The muscles that perform most of the action in producing the movement
agonists
Muscles that help the prime mover by contracting at the same time to assist in the movement so that the movement is more effective
synergists
Muscles that relax when the prime mover and synergists are contracting
antagonists
Raises eyebrows
epicranius
draws eyebrows together, wrinkles skin of forehead (frowning)
corrugator supercilii
closes eye
orbicularis oculi
raises lateral corners of mouth upward
zygomaticus major and minor
opens lips
levator labii superioris
draws corner of lip laterally, tenses lips
risorius
draws lower lip inferiorly (pout)
depressor labii inferioris
draws corners of mouth downward and laterally (tragedy mask grimace)
depressor anguli oris
closes lips, kissing and whistling
orbicularis oris
wrinkles chin, protrudes lower lip
mentalis
compresses cheek
buccinator
tenses skin of neck, depresses mandible
platysma
prime mover of jaw closure
masseter
closes jaw
temporalis
protracts tongue
genioglossus
depresses tongue
hyoglossus
retracts and elevates tongue
styloglossus
flexes and laterally rotates the head
sternocleidomastoid
elevate first two ribs
scalenes
extend or hyperextend head
splenius
extend and laterally flex the vertebral column, maintain posture
iliocostalis
extends vertebral column
spinalis
extend vertebral column and head and rotates them to opposite side
semispinalis
pull ribs toward one another to activate rib cage
external intercostals
draw ribs together and depress rib cage
internal intercostals
prime mover of inspiration, flattens on contraction
diaphragm
flex and rotate lumbar region of vertebral column
rectus abdominus
flex vertebral column and compress abdominal wall, trunk rotation and lateral flexion
external oblique
compresses abdominal contents
transverse abdominus
with ribs fixed, draws scapula forward and downward
pectoralis minor
rotates scapula so that its inferior angle moves laterally and upward
serratus anterior
helps stabilize and depress pectoral girdle
subclavius
stabilizes, raises, retracts, and rotates scapula
trapezius
elevates/adducts scapula
levator scapulae
stabilize scapula
rhomboids
prime mover of arm flexion, rotates arm medially, adducts arm
pectoralis major
prime mover of arm abduction when all its fibers contract simultaneously
deltoid
prime mover of arm extension, powerful arm adductor, medially rotates arm at shoulder
latissimus dorsi
chief medial rotator of humerus
subscapularis
initiates abduction of humerus
supraspinatus
rotates humerus laterally
infraspinatus
rotates humerus laterally also
teres minor
extends humerus, medially rotates, and adducts humerus
teres major
flexion and adduction of the humerus
coracobrachialis
powerful forearm extensor
triceps brachii
controls ulnar abduction during forearm pronation
anconeus
flexes elbow joint and supinates forearm
biceps brachii
a major forearm flexor, lifts ulna as biceps lift the radius
brachialis
powerful flexor of wrist, abducts hand
flexor carpi radialis
tenses skin and fascia of palm during hand movements
palmaris longus
prime mover of finger extension
extensor digitorum
extends index finger
extensor indicis
adducts, flexes and medially rotates thigh
pectineus
adducts thigh, flexes and medially rotates leg
gracilis
extends knee and flexes thigh at hip, one of quadriceps
rectus femoris
extends and stabilizes knee, one of quadriceps
vastus lateralis
extends knee, one of quadriceps
vastus medialis
major extensor of thigh
gluteus maximus
rotates thigh laterally and stabilizes hip joint
quadratus femoris
extends thigh and flexes knee laterally rotates leg, one of hamstrings
biceps femoris
extends thigh and flexes knee, medially rotates leg, one of hamstrings
semitendinosus
deep to semitendinosus, extends thigh and flexes knee
semimembranosus
prime mover of dorsiflexion, inverts foot
tibialis anterior
prime mover of toe extension
extensor digitorum longus
plantar flexes foot when knee is extended bc it also crosses knee joint, calf
gastrocnemius
Close body openings by contracting
circular
Has a broad origin; single tendon of insertion
convergent
Strap-like with an expanded belly; great ability to shorten but NOT very powerful
parallel
Fascicles are short and attach obliquely to a central tendon that runs the length of the muscle; do NOT shorten as much but are more powerful.
pennate
A rigid bar that moves on a fixed point
lever
The fixed point upon which a lever moves
fulcrum
The applied force
effort
the resistance
load
lever
radius
fulcrum
elbow joint
effort
biceps brachii
load
hand and what you are holding
Effort is applied at one end of the lever; the load at the other; fulcrum somewhere in between
first class lever
Effort applied at one end of the lever; the fulcrum located at the other; load between them
second class lever
Effort applied between the load and the fulcrum
third class lever
first class lever
lifting your head off your chest
second class lever
standing on tip toe
third class lever
flexing the corearm with the biceps brachii
The most common lever systems in the body are those that have the applied force between the fulcrum and the resistance. These are called ______ levers.
third class
A muscle that assists the muscle primarily responsible for a given action is a
synergist
A muscle that is inserted on the mandible is probably involved in:
chewing
A muscle whose name ends in the suffix -glossus would be found attached to the:
tongue
Damage to which of the following muscles would interfere with quiet breathing?
external intercostals
During abdominal surgery, the surgeon makes a cut through the muscle directly to the right of the linea alba. The muscle that is being cut is the
rectus abdominus
Muscles with fibers that run straight or parallel to the long axis of the body are called:
rectus
The muscular wall of the abdomen is composed of:
oblique and rectus muscles
The major abductor muscle of the upper arm is the
deltoid
The attachment site of the muscle tendon to the more-movable bone is called the:
insertion
The deltoid is a muscle named according to
shape
The extensor digitorum muscle is an example of a ____________ muscle.
pennate
The _______ nerve innervates all of the extrinsic tongue muscles
hypoglossal
Which of the following muscles divides the neck into two triangles?
sternocleidomastoid
Which of the following muscles lifts the rib cage during inspiration?
external intercostals
The linea alba is found in the
rectus abdominus
The _______________ assists the triceps brachii in forearm extension
anconeus
Which of the following adducts the fingers and wrist?
flexor carpi ulnaris
The prime mover for flexion of the thigh is the __________ muscle.
iliopsoas
The ________________ is the prime mover of dorisiflexion of the foot.
tibialis anterior
Shin splints are caused by
irritation of the tibialis anterior
__________ are muscles that oppose or reverse a particular movement.
antagonists
How many origins are there for the biceps brachii muscle?
2
Sphincters have a _______ arrangement of fascicles.
circular
The prime movers of back extension are the:
erector spinae
Voluntary control of urination is facilitated by the:
external urethral sphincter
straight
rectus
right angles
transverse
short
brevis
triangle
deltoid
rib
costal
wrist
carpi
Plantar flexion is the most powerful movement of the foot and ankle