Muscle Actions Flashcards
Buccinator
compresses cheek, pulls the corner of the mouth laterally
Epicranius frontal belly
wrinkles the skin of the forehead and elevates eyebrows (facial expressions)
Epicranius occipital belly
fix scalp in place or retract it
Orbicularis Oris
closes and purses lips
Orbicularis oculi
Closes eyes, allows to blink, wink and squint. Also lowers eyebrows.
Platysma
tenses skin of neck and pulls lower lip down and back. Also helps lower the mandible
Zygomaticus major and minor
pulls the corner of the mouth upward
masseter
raises mandible to close mouth
temporalis
raise and retract mandible
digastric
raises the hyoid and lowers mandible. (used in speech, swallowing and chewing)
sternocleidomastoid
flexes the neck when both are contracted, rotates the head and points face toward opposite shoulder when only one is contracted.
Deltoid
Main muscle that abducts arm, flexes and extends arm, rotates humerus.
Pectoralis major
main muscle that flexes the arm or humerus, adducts the arm, medially rotates the arm, and elevates chest upward.
Pectoralis minor
protract and lowers scapula, elevates rib cage
serratus anterior
superior rotation of scapula, protract scapula, causes punching or pushing movement
external intercostals
raises ribcage when inhaling
internal intercostals
lowers ribcage when exhaling
diaphram
moves down and flattens when you inhale, bulges upward when exhaling
rectus abdominus
flexes and rotates vertebral column, increases abdominal pressure, steadies the pelvis when walking, lowers ribcage
transverse abdominus
helps to support abdominal contents
external oblique and internal oblique
compresses abdominal wall, laterally flexes vertebral column, steadies vertebral column when lifting something heavy, plays a role in posture, plus all rectus abdominus actions.
linea alba
tendon-like band between rectus abdominus
what does the erector spinae group consist of
iliocostalis, longissimus, spinalis
erector spinae group
extend and laterally flex their vertebral column, and extends and rotates the neck
trapezius
raises, lowers scapula, rotates and pulls scapula toward midline
latissimus dorsi
main muscle that extends the arm, adducts arm, rotates humerus medially
teres minor
rotates humerus laterally
supraspinatus
abducts arm
infraspinatus
rotates humerus laterally
subscapularis
rotates humerus medially
rhomboid minor and major
rotates scapula to help lower arm, helps pull scapula toward midline
levator scapulae
helps pull scapula toward midline, elevates scapula, laterally flexes the neck.
Coracobrachialis
flexes and rotates humerus medially
Biceps brachii
main muscle that flexes the forearm, also supinates forearm
brachialis
flexes forearm
brachioradialis
flexes forearm
triceps brachii
main muscle that extends forearm
supinator
supinates forearm
pronator teres
rotate (pronate) forearm
flexor carpi radialis
flexes wrist, abducts hand
flexor carpi ulnaris
flexes wrist, adducts hand
flexor digitorum superficialis
flexes fingers and wrist (not thumb)
flexor digitorum profundus
flexes fingers and wrist (not thumb)
flexor pollicus longus
thumb flexor
pulmaris longus
flexes wrist, tenses skin of palm
flexor retinaculum
holds flexor tendons in the wrist (connective tissue collar)
extensor carpi radialis longus
extends wrist, abducts hand
extensor carpi radialis brevis
extends wrist, abducts hand
extensor carpi ulnaris
wrist extender, adducts hand
extensor digitorum
finger and wrist extender
extensor pollicis longus
thumb extender
extensor pollicis brevis
thumb extender
extensor retinaculum
holds extensor tendons on wrist (connective tissue collar)
iliopsoas
consists of psoas major and illiacus
illiacus
flex the thigh and vertebral column, laterally flexes vertebral column
sartorius
flexes thigh, abducts thigh and rotates thigh laterally, also flexes leg
gracilis
adducts thigh, flexes and medially rotates leg below the knee
gluteus maximus
abducts thigh, rotates thigh laterally, extends thigh when walking up an incline
gluteus medius and minimus
abducts thigh, rotates thigh medially, steadies pelvis
tensor fasciae latae
flex thigh, abduct thigh, rotate thigh medially, steadies trunk and braces the knee
adductor longus and brevis
adducts thigh, rotates thigh medially, flexes thigh
adductor mangus
adducts thigh, rotate thigh medially, can flex the thigh, extend thigh
quadriceps group
consists of rectus femoris, vastus lateralis, vastus medialis, and vastus intermedius
rectus femoris
extends leg, stabilizes the knee, flexes thigh and vertebral column
vastus lateralis, medialis, and intermedius
extends leg, stabilizes the knee
