________
____________________________________________________________________
3.
After observing the models, identify one method that you could use to differentiate between
the anterior and posterior surfaces of the heart:
_____________________________________________________________________
_____________________________________________________________________
_____________________________________________________________________
4. Identify one method that you could use to differentiate the right and left sides of the heart.
_____________________________________________________________________
_____________________________________________________________________
5.
What structure is present in the right ventricle of the sheep’s heart, but not in the left ventricle?
______________________
6.
Make a labeled sketch of cardiac muscle as you observed it under the microscope. Label
the nucleus, intercalated discs, sarcolemma and striations.
Cardiac Muscle
Magnification:
2.18
___________
7.
Identify two differences between the structure of cardiac muscle tissue and skeletal muscle
tissue.
Cardiac muscle tissue
2.19
Skeletal muscle tissue