The key difference between true syncytium and functional syncytium is that true syncytium is a multinucleated mass of cytoplasmic cells that results from the fusion of cells while functional syncytium is a unit of contraction that comprise a network of electrically connected cardiac muscle cells.
The syncytium is a cell-like structure that forms by joining two or more cells together. It develops either by a division of the cell nucleus and does not split into several cells afterwards or by several cells merging together, retaining the nuclei without the separation of cell membranes. Syncytia serve an important function within the human body as well as in other aspects. True syncytium and functional syncytium are two types present in the human body.
CONTENTS
1. Overview and Key Difference
2. What is True Syncytium
3. What is Functional Syncytium
4. Similarities – True Syncytium and Functional Syncytium
5. True Syncytium vs Functional Syncytium in Tabular Form
6. Summary – True Syncytium vs Functional Syncytium
What is True Syncytium?
A true syncytium is a multinucleated cell that results from multiple cell fusions of uninuclear cells. Muscle cells make up skeletal muscles and are an example of a true syncytium. During the formation of skeletal muscles, thousands of individual muscle cells fuse together to form large skeletal muscle fibres. These skeletal muscles provide flexibility and strength. The advantage of these syncytia is rapid communication and response between muscles and the brain. The absence of separate membranes enables the impulses from the brain to move faster between the nuclei. Faster the impulses move, the faster the reaction of muscles.
Figure 01: Skeletal Muscle
Another example of true syncytium is in pregnant women. The formation of such syncytium occurs during the early developmental process when the baby is in the embryonic stage. Here, the syncytium serves as a barrier between the mother and the foreign cell that enters the body. This syncytium consists of cells from the embryo and placenta. The purpose of the barrier is to regulate what the embryo is exposed to. It allows the nutrients to move through the placenta for the embryo to grow and block harmful cells.
What is Functional Syncytium?
A functional syncytium is a unit of contraction comprised of a network of electrically connected cardiac muscle cells. Functional syncytium allows the heart to work as a unit. The wave of contraction begins with pacemaker cells, and they are self-excitable. They depolarize to threshold and fire action potentials. This process is known as auto-rhythmicity.
The pacemaker cells respond to signals from the autonomous nervous system to fluctuate the heart rate. It also responds to various hormones that modulate the heart rate to control blood pressure. The auto-rhythmicity process determines the heart rate. They connect with gap junctions that surround muscle fibres and specialized fibres of the conducting system in the heart. Pacemaker cells transfer the depolarization to the other cardiac muscle fibres. Cardiac muscles have relatively long action potentials in their fibres. Cardiac muscles are striated and uni-nucleated. Contractions of cardiac muscles trigger by calcium ions.
What are the Similarities Between True Syncytium and Functional Syncytium?
- True syncytium and functional syncytium are present in the human body.
- Both help in the function of muscles.
What is the Difference Between True Syncytium and Functional Syncytium?
True syncytium refers to a skeletal muscle cell that is multinucleated, while functional syncytium is the cardiac muscle cell that is not multinucleated. Thus, this is the key difference between true syncytium and functional syncytium. Moreover, the true syncytium is located in skeletal muscles, while the functional syncytium is located in the heart.
The below infographic presents the differences between true and functional syncytium in tabular form for side by side comparison.
Summary – True Syncytium vs Functional Syncytium
The syncytium is a cell-like structure developed by joining two or more cells together. The key difference between true syncytium and functional syncytium is that true syncytium is the skeletal muscle cell that is multinucleated. The functional syncytium is the cardiac muscle cell that is not long and multinucleated. Skeletal muscles and placenta are two important true syncytia. Skeletal muscles provide rapid communication and response between the muscles and the brain, and the placenta acts as a barrier between the mother and foreign cells. The functional syncytium is the contractions that allow the heart to work as a unit. These begin with pacemaker cells, and they are self-excitable. So, this summarizes the difference between true syncytium and functional syncytium.
Reference:
1. Betts, J. Gordon, et al. “Cardiac Muscle Tissue.” Anatomy and Physiology, OpenStax.
2. “Syncytium Definition Function.” Study.com.
Image Courtesy:
1. “Blausen 0801 SkeletalMuscle” Blausen.com staff (2014). “Medical gallery of Blausen Medical 2014”. WikiJournal of Medicine 1 (2). DOI:10.15347/wjm/2014.010. ISSN 2002-4436. – Own work (CC BY 3.0) via Commons Wikimedia