Muscles Lab

Epicranius

Location: covers forehead

Bony Attachment: epicranial aponeurosis

Soft Tissue Attachment: skin of forehead

Action: elevates eyebrows and wrinkles forehead

Orbicularis oculi

Location: surrounds orbit

Bony Attachment: skin around the orbit

Soft Tissue Attachment: skin around eyelids

Action: closes eyelids; blinking/squinting of eye

Zygomaticus (major, minor)

Location: extends diagonally from cheek to mouth

Bony Attachment: zygomatic bone

Soft Tissue Attachment: skin around mouth

Action: pulls corners of mouth posteriorly and superiorly (smile)

Orbicularis Oris

Location: surrounds mouth

Bony Attachment: maxilla and mandible

Soft Tissue Attachment: skin around lips

Action: purses and protrudes lips; puckering- kissing motion

Platysma

Location: superficial neck muscle

Bony Attachment: fascia of upper thorax and lower neck

Soft Tissue Attachment: mandible

Action: depresses lower lip, tenses skin of neck; depresses the mandible

Temporalis

Location: covers temporal bone

Superior Attachment: temporal bone

Inferior Attachment: coronoid process of mandible

Action: elevates and retracts mandible

Masseter

Location: covers lateral portion of ‘jaw’

Superior Attachment: zygomatic arch

Inferior Attachment: ramus of mandible

Action: elevates and protracts mandible

Sternocleidomastoid

Location: runs diagonally across neck from sternum and clavicle to temporal bone; deep to platysma

Superior Attachment: mastoid process of temporal bone

Inferior Attachment: sternum and clavicle

Action:

alone: laterally rotates neck to opposite side

together: flexes neck

External Intercostals

Location: between ribs; fibers run inferiorly and anteriorly

Superior Attachment: ribs

Inferior Attachment: ribs

Action: elevates ribs during inspiration

Internal Intercostals

Location: between ribs; fibers are deep to external intercostals and run in opposite direction

Superior Attachment: ribs

Inferior Attachment: ribs

Action: depresses ribs during expiration

Diaphragm

Location: large dome shaped muscle that divides the thoracic and abdominopelvic cavities

Superior Attachment: central tendon

Inferior Attachment: lumbar vertebrae, cartilage of ribs, xiphoid process

Action: primary driver of inspiration

Rectus Abdominis

Location: centrally located muscle of abdomen

Action: compression of abdomen; flexion and rotation of trunk/vertebral column

External Oblique

Location: Superficial lateral muscle with fibers running medially on an angle

Action: 

compression of abdomen;

alone: rotation of trunk/vertebral column

together: flexion of trunk/vertebral column

Internal Oblique

Location: Deep to external oblique; fibers run in opposite orientation

Action:

compression of abdomen;

alone: rotation of trunk/vertebral column

together: flexion of trunk/vertebral column

Transversus Abdominis

Location: Deep to internal oblique; fibers run in a transverse plane

Action: compression of abdomen

Rectus Sheath

connective tissue sheath surrounding the rectus abdominis;

formed from aponeuroses of external and internal oblique and transversus abdominis muscles

Linea Alba

tendinous structures that serves as an insertion point for external and internal oblique and transversus abdominis muscles

Serratus Anterior

Location: lateral portion of thoracic wall

Action: protracts scapula; rotates scapula superiorly; holds scapula against ribcage

Pectoralis Minor

Location: deep to pectoralis major

Action: protracts and depresses scapula; elevates ribcage; flexes, adducts, medially rotates arm

Trapezius

Location: diamond shaped muscle on superior portion of back (superficial)

Action: elevates and rotates scapula; retracts scapula; depresses scapula

Rhomboids (major and minor)

Location: deep to Trapezius

Action: retracts, elevates, and adducts scapula; stabilizes scapula

Pectoralis Major

Location: upper thorax

Action: flexes, adducts, medially rotates arm

Pectoralis Minor

Location: deep to pectoralis major

Action: protracts and depresses scapula; elevates ribcage; flexes, adducts, medially rotates arm

Deltoid

Location: superior muscle of shoulder

Distal Attachment: deltoid tuberosity of humerus

Action: flexes,  extends, adducts, abducts, medially, laterally rotates arm (a does it all kinda muscle!)

Biceps Brachii

Location: superficial muscle on anterior arm

Action: weakly flexes arm; powerfully flexes forearm; supinates forearm

Brachialis

Location: deep to biceps brachii

Action: flexes forearm

Brachioradialis

Location: lateral anterior forearm

Action: flexes forearm

Pronator Teres

Location: anterior elbow and proximal forearm

Action: pronates forearm

Triceps Brachii

Location: superficial muscle on posterior arm

Action: extends forearm; extends arm

Latissimus Dorsi

Location: broad muscle of lower back

Action: extends, adducts, medially rotates arm

Flexor Carpi Radialis/Ulnaris

2x

Location: anterior forearm

Action: flexes, abducts wrist

Palmaris Longus

Location: anterior forearm

Action: flexes wrist

Flexor Digitorum Superficialis

Location: anterior forearm, deep to flexor carpi radialis/ulnaris and palmaris longus

Action: flexes digits

Extensor Carpi Radialis Longus/Brevis

2x

Location: lateral posterior forearm

Action: extends, abducts wrist

Extensor Digitorum

Location: medial posterior forearm

Action: extends digits and wrists

Extensor Carpi Ulnaris

Location: medial posterior forearm

Action: extends and adducts wrist

Iliopsoas

Location: anterior and proximal thigh

Action: flexes thigh

Tensor Fasciae Latae

Location: Lateral thigh

Action: flexes and abducts thigh

Sartorius

Location: runs diagonally across anterior thigh

Action: flexes, abducts, laterally rotates thigh; flexes knee/leg

Rectus Femoris

Location: superficial muscle of anterior thigh, part of quadriceps femoris group

Action: flexes thigh, extends knee/leg

Vastus Lateralis

Location: anterior lateral thigh, part of quadriceps femoris group

Action: extends knee/leg

Vastus Medialis

Location: anterior medial thigh, part of quadriceps femoris group

Action: extends knee/leg

Vastus Intermedius

Location: deep to rectus femoris, part of quadriceps femoris group

Action: extends knee/leg

Adductor Longus, Adductor Brevis, Adductor Magnus

x3

Location: Medial thigh

Action: adducts, laterally rotates thigh

Gracilis

Location: medial thigh

Action: adducts thigh

Gluteus Maximus

Location: large superficial muscle over gluteal region

Action: powerful thigh extensor

Gluteus Medius

Location: deep to gluteus maximus, covers ilium

Action: abducts, medially rotates thigh

Gluteus Minimus

Location: deepest gluteal muscle

Action: abducts, medially rotates thigh

Semimembranosus

Location: deep to semitendinosus, part of hamstrings

Action: extends thigh, flexes knee/leg, medially rotates leg

Biceps Femoris

Location: posterior and lateral muscle of thigh, part of hamstrings

Action: extends thigh, flexes knee/leg, laterally rotates leg

Semitendinosus

Location: medial to biceps femoris, part of hamstrings

Action: extends thigh, flexes knee/leg, medially rotates leg

Fibularis Longus

Location: lateral muscle on leg

Action: plantar flexes, everts foot

Tibialis Anterior

Location: anterior muscle on leg

Action: dorsiflexes, inverts foot

Fibularis Brevis

Location: lateral muscle on leg, deep to Fibularis longus

Action: plantar flexes, everts foot

Extensor Digitorum Longus

Location: deep and lateral to the tibialis anterior

Action: extends digits, dorsiflexes foot

Gastrocnemius

Location: large posterior calf muscle

Action: plantar flexes foot

Soleus

Location: deep to gastrocnemius

Action: plantar flexes foot