Performance Test

Title: Artery or Vein?

Description:Students will discover the nature of the blood vessels under the skin of their hands.

Materials:None

Background: Students should have knowledge of the circulatory system and the work of blood.

Time Required: One 45 minute class period.

Procedure:Hand out the student procedure sheet. Allow students time to work. Discuss findings and see if students can figure out what might hold the blood in place and not let it flow backwards. Give them several opportunities to guess and really make them think about it.

Scoring Guide

1. Student makes prediction…………………………………………………….2 pts

2. Student completes observations and fills out data………………………15 pts

3. Student correctly answers questions………………………………………..7 pts

answers to questions:

1. blood is moving toward the body

2. veins

3. arteries must be deeper in the arm

4. one way valves keep blood from flowing backward

5. arteries do not have them, blood is under high enough pressure to flow the correct direction

6. tissues need blood for food and oxygen

7. blood carries wastes away from cells.

4. Conclusion carefully written………………………………………………….2 pts

Total……………………….26 pts

Sample Student Page

Name______Period______Date______

Title: Artery or Vein?

Introduction: Are the blood vessels visible on the outside of your hand arteries or veins. What is the difference between the two different types of blood vessels? What direction are they carrying blood? In this activity, you will find out.

Procedures

  1. Divide into groups of two. One will observe and record, and the other one will be the subject.
  2. Have the subject stand with both arms down to their sides until the veins on the back of the hand stand out.
  3. The observer should place a finger on one of the subjects raised veins.
  4. The observer slides his/her finger upward (toward the body) along the vein for about 4 cm, pressing firmly but gently.
  5. The observer writes the observations in the data table.
  6. The observer slides his/her finger backward (toward the hand) along the vein.
  7. The observer writes the observations in the data table.
  8. The observer places two fingers on the same vein about 4 cm apart.
  9. The observer releases the finger closest to the hand and leaves the other in place and writes the observation in the data table.
  10. The observer releases the finger closest to the body and leaves the other in place and writes the observation in the data table.
  11. Switch roles and repeat steps 2-10.

Prediction:

Observations

Data Table

Step / Effect on Vein
Person 1 / Person 2
4
6
9
10

Analysis

  1. What direction is the blood moving in these blood vessels?

2. Veins carry blood towards the heart, arteries carry it away. Which type of vessels are on the outside of your hand?

3. Where are the arteries?

4. What keeps the blood from flowing backward in the veins?

5. Do you think arteries have them? Why or why not?

6. Why do tissues need blood?

7. What does blood take away from tissues?

Conclusion: