Lesson Notes By Weeks and Term v3 - Senior Secondary 1
Circulatory system
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Circulatory system
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Subject: Physical Education
Class: Senior Secondary 1
Term: 3rd Term
Week: 3
Theme: Basic Human Anatomy And Physiology In Relation To Physical Activities
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Watch on YouTubelabel parts of the heart differentiate between veins and arteries list the effects of training on the heart
Pulsation | Blood flows in pulses (can be felt as a pulse). | Blood flows smoothly, no pulse. | Capillaries: These are microscopic blood vessels that connect arteries (arterioles) and veins (venules). They have extremely thin walls (one cell thick) to facilitate the exchange of oxygen, nutrients, and waste products between blood and body tissues. C. Effects of Training on the Heart Regular physical training, especially cardiovascular or aerobic exercise, leads to significant adaptations in the heart, improving its efficiency and overall cardiovascular health.
1. Cardiac Hypertrophy (Enlargement of the Heart Muscle): Explanation: Long-term training causes the heart muscle, particularly the left ventricle, to become stronger and larger. This is a beneficial physiological adaptation (unlike pathological hypertrophy caused by disease).
Impact: A stronger heart can pump more blood with each beat.
Example: A marathon runner's heart can pump a significantly higher volume of blood per beat compared to a sedentary individual.
2. Increased Stroke Volume: Explanation: Stroke volume is the amount of blood pumped out of the left ventricle with each contraction. Due to cardiac hypertrophy, the heart chambers can hold more blood, and the stronger muscle can eject more blood per beat.
Impact: More blood, and therefore more oxygen and nutrients, are delivered to the muscles and tissues with each pump. This is crucial for sustained physical activity.
Example: During a football match, a well-trained player's heart will deliver more oxygenated blood to their leg muscles per beat, delaying fatigue.
3. Decreased Resting Heart Rate (Bradycardia): Explanation: A trained heart is more efficient. Because it has a higher stroke volume, it does not need to beat as frequently to pump the same amount of blood around the body.
Impact: A lower resting heart rate indicates a more efficient cardiovascular system, putting less strain on the heart over time. This is a key indicator of cardiovascular fitness.
Example: A fit individual might have a resting heart rate of 50-60 beats per minute, while an untrained individual might have 70-80 bpm or higher.
4. Improved Oxygen Delivery and Utilization: Explanation: Training improves the heart's ability to pump oxygenated blood to the muscles and the muscles' ability to extract and use that oxygen. This includes an increase in capillary density around muscle fibers.
Impact: Enhanced aerobic capacity, allowing individuals to perform physical activities for longer periods without fatigue.
Example: A trained swimmer can sustain their pace for a longer duration due to more efficient oxygen delivery to their muscles.
5. Faster Recovery Rate: Explanation: The heart rate of a trained individual returns to its resting level more quickly after exercise compared to an untrained individual.
Impact: This indicates a more robust and resilient cardiovascular system, capable of adapting quickly to stress. *
Example: After a strenuous burst of activity, a trained student recovers their breath and normal heart rate faster than an untrained peer. A. The Human Heart The heart is a muscular organ, roughly the size of a clenched fist, located slightly to the left of the center in the chest between the lungs. Its primary function is to pump blood throughout the body, ensuring the delivery of oxygen and nutrients and the removal of waste products.
Parts of the Heart: The human heart is a four-chambered organ, consisting of two atria (upper chambers) and two ventricles (lower chambers). It is divided into left and right sides by a muscular wall called the septum.
1. Right Atrium (RA): Receives deoxygenated blood from the body (via the superior and inferior vena cava).
2. Right Ventricle (RV): Pumps deoxygenated blood to the lungs (via the pulmonary artery).
3. Left Atrium (LA): Receives oxygenated blood from the lungs (via the pulmonary veins).
4. Left Ventricle (LV): Pumps oxygenated blood to the rest of the body (via the aorta). This is the strongest chamber as it needs to generate high pressure to distribute blood throughout the entire systemic circulation.
5. Septum: The muscular wall that separates the right and left sides of the heart, preventing the mixing of oxygenated and deoxygenated blood.
6. Valves: The heart has four main valves that ensure one-way blood flow and prevent backflow: Tricuspid Valve: Between the right atrium and right ventricle.
Pulmonary Valve: Between the right ventricle and the pulmonary artery.
Mitral (Bicuspid)
Valve: Between the left atrium and left ventricle.
Aortic Valve: Between the left ventricle and the aorta.
7. Major Blood Vessels Connected to the Heart: Superior Vena Cava: Returns deoxygenated blood from the upper body (head, arms) to the right atrium.
Inferior Vena Cava: Returns deoxygenated blood from the lower body (trunk, legs) to the right atrium.
Pulmonary Artery: Carries deoxygenated blood from the right ventricle to the lungs. (
Note: This is an artery carrying deoxygenated blood, an exception to the general rule).
Pulmonary Veins: Carry oxygenated blood from the lungs to the left atrium. (
Note: These are veins carrying oxygenated blood, an exception).
Aorta: The largest artery in the body; carries oxygenated blood from the left ventricle to the rest of the body. (Teacher may draw a simple schematic diagram of the heart on the board, indicating the chambers, valves, and major vessels as they explain each part.) B. Arteries and Veins These are the primary types of blood vessels responsible for carrying blood throughout the body. | Feature | Arteries | Veins | | :-------------------- | :------------------------------------------------------------------------ | :---------------------------------------------------------------------------- | | Direction of Blood Flow | Carry blood away from the heart. | Carry blood towards the heart. | | Oxygenation of Blood | Mostly carry oxygenated blood (bright red) – exception: Pulmonary Artery. | Mostly carry deoxygenated blood (dark red/purplish) – exception: Pulmonary Veins. | | Wall Thickness & Elasticity | Thick, muscular, and highly elastic walls to withstand high blood pressure from the heart. | Thinner, less muscular, and less elastic walls as blood pressure is lower. | | Lumen (Internal Diameter) | Narrower lumen to maintain high pressure. | Wider lumen to accommodate larger volume of blood at lower pressure. | | Valves | No valves (except at the exit from the heart, e.g., aortic and pulmonary valves). | Contain one-way valves, especially in limbs, to prevent backflow of blood due to low pressure and gravity. | | Location | Generally located deeper within the body, protected by muscles and bones. | Often found closer to the surface of the skin. | | Pressure | High blood pressure. | Low blood pressure. | | Pulsation | Blood flows in pulses (can be felt as a pulse). | Blood flows smoothly, no pulse. | Capillaries: These are microscopic blood vessels that connect arteries (arterioles) and veins (venules). They have extremely thin walls (one cell thick) to facilitate the exchange of oxygen, nutrients, and waste products between blood and body tissues. C. Effects of Training on the Heart Regular physical training, especially cardiovascular or aerobic exercise, leads to significant adaptations in the heart, improving its efficiency and overall cardiovascular health.
1. Cardiac Hypertrophy (Enlargement of the Heart Muscle): Phase 1: Introduction and Prior Knowledge (10 minutes)
Teacher Activity: Begins by asking students what they know about the body's transportation system. Asks students to place their hand on their chest and feel their heartbeat, or feel their pulse at the wrist/neck. Prompts a discussion on why the heart is important, especially during physical activity.
Student Activity: Share their prior knowledge about the heart and blood. Locate and feel their pulse. Participate in the discussion.
Phase 2: Explaining the Heart (20 minutes)
Teacher Activity: Presents a large, clear diagram of the human heart (or draws a simplified version on the board). Systematically explains each part of the heart (chambers, valves, major vessels) as outlined in the "Key Concepts" section, pointing to them on the diagram. Emphasizes the flow of blood through the heart and the role of each part. Encourages questions for clarification.
Student Activity: Observe the diagram and listen attentively to the explanations. Take notes on the parts of the heart and their functions. Ask questions for better understanding. (Optional: If feasible, students can draw a simple outline of the heart in their notebooks and attempt to label parts as the teacher explains).
Phase 3: Differentiating Arteries and Veins (15 minutes)
Teacher Activity: Introduces arteries and veins as the blood vessels that carry blood. Uses a comparative table (as in "Key Concepts") to highlight the differences between arteries and veins in terms of blood flow direction, oxygenation, wall structure, presence of valves, and pressure. Explains the role of capillaries briefly. Uses examples relevant to blood circulation, like how blood flows from the heart to the hands and back.
Student Activity: Listen and take notes on the distinguishing features of arteries and veins. Participate in a quick Q&A session to confirm understanding. (Optional: Students can draw simple representations of an artery and a vein showing their relative wall thicknesses.)
Phase 4: Effects of Training on the Heart (15 minutes)
Teacher Activity: Initiates a discussion by asking students how they feel after exercising regularly (e.g., "Do you get tired less quickly?"). Explains the key physiological adaptations of the heart due to regular physical training: cardiac hypertrophy, increased stroke volume, decreased resting heart rate, improved oxygen delivery, and faster recovery rate. Relates these effects to improved athletic performance and general health, using Nigerian sporting examples (e.g., Super Eagles players, local marathon runners).
Student Activity: Share personal experiences with exercise and its effects. Listen and take notes on the effects of training on the heart. Discuss how these effects benefit athletes and everyday individuals.
Phase 5: Consolidation and Review (10 minutes)
Teacher Activity: Conducts a quick oral recap of the main points covered. Addresses any remaining questions or misconceptions. Assigns a brief individual task or a pair-share activity based on the learning objectives.
Student Activity: Participate in the recap, answering questions. Ask clarifying questions. Complete the assigned task.
Question 1: Heart Labelling A teacher shows a simplified diagram of the human heart (outline provided below for teacher to use or draw). Students are asked to identify and label five parts correctly. (Teacher describes the labels for the students to identify on a projected or drawn diagram)
Instructions for students: "Look at the diagram of the heart.
Identify the following parts: (a) The chamber that receives deoxygenated blood from the body. (b) The vessel that carries oxygenated blood to the body. (c) The muscular wall separating the left and right sides. (d) The chamber that pumps blood to the lungs. (e) The valve between the left atrium and left ventricle." Solution 1: (a) Right Atrium (b) Aorta (c) Septum (d) Right Ventricle (e) Mitral (Bicuspid) Valve
Commentary: This question directly assesses the first performance objective, ensuring students can identify key anatomical features of the heart. By focusing on function, it aids recall and understanding.
Question 2: Veins vs. Arteries Mr. Emeka, a Physical Education teacher, explained that blood vessels are crucial for circulation. Students are discussing the differences between arteries and veins. (a) State two structural differences between arteries and veins. (b) Give one functional difference between arteries and veins.
Solution 2: (a)
Structural Differences: Arteries have thick, muscular, and elastic walls; veins have thinner, less muscular, and less elastic walls. Arteries generally have a narrower lumen (internal diameter); veins have a wider lumen. Veins contain one-way valves to prevent backflow; arteries do not (except at the heart's exit). Arteries are located deeper in the body; veins are often closer to the surface. (b)
Functional Differences: Arteries carry blood away from the heart, while veins carry blood towards the heart. Arteries typically carry oxygenated blood (exception: pulmonary artery); veins typically carry deoxygenated blood (exception: pulmonary veins). Blood pressure is high in arteries and low in veins. Arteries exhibit a pulse; veins do not.
Commentary: This question addresses the second performance objective, requiring students to differentiate between arteries and veins based on both their physical characteristics and their roles in the circulatory system.
Question 3: Effects of Training A Nigerian secondary school student, Tunde, has been consistently training for the school's inter-house sports competition, focusing on long-distance running. (a) Explain what will happen to Tunde's resting heart rate as a result of his training. (b) Discuss two other positive effects his consistent training will have on his heart.
Solution 3: (a)
Effect on Resting Heart Rate: Tunde's resting heart rate will decrease (become lower). This is because his heart muscle will become stronger and more efficient due to training. A stronger heart (due to cardiac hypertrophy) can pump more blood with each beat (increased stroke volume), so it doesn't need to beat as many times per minute to supply the body with the necessary oxygen and nutrients. This indicates improved cardiovascular fitness. (b)
Two other positive effects: Increased Stroke Volume: Tunde's heart will be able to pump a larger volume of blood with each beat. This means more oxygen and nutrients are delivered to his muscles per contraction, which is essential for endurance activities like long-distance running. Cardiac Hypertrophy (Stronger Heart Muscle): His heart muscle, especially the left ventricle, will become thicker and stronger. This allows the heart to pump blood more powerfully and efficiently throughout his body, improving overall circulatory function.
Improved Oxygen Delivery and Utilization: Training enhances the heart's ability to deliver oxygen to working muscles and improves the muscles' capacity to extract and use this oxygen. This will improve Tunde's stamina and delay fatigue during his long-distance runs.
Faster Recovery Rate: After intense exercise, Tunde's heart rate will return to his resting level more quickly. This signifies a more robust and resilient cardiovascular system, indicating he is fitter and his body can adapt to stress more effectively.
Commentary: This question directly targets the third performance objective, requiring students to list and explain the physiological effects of training on the heart in a relatable context.
Preventing Cardiovascular Diseases in Nigerian Communities: Application: Teach students how understanding the circulatory system empowers them to advocate for and practice healthy lifestyles to prevent non-communicable diseases like hypertension and stroke, which are increasingly common in Nigeria.
Context: Discuss how local diets (e.g., high-salt, high-fat foods in some traditional dishes) and sedentary lifestyles contribute to circulatory problems. Emphasize the role of physical activity (like walking to the market, farming, local sports) in maintaining a strong heart and healthy blood vessels. Encourage the consumption of local fruits and vegetables that support heart health. Enhancing Sports Performance and Longevity for Nigerian Athletes: Application: Connect the effects of training on the heart (e.g., increased stroke volume, decreased resting heart rate) to improved performance in popular Nigerian sports like football, athletics (e.g., long-distance running, sprinting), and boxing.
Context: Discuss how top Nigerian athletes (e.g., Super Eagles players, Olympic medalists) undergo rigorous cardiovascular training to optimize their heart's efficiency, allowing them to perform at high intensity for longer periods and recover faster. This knowledge helps aspiring athletes understand the physiological basis of their training. Understanding Emergency Health Situations and First Aid: Application: Knowledge of the heart and blood vessels is critical for understanding and responding to medical emergencies.
Context: For example, knowing the location of major arteries allows for effective control of severe bleeding (e.g., after an accident involving a motorcycle or a cut during farming). Understanding that a sudden sharp chest pain might indicate a heart problem can prompt timely medical intervention, which is crucial given limited access to advanced healthcare facilities in some rural areas of Nigeria. Students can learn the basics of checking a pulse as an indicator of heart function.