Which points are correct for cardiac muscles of
(A) They are striated (B) They are unbranched
(C ) They are involuntary
(D) Intercalacted disc are present

Options

A. A,B,C
B. B,C,D
C. A,C,D
D. A,B,D

Answer

To determine which points are correct regarding cardiac muscles, we will analyze each statement one by one.

**Step 1: Analyze Statement A - "They are striated."**
- Cardiac muscles are indeed striated. This means that under a microscope, they show a banded appearance due to the arrangement of actin and myosin filaments. Thus, this statement is correct.

**Step 2: Analyze Statement B - "They are unbranched."**
- This statement is incorrect. Cardiac muscle fibers are branched, which is a characteristic feature that distinguishes them from skeletal muscles, which are long and unbranched. Therefore, this statement is not correct.

**Step 3: Analyze Statement C - "They are involuntary."**
- Cardiac muscles are involuntary, meaning they are not under conscious control. The heart beats automatically due to the intrinsic conduction system. Hence, this statement is correct.

**Step 4: Analyze Statement D - "Intercalated discs are present."**
- Intercalated discs are specialized connections between cardiac muscle cells that facilitate synchronized contraction and communication between cells. This structure is indeed present in cardiac muscles, making this statement correct.

**Conclusion:**
- The correct points about cardiac muscles are:
- (A) They are striated - Correct
- (B) They are unbranched - Incorrect
- (C) They are involuntary - Correct
- (D) Intercalated discs are present - Correct

**Final Answer: A, C, and D are correct.**

---