Exam 2 Flashcards
What is the origin or proximal attachment of a muscle?
The attachment to the bone that does not move when the muscle shortens.
What is the insertion or distal attachment of a muscle?
The attachment to the bone that moves when the muscle shortens.
What is the belly of a muscle?
The largest portion of the muscle between origin and insertion.
What movement does the biceps brachii primarily perform?
Flexion.
What movement does the triceps brachii primarily perform?
Extension.
What occurs during muscle contraction regarding origin and insertion?
Typically, the insertion moves towards the origin.
Fill in the blank: The action of a muscle is the ______ accomplished when the muscle contracts.
[movement]
What is innervation in the context of muscles?
The supply of nerves to a muscle.
Where do the origins of the biceps brachii attach?
On the scapula.
Where do the origins of the triceps brachii attach?
On the scapula and humerus.
What is the insertion of the biceps brachii?
On the radial tuberosity.
What is the insertion of the triceps brachii?
On the olecranon process.
What is the role of the prime mover in muscle interactions?
The prime mover (agonist) is the primary muscle that performs a specific muscle action, usually the most important action of the joint.
Which muscle is considered the prime mover for elbow flexion?
Brachialis
What is the function of synergist muscles?
Synergists are muscles that perform the same action as the muscle to which you are comparing it.
Which muscle acts as a synergist to the brachialis?
Biceps brachii
What is the role of antagonist muscles?
Antagonists are muscles that perform the opposite action of the muscle to which you are comparing it.
Which muscle acts as the antagonist to the biceps brachii during elbow flexion?
Triceps brachii
What is a fixator muscle?
A fixator is a muscle that holds a body part, such as the scapula, firmly in place.
Which muscle is an example of a fixator for the scapula?
Rhomboids
In the context of muscle interactions, what happens to the hamstrings during knee extension?
Hamstrings lengthen and work as antagonists.
In the context of muscle interactions, what happens to the quadriceps during knee extension?
Quadriceps contract and work as agonists.
Fill in the blank: Bones in joints are usually moved by several muscles in several different _______.
ways
