Skeletal Muscle Cells
A look at the structure & function of skeletal muscle cells.
Main Function
Skeletal Muscle Cells
Skeletal Muscle Cells
Skeletal Muscle Cells
The 3 most prevalent organelles are...
Mitochondria, Sarcoplasmic Reticulum, & Nuclei
There are a tremendous amount of mitochondria per muscle cell because a majority of ATP is produced through aerobic respiration within the inner folds of the mitochondria (the folds allow more surface area for the production of ATP).
Why is so much ATP necessary?
Because muscle contractions require SO MUCH ATP, so it helps to have the structure of muscles (the tissues and individual cells) loaded with mitochondria.
Sarcoplasmic Reticulum
The SR is similar to endoplasmic reticulum (ER) in other cells. In skeletal muscle cells, the SR is a transportation highway for proteins and for ions, especially calcium (Ca2+).
Why calcium in muscles?
Calcium ions are actually vital for the molecular process of muscle contractions - milk isn't just great for your bones!
Nuclei
Skeletal muscles cells are actually multi-nucleated which is quite uncommon among cells.
Why so many nuclei?
During embryonic development, hundreds of small muscle cells (called myoblasts) merged together to form one single muscle cell. Individual muscle cells are very long!
Why are skeletal muscle cells long?
It is necessary for the structure of skeletal muscle cells to be long in order to carry out their function of shortening!
Mitochondia
Sarcoplasmic Reticulum
Nuclei
Skeletal Muscle Cells --> Skeletal Muscle Tissue --> Muscles
Skeletal Muscle Tissue
A mass of skeletal muscle cells creates skeletal muscle tissue.Skeletal Muscle as an Organ
Skeletal muscle tissue is one of several tissues found within a skeletal muscle (ie: deltoid, biceps, abdominals). The muscular organ needs the skeletal muscle cells in order to carry out the process of contraction. The other tissues in the organ compartmentalize and feed the skeletal muscle cells.