Anatomy and Embryology of Skeletal Muscle

Fill in the blanks to give the names of each classification of muscle according to its function.
muscles bend a joint, decreasing its angle.
muscles straighten a joint, increasing its angle.
The or agonist muscle performs concentric contraction to bring about movement.
The muscle opposes the action of the primer mover to return it to its normal position.
The muscle steadies the position produced by the prime mover by isometric contraction.
The muscle complements the action of the prime mover by performing the same contraction.

Fill in the blanks below to describe the structure of muscle based on the divisions by the different layers of connective tissue.
The is the tough outermost layer surrounding the entire muscle.
The surrounds bundles of muscle fibres to create fascicles.
The surrounds each muscle fibre within the fascicles.

Fill in the blanks below to describe the formation of skeletal muscle.
1. A single cell exists in a medium containing growth factor.
2. The cell .
3. Multiple cells fuse to form .
4. Myotubes gather to form .

Type I slow muscle fibres are suited to -term contraction for work. They are red and contract with slow velocity. They have a higher density of so are better suited to aerobic respiration. They are therefore fatigue . However, they produce instantaneous force so are described as 'weak'. They store energy in the form of .

Type II muscle fibres are better suited to -term contraction. They are in colour due to a lack of myoglobin. They contract with twitch velocity and are more prone to aerobic respiration. They therefore fatigue easily, but produce more instantaneous force. They store energy in the form of ATP and creatine phosphate.

Type II muscle fibres are better suited to -term contraction. They are in colour due to a lack of myoglobin. They contract with twitch velocity and are more prone to respiration. They therefore fatigue easily, but produce more force. They store energy in the form of ATP and .

The Type IIa fast muscle fibres have higher concentrations of and mitochondria. They are therefore the most resistant to of the Type II fibres and are used in term anaerobic activities.
Type IIb fast muscle fibres have low concentrations of myoglobin and so fatigue easily but contract with high power. They are therefore used in short term activities.
Type IIx super-fast muscle fibres have the lowest concentrations of muscle fibres so are very vulnerable to . They do, however, contract the fastest with the largest amount of .

The C-terminus of dystrophin binds to the (DAPC) found at the .
The N-terminus of dystorphin binds to filamentous in the cytoskeleton.

The limb and trunk muscles are derived from embryonic structures known as - buds of the mesoderm. The are divided into sections which will give rise to different parts of the body.
The will give rise to the skeletal muscle, the satellite cells and the overlying dermis.
The will give rise to cartilage, joints and tendons.
The will form differentiated myocytes.