Download 9 Cardiovascular System

Laboratory
9
Cardiovascular System
(LM pages 115–128)
Time Estimate for Entire Lab: 2.0 hours
Note: Because humans stand upright, the proper terms are the superior vena cava and the inferior vena cava,
but because pigs are tetrapods, these same vessels should be called the anterior vena cava and the posterior vena cava (pl., vena cavae).
Seventh Edition Changes
This was lab 8 in the previous edition. In section 9.3 Systemic Circuit, Blood Vessels of the Thoracic Cavity
has been rewritten to increase active participation by the student.
New or revised figures: 9.2 Human fetal circulation; 9.3 Ventral view of fetal pig heart; 9.5 Arteries in the
thoracic cavity of the fetal pig; 9.6 Veins in the thoracic cavity of the fetal pig; 9.9 Scanning electronmicrograph of an artery and a vein
MATERIALS AND PREPARATIONS1
9.1
Path of Blood in an Adult Versus a Fetus (LM pages 116-117)
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model, human fetal circulatory system (Carolina 56-3150)
9.2 – 9.3 Pulmonary Circuit and Systemic Circuit (LM pages 119-126)
_____
fetal pigs, preserved, for dissection (Carolina 22-8400 to -8492)
_____
dissecting pans, pins, tools, and trays (see Carolina’s “Apparatus: Dissecting” sections)
_____
wax pencils
_____
labels, for labeling individual pigs
_____
plastic bags or containers for pig storage
_____
string, heavy, for tying pigs into dissection pans and for tying bags
Fetal pigs. Fetal pigs for dissection are available from many supply houses. Large, double-injected specimens are recommended.
9.4 Blood Vessel Comparison (LM pages 126-127)
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slide, prepared: artery and vein, cross section (Carolina 31-4088, -4094)
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microscopes, compound light
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lens paper
EXERCISE QUESTIONS
9.1 Path of Blood in an Adult Versus a Fetus (LM page 116)
Path of Blood in Adult Humans (LM page 116)
Pulmonary Circuit (LM page 117)
1. Trace the path of blood in the pulmonary circuit from the heart to the lungs, and then from the
lungs to the heart.
right ventricle of heart, pulmonary artery, lungs, pulmonary veins, lungs
lungs, pulmonary veins, left atrium of heart
1 Note: “Materials and Preparations” instructions are grouped by exercise. Some materials may be used in more than one exercise.
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Systemic Circuit (LM page 117)
2. Trace the path of blood in the systemic circuit from the heart to the kidneys, and then from the
kidneys to the heart.
left ventricle of the heart, aorta, renal artery, kidneys
kidneys, renal vein, inferior vena, cava, right atrium of the heart
Names of Blood Vessels (LM page 117)
Table 9.1 Major Blood Vessels in the Systemic Circuit
Body Part
Artery
Vein
Head
Carotid
Jugular
Arms
Subclavian
Subclavian
Kidney
Renal
Renal
Legs
Iliac
Iliac
Intestines
Mesenteric
Hepatic portal
Path of Blood in Fetal Humans (LM page 117)
Through the Heart (LM page 119)
1. Trace the path of blood from the right atrium to the aorta, going through the oval opening.
2. Trace the path of blood from the right atrium to the aorta, going through the arterial duct.
First pathway: right atrium, oval opening, left atrium, left ventricle, aorta
Second pathway: right atrium, right ventricle, pulmonary trunk, arterial duct, aorta
To the Placenta and Return (LM page 119)
3. Trace the path of blood from the aorta to the placenta and from the placenta to the inferior
vena cava.
aorta, iliac artery, umbilical artery, placenta
placenta, umbilical vein, venous duct, inferior vena cava
Comparison (LM page 119)
Table 9.3 Comparison of Human Fetal and Adult Circulation
Fetus
Adult
Vessel with the highest oxygen concentration
Umbilical vein
Aorta
Passage from right to left side of heart
Oval opening
Pulmonary artery to lungs and pulmonary vein
from lungs
Entrance of blood into aorta
Arterial duct
Left ventricle
Area of gas exchange
Placenta
Lungs
9.2 Pulmonary Circuit (LM pages 119-120)
Observation: Pulmonary Circuit (LM page 119)
Pulmonary Veins (LM page 120)
2. In the adult, which blood vessels carry O2-rich blood? pulmonary veins
9.3 Systemic Circuit (LM pages 120-126)
Observation: Blood Vessels of the Thoracic Cavity (LM page 122)
Carotid Arteries and Jugular Veins (LM page 122)
3. What part of the body is serviced by the carotid arteries and the jugular veins? the head
5. Name and locate all veins that join to form the anterior vena cava. left internal jugular, left external
jugular, left subscapular, left subclavian, right brachiocephalic
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9.4 Blood Vessel Comparison (LM pages 126-127)
Do you predict that arteries or veins are generally more superficial in the body? veins
Wall of Artery Compared to Wall of Vein (LM page 126)
Observation: Blood Vessel Comparison (LM page 127)
4. Does this layer appear thicker in arteries than in veins? yes
5. Considering the relationship of arteries and veins to the heart, why is this reasonable? Arteries take
blood away from the heart. The blood is under high pressure, and it is unlikely that it will flow backwards.
Veins take blood to the heart; the lower blood pressure of the veins, combined with gravity, makes one-way
valves essential to prevent pooling of blood in the arms and legs.
Conclusions (LM page 127)
• Which type of blood vessel (arteries or veins) has thicker walls? arteries
• Which type of blood vessel has thinner walls? veins
• Which type of blood vessel is more apt to lose its elasticity, leading to a discoloration that can be
externally observed? veins What is this condition called? varicose veins
LABORATORY REVIEW 9 (LM page 128)
1. What fetal structure connects the pulmonary trunk to the aorta? arterial duct
2. What fetal blood vessel contains the most oxygen? umbilical vein
3. What structure allows the blood to pass from the right to the left side of the heart into the fetus?
oval opening
4. Does the pulmonary artery in adults carry O2-rich or O2-poor blood? O2-poor blood
5. The coronary arteries and cardiac veins serve what organ? the heart
6. Identify the blood vessel that conducts blood to the head. vein
7. Identify the artery that serves the kidney. renal artery
8. Identify the large artery that runs dorsally along the wall of the abdominal cavity. aorta
9. Identify the arteries that take blood from the aorta to the legs. iliac arteries
10. What part of the human body is served by the subclavian vessels? shoulder
11. Identify the large abdominal vein that runs alongside the aorta and enters the right atrium.
inferior vena cava
12. What part of the body is not served by the systemic circuit? lungs
13. Which type of blood vessel (artery or vein) has thicker walls? artery
14. Which type of blood vessel (artery or vein) has valves? veins
Thought Questions
15. Do arteries always carry O2-rich blood? Explain. No. In the adult, pulmonary arteries carry O2-poor
blood from the heart to the lungs. In the fetus, umbilical arteries carry O2-poor blood to the placenta.
16. Trace the path of blood from the left ventricle to the kidneys and back to the right atrium. Blood
leaves the left ventricle and goes to the aorta, to the renal artery, to capillaries, to the renal vein, to the inferior
vena cava, to the right atrium.