How Does A Human Heart Compare To A Frog Heart? Grade Levels: 10-12 Time Frame: 1 ½ periods Big Idea: The goal of this activity is for students to learn about and compare the structure of the mammal heart and amphibian heart by constructing 3-dimensional models of a human and a frog heart. Students also gain experience-interpreting diagrams as the model for their directions. Objective/Outcomes/Expectations Students should learn that the human heart has 4 chambers, compared to a frog, which has 3 chambers. Assessment The appropriate number of chambers should be present. Students should learn the names of the four (three in the frog) chambers. Chambers should be labeled correctly. Students should be able to differentiate the right side of the heart from the left. Chambers should be labeled right or left. (Right Atrium, Left Ventricle etc.) Students should know which side has oxygenated blood and de-oxygenated blood (and blood mixes in the frog). Labels should be in red (oxygenated) or blue (de-oxygenated), or purple (frog). For higher level classes, the names of the blood vessels can be included. Straws (vessels) should be labeled correctly. Materials: Straws 7 Plastic or Paper Cups – although red & blue ones are ideal, any type will do Scissors Masking Tape or Glue (Tape sticks better to plastic cups) Colored pencils or crayons: red, blue, purple Heavy paper - cut up old file folders work well Procedures Building a Three-Chambered Heart Model 1. Remove the bottom of two paper cups, 4 cm from the bottom. Save the bottoms of the cups. 2. Put a small hole (big enough for a straw to fit through) into the center of the bottom surface of the cups. 3. Put a small hole into the center of the thick paper. 4. Place the two cup bottoms, open ends facing down, on either side of the center hole on the thick paper. Trace a circle around each. 5. Trace another circle 1-2 cm larger than the combined diameter of both cup bottoms. 6. Cut two small flaps into the thick paper in positions which will lie in the center of the two cup bottoms. (Refer to the diagram for placement.) 7. Label the two atria and the ventricle with to better understand the labels. 8. Label the blood vessels with the direction models of blood flow, and the appropriate color. Academic Adaptations When teaching it is helpful to remember that not all students can learn through discovery. Some students are not able to processing information at an abstract level and/or through reasoning. Therefore, doing a demonstration can help students with processing problems make a connection between the information being presented, using pasted information and a connection to the lab being done in class. 2. If possible to make 3.when assigning students to groups it may be helpful to may be helpful to pair students with a cognitive or learning disability to be paired with a high level student. 4. depending on the severity of the disability some students may need to be assigned assigned a specific job within the job so that they can feel that they count and earn a grade. 5. Remember to identify what way the youth learns. For example does the youth learn visually, audit orally or through the use of all sense? Behavioral/Social Adaptations 1. As much as possible, pair students with less ability to follow directions with someone of higher ability. Assistive Technology 2. For students with physical, or cognitive disabilities they could be give a picture of a two- dimensional heart to label. If writing is particularly difficult they could be given mailing labels with the terms on them to adhere to the model. 2. Circulate around room to ensure that students are on task. If a certain group of 3. The worksheet students are off-task or misbehaving, stand question again could be saved as a template near that group. or printed out and the 3. Have all materials answer prepared on for each group set out stickers to be adhered. on trays ahead of time. 4. Only have 1 partner per group retrieve supplies. Diagrams: Background Knowledge: The heart is a muscle that pumps blood. Even though all hearts pump blood, the hearts of different animals vary in several ways. Hearts can be different sizes and shapes, and they can differ in the number of chambers they have. You know that your heart has four chambers – two on the top (atria) and two on the bottom (ventricles). All mammals have four chambered hearts. On the other hand, amphibians (frogs, salamanders) have hearts with three chambers – two atria, and one ventricle at the bottom. Fish have hearts with only two chambers – one atrium and one ventricle. When looking at a body (or organ) from the front, the right and left appear to be reversed. (Ask students to figure out why this is.) In humans, the left side of the heart has oxygen-rich blood, and the right side has oxygen-poor blood. Guide students to understand that oxygen-rich blood must be coming from the lungs and on its way to the body cells, while oxygen-poor blood must be coming from the body and on its way to the lungs. Staging/Tips: - Supplies can be place at each individual table, or at a central location for students to access. Students can work in pairs – each participating in the construction of both hearts. A completed model available for reference at the front desk is useful for students to see what the end result should look like. To attach the thick paper circles to the tops of the cups, attach two pieces of masking tape to the inside of the cup, leaving a short piece hanging out on each, and gently press onto the circle. Worksheet Questions: THREE-CHAMBER HEART 1. What kinds of animals have three-chambered hearts? __________________________ 2. What are the names of the three chambers? __________________________________ 3. Are the straws in the small cups arteries or veins? _____________________________ 4. Is the straw in the large cup an artery or a vein? _______________________________ 5. Describe the direction in which blood flows through a three-chambered heart: ________ ___________________________________________________________________ 6. Describe the condition of the blood in each chamber: ___________________________ ___________________________________________________________________ 7. What is a disadvantage of having a three-chambered heart? ______________________ ___________________________________________________________________ FOUR-CHAMBER HEART 1. What kind of animals has four chamber hearts? _______________________________ 2. What are the names of the four chambers? ___________________________________ 3. Are the straws in the small cups arteries or veins? ______________________________ 4. Are the straws in the large cups arteries or veins? ______________________________ 5. Describe the direction of blood flow starting with the right atrium: __________________ ___________________________________________________________________ 6. Describe the condition of blood in each chamber: ______________________________ ___________________________________________________________________ 7. What is an advantage of having a four-chambered heart? ________________________ ___________________________________________________________________ Other Resources: www.pbs.org/wgbh/nova/eheart - has a heart “map”, shows blood flow, good information www.sln2.fi.edu/biosci/heart.html – on-line heart exploration This lesson was modified for science by the Science PK16 Leadership Team and accommodations were created by the Special Education and Assistive Technology PK16 Leadership Team Members. The development of all lessons was supported by funding from the PK16 UW System Technology Initiative Grant Project. The original source of the lesson was: Title: "How do Hearts of Different Animals Compare?" Book Title: Biology Laboratory Experiences Pages: p.85-88 Year: 1988 Publisher: Merrill Publishing Company Authors: Kaskel, Hummer, Daniel