Practicum 3 - Muscle Functions

What is the function of the frontalis?

• Elevates eyebrows (suprise)

Corrugator Supercilii

• Adducts eyebrows (frown)

Orbicularis oculi

• Closes eye

Orbicularis oris

• Closes mouth

Buccinator

• Compresses cheeks (straw sipping)

Zygomaticus

• Elevating corners of mouth (smiling)

Risorius

• Opens mouth laterally (open wide)

Mentalis

• Pushes lower lip out (pouting)

Masseter and Temporalis

• Elevates mandible

Platysma

• Teases anterior neck, depresses mandible, pulls lips laterally and inferiorly

Mylohyoid

Higher

• Elevates hyoid

Digastric

Higher

• Elevates hyoid, depresses mandible

Stylohyoid

Higher

• Elevates and retracts hyoid

Sternocleidomastoid

• Flex neck

Sternohyoid

Lower

• Depresses hyoid

Pectoralis major

• Flexes, medially rotates and adducts arm

External/Internal Oblique

Abs

• Lateral trunk rotation, abdominal compression

Transverse abdominis

• Abdominal compression

Rectus abdominus

• Flexes vertebral column

External intercostals

• Elevates ribs (breathing in)

Pectoralis minor

• Protracts and depresses scapula

Serratus anterior

• Protract scapula

Latissimus dorsi

• Adducts arm

Trapezius

• Elevates and adducts scapula, extends neck

Deltoid

• Abducts arm

Levator scapulae

• Elevates scapula

Rhomboideus major and minor

• Adducts scapula

What is a rotator cuff?

Supraspinatus

Rotator cuff

• Abducts arm

Infraspinatus

Rotator cuff

• Lateral arm rotation

Teres minor

Rotator cuff

• Lateral arm rotation

Subscapularis

Rotator cuff

• Stabilize humerus, medial arm rotation

Teres major

• Adducts arm, medial arm rotaion

Biceps brachii? Anterior or posterior?

Anterior flexors

• Flexes elbow

Brachialis? Anterior or posterior?

Posterior to biceps brachii

• Flexes elbow

Brachioradialis? Anterior or posterior?

Anterior flexors

• Flexes elbow

Triceps brachii? Anterior or posterior?

Posterior extensor

• Extends elbow

Pronator teres? Anterior or posterior?

Anterior

• Pronates forearm

Flexor carpi radialis? Anterior or posterior?

Anterior

• Flexes and abducts wrist

Palmaris longus? Anterior or posterior?

Anterior

• Flexes wrist

Flexor carpi ulnaris? Anterior or posterior?

Anterior

• Flexes and adducts wrist

Extensor carpi radialis longus? Anterior or posterior?

Posterior

• Extends and abducts wrist

Extensor carpi radialis brevis? Anterior or posterior?

Posterior

• Extends and abducts wrist

Extensor digitorum? Anterior or posterior?

Posterior

• Extends digits

Extensor digiti minimii? Anterior or posterior?

Posterior

• Extends digits

Extensor carpi ulnaris? Anterior or posterior?

Posterior

• Extends and adducts wrist

Sartorius

Muscles of thigh

• Flexes thigh and flexes knee

Gluteus maximus

Muscles of thigh

• Extends the thigh

Gluteus medius

• Abducts the thigh

Tensor fascia latae

• Abducts the thigh, extends the knee (leg)

Iliacus

• Flexes the thigh (hip)

Psoas major

• Flexes the thigh (hip)

Rectus femoris

• Extends the knee, flexes the thigh

Vastus lateralis

• Extends the knee

Vastus intermedius

• Extends the knee (leg)

Vastus medialis

• Extends the knee (leg)

Biceps femoris

Hamstring group

• Flexes the knee (leg), Extends the thigh (hip)

Semimembranosus

Hamstring group

• Flexes the knee (leg), Extends the thigh (hip)

Semitendinosus

Hamstring group

• Flexes the knee (leg), Extends the thigh (hip)

Gracilis

Adductor group

• Flexes knee (leg), Adducts thigh (hip),

Pectineus

Adductor group

• Adducts thigh (hip)

Adductor longus

Adductor group

• Adducts thigh (hip)

Adductor magnus

Adductor group

• Adducts thigh (hip)

Gastrocnemius

Muscle of Lower Leg

• Plantar flexes foot

Plantaris

Muscle of Lower Leg

• Plantar flexes foot

Soleus

Muscle of Lower Leg

• Plantar flexes foot

Tibialis anterior

Tibial muscles

• Dorsiflexes and inverts foot

Extensor digitorum longus? Anterior or posterior?

Anterior

• extends toes 2-5

Flexor digitorum longus? Anterior or posterior?

Posterior

• Flexes toes 2-5

Tibialis posterior

Tibial muscles

• Inverts foot

Fibularis longus

Lateral

• Everts foot

Fibularis brevis

Lateral and Lower

• Everts foot