Given below are four statement regarding human blood vascular system
(a) there is no role of calcium ions in blood clotting
(b)cardiac output is the amount of blood pumped by each ventricle in one second
(c )arteries are thin walled and have narrow lumen as compared to veins
(4)the stage of cardiac cycle where all the four chambers are relaxed stage is called joint Diastole
How many of the above statement are correct ?

Options

A. one
B. two
C. three
D. four

Answer

To determine how many of the given statements about the human blood vascular system are correct, we will evaluate each statement one by one.

### Step-by-Step Solution:

1. **Evaluate Statement (a)**: "There is no role of calcium ions in blood clotting."
- **Analysis**: Calcium ions (Ca²⁺) play a crucial role in the blood clotting process. They are essential for the activation of various clotting factors and the conversion of prothrombin to thrombin. Therefore, this statement is **false**.

2. **Evaluate Statement (b)**: "Cardiac output is the amount of blood pumped by each ventricle in one second."
- **Analysis**: Cardiac output refers to the total volume of blood pumped by the heart per minute, not per second. It is typically calculated based on the left ventricle's output. Since this statement incorrectly describes cardiac output, it is also **false**.

3. **Evaluate Statement (c)**: "Arteries are thin-walled and have narrow lumen as compared to veins."
- **Analysis**: Arteries are actually thick-walled and have a narrow lumen compared to veins. This statement is incorrect because it reverses the characteristics of arteries and veins. Thus, this statement is **false**.

4. **Evaluate Statement (d)**: "The stage of the cardiac cycle where all four chambers are relaxed is called joint diastole."
- **Analysis**: During joint diastole, all four chambers of the heart are indeed relaxed, allowing for filling with blood. This statement is **true**.

### Conclusion:
- Out of the four statements, only **one statement (d)** is correct. Therefore, the answer is that **1 statement is correct**.