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Heart Dissection Lesson

Heart Dissection Lesson

Welcome to our Heart Dissection Lesson aimed at GCSE students.

We have a heart dissection video demonstrating the methodology of the classroom dissection of a pig’s heart.  We have included a lesson plan and risk assessments that can be downloaded or simply reviewed here.

We hope to guide pupils through discovering as much as they can from the heart!

Aim: To explain how the structure of the heart is related to its function

GCSE Biology

Methodology:

  • Place heart in dissection tray. The left side of the heart, with the thicker wall, should be to the right as you look at it.
  • The coronary artery runs across the front surface of the heart.
  • Trace the artery up to the top of the heart and try to find where it comes from the aorta. You may need to carefully trim some fat away.
  • Identify the two atria and the two ventricles and feel the differences in the wall thicknesses.
  • Use your scalpel to pierce the left atrium wall and use the scissors to cut down the heart from the left atrium to the left ventricle in a straight line.
  • Open up the left atrium and the left ventricle to the apex of the heart.
  • Trace where the aorta leaves the left ventricle and spot the valve in the aorta.
  • Cut open the right side of the heart in the same way as the left.
  • Measure the thickness of the atrium and ventricle walls.

Teaching Notes:

  • The heart is an organ that pumps blood around the body in a double circulatory system.
  • The right ventricle pumps blood to the lungs where gas exchange takes place. The right ventricle doesn’t need a thick muscle wall.
  • The left ventricle pumps blood around the rest of the body. The left ventricle has a very thick muscle wall.
  • Blood flows into the pulmonary vein, to the left atrium, left ventricle, aorta and to the capillaries in the body tissues.
  • From the tissues, blood travels to the vena cava, to the right atrium and right ventricle and then out of the heart via the pulmonary artery and back to the lungs.
  • The function of the coronary artery is to supply the heart muscle itself with oxygen and nutrient-carrying blood.

Observations to point out:

  • The two atria will have collapsed onto the top of the heart since they are no longer filled with blood.
  • The atria chambers can be easily stretched to show their thinness.
  • All four chambers will have the same capacity.
  • The heart strings attach valves to the ventricle walls and prevent the valves inverting. This helps to prevent any back flow of blood and maintain the blood flow in one direction only.
  • Samples for Schools Heart
  • Dissection tray
  • Scalpel
  • Scissors
  • Mounting needle
  • Ruler or callipers with mm divisions
  • Paper towel

AQA: Topic 4.2.2.2 and 4.2.2.4

Students should know the structure and functioning of the human heart.

Students should be able to evaluate the advantages and disadvantages of treating cardiovascular diseases by drugs, mechanical devices or transplant.

Edexcel: Topic 8.8

Explain how the structure of the heart and circulatory system is related to its function, including the role of the major blood vessels, the valves and the relative thickness of chamber walls.

Eduqas: Topic 2.2

Learners should be able to:

(a)  describe the human circulatory system as a double circulatory system and its relationship with the gaseous exchange system.

(b)  label on a given diagram of the heart: the left and right atria and ventricles, semi-lunar, bicuspid and tricuspid valves, pulmonary artery, pulmonary vein, aorta and vena cava.

(c)  explain how the structure of the heart is adapted to its function.

(d)  describe the passage of blood through the heart including explaining the functions of the valves in preventing backflow of blood.

OCR 21st Century: Topic B5.1

Students should explain how the structure of the heart is adapted to its function, including cardiac muscle, chambers and valves.

OCR Gateway: Topic B2.2d

Students should explain how the structure of the heart and the blood vessels are adapted.

Students should explain the structure of the mammalian heart with reference to valves, chambers, cardiac muscle and the structure of blood vessels with reference to thickness of walls, diameter of lumen, presence of valves.