Blood flow changes are least during exercise in

Options

A. 1)Intestine
B. 2)Brain
C. 3)Skin
D. 4)Heart

Answer

To determine where blood flow changes the least during exercise, we will analyze each option provided in the question.

### Step-by-Step Solution:

1. **Understanding Blood Flow Changes During Exercise:**
- During exercise, the body redistributes blood flow to meet the increased demands of active muscles and other vital organs.

2. **Analyzing Each Option:**
- **Option 1: Intestine**
- During exercise, blood flow to the intestines decreases significantly as blood is redirected to the skeletal muscles and lungs. Normal blood flow is about 1300 ml, which decreases to around 600 ml during exercise. This indicates a large change in blood flow.
- **Conclusion:** Incorrect option.

- **Option 2: Brain**
- The brain maintains a relatively stable blood flow during exercise. Normal blood flow is approximately 650 ml, which increases slightly to about 750 ml during exercise. This represents a minimal change in blood flow.
- **Conclusion:** Correct option.

- **Option 3: Skin**
- Blood flow to the skin increases during exercise due to vasodilation, which helps in heat dissipation. Normal blood flow is about 500 ml, which can increase to approximately 1900 ml during exercise. This indicates a significant change.
- **Conclusion:** Incorrect option.

- **Option 4: Heart**
- The heart experiences a substantial increase in blood flow during exercise to support increased cardiac output. Normal blood flow is around 250 ml, which can increase to about 750 ml during exercise. This is also a considerable change.
- **Conclusion:** Incorrect option.

3. **Final Answer:**
- The option where blood flow changes the least during exercise is **Option 2: Brain**.