Labster Logo

Muscle Tissue

Muscle is one of the most abundant tissues in animals and humans. It is composed of cells with the ability to contract and therefore provide a particular movement to different parts of the body.

There are three types of muscle tissue in the human body: skeletal, smooth, and cardiac. Each of these muscle tissue types has a specific structure and function. While skeletal muscle is controlled voluntarily by the somatic nervous system, whereas the smooth muscle tissues are controlled involuntarily by the autonomic nervous system, also known as ANS.

Cardiac muscles can be influenced by the ANS but are regulated by the internal electrical cardiac conduction system of the heart itself. This includes the sinoatrial (SA) node, atrioventricular (AV) node, bundle branches and purkinje fibers.

The sarcomere is the basic contractile unit of muscle fiber, and it is composed of two protein filaments: actin and myosin. Without these two protein filaments, muscular contraction would not be possible.

The table below summarises the key features of each muscle type:

The types of muscle tissue. The skeletal muscle is located between the bones - indicated in a table by a picture of muscles surrounding the arms bone. The type of the cells is represented by a horizontal stack of cylindrical, red tubes with purple spheres on the peripheries of each tube. The histology is represented by thick red and thin white stripes running across the image with small dark dots on peripheries of red stripes. The smooth muscle is located in the gut - represented by an image of the stomach with yellow guts surrounding it. The type of cells is represented by a horizontal stack of thin, red, smooth tubes with purple spheres on the periphery of each tube. The histology presents very thin vertical light pink stripes with dark ovals aligned with the stripes. The cardiac muscle is located in the heart - represented by an image of the human heart. The type of cells is represented by two red, horizontally stacked, slightly bent tubes which branch out at the opposite end with purple spheres at the periphery of each tube. The histology presents a similar image as in the case of skeletal muscle, but the stripes are less thick and more chaotically aligned, with bigger dark spheres on their peripheries.

Figure 1. Key features of skeletal, smooth and cardiac muscle.

Referred from:

Article
Cardiac muscle
Article
Cardiac Muscle
Article
SERCA