Detailed tables on human muscles anatomy

Facial Muscles

Muscles of Facial Expression

All are innervated by the facial nerve (CN VII)

Muscle Origin Insertion Action Innervation

Skull

Frontalis Cales aponeurotica Skin of eyebrows and root of nose Raises eyebrows; wrinkles forehead Facial nerve (CN VII)

Occipitalis Occipital and temporal bone Skull Galea aponeurotica Pulls scalp posteriorly Facial nerve (CN VII)

Orbicularis oculi Frontal and maxillary bones Tissue of the eyelid Produces blinking, squinting, and draws eyebrows inferiorly Facial nerve (CN VII)

Buccinator Maxilla and mandible Orbicularis oris NOT Oculi Compresses the cheek (as in whistling) Facial nerve (CN VII)

Orbicularis oris Arises indirectly from the maxilla and mandible Encircles the mouth, inserts onto skin and muscles at lateral corners of mouth Closes the lips; purses and protrudes the lips, as in whistling and kissing Facial nerve (CN VII)

Mentalis Mandible Skin of the chin Protrudes lower lip; wrinkles the chin Facial nerve (CN VII)

Muscles of Mastication (Chewing)

All are innervated by the trigeminal nerve (CN V)

Muscle Origin Insertion Action Innervation

Masseter Zygomatic arch Mandible Elevates mandible Trigeminal nerve (CNV)

Temporalis Occipital and temporal bone Mandible Elevates mandible Trigeminal nerve (CNV)

Muscles of the Neck and Back

All are innervated by spinal nerves except sternocleidomastoid

Muscle Origin Insertion Action Innervation

Splenius Vertebrae Cz-T6 Temporal and occipital bone Acting together extend the head; acting alone head is rotated and bent toward the same side Spinal nerves

Sternocleidomastoid Sternum and clavicle Mastoid process of the temporal bone Acting together flex the head; acting alone rotates head toward the opposite shoulder Accessory nerve (CN XI)

Semispinalis Vertebrae C7-T12 Occipital bone and cervical and thoracic vertebrae (to T4) Extends vertebral column and head, rotates to opposite side Spinal nerves

Erector spinae group - prime movers of back extension, arranged as three vertically running columns from medial to lateral:

Spinalis (most medial) Upper lumbar to lower thoracic vertebrae Upper thoracic to cervical vertebrae Extends vertebral column Spinal nerves

Longissimus (intermediate) Lumbar through cervical vertebrae Thoracic through cervical vertebrae and rib Extend and laterally flex vertebral column

Muscles of the Thorax

Muscles of the Thorax Relating to Respiratory Movements

All are innervated by intercostal nerves except the respiratory diaphragm

Muscle Origin Insertion Action Innervation

External intercostals Inferior border of the rib above Superior boarder of the rib below Elevates rib cage, assists in forced inspiration Intercostal nerves

Internal intercostals Superior border of the rib below Inferior border of the rib above Depress the rib cage, assists in forced expiration

Respiratory diaphragm Rib cage, sternum, and lumbar vertebrae Central tendon Prime mover of inspiration Phrenic nerve

Muscles of the Thorax Relating to Movements of the Scapula

Muscle Origin Insertion Action Innervation

Pectoralis minor Ribs 3-5 Scapula Stabilizes scapula by drawing it forward and downward Pectoral nerves

Serratus anterior Ribs 1-8 Scapula Protracts and holds scapula against the thoracic wall Long thoracic nerve

Trapezius Superior nuchal line, ligamentum nuchae, and vertebrae C7 through T12 Clavicle, scapula Elevates, retracts, and rotates scapula Accessory nerve (CN XI)

Levator scapulae Vertebrae C1 through C4 Scapula Elevates the scapula Cervical spinal nerves and dorsal scapular nerve

Rhomboids Vertebrae C7 through T5 Scapula Retracts and stabilizes scapula Dorsal scapular nerve

Muscles Acting on the Arm

Anterior Group

Muscle Origin Insertion Action Innervation

Pectoralis major Sternum, costal cartilages, and clavicle Humerus Flexes, adducts, and medially rotates arm Pectoral nerves

Deltoid (anterior fibers) Clavicle (scapula for lateral and posterior fibers) Deltoid tuberosity of the humerus Flexes, extends, abducts, and medially rotates arm Axillary nerve

Coracobrachialis Scapula Humerus Flexes and adducts arm Musculocutaneous

Biceps brachii Long head Short head Scapula Radius Weak shoulder flexion (also flexes the elbow and supinates forearm) Musculocutaneous

Posterior Group

Muscle Origin Insertion Action Innervation

Deltoid (lateral and posterior part) Scapula Humerus Flexes, extends, abducts, and laterally rotates arm Axillary nerve

Supraspinatus* Scapula Greater tubercle of the humerus Assists in arm abduction, stabilizes shoulder joint Suprascapular nerve

Infraspinatus* Scapula Greater tubercle of the humerus Laterally rotates arm, stabilizes shoulder joint Suprascapular nerve

Teres minor* Scapula Greater tubercle of the humerus Laterally rotates arm, stabilizes shoulder joint Axillary nerve

Subscapularis* Scapula Lesser tubercle of the humerus Medially rotates arm, stabilizes shoulder joint Subscapular nerve

Teres major Scapula Humerus Extends, adducts, and medially rotates arm Subscapular nerve

Triceps brachii long head Scapula Ulna Extends and assists in arm adduction Radial nerve

Latissimuss Dorsi Thoracic and lumbar vertebrae, ribs, iliac crest Humerus Extends, adducts and medially rotates arm Thoracodorsal nerve

*SITS = muscles of the rotator cuff, major stabilizer of the shoulder joint

Muscles Acting on the Forearm

Anterior Flexor Compartment

Muscle Origin Insertion Action Innervation

Biceps brachii Scapula Radius Flex and supinate forearm Muculocutaneous nerve

Bracialis Humerus Ulna Flex forearm

Pronator Teres Humerus and proximal ulna Radius Pronates forearm Median nerve

Brachioradialis Humerus Radius Flexes forearm Radial nerve

Posterior Extensor Compartment

All are innervated by the radial nerve

Muscle Origin Insertion Action Innervation

Triceps brachii Long head Scapula Lateral head Humerus Ulna Extends forearm at elbow Radial nerve

Medial head Humerus

Supinator Humerus and ulna Radius Supinates forearm

Muscles Acting on the Wrist and Hand

Anterior Flexor Compartment

Muscle Origin Insertion Action Innervation

Palmaris longus Medial epicondyle of the humerus Palmar aponeurosis Flex wrist Median nerve

Flexor carpi ulnaris Medial epicondyle of the humerus and ulna Fifth metacarpal and pisiform and hammate Flex wrist, adducts hand Ulnar nerve

Flexor carpi radialis Medial epicondyle of the humerus Second and third metacarpal Flex wrist, abducts hand Median nerve

Flexor digitorum superficialis Medial epicondyle of the humerus, ulna, and radius Phalanges of fingers 2-5 Flexes wrist and middle phlanges of fingers 2-5 Median nerve

Flexor digitorum profundus Ulna Phalanges of fingers 2-5 Flexes distal and proximal interphalangeqal joint, metacarpophalangeal joint, and wrist Median (lateral half) and ulnar (medial half) nerves

Flexor pollicis longus Radius Thumb Flexes distal phalanx of the thumb Median nerve

Posterior Extensor Compartment

All are innervated by the radial nerve

Muscle Origin Insertion Action Innervation

Extensor carpi radialis longus Second metacarpal Extends and abducts wrist

Extensor carpi radialis brevis Third metacarpal Extends and abducts wrist Lateral epicondyle of the humerus Radial nerve

Extensor carpi ulnaris Fifth metacarpal Extends and adducts wrist

Extensor digitorum Phalanges of fingers 2-5 Prime mover of finger extension, extends wrist

Muscles of the Anterior and Lateral Abdominal Wall

• All are innervated by intercostal nerves

Muscle Origin Insertion Action Innervation

External abdominal oblique Lower 8 ribs Linea alba Rotates vertebral column and compresses abdominal contents

Internal abdominal oblique Iliac crest Linea alba Rotates vertebral column and compresses abdominal contents Intercostal nerves

Rectus abdominus Pubis Xiphoid process and ribs Flexes vertebral column and compresses abdominal contents

Transversus abdominus Last 6 ribs and iliac crest Linea alba Compresses abdominal contents

Hip Flexors

Anterior Compartment Hip Flexors

All are innervated by the femoral nerve

Muscle Origin Insertion Action Innervation

Iliacus Ilium Femur Flexes thigh

Psoas Lumbar vertebrae Femur Flexes thigh

Rectus femoris Ilium Tibia Flexes thigh (and extends knee) Femoral nerve

Sartorius Ilium Tibia Flexes, abducts, and laterally rotates the thigh ("tailor's muscle")

Pectineus Pubis Femur Flexes, adducts and medially rotates thigh

Hip Extensors

Posterior Compartment Hip Extensors

• All are innervated by the sciatic nerve (except for gluteus maximus)
• Have an origin on the ischial tuberosity (except for the gluteus maximus)

Semimembranosus, semitendinosus, and biceps femoris are collectively known as the hamstrings

Muscle Origin Insertion Action Innervation

Gluteus maximus Ilium and sacrum Gluteal tuberosity of the femur Extends, abducts and laterally rotates thigh Inferior gluteal nerve

Semitendinosus Tibia

Semimembranosus Ischial tuberosity Tibia Extends thigh; flexes knee Sciatic nerve

Biceps femoris Fibula8

Hip Adductors

Medial Compartment Hip Adductors

• All are innervated by the obturator nerve (except for the pectinius)
• Have an origin on the ishium and/or pubis
• Insert onto the medial aspect of the femur (except for the gracilis)

Muscle Origin Insertion Action Innervation

Adductor magnus Ischiopubic ramus Femur Adducts, flexes, and medially rotates thigh

Adductor longus Pubis Femur Adducts, flexes, and medially rotates thigh Obturator nerve

Adductor brevis Pubis Femur Adducts, flexes, and medially rotates thigh

Pectineus Pubis Femur Adducts, flexes, and medially rotates thigh Femoral nerve

Gracilis Ischiopubic ramus Tibia Adducts, flexes, and medially rotates thigh; flexes knee Obturator nerve

Hip Abductors

Lateral Compartment Hip Abductors

• All are innervated by the superior gluteal nerve
• Have an origin on the ilium
• Insert onto the greater trochanter of the femur (except for the tensor fasciae latae)

Muscle Origin Insertion Action Innervation

Gluteus medius Femur Abducts and aids in medial rotation of the thigh

Gluteus minimus Ilium Superior gluteal nerve

Tensor fasciae latae Iliotibial tract Abducts, flexes, and aids in medial rotation of the thigh

Extensors of the Knee

Anterior Compartment Extensors of the Knee

• All are innervated by the femoral nerve
• Insert onto the tibial tuberosity
• All four muscles are collectively known as the the quadriceps femoris

Muscle Origin Insertion Action Innervation

Rectus femoris* Ilium

Vastus lateralis Tibial tuberosity Extends knee (rectus femoris also flexes thigh) Femoral nerve

Vastus intermedius Proximal femur

Vastus medialis Femur