Muscle Practical #2 BIOL 124 GMU

Triceps brachii

Origin: long head: Infraglenoid tubercle

lateral head: proximal humerus

medial head: posterior humerus

Insertion: Olecranon process

Action: extends forearm

Biceps brachii

Origin: Long head: supraglenoid tubercle

Short head: Coracoid process

Insertion: Radial tuberosity

Action: flexes and supinates forearm

Brachialis

Origin: Distal anterior humerus

Insertion: Coronoid process of ulna

Action: flexes forearm

Brachioradialis

Origin: distal humerus

Insertion: Styloid process of radius

Action: flexes forearm

Flexor carpi radialis

Origin: Medial epicondyle of humerus

Insertion: second and third metacarpal

Action: flexes and abducts hand

Flexor carpi ulanaris

Origin: Medial epicondyle of humerus

Insertion: medial carpals; fifth metacarpal

Action: flexes and adducts hand

Extensor carpi radialis longus

Origin: Lateral distal humerus

Insertion: second metacarpal

Action: Extends and abducts hand

Extensor carpi ulnaris

Origin: Lateral epicondyle of humerus

Insertion: fifth metacarpal

Action: Extends and adducts hand

Psoas major

origin: transverse processes and bodies of lumbar vertebrae

Insertion: Lesser trochanter

Action: Flexes thigh

Iliacus

Origin: Iliac fossa

Insertion: Lesser trochanter

Action: Flexes thigh

Sartorius

Origin: Anterior superior iliac spine

Insertion: Medial condyle of the tibia

Action: Flexes, abducts, and laterally rotates thigh; flexes leg

Gracilis

Origin: body and inferior ramus of pubis

Insertion: Medial surface of proximal tibia

Action: Adducts thigh; flexes leg

Rectus femoris

Origin: Anterior inferior iliac spine

Insertion: tibial tuberosity via patellar ligament

Action: flexes thigh; extends leg

Vastus lateralis

Origin: Greater trochanter; proximal linea aspera

Insertion: tibial tuberosity via patellar ligament

Action: extends leg

Vastus medialis

Origin: Linea aspera and medial femur

Insertion: tibial tuberosity via patellar ligament

Action: Extends leg

Tensor fasciae latae

Origin: iliac crest and anterior superior iliac spine

Insertion: Iliotibial tract

Action: flexes, abducts, and medially rotates thigh

Gluteus maximus

Origin: posterior ilium, sacrum, and coccyx

Insertion: Gluteal tuberosity

Action: extends, abducts, and laterally rotates thigh

Gluteus medius

Origin: posterior surface of ilium

Insertion: Greater trochanter

Action: abducts and medially rotates thigh

Biceps femoris

Origin: long head: Ischial tuberosity

short head: posterior femur

Insertion: Head of fibula; lateral condyle of tibia

Action: Extends thigh; flexes leg

Semitendinosus

Origin: Ischial tuberosity

Insertion: proximal medial tibia

Action: Extends thigh; flexes leg

Semimembranosus

Origin: Ischial tuberosity

Insertion: posterior medial condyle of tibia

Action: Extends thigh; flexes leg

Tibialis anterior

Origin: Lateral condyle and proximal tibia

Insertion: medial tarsal and first metatarsal

Action: dorsiflexes foot; inverts foot

Fibularis (peroneus) longus

Origin: proximal lateral fibula

Insertion: medial tarsal and first metatarsal

Action: Plantar flexes foot and everts foot

Gastrocnemius

Origin: femoral condyles

Insertion: Calcaneus

Action: flexes leg and plantar flexes foot

Soleus

Origin: head of fibula, proximal tibia

Insertion: Calcaneus

Action: Plantar flexes foot