muscular system (lab) Flashcards
buccinator
action (compresses cheeks) origin (molar region of maxilla and mandible) insertion (orbicularis oris).
epicranius frontalis
action (raises eyebrow and wrinkles forehead) origin (epicranial aponeurosis) insertion (skin of eyebrows and root of nose).
epicranius occipitalis
action (raises the eyebrow; pulls scalp posteriorly), origin (occipital and temporal bones), insertion (epicranial aponeurosis).
orbicularis oculi
action (closes eye tightly or squinting) no insertion or origin.
orbicularis oris
action (closes and protrudes [puckers] lips), no origin or insertion.
zygomaticus major and minor
action (raises corners of mouth [smiling]), origin (zygomatic bone), insertion (skin, muscle of upper lips).
masseter
action (closes the jaw [mandible]), origin (zygomatic arch and bone), insertion (angle of mandible).
temporalis
action (closes the jaw [elevates and retracts the mandible]) no origin or insertion.
sternocleidomastoid
action (one side contracting = turning head to the opposite side, both sides contracting = pulling head toward chest, raising the sternum), origin (manubrium of sternum and medial portion of clavicle), insertion (mastoid process of temporal bone and superior nuchal line of occipital bone).
platysma
action (draws the angles of the mouth downward) no insertion or origin.
external oblique
action (tenses the abdominal wall; compresses the abdominal contents) no origin or insertion.
internal oblique
action (tenses the abdominal wall; compresses the abdominal contents).
rectus abdominis
action (flexes and rotates vertebral column; compresses the abdominal contents; also flexes the torso at the waist as in sit-ups), origin (pubic crest and symphysis), insertion (xiphoid process, costal cartilages of ribs 5-7).
transversus abdominis
action (tenses the abdominal wall; compresses the abdominal contents). no origin and insertion.
pectoralis major
action (pulls the arm forward and across the chest; adducts and medially rotates the humerus), origin (clavicle, sternum, cartilage of ribs 1-6, and aponeurosis of external oblique muscle), insertion (fibers converge to insert by short tendon into intertubercular sulcus of humerus).
pectoralis minor
action (pulls the scapula forward and downward; raises the ribs), no origin and insertion.
serratus anterior
action (pulls the scapula anteriorly and downward), no insertion and origin.
diaphragm
action (enlarges the volume of the thoracic cavity to cause inhalation), no insertion and origin.
external intercostals
action (causes forceful inhalation) no origin and insertion.
internal intercostals
action (causes forceful exhalation), no insertion and origin.
deltoid
action (abducts the humerus; flex or extend the humerus), origin (lateral 1/3 of clavicle; acromion and spine of scapula), insertion (deltoid tuberosity of humerus).
latissimus dorsi
action (extends and adducts the humerus; pulls shoulder down and back), origin (indirect attachment to spinous processes of lower 6 thoracic vertebrae, lumbar vertebrae, last 3 to 4 ribs, and iliac crest), insertion (floor of intertuber cular sulcus of humerus).
levator scapulae
action (elevates the scapula), origin (transverse processes of C1-C4), insertion (medial border of scapula superior to spine).
rhomboid major
action (raises and adducts the scapula) no origin and insertion.
teres major
action (extends, adducts, and medially rotates the humerus), no origin and insertion.
teres minor
action (laterally rotates the humerus), no insertion and origin.
trapezius
action (several movement of the scapula) origin (occipital bone; ligamentum nuchae; spines of C7 and all thoracic vertebrae) insertion (acromion and spinous process of scapula; lateral third of clavicle).
biceps brachii
action (flexes the forearm at the elbow) origin (short head: coracoid process; long head: supraglenoid tubercle and lip of glenoid cavity; tendon of long head runs in the intertubercular sulcus and within capsule of shoulder joint), insertion (radial tuberosity).
brachialis
action (flexes the forearm at the elbow, no origin and insertion.
extensors
action (several muscles on the dorsal surface of the forearm which extend either the wrist of the fingers), no origin and insertion.
flexors
action (several muscles on the anterior surface of the forearm which flex either the wrist or the fingers), no origin and insertion.
infraspinatus
action (laterally rotates the humerus), no origin and insertion.
subscapularis
action (medially rotates the humerus), no origin and insertion.
supraspinatus
action (abducts the humerus), no origin and insertion.
triceps brachii
action (extends the forearm at the elbow), origin (long head: inferior margin of glenoid cavity; lateral head: posterior humerus; medial head: distal radial groove on posterior humerus), insertion (olecranon of ulna).
adductor longus, magnus, and brevis
action (adduct and medially rotate and flex the thigh), no origin and insertion.
gastrocnemius
action (plantar flexes foot; flexes leg at knee), origin (by two heads from medial and lateral condyles of femur), insertion (calcaneus via calcaneal tendon).
gluteus maximus
action (extends the thigh at the hip), origin (dorsal ilium, sacrum, and coccyx), insertion (gluteal tuberosity of femur and iliotibial tract).
gluteus medius
action (abducts the thigh) no origin and insertion.
gracilis
action (adducts the thigh) no origin and insertion.
hamstrings (biceps femoris, semitendinosus, semimembranosus)
action (flex the leg; extend the thigh) origin (ischial tuberosity [long head]; linea aspera and distal femur [short head]), insertion (tendon passes laterally to insert into head of fibula and lateral condyle of tibia).
iliopsoas (iliacus, psoas major)
action (flexes the thigh [or the torso] at the hip) no origin and insertion.
quadriceps femoris (rectus femoris, vastus lateralis, medialis, and intermedius)
action (extend the leg at the knee and flexes thigh), origin (anterior inferior iliac spine and superior margin of acetabulum), insertion (tibial tuberosity and patella).
sartorius
action (crosses the legs “tailior style”; a common cross-legged position when seated on floor), origin (anterior superior iliac spine), insertion (by an aponeurosis into the medial aspect of proximal tibia).
tensor fasciae latae
action (abducts the thigh) no origin and insertion.
tibialis anterior
action (dorsiflexion of the foot), origin (lateral condyle and upper 2/3 of tibia; interosseous membrane), insertion (by tendon into inferior surface of first cuneiform and metatarsal).
