Question

Mitochondria in cardiac muscles are
(a) More than other muscle fibers
(b) Less than other muscle fibers
(c) Equal to other muscle fibers
(d) None of the above

Answer 1

Hint: Cardiac muscle cells are highly resistant to fatigue and are supplied with many molecules of myoglobin for continuous aerobic respiration. Cells are resistant to fatigue when there is more supply of energy i.e., ATP and oxygen.

Complete answer:
Like skeletal muscle, cardiac muscle is also striated. Those striations are due to the presence of sarcosomes. Mitochondria present in the muscle cells are called sarcosomes. The human heart is made up of cardiac muscles especially found in the myocardium of the heart. One of the important features of cardiac muscle is it is highly resistant to fatigue. This is due to the presence of sarcosomes i.e., mitochondria. When compared to other muscle cells cardiac muscle has more number of sarcosomes.

Additional Information: - Group of cells originated from the mesoderm of the embryo that shows essential properties like excitability, conductivity, and contractility is called muscle tissue.
- Myology is the study of muscle cells or muscular tissue.
- In the movement of a body, adjusting to the changes in the surrounding environment and for maintaining posture, muscle cells play an important role.
- Muscles in the body are of three types: Skeletal muscles, Smooth muscle, and Cardiac muscle.
- Long, cylindrical, unbranched, multinucleated cells with striped and voluntary movement are skeletal muscle cells.
- Smooth muscles are unstriped, involuntary, uninucleate cells that are controlled by the autonomic nervous system.
- Short, cylindrical, mononucleate, or binucleate, striped, involuntary cells are cardiac cells.
- They do not require any nerve stimulation because of an auto-rhythmic structure called a pacemaker that can produce impulses spontaneously.
- Cardiac muscles show functional syncytium and it is highly resistant to fatigue due to the presence of numerous sarcomeres and many molecules of myoglobin.

So the correct answer is ‘more than other muscle cells’.

Note: - All the muscles are mesodermal in origin except muscles of the iris and ciliary bodies that are ectodermal in origin.
- In muscle plasma membranes are called scleroderma, hemoglobin is called myoglobin, the endoplasmic reticulum is sarcoplasmic reticulum, and mitochondria are called sarcosomes.