Lab #6 Muscles and Movements

orbicularis oculi

Orbicularis oculi

Origin: bones and ligments around orbit Insertion: tissue of eyelid Action: closes eye, produces blinking, squinting and draws eyebrows

orbicularis oris

Orbicularis Oris

Origin: maxilla and mandible Insertion: encircles mouth Action: closes lips; purses and protrudes

Temporalis

Temporalis

Origin: Temporal fossa Insertion: mandible Action: closes jaw; elevates and retracts mandible

sternocleidomastoid

Sternocleidomastoid

Origin: (2) manubrium of sternum, and medial portion of clavicle Insertion: Temporal bone and occipital bone Action: flexion of neck; rotate head toward shoulder on opposite side

Trapezius

Trapezius

Origin: occipital bone and spine/vertebrae Insertion: scapula and lateral third of clavicle Action: extends hear; raises, rotates, and retracts (adducts) scapula and stabilizes it

Deltoid

Deltoid

Origin: Lateral 1/3 of clavicle Insertion: humerus Action: whole prime mover of arm abduction

Masseter

Masseter

Origin: zygomatic bone Insertion: angle of mandible Action: Prime mover of jaw closure; elevates mandible

Pectoralis major

Pectoralis Major

Origin: clavicle, sternum, cartilage of ribs (1-6) and external oblique muscle Insertion: humerus Action: Prime mover of arm flexion; adducts medially rotates arm

Pectoralis minor

Pectoralis minor

Origin: anterior surface of ribs near costal cartilage Insertion: scapula Action: draws scapula forward and inferiorly; draws rib cage superiorly

Intercostals

Intercostals

Origin: above and below ribs Insertion: above and below ribs Action: pulls ribs together and apart to elevate and depress ribcage

Rectus Abdominis

Rectus abdominis

Origin: pubic crest and symphysis Insertion: xiphoid process and costal cartilage of ribs Action: flexes the vertebral column, increases abdominal pressure, stabilized pelvis during walking

External oblique

External oblique

Origin: anterior lower 8 ribs Insertion: pubic crest and iliac crest Action: compresses abdominal wall; trunk rotation and lateral flexion

(the deeper layer, not the superficial layer)

Internal oblique

Internal oblique

Origin: iliac crest Insertion: pubic crest and costal cartilage of last 3 ribs Action: same as external oblique

(deepest layer of abdominal region muscles)

Transversus Abdominis

Transversus Abdominis

Origin: iliac crest, lumbar, and cartilage of ribs (last 5-6) Insertion: pubic crest Action: compresses abdominal contents

Latissimus dorsi

Latissimus dorsi

Origin: (lower 6) thoracic vertebrae, lumbar vertebrae, (last 4) ribs, iliac crest Insertion: intertubercular sulcus of humerus Action: prime mover of arm extension; adducts and medially rotates arm

Triceps brachii

Triceps brachii

Origin: glenoid cavity, humerus Insertion: olecranon of ulna Action: powerful forearm extensor

Biceps brachii

Biceps brachii

Origin: glenoid cavity, shoulder joint Insertion: lateral aspect of olecranon of ulna Action: flexion (powerful) and supination of forearm

Brachialis

Brachialis

Origin: distal portion of anterior humerus Insertion: coronoid process of ulna Action: flexor of forearm

Extensor carpi raadialis Longus

Extensor Carpi radialis Longus

Origin:lateral ridge of humerus Insertion: base of metacarpal II Action: extends and abducts hand

(pronated arm view)

Extensor digitorum

Extensor digitorum

Origin: lateral humerus Insertion: 4 tendons into distal phalanges of fingers III-V Action: prime mover of finger extension; extends hand

(supinated arm view)

Flexor digitorum superficialis

(supinated view of arm)

Flexor Carpi radialis

Flexor Carpi radialis

Origin: Medial epocondyle of the humerus Insertion: base of metacarpals of II and III Action: to flex and radially deviate (abduct) the wrist

Gluteus maximus

Gluteus Maximus

Origin: dorsal ilium, sacrum, and coccyx Insertion: gluteal tuberosity of femur and iliotibial tract Action: powerful thigh extensor, laterally rotates and abducts thigh

Gluteus medius

Gluteus Medius

Origin: Upper lateral surface of ilium Insertion: Greater Trochanter of femur Action: abducts and medially rotates thigh; steading pelvis during walking

Sartorius

Sartorius

Origin: anterior superior iliac spine Insertion: medial aspect of proximal tibia Action: flexes, abducts, and laterally rotates thigh; flexes leg (helps effect cross-legged position)

Gracilis

Gracilis

Origin: inferior ramus and body of pubis Insertion: medial surface of tibia just inferior to medial condyle Action: adducts thigh; flexes and medially rotates leg

Quadriceps femoris

Rectus femoris

Rectus femoris

Origin: anterior inferior iliac spine and superior margin of acetabulum Insertion: tibial tuberosity and patella Action: extends leg and flexes thigh

Vastus Lateralis

Vastus lateralis

Origin: greater trochanter Insertion: tibial tuberosity and patella Action: extends leg and stabilizes knee

Vastus Medialis

Vastus medialis

Origin: linea aspera and intertrochanteric line Insertion: tibial tuberosity and patella Action: extends leg; stabilizes patella

Vastus intermedius

Vastus intermedius

Origin: anterior and lateral surface of femur Insertion: tibial tuberosity and patella Action: Extends leg

Biceps femoris

Biceps femoris

Origin: ischial tuberosity and distal femur Insertion: head of fibula and lateral tibia Action: extends thigh; laterally rotates leg, flexes leg

(posterior view)

Semimembranous

Semimembranous

Origin: ischial tuberosity Insertion: medial tibia; lateral femus’s Action: extends thigh; flexes legm medially rotates leg

Gastrocnemius

Gastrocnemius

Origin: two heads from medial and lateral condyles of femur Insertion: calcaneus Action: plantar flexes foot when leg is extended

Flexor digitorum Longus

Flexor digitorum Longus

Origin: posterior tibia Insertion: phalanges II-V Action: flexes toes; plantar flexes and inverts foot

Extensor digitorum Longus

Extensor digitorum Longus

Origin: lateral tibia/fibula Insertion: phalanges II-V Action: prime mover of toe extension, dorsiflexes foot

Tibialis Anterior

Tibialis anterior

Origin: lateral/upper tibia Insertion: metatarsal I Action: prime mover of dorsiflexion; inverts foot, supports longitudinal arch of foot

Dorsiflexion

(downward movement)

Plantar flexion

(downward position)

pronation

(upward position)

supination

abduction

(movement inwards)

adduction

flexion

Origin

the fixed, stationary more stable end of a muscle; typically more proximal (located closer to the torso or center); acts as an anchor during movement

Insertion

the mobile, moveable end of a muscle; typically located distally, is pulled toward the origin to create action

Epimysium

Epimysium

Connective tissue covering the entire muscle

(the section in green)

Fascicle

Fascicle

Bundle of muscle fibers surrounded by perimysium

(green)

Perimysium

Perimysium

Connective tissue surrounding a fascicle

(most inner section at the top right)

Muscle fiber

Muscle fiber

a single muscle cell

(the portion between individual muscle fibers)

endomysium

Endomysium

Connective tissue covering a single muscle fiber