Exam 8: Muscular System

The two neurotransmitters that affect smooth muscle cells are acetylcholine and __________.

Neurons that control effectors are called

Recruitment refers to increasing the number of motor units involved in a muscle contraction.

The increase in the number of motor units activated as a result of more intense stimulation is called

In the absence of oxygen,small amounts of ATP may be generated by this process.

Acetylcholinesterase decomposes the crossbridge linkages of myosin to actin.

Myofibrils are composed primarily of

The enlargement of muscle fibers as a result of exercise is called ________.

In a recording of a muscle twitch,the delay between the time a stimulus is applied and the time the muscle responds is called the

Bundles of skeletal muscle fibers are called

A motor neuron and the muscle fibers that it controls constitute a motor unit.

A myofibril may be thought of as many of these joined end-to-end.

In this type of muscle cell,the sarcoplasmic reticulum is not well developed.

When a muscle is stimulated repeatedly so that it cannot completely relax between contractions,_________ occurs.

The moveable end of a muscle is attached at its

This molecule,only present in muscle cells,is used to temporarily store oxygen for use in aerobic respiration.

The muscle primarily responsible for opposing a particular action is called the

Bundles of actin and myosin filaments form structures called ________.

The enzyme ATPase occurs in the globular portion of myosin molecules.

The zygomaticus muscle