Select the correct match regarding the effect of autonomic nervous system on stroke volume and cardiac output.

Options

A. Parasympathetic nervous system (Autonomic neural system) Increase (Stroke volume) Decrease (Cardiac output)
B. Sympathetic nervous system (Autonomic neural system) Increase (Stroke volume) Decrease ( Cardiac output)
C. Parasympathetic nervous system (Autonomic neural system) Decrease (Stroke volume) Increase (Cardiac output)
D. Sympathetic nervous system (Autonomic neural system) Increase (Stroke volume) Increase (Cardiac output)

Answer

To solve the question regarding the effect of the autonomic nervous system on stroke volume and cardiac output, let's break it down step by step.

### Step-by-Step Solution:

1. **Understanding Stroke Volume and Cardiac Output**:
- **Stroke Volume (SV)**: This is the amount of blood ejected from each ventricle of the heart during one contraction. It is typically measured in milliliters (mL).
- **Cardiac Output (CO)**: This is the total volume of blood pumped by the heart in one minute. It is calculated as the product of stroke volume and heart rate (CO = SV × HR).

2. **Role of the Autonomic Nervous System**:
- The autonomic nervous system (ANS) is divided into two main branches: the sympathetic nervous system (SNS) and the parasympathetic nervous system (PNS).
- **Sympathetic Nervous System**: Generally prepares the body for 'fight or flight' responses, increasing heart rate and stroke volume, thus increasing cardiac output.
- **Parasympathetic Nervous System**: Generally promotes 'rest and digest' activities, decreasing heart rate and stroke volume, thus decreasing cardiac output.

3. **Analyzing the Options**:
- **Option 1**: Parasympathetic Nervous System increases stroke volume and decreases cardiac output.
- **Analysis**: This is incorrect. The PNS decreases stroke volume and cardiac output.
- **Option 2**: Sympathetic Nervous System increases stroke volume and decreases cardiac output.
- **Analysis**: This is incorrect. The SNS increases both stroke volume and cardiac output.
- **Option 3**: Parasympathetic Nervous System decreases stroke volume.
- **Analysis**: This is partially correct but does not mention the effect on cardiac output, which also decreases.
- **Option 4**: Sympathetic Nervous System increases stroke volume and cardiac output.
- **Analysis**: This is correct. The SNS increases both stroke volume and cardiac output.

4. **Conclusion**:
- The correct match regarding the effect of the autonomic nervous system on stroke volume and cardiac output is the last option: **Sympathetic Nervous System increases stroke volume and cardiac output**.