Question

multiple choice question

cardiac muscles are connected to each other through

intercalated discs.
acetylcholine.
neurotransmitters.
peristalsis.

Explanation:

Analyze the question prompt

The question asks for the structural feature that connects cardiac muscle cells (cardiomyocytes) to one another.

Evaluate the options

• intercalated discs: These are specialized microscopic structures in cardiac muscle that contain gap junctions and desmosomes, allowing direct electrical and physical connection between adjacent cardiac cells.
• acetylcholine: This is a neurotransmitter used at the neuromuscular junction of skeletal muscles and in the autonomic nervous system, not a physical connector between cardiac muscle cells.
• neurotransmitters: These are chemical messengers released by neurons to transmit signals across synapses, not physical junctions connecting muscle fibers.
• peristalsis: This is a series of wave-like muscle contractions that moves food through the digestive tract, which is a functional process of smooth muscle rather than a structural connection.

Determine the correct answer

Intercalated discs physically and electrically couple cardiac muscle cells, enabling synchronized contraction of the heart.

Answer:

• (A) intercalated discs. (Correct answer)
• (B) acetylcholine.
• (C) neurotransmitters.
• (D) peristalsis.