science

Blood Circulation Through the Heart

🩸 Detailed Science Reviewer with Visual Aids

📌 Circulatory System & Blood Flow

The circulatory system is responsible for transporting oxygen, nutrients, hormones, and waste throughout the body. It consists of the heart, blood vessels, and blood.

🔹 Components of the Circulatory System

🩺 Blood Flow Through the Heart (Systemic & Pulmonary Circulation)

The diagram above shows the correct pathway of blood circulation through the heart.

✔ Systemic Circulation – Moves oxygenated blood from the heart to the body.
✔ Pulmonary Circulation – Moves deoxygenated blood to the lungs for oxygenation.

🔄 Correct Blood Flow Order

1⃣ Superior & Inferior Vena Cava → Carries deoxygenated blood from the body to the heart.
2⃣ Right Atrium → Receives deoxygenated blood from the vena cava.
3⃣ Right Ventricle → Pumps blood to the lungs.
4⃣ Pulmonary Artery → Carries deoxygenated blood to the lungs.
5⃣ Lungs (Alveoli) → Gas exchange happens (O₂ enters, CO₂ leaves).
6⃣ Pulmonary Vein → Carries oxygenated blood from the lungs to the heart.
7⃣ Left Atrium → Receives oxygen-rich blood from the pulmonary vein.
8⃣ Left Ventricle → Pumps oxygenated blood to the entire body.
9⃣ Aorta → The largest artery, distributing blood to the body.

💡 Remember: Arteries carry blood away from the heart, and veins carry blood to the heart.

🫁 Respiratory System & Gas Exchange

The respiratory system works with the circulatory system to supply oxygen and remove carbon dioxide.

🔹 Major Parts of the Respiratory System

🔬 How Gas Exchange Works

• Inhalation: Oxygen enters the alveoli and diffuses into the bloodstream.

• Exhalation: Carbon dioxide diffuses from the blood into the alveoli and is expelled.

🔹 Gas Exchange at the Alveoli

💡 Capillaries surround the alveoli, allowing fast gas exchange.

🧬 Heredity: Inheritance & Variation

Heredity is the passing of traits from parents to offspring through genes.

🔹 Mendelian Genetics (Dominant & Recessive Traits)

🔹 Punnett Square Example (Eye Color)

✔ BB & Bb = Brown eyes (dominant).
✔ bb = Blue eyes (recessive).

🔹 Non-Mendelian Inheritance

1⃣ Incomplete Dominance – Blended traits.

• Example: Red (RR) + White (WW) = Pink (RW).
  2⃣ Codominance – Both traits are visible.

• Example: Blood type AB (both A and B are expressed).
  3⃣ Polygenic Traits – Controlled by multiple genes.

• Example: Height, skin color, eye color.

📖 Practice Questions

Circulatory & Respiratory System

1⃣ Explain why the left ventricle is more muscular than the right ventricle.
2⃣ What happens when the pulmonary artery is blocked?
3⃣ How does the diaphragm help in breathing?
4⃣ Why do capillaries have thin walls?
5⃣ What role does hemoglobin play in oxygen transport?

Heredity & Genetics

6⃣ What is the difference between dominant and recessive traits?
7⃣ If both parents have blood type AB, what blood types could their child have?
8⃣ What is the function of meiosis in heredity?
9⃣ How does genetic variation occur in siblings?
🔟 What is the probability of having a blue-eyed child if both parents are heterozygous for brown eyes?