BIOLOGY
Major94
Unit4CirculatorySystemLab.rtf
1
BIOLOGY 102: BIOLOGY, HEALTH AND THE ENVIRONMENT LABORATORY
LAB 4 : Circulatory System
Laboratory Exercise:
Video presentation
Completion of study exercises
Objectives:
Upon completion of today’s exercises a student should be able to:
- demonstrate basic understanding of the circulatory system
define and take pulse rate
compare a healthy heart with a non-healthy heart
Circulatory System
Blood is considered a connective tissue in the body. It is carried throughout the body by the circulatory system. In its circuit through the body, the heart pumps blood away in arteries and arterioles and the blood is returned by venules and veins. The connection between the arterioles and the venules is achieved via capillary beds.
These two parts of the circulation are divided into a pulmonary circuit and a systemic circuit. In the pulmonary circuit, deoxygenated blood travels to the lungs via the pulmonary artery. After picking up oxygen and dropping off carbon dioxide, the pulmonary veins return the blood to the heart. The systemic circuit carries blood away from the heart via the aorta and delivers it to other parts of the body where it passes first through arterioles into the capillaries then to the venules. It enters various veins eventually returning to the heart via the superior and inferior vena cavae.
There are four chambers to the heart. The two upper chambers are called atria and they are thin-walled. The two lower, thick-walled chambers are known as ventricles. During a heartbeat, the atria contract simultaneously; followed by simultaneous contraction of the two ventricles. The heartbeat is controlled by the sinoatrial node. Blood pressure is created by the pumping of the heart.
Your pulse rate or heart rate is the number of times your heart beats in one minute. These rates may vary from person to person. When you are at rest, your pulse rate is lower and it increases when you exercise. Many athletes take their pulse rate when evaluating their exercise program.
Age Group
Normal Heat Rate at Rest
Children (ages 6-16)
70-100 beats per minute
Adult (ages 17 and over)
60-100 beats per minute
Name: ____________________________ Lab Day and Time__________________
Pre-Lab Activity
1) How is the body dependent upon the circulatory system?
2) What are the differences between arteries and veins in terms of their structures and functions?
3) Why are the arteries usually illustrated by the color red and the veins blue?
4) Describe the structure of the heart.
5) What causes the familiar sound of the heartbeat?
6) What is the role of the pacemaker?
7) What is the effect of adrenaline on the heart? Where is it produced?
8) Describe the conditions in the heart’s coronary arteries that lead to heart attack.
Name: ____________________________ Lab Day and Time__________________
Taking your pulse
- Place the tips of your index, second and third fingers on the palm side of your other wrist below the base of the thumb. Or, you could take your index and second fingers and place them on your lower neck on either side of your windpipe.
Using your fingers, press lightly until you feel the blood pushing under your finger tips. You may need to move your fingers up and down gently until your feel the pulsing.
Use a watch or clock and count the beats you feel in 10 seconds. Multiply this number by six to get your heart rate (pulse) per minute.
Count your pulse: ______________ beats in 10 seconds x 6 =
____________________beats/minute
Test your heart rate
Now perform a physical activity (jogging in place, walking, jump n jacks, etc) for 1 minute. Then take your pulse rate.
Count your pulse after activity: ______________ beats in 10 seconds x 6 =
____________________beats/minute
Discussion
Did your pulse rate increase or decrease? Explain why or why not.
- How is the heart of an athlete different from a non-athlete?
- How can you maintain a healthy heart?
