Muscle Type Cardiac Skeletal Smooth
Shape of cell Branching Long, cylindrical Elongated
# of nuclei Uninucleate Multinucleate Uninucleate
Striations Yes Yes No
Control Involuntary Voluntary Involuntary 2. What attaches muscles to bone? Tendons. 3. The whole muscle is composed of muscle cells (fibers) grouped in bundles called fascicles. 4. Name the connective tissue coverings surrounding the following:
1. Whole muscle ___Epimysium___
2. Fascicles ___Perimysium___
3. Muscle cell ___Endomysium___
5. Match the following three terms with their definitions:
1. Sarcolemma __2__ endoplasmic reticulum in muscle cell
2. Sarcoplasmic reticulum __3__ intracellular fluid around organelles
3. Cytosol __1__ plasma membrane of muscle cell 6. Match the following three terms with their definitions:
1. Terminal cisternae __3__ T tubule + 2 terminal cisternae
2. T tubules __2__ part of sarcolemma—carries action potential
3. Triad __1__ part of sarcoplasmic reticulum—stores calcium ions 7. Myofibrils consist of contractile proteins called myofilaments.
Name the two types and what they’re composed of:
Thick filaments composed of myosin (red)
Thin filaments composed of actin (blue) 8. Arrangement of myofilaments. Give the letter name of each band: Dark band __A__ band Light band __I__ band
Match two definitions with each band:
__I__ contains only thin filaments
__A__ contains both thick and thin filaments
__A__ defined by length of thick filament
__I__ defined as distance between two thick filaments 9. Define these two terms:
1. Z line (disc) Midline interruption, darker area in I bands.
2. H zone Only thick filaments, A band. 10. What happens to these areas during contraction?
Z line (disc) It moves closer together.
H zone The muscles shorten.