Blood is carried away from the heart by_I_ard carried back to the heart by __II___ . Which alternative completes the above sentence?

Options

A. i - kidney, ii - Lungs
B. i - arteries, ii - veins
C. i'- lungs, ii - kidney
D. i - veins, ii - arteries

Answer

To complete the sentence "Blood is carried away from the heart by ___I___ and carried back to the heart by ___II___," we need to identify the correct terms for the blood vessels involved in these processes.

### Step-by-Step Solution:

1. **Understanding Blood Flow**: The heart is responsible for pumping blood throughout the body. Blood flows in two main circuits: the systemic circuit (which delivers oxygenated blood to the body) and the pulmonary circuit (which carries deoxygenated blood to the lungs).

2. **Identifying Blood Vessels**:
- **Arteries**: These are the blood vessels that carry oxygenated blood away from the heart to the rest of the body. The primary artery that carries oxygenated blood from the heart is the aorta.
- **Veins**: These are the blood vessels that carry deoxygenated blood back to the heart. The major veins that return blood to the heart include the superior and inferior vena cavae.

3. **Filling in the Blanks**:
- For the first blank (I), we write "arteries."
- For the second blank (II), we write "veins."

4. **Final Sentence**: "Blood is carried away from the heart by **arteries** and carried back to the heart by **veins**."