Anatomy Chapter 11

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

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

First- class lever

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

The origin of the muscle

Antagonist

A muscle whose action opposes that of a particular agonist

Agonist (Prime Mover)

A muscle whose contraction is mostly responsible for producing a PARTICULAR movement

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

Sphincters

A lever moves on a fixed point called __________.

Fulcrum

There are approximately how many muscles in the human body?

700

A fixator is __________.

A synergist that assists an agonist by preventing movement at another joint, thereby stabilizing the origin of the agonist

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

Agonist (Prime Mover)

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

Antagonist

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

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

Circular

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

Second-Class Lever

The load (L) lies between the applied force (AP) and the fulcrum (F)

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

Insertion

Convergent Muscle

Muscle fascicles extending over a broad area come together, or converge, on a common attachment site

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

Origin

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

Parallel Muscle

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

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

Third-Class Lever

The applied force (AF) is between the load (L) and the fulcrum (F)

Parallel Muscle

The fascicles are parallel to the long axis of the muscle

Pennate Muscles

The fascicles form a common angle with the tendon

First-Class Lever

The fulcrum (F) lies between the applied force (AF) and the load (L)

What happens when a muscle contracts and its fibers shorten?

The insertion moves toward the origin.

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

Third- class lever

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

Synergist

When contracts it helps a larger agonist work efficiently