Heart muscle cells would tend to separate without __
a. stroma
b. intercalated discs
c. flana
d. myofilaments
The Correct Answer and Explanation is:
The correct answer is b. intercalated discs.
Explanation:
Heart muscle cells, or cardiomyocytes, are highly specialized cells that make up the myocardium, the thick muscle layer of the heart. These cells are interconnected in a way that allows for efficient contraction of the heart. One of the key structures that help to maintain the integrity and function of heart muscle cells is the intercalated discs.
Intercalated discs are specialized junctions that connect individual heart muscle cells (cardiomyocytes) to each other. They are composed of gap junctions, desmosomes, and fascia adherens:
- Gap junctions allow for the rapid transmission of electrical impulses between adjacent cells, which is essential for coordinating the heartbeat. This ensures that the muscle cells contract together in a synchronized manner, allowing the heart to pump effectively.
- Desmosomes provide mechanical strength, ensuring that the cells remain physically connected under the stress of constant contraction. They act like rivets, preventing the separation of cells during the powerful contractions of the heart.
- Fascia adherens help anchor actin filaments to the plasma membrane, contributing to the overall structure and stability of the heart muscle.
Without intercalated discs, the heart muscle cells would not be able to work as a coordinated unit. They might separate or not contract in sync, which would impair the heart’s ability to pump blood effectively, potentially leading to arrhythmias or even heart failure.
Why the other options are incorrect:
- a. Stroma: Stroma refers to the supportive tissue in organs, such as connective tissue, but it is not directly involved in holding heart muscle cells together.
- c. Flana: This option is not relevant to the structure or function of heart muscle cells. It appears to be a non-standard or incorrect term.
- d. Myofilaments: Myofilaments (actin and myosin) are responsible for the contraction of muscle fibers, but they do not serve to physically connect individual heart muscle cells. The function of connecting and synchronizing the cells falls to the intercalated discs.