Bio 142 Muscles Exam

What are the functions of skeletal muscles

Attaches muscles to bone.

The collagenous fibers that line and bind fascicles

Collagenous fiber lining that encapsulates an entire muscle, and is connected to the deep faciae

The connective tissue that surrounds and protects each  individual muscle fiber within the fascicle.

a broad sheet of connective tissue that muscles bind to. may connect to multiple bones.

Muscle cells are also considered

cylindrical structures that fill the sarcoplasm of each muscle cell.

functional units of myofilaments that contract

Thin Filaments

Thin Filaments

Point where the motor neuron interacts with muscle fibers by releases acetylcholine vesicles into the synaptic cleft.

What happens at neuromuscular junction.

Zone of muscle cell with no thick filaments

Serves as the boundary between two thin filaments

zone in a resting cell that contains thick filaments but no thin filaments

Joins each of the thick filaments by their midpoint

Dense region of the sarcomere that contains the thick filaments

how do muscles move

When the active site on the actin is open, the myosin head becomes attracted to it, and it binds dropping the ADP. The myosin recocks when another ATP molecule binds, and it recocks allowing it to powerstroke again to the next active site

a graph of tension development in muscle fibers

All the muscle fibers controlled by a single motor neuron

resting tension in a skeletal muscle

tension rises exceeding the load, and the muscle length changes

Muscle contracts not exceeding the load, muscle does not change in length

Load - fulcrum - force

Fulcrum - Load - Force

Fulcrum - Force - Load