Major Muscles and Diseases

Frontalis

• Eyebrows to occipital

• Raise eyebrows

Orbicularis oculi

• Surrounds the eye

• Close eyelid

Orbicularis oris

• Surrounds the mouth

• “Kissing muscle”

• Close lips, pucker

Zygomaticus

• Zygomatic to mouth, cheeks

• “Smiling muscle”

• Elevates corners of the mouth

Masseter

• Zygomatic to mandible

• Mandible elevation

• Mastication (chewing)

Temporalis

• Temporal to mandible

• Mandible elevation

• Mastication (chewing)

Sternocleidomastoid

• Temporal bone (mastoid process) to sternum and clavicle

• Rotates and flexes head/neck

Trapezius

• Posterior neck and superior back

• Head/neck extension, scapula elevation

Pectoralis major

• Chest to humerus

• Shoulder adduction and flexion

Latissimus dorsi

• Inferior and lateral back to humerus

• Shoulder extension and adduction

Deltoid

• Over the shoulder

• Shoulder abduction

Biceps brachii

• Anterior upper arm

• Elbow flexion

Triceps brachii

• Posterior upper arm

• Elbow extension

Iliopsoas

• Spine to ilium and femur

• Hip and trunk flexion

Gluteus maximus

• Butt

• Hip extension

Sartorius

• Ilium to tibia

• Hip flexion and rotation

Adductor group

• Medial thigh (groin)

• Hip adduction

Semimembranosus

• Ischium to tibia

• Extension of the hip

• Flexion of the knee

Semitendinosus

• Ischium to tibia

• Extension of the hip

• Flexion of the knee

Biceps femoris

• Ischium to fibula

• Extension of the hip

• Flexion of the knee

Rectus femoris

• Ilium to tibia

• Extension of the knee

• Flexion of the hip

Vastus lateralis, vastus medialis, vastus intermedius

• Femur to tibia

• Extension of the knee

Gastrocnemius

• Femur to calcaneus (Achilles tendon)

• Plantar flexion of ankle

Soleus

• Lower leg to calcaneus (Achilles tendon)

• Plantar flexion of ankle

Tibialis anterior

• Tibia to foot

• Dorsiflexion of ankle

Muscle strain

Stretching or tearing a muscle or tendon

Muscle contusion

A bruise usually caused by a blow to the muscle

Poliomyelitis

• Caused by virus

• Infects the nervous system causing muscles to atrophy, wasting away or decrease in size of muscle

Muscle dystrophy

Genetic disorders causing progressive atrophy of muscle tissue

Duchenne muscular dystrophy

• Lack of protein that helps keep muscles intact

• Muscles atrophy

• X-linked genetic disease

  • XX = girl

  • XY = boy

    • More common in men

    • Women carry it