Question

1)Explain the need for numerous mitochondria in skeletal muscle tissue.

2) Describe the shape and appearance of the muscle cells in skeletal, cardiac, and smooth muscle tissue.

would you plese anwer that two questions above?!

thank you for your help.

Answer 1

1. Explain the need for numerous mitochondria in skeletal muscle tissue?

Skeletal muscle contraction is critical for all voluntary movements which is achieved by repetitive stepping (ATP dependant) of myosin which binds another protein called actin. Numerous myosin composed together form myofilaments which bundled to form myofibrils. An average muscle cell has few dozens to 1,000 myofibrils. For a noticeable motion, hundreds or thousands of muscle cells contraction to occur which sum upto enormous power stoking of myosin. This makes the more energy demand in skeletal muscle. On addition, it also requires ATP for relaxation which even add more energy demand. These energy demand makes the skeletal muscle to possess enormous mitochondria, the power house of the cell where the ATP is being generated.

2. Describe the shape and appearance of the muscle cells in skeletal, cardiac, and smooth muscle tissue.?

Cardiac muscle - Striated; has sarcomere; irregular angle of arrangements called intercalated disc.

Skeletal muscles - Striated; regularly arranged parallel bundles of sarcomeres. Further subdivided into:

• Type I- slow oxidative - dense capillaries and is rich in mitochondria and myoglobin.
• Type II-  fast-twitch muscle; Type IIa - aerobic slow muscle; Type IIx - less dense in mitochondria; Type iib anerobic glycolytic.

Smooth muscle -  Smooth muscle is an involuntary non-striated muscle. It is of two types: single unit which contracts as a syncytium and multi unit which innervate much like motor unit recruitment in skeletal muscle.