Gap juction are characteristically found in

Options

A. Skeletal muscle
B. Cardiac muscles
C. Multi-unit smooth muscles
D. Striated muscles

Answer

**Step-by-Step Text Solution:**

1. **Understanding Gap Junctions**:
- Gap junctions are specialized intercellular connections that allow for the direct transfer of ions and small molecules between adjacent cells. They facilitate communication and coordination among cells.

2. **Identifying the Function of Gap Junctions**:
- In the context of muscle tissues, gap junctions play a crucial role in allowing electrical signals (depolarization currents) to pass from one muscle cell to another. This is essential for coordinated contractions.

3. **Analyzing the Options**:
- The options given are:
- Skeletal muscles
- Cardiac muscles
- Multi-unit smooth muscles
- Striated muscles
- We need to determine which type of muscle tissue characteristically contains gap junctions.

4. **Examining Each Muscle Type**:
- **Skeletal Muscles**: These muscles are under voluntary control and do not have gap junctions connecting the fibers. They are innervated by motor neurons.
- **Cardiac Muscles**: These muscles are involuntary and are interconnected by gap junctions, allowing for the rapid spread of action potentials, which is crucial for synchronized heart contractions.
- **Multi-Unit Smooth Muscles**: These muscles are also under involuntary control and typically do not have gap junctions; they function independently.
- **Striated Muscles**: This term generally refers to skeletal muscles and cardiac muscles, but it does not specifically indicate the presence of gap junctions.

5. **Conclusion**:
- Based on the analysis, gap junctions are characteristically found in cardiac muscles. They are particularly concentrated at the intercalated discs, which are specialized connections between cardiac muscle fibers that facilitate communication.

**Final Answer**: Gap junctions are characteristically found in **cardiac muscles**.

---