What are the characteristics of the cardiac muscle?
Cardiac muscle is specialized tissue that is found only in the heart. It has characteristics similar to both smooth and skeletal muscle tissue, as well as specialized properties, that allow it to function with fast but sustained contractions, rapid conduction and coordinated movement.
Cardiac muscle cells or cardiomyocytes (also known as myocardiocytes or cardiac myocytes) are the muscle cells (myocytes) that make up the cardiac muscle (heart muscle). Unlike multinucleated skeletal cells, the majority of cardiomyocytes contain only one nucleus, although they may have as many as four.
- Cardiac muscle is specialized tissue that is found only in the heart. It has characteristics similar to both smooth and skeletal muscle tissue, as well as specialized properties, that allow it to function with fast but sustained contractions, rapid conduction and coordinated movement.
- Smooth muscle is found in the walls of hollow organs like your intestines and stomach. They work automatically without you being aware of them. Smooth muscles are involved in many 'housekeeping' functions of the body. The muscular walls of your intestines contract to push food through your body.
- Contraction. The heart's main function is to pump oxygen-rich blood throughout the body to provide cells with vital nutrients. In order to do this, the cardiac cells must contract. In fact, the American Heart Association reports that the average adult heart contracts 100,000 times a day.
Like skeletal muscle, cardiac muscle cells are striated due to a similar arrangement of contractile proteins. Unique to the cardiac muscle are a branching morphology and the presence of intercalated discs found between muscle fibers. They are often seen as zigzagging bands cutting across the muscle fibers.
- Skeletal muscle tissue is found in our skeletal muscles; for example, the biceps. Cardiac muscle is found in our heart, and smooth muscle is found in our visceral, or hollow, organs - for example, blood vessels and intestines.
- Predicting Consequences: If aerobic exercise improves heart strength, what likely happens to heart rate as the heart gets stronger? Explain your answer. Example: As the heart gets stronger, the heart likely will pump more blood with each beat. The heart will not need to work as hard to pump the same amount of blood.
- Replacement means that over a lifetime, the average age of individual skeletal muscle cells drops. According to carbon-14 techniques that measure the age of individual cells, the lifespan of skeletal muscle cells in a human adult averages 10 to 16 years.
Updated: 19th September 2018