Which of the following sequences is truly a systemic circulation pathway ?

Options

A. a) Right ventricle `rarr` Pulmonary aorta `rarr` Tissues `rarr` Pulmonary veins `rarr` Left auricle
B. b) Right auricle `rarr` Left ventricle `rarr` Aorta `rarr` Tissues `rarr` Veins `rarr` Right auricle
C. c) Left auricle `rarr` Left ventricle `rarr` Pulmonary aorta `rarr` Tissues `rarr` Right auricle
D. d) Left auricle `rarr` Left ventricle `rarr` Aorta `rarr` Areries `rarr` Tissues `rarr` Veins `rarr` Right atrium

Explanation

To determine the correct sequence of the systemic circulation pathway, we need to understand the flow of oxygenated and deoxygenated blood through the heart and the body. Here’s a step-by-step breakdown of the systemic circulation pathway:

### Step-by-Step Solution:

1. **Oxygenated Blood from the Lungs**: The process begins when oxygenated blood from the lungs enters the heart. This blood first enters the **left auricle** (or left atrium) of the heart.

2. **Left Auricle to Left Ventricle**: From the left auricle, the oxygenated blood flows into the **left ventricle**. This is the second step in the pathway.

3. **Left Ventricle to Aorta**: The left ventricle then pumps the oxygenated blood into the **aorta**, which is the largest artery in the body. This is the third step.

4. **Aorta to Arteries**: The aorta branches into smaller arteries that distribute the oxygenated blood to various parts of the body. This is the fourth step.

5. **Arteries to Tissues**: The blood travels through these arteries and reaches the **tissues** of the body, where oxygen is delivered and carbon dioxide is picked up. This is the fifth step.

6. **Tissues to Veins**: After delivering oxygen, the blood becomes deoxygenated and is collected by **veins**. This is the sixth step.

7. **Veins to Right Auricle**: Finally, the deoxygenated blood is returned to the heart, entering the **right auricle** (or right atrium). This is the seventh step.

### Summary of the Sequence:
- **Left Auricle → Left Ventricle → Aorta → Arteries → Tissues → Veins → Right Auricle**

### Correct Option:
Based on the above sequence, the correct option for the systemic circulation pathway is the one that follows this exact order.

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