Grade 6: The Heart and Circulatory System

Lesson 1: The Heart

Objectives

• Identify the four chambers of the heart.
• Understand structures of the Circulatory System and their functions.
• Explain heart rate and measure resting and active heart rates.
• Describe functions of the Circulatory System.
• Explain the heart's role in circulation.
• Understand the cardio-pulmonary sequence.
• Describe systemic circulation.

Materials

• Animal heart (cow, pig, or sheep)
• Note cards, heart diagram, dissection tools

Key Concepts

• Main function of the heart: pump blood throughout the body.
• Heart location: chest cavity, protected by sternum and ribs.
• Heart size: roughly a fist, weighs about 300 grams.
• Pumps about 2,000 gallons of blood daily.
• Blood vessels total more than 60,000 miles.
• Heart structure: four chambers (two ventricles and two atria).
• Blood flow: body -> heart -> lungs -> heart -> body.
• Atria: receive blood; Ventricles: pump blood.
• Valves: control blood movement.

Heart and Lungs Interaction

• Pulmonary circulation sequence:
  1. Blood enters right atrium from body.
  2. Moves to right ventricle.
  3. Pumped to pulmonary artery -> lungs.
  4. Returns to heart via left atrium.
  5. Moves to left ventricle -> aorta -> body.

Lesson 2: The Heart Rate

Key Concepts

• Average adult heart rate: 72 beats per minute.
• Children's heart rate: higher, around 80 beats.
• Pulse measurement: carotid and wrist.
• Factors affecting heart rate: exercise, eating, fever, stress, and nervous system influences.
• Sympathetic nervous system: increases heart rate; parasympathetic: restores normal rate.

Activities

• Measure resting and active heart rates.
• Explore heart rate variance with activity.

Lesson 3: The Circulatory System and Blood

Key Concepts

• Circulatory System: transports blood with nutrients, oxygen, and waste removal.
• Blood composition: 5 liters; plasma (55%), red blood cells, white blood cells, platelets.
• Blood vessels: arteries (away), veins (toward), capillaries (exchange site).
• Blood pressure: systolic (high), diastolic (low).
• Systemic circulation: heart -> body -> heart.

Diseases

• Heart disease causes: cholesterol, plaque, calcium deposits.
• Prevention: healthy lifestyle choices (no smoking, proper nutrition, exercise).

Practical Activities

• Dissect animal heart; identify parts.
• Measure pulse rate; understand cardiac cycle.
• Create blood model with corn syrup and beads.
• Blood flow experiment with tubes and balloons.

Vocabulary

• Aorta, vena cava, ventricles, atria, arteries, veins, capillaries, cardiac cycle, heart rate, pulmonary, cholesterol.

Homework and Evaluation

• Create heart model.
• Study heart rate differences.
• Explain blood components to a parent.

Additional Resources

• Explore online resources about the heart and circulatory system.