Blood vessels activity - Free Printable

Here is the complete solution to the worksheet “HEALTH: BLOOD VESSELS”, including labeling the diagram and answering all 11 multiple-choice questions.

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## ✔ PART 1: Labeling the Diagram (Drag and Drop)

Based on the image and the labels provided:

- Red vessel (carrying blood away from heart) → Artery
- Blue vessel (carrying blood toward heart) → Vein
- Network of tiny vessels between them → Capillaries

Now, assign the labels to the boxes in the diagram:

> ⚠️ Note: The diagram has 5 blank boxes pointing to different parts.

From left to right, top to bottom:

1. Top-left box (pointing to red vessel entering capillary network) → Artery
2. Middle-left box (side of red vessel) → Artery (or sometimes labeled “elastic artery” or “muscular artery” — but for this level, just “Artery”)
3. Middle box (pointing to capillary network) → Capillaries
4. Middle-right box (side of blue vessel) → Vein
5. Top-right box (pointing to blue vessel leaving capillary network) → Vein

Also, arrows below indicate direction:
- “from heart” → points to Artery
- “to heart” → points to Vein

✔ So, final drag-and-drop matching:

- Artery → Red vessel (both top and side labels)
- Vein → Blue vessel (both top and side labels)
- Capillaries → Middle network

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## ✔ PART 2: Choose the Best Answer

Let’s answer each question with explanation.

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1. What blood vessel with thick muscular wall and narrow lumen takes away the blood from the heart?

✔ Answer: Artery

Explanation: Arteries carry oxygenated blood *away* from the heart (except pulmonary artery). They have thick, elastic, muscular walls to withstand high pressure and narrow lumens to maintain pressure.

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2. The arteries have valves:

✔ Answer: False

Explanation: Arteries do not have valves. Valves are found in veins and the heart to prevent backflow. Arteries rely on high pressure from the heart to keep blood moving forward.

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3. The largest artery is the ______.

✔ Answer: Aorta

Explanation: The aorta is the main and largest artery in the body. It originates from the left ventricle of the heart and carries oxygenated blood to the systemic circulation.

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4. The artery carries _______ blood to all the different parts of the body.

✔ Answer: Oxygenated

Explanation: Most arteries carry oxygen-rich (oxygenated) blood. The exception is the pulmonary artery, which carries deoxygenated blood to the lungs — but generally, when we say “artery carries blood to the body,” we mean systemic arteries carrying oxygenated blood.

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5. What blood vessel with thin muscular walls and large lumen takes blood towards the heart?

✔ Answer: Vein

Explanation: Veins carry blood *toward* the heart. They have thinner walls and larger lumens compared to arteries because blood pressure is lower in veins.

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6. Veins have valves to prevent back flow.

✔ Answer: True

Explanation: Yes, veins contain one-way valves that ensure blood flows only toward the heart and doesn’t pool or flow backward due to low pressure.

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7. The largest vein is the ______.

✔ Answer: Vena cava

Explanation: There are two venae cavae — superior and inferior — but together they are considered the largest veins. They return deoxygenated blood to the right atrium of the heart.

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8. The smallest blood vessel is ______. It has one cell thick walls and very small lumen.

✔ Answer: Capillaries

Explanation: Capillaries are microscopic vessels connecting arterioles and venules. Their walls are only one endothelial cell thick, allowing exchange of gases, nutrients, and wastes.

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9. Capillaries carry blood at ______ pressure.

✔ Answer: Low

Explanation: Blood pressure drops significantly as it moves through arterioles into capillaries. Capillaries operate under low pressure to allow time and space for diffusion without damaging delicate tissues.

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10. The blood vessel where gases, nutrients and wastes are exchanged.

✔ Answer: Capillaries

Explanation: Capillaries are the site of exchange between blood and tissues. Oxygen and nutrients diffuse out; carbon dioxide and wastes diffuse in.

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11. The walls of the capillaries are ______ to allow easy diffusion of gases, nutrients.

✔ Answer: Thin

Explanation: Capillary walls are extremely thin (one cell layer) to facilitate rapid diffusion of substances between blood and surrounding cells.

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## 📝 FINAL ANSWER KEY

Diagram Labels (Top to Bottom, Left to Right):

1. Artery
2. Artery
3. Capillaries
4. Vein
5. Vein

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Multiple Choice Answers:

1. Artery
2. False
3. Aorta
4. Oxygenated
5. Vein
6. True
7. Vena cava
8. Capillaries
9. Low
10. Capillaries
11. Thin

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✔ You’re all set! This covers both the diagram labeling and all 11 questions with clear explanations. Great job learning about blood vessels! 💉🩸