Chapter 11: The Muscular System 11.1-11.3

The movable attachment of muscle to bone or other connective tissue is referred to as the __________.

insertion

A muscle in the body that is spindle-shaped is an example of a(n) __________.

parallel muscle

In what class of lever is the fulcrum between the load and the applied force?

First-class lever

In a convergent muscle, the muscle fibers are __________.

based over a broad area, but all the fibers come together at a common attachment site

The effect of an arrangement in which a force is applied between the load and the fulcrum illustrates the principles of __________.

third-class levers

There are approximately how many muscles in the human body?

700

Which type of muscle contains fascicles that are organized in concentric rings around an opening?

Circular

What is the term for the site where the muscle attaches that does NOT move when the muscle contracts?

Origin

What are the four types of muscles identified by different patterns of organization?

Parallel, convergent, pennate, and circular

Which type of fascicle arrangement produces more tension than others?

Pennate muscle

The calf muscles pull on the calcaneus and extend the ankle, lifting the person onto their toes. That makes this arrangement an example of what class of lever?

Second-class lever

What happens when a muscle contracts and its fibers shorten?

The insertion moves toward the origin.

Which class of lever improves the speed of movement and the distance the load is moved more than it improves lifting the load?

Third-class lever

Which class of levers is the most common in the body?

Third-class lever

If the biceps brachii muscle flexes the forearm, and the triceps brachii muscle causes extension of the forearm, then the triceps brachii is the __________ of the biceps brachii.

antagonist

A lever moves on a fixed point called __________.

a fulcrum

A muscle whose contraction is chiefly responsible for producing a particular movement is called __________.

a prime mover

A fixator is __________.

a synergist that prevents movement at another joint and stabilizes the origin of the agonist

A muscle whose action opposes that of another muscle, or agonist, is __________.

antagonist

A muscle like the pectoralis major muscle in the chest, whose fascicles originate over a large area and insert on a common point, the anterior humerus, is an example of a __________ muscle.

convergent muscle

The triceps brachii muscle attaches to the olecranon process of the ulna crossing the posterior side of the elbow joint. That will allow the triceps to be a(n) __________ of the elbow joint.

extensor

The structural commonality of the rectus femoris and the rectus abdominis is that they are __________.

parallel muscles whose fibers run along the long axis of the body

Circular muscles that guard entrances and exits of internal passageways are called __________.

sphincters

A first-class lever is one in which __________.

the fulcrum lies between the applied force and the load

If the biceps brachii muscle flexes the forearm, that means that its attachment to the humerus and scapula is __________.

the origin of the muscle