Download 10 Features of the Cardiovascular System

Laboratory
10
Features of the Cardiovascular System
(LM pages 129–140)
Time Estimate for Entire Lab: 2.0 hours
Special Requirements
Living material (order in advance for timely delivery): goldfish, frogs
Seventh Edition Changes
This was lab 9 in the previous edition.
New and revised figures. 10.4 Control of the heartbeat
MATERIALS AND PREPARATIONS1
10.1 The Blood (LM pages 130-132)
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slide, prepared: human blood smear (Carolina 31-3158)
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goldfish, live (Carolina 14-5280); or frog, live (Carolina’s
“Living Organisms: Animals, Frogs” section )
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cotton, absorbent
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cheesecloth or paper toweling
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petri dishes
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tape, cellophane
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corkboard
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pins, dissecting; or thread
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ice
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microscopes, compound light with oil immersion lens
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microscopes, binocular dissecting
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microscope slides
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lens paper
10.2 The Heart (LM pages 133-136)
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model, heart (Carolina 56-6802 to -6806, -6810, -6812, -6821); or sheep heart, preserved
(Carolina 22-8770)
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dissecting pans and scalpels (see Carolina’s “Apparatus: Dissecting” sections)
Blood smear slide. The same blood smear slide can be used for observing of both red blood cells and white
blood cells. This slide has been treated with Wright stain.
Live goldfish. A variety of goldfish are available from the Carolina Biological Supply Company and from
local aquarium shops. Wrap the body of the goldfish in wet absorbent cotton so that only the tail is exposed.
Place it in a petri dish with a small amount of water. Cover the tail with a glass slide to hold it flat and
expanded. Examine under low and high power of a binocular dissecting microscope. Observe the swiftly
moving blood in the arterioles and the more slowly moving blood in the venules (moving in the opposite
direction). Look carefully for blood cells floating in the bloodstream. Set up similar demonstrations so that
all students may observe circulation within a 15-minute period. Return fish to the aquarium.
1 Note: “Materials and Preparations” instructions are grouped by exercise. Some materials may be used in more than one exercise.
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Live frogs. A wide variety of live frogs are available from Carolina Biological Supply Company. Wrap a live
frog in wet cheesecloth, paper toweling, or absorbent cotton. Lay the animal on a frog board made of cork,
and secure in position with cellophane tape. Punch a hole in one corner of the corkboard, and spread the
web of one foot over this hole; use thread wound around the toes and secured with pins to keep the toes
immobile. Keep the frog’s skin wet during the demonstration. Place the board on the stage of the binocular
dissecting microscope, and focus on the webbed foot. Observe capillaries, arterioles and venules, and the
rate of blood flow. Notice the direction of the blood flow and the pulsations of the blood vessels. Estimate
the diameter of the capillaries using the size of the red blood cells as a reference: 22 microns long, 15 microns
wide, and 4 microns thick. Under high power, compare the movement of both red and white blood cells.
Notice the appearance and disappearance of capillaries. To study the effect of temperature on circulation,
place a small piece of ice on the web.
10.3 Heartbeat (LM pages 137-138)
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stethoscope (Carolina 69-1634 to -1643)
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stopwatches (Carolina 69-6908) or other timing devices (students can use their
wristwatches)
10.4 Blood Pressure (LM pages 138-140)
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sphygmomanometer (Carolina 69-1202, or see Carolina’s Physiology: Human for a vari
ety of blood pressure sets and kits)
EXERCISE QUESTIONS
10.1 The Blood (LM pages 130-132)
Red and White Blood Cells (LM pages 130-131)
Observation: Blood Slide (LM page 130)
Table 10.1 Slide of Blood
Relative Number
Relative Size
Presence of Nucleus
Function
Red blood cells
More numerous
Smaller
No
Carries O2
White blood cells
Less numerous
Larger
Yes
Fights infection
Blood Flow (LM page 132)
Experimental Procedure: Blood Flow (LM page 132)
6. In what way is this feature (thin-walled vessels) useful to the organism? Diffusion of nutrients and
waste products across the capillary wall is facilitated.
10.2 The Heart (LM pages 133-136)
Heart Model or Preserved Sheep Heart (LM pages 133-135)
Observation: Heart Chambers (LM page 134)
2. Which ventricle is more muscular? left ventricle
Why is this appropriate? The left ventricle pumps blood to the systemic circuit.
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Path of Blood through the Heart (LM page 135)
To demonstrate that O2-poor blood is kept separate from O2-rich blood, trace the path of blood from
the right side of the heart to the aorta.
Venae Cavae
Right atrium
Lungs
Pulmonary veins
AV valve
Left atrium
Right ventricle
AV valve
Semilunar valve
Left ventricle
Pulmonary artery
Semilunar valve
Lungs
Aorta
Conduction System of the Heart (LM pages 135-136)
Observation: Nodes (LM page 136)
2. Why is an arrow drawn between the SA node and the P wave? The P wave indicates that atrial contraction is about to occur, and the SA node causes atrial contraction.
Why is an arrow drawn between the AV node and the QRS wave? The QRS wave indicates that ventricular contraction is about to occur, and the AV node causes ventricular contraction.
The voltage changes in an ECG are related to the electrical activity of cardiac muscles.
10.3 Heartbeat (LM pages 137-138)
Heartbeat at Rest (LM page 137)
Experimental Procedure: Heartbeat at Rest (LM page 137)
Stethoscope Method (LM page 137)
2. Which of the two sounds (lub or dub) is louder? dub
3.& 4. Answers will depend on the individuals.
Pulse-Rate Method (LM page 137)
1. Data will depend on the individual.
3. Are the number of heartbeats the same regardless of the method used to determine the rate? yes
Explain. The “pulse” results from momentary increases in blood pressure caused by contraction of the left
ventricle of the heart.
Table 10.2 Heartbeat at Rest
Method
Partner
Yourself
Stethoscope
Data will depend on the individual, but the heartbeat at rest will probably be around 72 beats per minute
using either method.
Pulse rate
Heartbeat After Exercise (LM page 138)
Experimental Procedure: Heartbeat After Exercise (LM page 138)
Table 10.3 Heartbeat at Rest and After Exercise
Before Exercise (from Table 10.2)
Partner
Yourself
Data will depend on the indivuals involved.
After Exercise
Partner
Yourself
2. Why is it advantageous to have an increased heartbeat during exercise? More O2-rich blood is delivered to the skeletal muscles.
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10.4 Blood Pressure (LM pages 138-140)
Blood pressure is highest just after ventricular systole, and it is lowest during ventricular diastole.
Why? Because during ventricular systole, the left ventricle is pumping the blood out into the systemic system.
and during ventricular diastole, the left ventricle is resting.
Blood Pressure at Rest (LM page 138)
We would expect a person to have lower blood pressure at rest than after exercise. Why? When a person
is at rest, the heart does not pump as hard.
Experimental Procedure: Blood Pressure at Rest (LM pages 138-139)
Table 10.4 Blood Pressure at Rest
Partner
Yourself
Systolic/diastolic
Systolic/diastolic
Data will depend on the individual, but blood pressure of 120/80 is considered normal.
Blood Pressure After Exercise (LM page 139)
We would expect higher values for blood pressure just after a person exercises. Why? The heart pumps
harder when a person exercises.
Experimental Procedure: Blood Pressure After Exercise (LM pages 139-140)
Table 10.5 Blood Pressure After Exercise
Partner
Yourself
Systolic/diastolic
Systolic/diastolic
Explain
Data will depend on the individual.
LABORATORY REVIEW 10 (LM page 140)
What type of blood cells are lymphocytes and monocytes? white
What is the function of red blood cells? carry O2
What is the function of white blood cells? fight infection
Nutrients exit and wastes enter which type of blood vessel? capillary
Which blood cells contain a respiratory pigment? red blood cells
Which chamber of the heart receives venous blood from the systemic circuit? right atrium
Identify the vessel that conducts blood from the left ventricle. aorta
The pulmonary artery leaves which chamber? right ventricle
Identify the artery that nourishes the heart tissue. coronary
Which heart chamber pumps blood throughout the body? left ventricle
How many times a minute does the heart normally beat in a young adult? between 60 and 80 beats
per minute
12. What is it called when a heart chamber contracts? systole
13. Which is higher—systolic or diastolic pressure? systolic pressure
14. What is the normal resting blood pressure of a young adult? 120/80
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Thought Questions
15. Why is the body better served by having several different types of white blood cells? Each type of
white blood cell has a different function.
16. Under what conditions in everyday life would you expect the heartbeat and the blood pressure to
increase? When might this be an advantage? A disadvantage? The heartbeat and blood pressure
increase with physical exercise and stress. This is an advantage with physical exercise and also stress due to an
emergency because oxygen and glucose get to the muscles faster when the heartbeat increases. This is a disadvantage when stress is not due to an emergency because high blood pressure can cause illness in the long run.