Chapter 9-11 Test Flashcards
Agonist
the main muscle that contracts to perform action, also know as the prime mover
Antagonist
the opposing muscle that stretches and yields to the actions of the agonist
Origin of Brachialis
lower half of anterior shaft of humerus
Insertion of Brachialis
Tuberosity of ulna
Action of Brachialis
Flex elbow
Origin of Extensor digitorum longus
Lateral epicondyle of tibia, proximal two-thirds of anterior shaft of fibula
Insertion of Extensor digitorum longus
Middle and distal phalanges of four lateral toes
Action of Extensor digitorum longus
Extends four lateral toes; dorsiflexion of ankle
Origin of levator scapula
C1-C4 transverse processes
Insertion of levator scapula
Vertebral border of scapula from superior angle to root of spine of scapula
Action of levator scapula
Elevation and downward rotation of scapula
Origin of masseter
Zygomatic arch
Insertion of masseter
mandible
Action of masseter
Close jaw
Origin of rectus abdominis
Costal cartilages 5, 6, and 7
Insertion of rectus abdominis
Pubis
Action of rectus abdominis
flex trunk; compress abdominal contents; stabilize trunk
two primary types of muscle fibers
slow-twitch fibers
and
fast-twitch fibers
slow-twitch fibers
tiny fibers that contract slowly and are capable of prolonged contraction (standing for hours)
fast-twitch fibers
are larger in diameter than slow-twitch and produce the most powerful muscle contractions, but fatigue quickly
phantom pain
pain in a limb that has been removed
synovial membrane
fluid membrane that surrounds a joint