1 Openings in the Base of the Skull and the structures that pass through them Openings in the Skull Bone of the Skull Structures Transmitted Anterior Cranial Fossa Perforations in the Cribriform plate Ethmoid Olfactory nerves Middle Cranial Fossa Optic Canal Lesser wing of the Sphenoid Optic nerve, ophthalmic artery Superior Orbital Fissure Between lesser and greater wings of the Sphenoid Lacrimal, frontal, trochlear, oculomotor, nasociliary and abducent nerves; superior ophthalmic vein Foramen Rotundum Greater wing of the Sphenoid Maxillary Division of the Trigeminal Nerve Foramen Ovale Greater wing of the Sphenoid Mandibular division of the Trigeminal Nerve Foramen Spinosum Greater wing of the Sphenoid Middle meningeal artery Foramen Lacerum Between petrous part of temporal and Sphenoid Internal carotid artery Posterior Cranial Fossa Foramen Magnum Occipital Medulla Oblongata, spinal part of accessory nerve, and right and left vertebral arteries Hypoglossal Canal Occipital Hypoglossal nerve Jugular Foramen Between petrous part of temporal and condylar part of occipital Glossopharyngeal, vagus, and accessory nerves; sigmoid sinus becomes internal jugular vein Internal Acoustic Meatus Petrous part of temporal Vestibulocochlear and facial nerves Muscles of the Eyeball and Eyelids Muscle Origin Insertion Innervation Action Extrinsic Muscles of Eyeball (Striated Skeletal Muscle) Superior Rectus Tendinous ring on posterior wall of orbital cavity Superior surface of eyeball just posterior to corneoscleral junction CNIII Inferior Rectus Tendinous ring on posterior wall of orbital cavity Inferior surface of eyeball just posterior to corneoscleral junction CNIII Raises cornea upward and medially Depresses cornea downward and medially Medial Rectus Tendinous ring on posterior wall of orbital cavity Medial surface of eyeball just posterior to corneoscleral junction CNIII Rotates eyeball so that cornea looks medially Lateral Rectus Tendinous ring on posterior wall of orbital cavity Lateral surface of eyeball just posterior to corneoscleral junction CNVI Rotates eyeball so that cornea looks laterally Superior Oblique Posterior wall of orbital cavity Passes through pulley and is attached to superior surface of eyeball beneath superior rectus CNIV Rotates eyeball so that cornea looks downward and laterally Lateral surface of eyeball deep to lateral rectus CNIII Rotates eyeball so that cornea looks upward and laterally Inferior Oblique Floor of orbital cavity Intrinsic Muscles of Eyeball (Smooth Muscle) Sphincter Pupillae Parasympathetic via of Iris CNIII Dilatory Pupillae of Iris Sympathetic Constricts pupil 2 Dilates pupil Ciliary Muscle Parasympathetic via CNIII Controls shape of lens; in accommodation, makes lens more globular Facial nerve Closes eyelids and dilates lacrimal sac Facial nerve Throws skin around orbit into folds to protect eyeball Striated muscle oculomotor nerve, smooth muscle Raises upper lid Muscles of Eyelids Orbicularis Oculi ✔ Palpebral Part Medial palpebral ligament ✔ Orbital Part Medial palpebral ligament and adjoining bone Levator Palpebrae Superioris Back of orbital cavity Lateral palpebral raphe Loops return to origin Anterior surface and upper margin of superior tarsal plate Sympathetic Muscles of the Head Muscle Origin Insertion Innervation Action Muscle of Scalp Occipitofrontalis ✔ Occipital belly ✔ Frontal belly Highest nuchal line of occipital bone Epicranial aponeurosis Facial nerve Moves scalp on skull and raises eyebrows Skin and superficial facia of eyebrows Muscles of Facial Expression Orbicularis Oculi ✔ Palpebral Part Medial palpebral ligament ✔ Orbital Part Medial palpebral ligament and adjoining bone Lateral palpebral raphe Loops return to origin Facial nerve Closes eyelids and dilates lacrimal sac Facial nerve Throws skin around orbit into folds to protect eyeball Corrugator Supercilii Superciliary arch Skin of eyebrow Facial nerve Vertical wrinkles of forehead, as in frowning Compressor Nasi Frontal process of maxilla Aponeurosis of bridge of nose Facial nerve Compresses mobile nasal cartilages Dilator Naris Maxilla Ala of nose Facial nerve Widens nasal aperture Procerus Nasal bone Skin between eyebrows Facial nerve Orbicularis Oris Maxilla, mandible and skin Encircles oral orifice Facial nerve Compresses lips together Facial nerve Separate lips Wrinkles skin of nose Dilator Muscles of Lips Levator Labii Superioris Alaeque Nasi Levator Labii Superioris Zygomaticus Minor Zygomaticus Major Levator Anguli Oris Risorius Arise from bones and fascia around oral aperture and insert into substance of lips Depressor Anguli Oris Depressor Labii Inferioris Mentalis Buccinator Outer surface of alveolar margins of maxilla, Facial nerve mandible and pterygomandibular ligament Platysma Deep fascia over pectoralis major and deltoid Body of mandible and angle of mouth Compresses cheeks and lips against teeth Facial nerve cervical branch 3 Depresse s mandible and angle of mouth Muscles of Mastication Masseter Zygomatic arch Lateral surface ramus of mandible Mandibular division of trigeminal nerve Elevates mandible to occlude teeth Temporalis Floor of temporal fossa Coronoid process of mandible Mandibular division of trigeminal nerve Anterior and superior fibers elevate mandible; posterior fibers retract mandible Lateral Pterygoid (two heads) Greater wing of sphenoid and lateral pterygoid plate Neck of mandible and articular sac Mandibular division of trigeminal nerve Pulls neck of mandible forward Medial Pterygoid (two heads) Tuberosity of maxilla and lateral pterygoid plate Medial surface of angle of mandible Mandibular division of trigeminal nerve Elevates mandible Muscles of Tongue Muscle Origin Insertion Innervation Action Intrinsic Muscles Longitudinal Median septum and submucosa Mucous membrane Transverse Vertical Extrinsic Muscles CNXII Alters shape of tongue Genioglossus Superior genial spine of mandible Blends with other muscles of tongue CNXII Protrudes apex of tongue through mouth Hyoglossus Body of greater cornu of hyoid bone Blends with other muscles of tongue CNXII Depresses tongue Styloglossus Styloid process of temporal bone Blends with other muscles of tongue CNXII Draws tongue upward and backward Side of tongue Pharyngeal plexus Pulls roots of tongue upward and backward, narrows oropharyngeal isthmus Palatoglossus Palatine aponeurosis Muscles of the Neck Muscle Origin Insertion Innervation Action Platysma Deep fascia over pectoralis major and deltoid Body of mandible and angle of mouth Facial nerve cervical branch Depresses mandible and angle of mouth SCM Manubrium sterni and medial third of the clavicle Mastoid process of temporal bone and occipital bone Spinal part of accessory nerve and C2 and C3 Two muscles acting together extend head and flex neck; one muscle rotates head to opposite side ✔ Posterior belly Mastoid process of temporal bone Intermediate tendon is held to hyoid by fascial sling Facial nerve Depresses mandible or elevates hyoid bone ✔ Anterior belly Body of mandible Digastric Nerve to mylohyoid Stylohyoid Styloid process Body of hyoid bone Facial nerve Elevates hyoid bone Mylohyoid Mylohyoid line of body of mandible Body of hyoid bone and fibrous raphe Inferior alveolar nerve Elevates floor of mouth and hyoid bone or depresses mandible Geniohyoid Inferior mental spine of mandible Body of hyoid bone First cervical nerve 4 Elevates hyoid bone or depresses mandible Sternohyoid Manubrium sterni and clavicle Body of Hyoid bone Ansa cervicalis; C1, 2 & 3 Depresses hyoid bone Sternothyroid Manubrium sterni Oblique line on lamina of thyroid cartilage Ansa cervicalis; C1, 2 & 3 Depresses larynx Thyrohyoid Oblique line on lamina of thyroid cartilage Lower border of body of hyoid bone First cervical nerve Depresses hyoid bone or elevates larynx ✔ Inferior belly Upper margin of scapula and suprascapular ligament Intermediate tendon is held to clavicle and first rib by fascial sling Ansa cervicalis; C1, 2 & 3 Depresses hyoid bone ✔ Superior belly Lower border of body of hyoid bone Scalenius Anterior Transverse processes of 3rd, 4th 5th and 6th cervical vertebrae First rib C4, 5 & 6 Elevates first rib; laterally flexes and rotates cervical part of vertebral column Scalenius Medius Transverse processes of upper six cervical vertebrae First rib Anterior rami of cervical nerves Elevates first rib; laterally flexes and rotates cervical part of vertebral column Scalenius Posterior Transverse process of lower cervical vertebrae Second rib Anterior rami of cervical nerves Elevates second rib; laterally flexes and rotates cervical part of vertebral column Omohyoid Cranial Nerves Nerve Components Function Opening in Skull Olfactory Sensory Smell Openings in cribriform plate of ethmoid Optic Sensory Vision Optic canal Oculomotor Motor Lifts upper eyelid, turns eyeball upward, downward and medially; constricts pupil; accommodates eye Superior Orbital Fissure Trochlear Motor Assists in turning eyeball downward and laterally Superior Orbital fissure Trigeminal ✔ Ophthalmic division Sensory Cornea, skin of forehead, scalp, eyelids and nose; also mucous membrane of paranasal sinuses and nasal cavity Superior Orbital Fissure ✔ Maxillary division Sensory Skin of face over maxilla and the upper lip; teeth of upper jaw; mucous membrane of nose, the maxillary air sinus, and palate Foramen Rotundum ✔ Mandibular division Motor Sensory Muscles of mastication, mylohyoid, anterior belly of digastrics, tensor veli palatini and tensor tympani Foramen Ovale Skin of cheek, skin over mandible, lower lip and side of head; teeth of lower jaw and temporomandibular joint; mucous membrane of mouth and anterior two thirds of tongue 5 Abducent Motor Lateral rectus muscle: turns eyeball laterally Superior orbital fissure Facial Motor Muscles of face, cheek and scalp; stapedius muscle of middle ear; stylohyoid; and posterior belly of digastrics Internal acoustic meatus, facial canal stylomastoid foramen Sensory Taste from anterior two thirds of tongue, floor of mouth and palate Secretomotor parasympathetic Submandibular and sublingual salivary glands, lacrimal gland and glands of nose and palate ✔ Vestibular Sensory Position and movement of head ✔ Cochlear Sensory Hearing Motor Stylopharyngeus muscle; assists Vestibulocochlear Glossopharyngeal Internal acoustic meatus Jugular Foramen swallowing Secretomotor parasympathetic Parotid salivary gland Sensory General sensation and taste from posterior third of tongue and pharynx; carotid sinus and carotid body Motor Constrictor muscles of phaynx and intrinsic muscles of larynx; involuntary muscle of trachea and bronchi, heart, alimentary tract from pharynx to splenix flexure of colon; liver and pancreas Sensory Taste from epiglottis and vallecula and afferent fibers from structures named above ✔ Cranial root Motor Muscles of soft palate, pharynx and larynx ✔ Spinal root Motor Sternocleidomastoid and trapezius muscles Motor Muscles of tongue controlling its shape and movement (except palatoglossus) Vagus Jugular Foramen Accessory Hypoglossal Jugular Foramen Hypoglossal Canal 6 Muscles Connecting the Upper Limb to the Thoracic Wall/ Muscles of the Pectoral Region (except Serratus Anterior) Muscle Origin Insertion Innervation Action Pectoralis Major Clavicle, sternum and upper six costal cartilages Lateral lip of the bicipital groove of humerus Medial and lateral pectoral nerves form brachial plexus Adducts arm and rotates it medially; clavicular fibers also flex arm Pectoralis Minor 3rd, 4th and 5th ribs Coracoid process of scapula Medial pectoral nerve from brachial plexus Depresses point of shoulder; if the scapula is fixed, it elevates the ribs of origin Subclavius First costal cartilage Clavicle Nerve to subclavius from upper trunk of brachial plexus Depresses the clavicle and steadies this bone during movements of the shoulder girdle Serratus Anterior Upper eight ribs Medial border and inferior angle of the scapula Long thoracic nerve Draws the scapula forward around the thoracic wall; rotates the scapula Muscles Connecting the Upper limb to the Vertebral Column/ Superficial (Appendicular) Group of Back Muscles Muscle Origin Insertion Innervation Spinal part of accessory nerve (motor) and C3 and C4 (sensory) Action Trapezius Occipital bone, ligamentum nuchae, spine of 7th cervical vertebra, spines of all thoracic vertebra Upper fibers into lateral third of clavicle; middle and lower fibers into acromion and spine of the scapula Upper fibers elevate the scapula; middle fibers pull the scapula medially; lower fibers pull medial border of the scapula downward Latissimus Dorsi Iliac crest, lumbar fascia, spines of lower six thoracic vertebrae, lower three or four ribs, and inferior angle of the scapula Floor of bicipital groove of humerus Thoracodorsal nerve Extends, adducts and medially rotates the arm Levator Scapulae Transverse processes of first four cervical vertebrae Medial border of the scapula C3 and C4 and dorsal scapular nerve Raises medial border of the scapula Rhomboid Minor Ligamentum nuchae and spines of 7th cervical vertebra and 1st thoracic vertebra Medial border of the scapula Dorsal scapular nerve Raises medial border of scapula upward and medially Rhomboid Major 2nd to 5th thoracic spines Medial border of scapula Dorsal scapular nerve Raises medial border of scapula upward and medially Muscles Connecting the Scapula to the Humerus Muscle Origin Insertion Innervation Action Deltoid Lateral third of clavicle, acromion, spine of scapula Middle of lateral surface of shaft of humerus Axillary nerve Abducts arm; anterior fibers flex and medially rotate arm; posterior fibers extend and laterally rotate arm Supraspinatus Supraspinous fossa of scapula Greater tuberosity of humerus; capsule of shoulder joint Spurascapular nerve 7 Abducts arm and stabilizes shoulder joint Infraspinatus Infraspinous fossa Greater tuberosity of humerus; capsule of shoulder joint Suprascapular nerve Laterally rotates arm and stabilizes shoulder joint Teres Major Lower third of lateral border of scapula Medial lip of bicipital groove of humerus Lower subscapular nerve Medially rotates and adducts arm and stabilizes shoulder joint Teres Minor Upper two thirds of lateral border of the scapula Greater tuberosity of the humerus; capsule of shoulder joint Axillary nerve Laterally rotates arm stabilizes shoulder joint Subscapularis Subscapular fossa Lesser tuberosity of humerus Upper and lower subscapular nerves Medially rotates arm and stabilizes shoulder joint Muscles of the Arm Muscle Origin Insertion Innervation Action Anterior Compartment Biceps Brachii ✔ Long head Supraglenoid tubercle of scapula ✔ Short head Coracoid process of scapula Coracobrachialis Coracoid process of scapula Tuberosity of radius and bicipital aponeurosis into deep fascia of forearm Musculocutaneo us nerve Supinator of forearm and flexor of elbow joint; weak flexor of shoulder joint Medial aspect of shaft of humerus Musculocutaneo us nerve Flexes arm and also weak adductor Brachialis Front of lower half of humerus Coronoid process of ulna Musculocutaneo us nerve Flexor of elbow joint Radial nerve Extensor of elbow joint Posterior Compartment Triceps ✔ Long head Infraglenoid tubercle of scapula ✔ Lateral head Upper half of posterior surface of shaft of humerus ✔ Medial head Lower half of posterior surface of shaft of humerus Olecranon process of ulna Muscles of the Anterior Fascial Compartment of the Forearm Muscle Origin Insertion Innervation Action Medial epicondyle of humerus Lateral aspect of the shaft of radius Median nerve Pronation and flexion of forearm Pronator Teres ✔ Humeral head ✔ Ulnar head Medial border of coronoid process of ulna Flexor Carpi Radialis Medial epicondyle of humerus Bases of 2nd and 3rd metacarpal bones Median nerve Flexes and abducts hand at wrist joint Palmaris Longus Medial epicondyle of humerus Flexor retinaculum and palmar aponeurosis Median nerve Flexes hand Medial epicondyle of humerus Pisiform bone, hook of the hamate, base at 5th metacarpal bone Ulnar nerve Flexes and adducts hand at wrist joint Flexor Carpi Ulnaris ✔ Humeral head ✔ Ulnar head Medial aspect of olecranon process and posterior border of ulna Flexor Digitorum Superficialis 8 ✔ Humeroulnar head ✔ Radial head Medial epicondyle of humerus; medial border of coronoid process of ulna Middle phalanx of medial four fingers Median nerve Flexes middle phalanx of fingers and assists in flexing proximal phalanx and hand Oblique line on anterior surface of shaft of radius Flexor Pollicis Longus Anterior surface of shaft of radius Distal phalanx of thumb Anterior interosseus branch of median nerve Flexes distal phalanx of thumb Flexor Digitorum Profundus Anteromedial surface of shaft of ulna Distal phalanges of medial four fingers Ulnar (medial half) and median (lateral half) nerves Flexes distal phalanx of fingers; then assists in flexion of middle and proximal phalanges and wrist Anterior surface of shaft of ulna Anterior surface of shaft or radius Anterior interosseus branch of median nerve Pronates forearm Pronator Quadratus Muscles of the Lateral Fascial Compartment of the Forearm Muscle Origin Insertion Innervation Action Brachioradialis Lateral supracondylar ridge of humerus Base of styloid process of radius Radial nerve Flexes forearm at elbow joint; rotates forearm to the midprone position Extensor Carpi Radialis Longus Lateral supracondylar ridge pf the humerus Posterior surface of base of 2nd metacarpal bone Radial nerve Extends and abducts hand at wrist joint Muscles of the Posterior Fascial Compartment of the Forearm Muscle Extensor Carpi Radialis Brevis Extensor Digitorum Extensor Digiti Minimi Origin Insertion Innervation Action Lateral epicondyle of humerus Posterior surface of base of third metacarpal bone Deep branch of radial nerve Extends and abducts hand at wrist joint Lateral epicondyle of humerus Middle and distal phalanges of medial four fingers Deep branch of radial nerve Extends fingers and hand Lateral epicondyle of humerus Extensor expansion of little finger Deep branch of radial nerve Extends metacarpophalang eal joint of little finger Extensor Carpi Ulnaris Lateral epicondyle of humerus Base of fifth metacarpal bone Deep branch of radial nerve Extends and adducts hand at wrist joint Anconeus Lateral epicondyle of humerus Lateral surface of olecranon process of ulna Radial nerve Extends elbow joint Supinator Lateral epicondyle of humerus Neck and shaft of radius Deep branch of radial nerve Supination of forearm Abductor Pollicis Longus Posterior surface of shaft of radius and ulna Base of first metacarpal bone Deep branch of radial nerve Extends and abducts thumb Extensor Pollicis Brevis Posterior surface of shaft or radius Base of proximal phalanx of thumb Deep branch of radial nerve Extends metacarpophalang eal joint of thumb Extensor Pollicis Longus Posterior surface of shaft of ulna Base of distal phalanx of thumb Deep branch of radial nerve Extends distal phalanx of thumb Extensor Indicis Posterior surface of shaft of ulna Extensor expansion of index finger Deep branch of radial nerve Extends metacarpophalang eal joint of index finger 9 Small Muscles of the Hand Muscle Origin Insertion Innervation Action Palmaris Brevis Flexor retinaculum, palmar aponeurosis Skin of palm Superficial branch of ulnar nerve Corrugates skin to improve grip of palm Lumbricals (4) Tendons of flexor digitorum profundus Extensor expansion of medial four fingers 1st and 2nd (i.e. lateral two) median nerve; 3rd and 4th deep branch of ulnar nerve Flexes metacarpophalange al joints and extend interphalangeal joints of fingers except thumb First arises from base of 1st metacarpal; remaining three from anterior surface of shafts of 2nd, 4th and 5th metacarpals Proximal phalanges of thumb and index, ring and little fingers and dorsal extensor expansion of each finger Deep branch of ulnar nerve Palmar interossei adduct fingers toward center of third finger Interossei (8) ✔ Palmar (4) ✔ Dorsal (4) Contiguous sidesof shafts of metacarpal bones Proximal phalanges of index, middle and ring fingers and dorsal extensor expansion Deep branch of ulnar nerve Dorsal interossei abduct fingers from center of third finger; both palmar and dorsal flex metacarpophalange al joints and extend interphalangeal joints Short Muscles of Thumb (Thenar Muscles; pollicis- thumb) Abductor Pollicis Brevis Scaphoid, trapezium, flexor retinaculum Base of proximal phalanx of thumb Median nerve Abduction of thumb Flexor Pollicis Brevis Flexor retinaculum Base of proximal phalanx of thumb Median nerve Flexes metacarpophalange al joint of thumb Opponens Pollicis Flexor retinaculum Shaft of metacarpal bone of thumb Median nerve Pulls thumb medially and forward across palm Adductor Pollicis Oblique head; 2nd and 3rd metacarpal bones; transverse head; 3rd metacarpal bone Base of proximal phalanx of thumb Deep branch of ulnar nerve Adduction of thumb Short Muscles of Little Finger (Hypothenar Muscles; digiti minimi- 5th digit) Abductor Digiti Minimi Pisiform bone Base of proximal phalanx of little finger Deep branch of ulnar nerve Abducts little finger Flexor Digiti Minimi Flexor retinaculum Base of proximal phalanx of little finger Deep branch of ulnar nerve Flexes little finger Opponens Digiti Minimi Flexor retinaculum Medial border of 5th metacarpal bone Deep branch of ulnar nerve Pulls 5th metacarpal forward as in cupping the palm Summary of the Branches of the Brachial Plexus and their Distribution Branches Distribution Roots Dorsal Scapular Nerve (C5) Rhomboid minor, rhomboid major, levator scapulae Long Thoracic Nerve (C5, 6, 7) Serratus anterior Upper Trunk Suprascapular Nerve (C5, 6) Supraspinatus and infraspinatus Nerve to Subclavius (C5, 6) Subclavius Lateral Cord Lateral Pectoral Nerve (C5, 6, 7) Pectoralis major Musculocutaneous Nerve (C5, 6, 7) Coracobrachialis, biceps brachii, brachialis; supplies skin along lateral border of forearm when it becomes the lateral cutaneous nerve of the forearm Lateral root of Median Nerve (C5, 6, 7) 10 (See medial root of median nerve) Posterior Cord Upper Subscapular Nerve (C5, 6) Subscapularis Thoracodorsal Nerve (C6, 7, 8) Latissimus dorsi Lower Subscapular Nerve (C5, 6) Subscapularis and teres major Axillary Nerve (C5, 6) Deltoid and teres minor; upper and lateral cutaneous nerve of arm supplies skin over lower half of deltoid muscle Radial Nerve (C5, 6, 7, 8; T1) Triceps, anconeus, part of brachialis, ECRL; via deep radial nerve branch supplies extensor muscles of forearm: supinator, ECRB, ECU, ED, EDM, EI, AbPL, EPL, EPB; skin, lower lateral cutaneous nerve of arm, posterior cutaneous nerve of arm, and posterior cutaneous nerve of forearm; skin on lateral side of dorsum of hand and dorsal surface of lateral three and a half of fingers; articular branches to elbow, wrist and hand Medial Cord Medial Pectoral Nerve (C8; T1) Pectoralis major and pectoralis minor Medial Cutaneous Nerve of arm joined by intercostals brachial nerve from second intercostals nerve (C8; T1, 2) Skin of medial side of arm Medial Cutaneous Nerve of forearm (C8; T1) Skin of medial side of forearm Ulnar Nerve (C8; T1) FCU and medial half of FDP, FDM, ODM, AbDM, AdP, 3rd and 4th lumbricals, interossei, PB, skin of medial half of dorsum of hand and palm, skin of palmar and dorsal surfaces of medial one and a half fingers Medial root of Median Nerve (with lateral root) forms Median Nerve (C5, 6, 7, 8; T1) PT, FCR, PL, FDS, AbPB, FPB, OP, first two lumbricals (by way of anterior interosseus branch), FPL, FDP (lateral half), PQ, palmar cutaneous branch to lateral half of palm and digital branches to palmar surface of lateral three and a half fingers; articular branches to elbow, wrist and carpal joints 11 Muscles of the Gluteal Region Muscle Origin Insertion Nerve Supply Action Gluteus maximus Outer surface of ilium, sacrum, coccyx, sacrotuberous ligament Iliotibial tract and gluteal tuberosity of femur al nerve Extends and laterally oint; through iliotibial tract, it extends knee joint Gluteus medius Outer surface of ilium Lateral surface of greater trochanter of femur Superior gluteal nerve Abducts thigh at hip joint; tilts pelvis when walking to permit opposite leg to clear ground Gluteus minimus Outer surface of ilium Anterior surface of greater trochanter of femur Superior gluteal nerve Abducts thigh at hip joint; tilts pelvis when walking to permit opposite leg to clear ground Tensor fasciae latae Iliac crest Iliotibial tract Superior gluteal nerve Assists gluteus maximus in extending the knee joint Piriformis Anterior surface of sacrum Upper border of greater trochanter of femur First and second sacral nerves Lateral rotator of thigh at hip joint Obturator internus Inner surface of obturator membrane Upper border of greater trochanter of femur Sacral plexus Lateral rotator of thigh at hip joint Gemellus superior Spine of ischium Upper border of greater trochanter of femur Sacral plexus Lateral rotator of thigh at hip joint Gemellus inferior Ischial tuberosity Upper border of greater trochanter of femur Sacral plexus Lateral rotator of thigh at hip joint Quadratus femoris Lateral border of ischial tuberosity Quadrate tubercle of femur Sacral plexus Lateral rotator of thigh at hip joint Muscles of the Anterior Fascial Compartment of the Thigh Muscle Origin Insertion Nerve Supply Action Sartorius Anterior superior iliac spine Upper medial surface of shaft of tibia Femoral nerve Flexes, abducts, laterally rotates thigh at hip joint; flexes and medially rotates leg at knee joint Iliacus Iliac fossa of hip bone With psoas into lesser trochanter of femur Femoral nerve Flexes thigh on trunk; if thigh is fixed, it flexes the trunk on the thigh as in sitting up from lying down Psoas Transverse processes, bodies, and intervertebral discs of the 12th thoracic and five lumbar vertebrae With iliacus into lesser trochanter of femur Lumbar plexus Flexes thigh on trunk; if thigh is fixed, it flexes the trunk on thigh as in sitting up from lying down Pectineus Superior ramus of pubi aspera of shaft of femur Femoral nerve Flexes and adducts thigh at hip joint Quadrice ps femoris Rectus femoris Straight head: anterior inferior iliac spine Reflected head: ilium above acetabulum Quadriceps tendon into patella, then via ligamentum patellae into tubercle of tibia Femoral nerve Extension of leg at knee joint; flexes thigh at hip joint Vastus lateralis Upper end and shaft of femur Quadriceps tendon into patella, then via ligamentum patellae into tubercle of tibia Femoral nerve Extension of leg at knee joint Vastus medialis Upper end and shaft of femur Quadriceps tendon into patella, then via ligamentum patellae into Femoral nerve Extension of leg at knee joint; stabilizes patella tubercle of tibia Anterior and lateral surfaces of shaft of femur Quadriceps tendon into patella, then via ligamentum patellae into tubercle of tibia Femoral nerve 12 Extension of Vastus leg at knee joint intermedius articularis genus retracts synovial membrane Muscles of the Medial Fascial Compartment of the Thigh Muscle Origin Insertion Nerve Supply Action Gracilis Inferior ramus of pubis, ramus of ischium Upper part of shaft of tibia on medial surface Obturator nerve Adducts thigh at hip joint; flexes leg at knee joint Adductor longus Body of pubis, medial to pubic tubercle Posterior surface of shaft of femur (linea aspera) Obturator nerve Adducts thigh at hip joint and assists in lateral rotation Adductor brevis Inferior ramus of pubis Posterior surface of shaft of femur (linea aspera) Obturator nerve Adducts thigh at hip joint and assists in lateral rotation Adductor magnus Inferior ramus of pubis, ramus of ischium, ischial tuberosity Posterior surface of shaft of femur, adductor tubercle of femur Adductor portion: obturator nerve Hamstring portion: sciatic nerve Adducts thigh at hip joint and assists in lateral rotation; hamstring portion extends thigh at hip joint Obturator externus Outer surface of obturator membrane and pubic and ischial rami Medial surface of greater trochanter Obturator nerve Laterally rotates thigh at hip joint Muscles of the Posterior Fascial Compartment of the Thigh Muscle Biceps femoris Origin Long head: ischial tuberosity Insertion Head of fibula Nerve Supply Long head: tibial portion of sciatic nerve Action Flexes and laterally rotates leg at knee joint; long head also extends thigh at hip joint Short head: linea aspera, lateral supracondylar ridge of shaft of femur Short head: common peroneal portion of sciatic nerve Semitendinosus Ischial tuberosity Upper part of medial surface of shaft of tibia Tibial portion of sciatic nerve Flexes and medially rotates leg at knee joint; extends thigh at hip joint Semimembranos us Ischial tuberosity Medial condyle of tibia Tibial portion of sciatic nerve Flexes and medially rotates leg at knee joint; extends thigh at hip joint Adductor magnus (hamstring portion) Ischial tuberosity Adductor tubercle of femur Tibial portion of sciatic nerve Extends thigh at hip joint Muscles of the Anterior Fascial Compartment of the Leg Muscle Origin Insertion Nerve Supply Action Tibialis anterior Lateral surface of shaft of tibia and interosseous membrane Medial cuneiform and base of first metatarsal bone Deep peroneal nerve Extendsb foot at ankle joint; inverts foot at subtalar and transverse tarsal joints; holds up medial longitudinall arch of foot Extensor digitorum longus Anterior surface of shaft of fibula Extensor expansion of lateral four toes Deep peroneal nerve Extends toes; extends foot at ankle joint Peroneus tertius Anterior surface of shaft of fibula Base of fifth metatarsal bone Deep peroneal nerve Extends foot at ankle joint; everts foot at subtalar and transverse tarsal joints Extensor hallucis Anterior surface of shaft of fibula Base of distal phalanx of great toe Deep peroneal nerve Extends big toe; extends foot at ankle joint; inverts foot at longus Extensor digitorum brevis subtalar and transverse tarsal joints Calcaneum By four tendons into the proximal phalanx of big toe and long extensor tendons to second, third, and fourth toes Deep peroneal nerve 13 Muscles of the Lateral Fascial Compartment of the Leg Muscle Origin Insertion Nerve Supply Action Peroneus longus Peroneus brevis shaft of fibula Lateral surface of shaft of fibula Base of first metatarsal and the medial cuneiform Lateral surface of fibu bone Superficial peroneal nerve Plantar flexes foot at ankle joint; everts foot at subtalar and transverse tarsal joints; supports lateral longitudinal and transverse arches of foot Superficial peroneal nerve Plantar flexes foot at ankle joint; everts foot at subtalar and transverse tarsal joint; supports lateral longitudinal arch of foot Muscles of the Posterior Fascial Compartment of the Leg Muscle Origin Insertion Nerve Supply Action Superficial Group Gastrocnemi us Lateral head from lateral condyle of femur and medial head from above medial condyle Via tendo calcaneus into posterior surface of calcaneum Tibial nerve Plantar flexes foot at ankle joint; flexes knee joint Plantaris Lateral supracondylar ridge of femur Posterior surface of calcaneum Tibial nerve Plantar flexes foot at ankle joint; flexes knee joint Soleus Shafts of tibia and fibula Via tendo calcaneus into posterior surface of calcaneum Tibial nerve Together with gastrocnemius and plantaris is powerful plantar flexor of ankle joint; provides main propulsive force in walking and running Deep Group Popliteus Lateral surface of lateral condyle of femur Posterior surface of shaft of tibia above soleal line Tibial nerve Flexes leg at knee joint; unlocks knee joint by lateral rotation of femur on tibia and slackens ligaments of joint Flexor digitorum longus Posterior surface of shaft of tibia Bases of distal phalanges of lateral four toes Tibial nerve Flexes distal phalanges of lateral four toes; plantar flexes foot at ankle joint; supports medial and lateral longitudinal arches of foot Flexor hallucis longus Posterior surface of shaft of fibula Base of distal phalanx of big toe Tibial nerve Flexes distal phalanx of big toe; plantar flexes foot at ankle joint; supports medial longitudinal arch of foot Tibialis posterior Posterior surface of shafts of tibia and fibula and interosseous membrane Tuberosity of navicular bone and other neighboring bones Tibial nerve Plantar flexes foot at ankle joint; inverts foot at subtalar and transverse tarsal joints; supports medial longitudinal arch of foot Muscles of the Sole of the Foot Muscle Origin Insertion Nerve Supply Action First Layer Abductor Medial tuberosity of Base of proximal hallucis calcaneum and flexor retinaculum phalanx of big toe Flexor digitorum brevis Medial tubercle of calcaneum Four tendons to four lateral toes— inserted into borders of middle phalanx; tendons perforated by those of flexor digitorum longus nerve Flexes and abducts big braces medial longitudinal arch 4 Medial plantar nerve our toes; braces medial and lateral longitudinal arches Abductor digiti minimi Medial and lateral tubercles of calcaneum Base of proximal phalanx of fifth toe nerve Flexes and abducts fifth toe; braces lateral longitudinal arch Second Layer Quadratus plantae Medial and lateral sides of calcaneum Tendon of flexor digitorum longus Lumbricals (4) Tendons of flexor digitorum longus Dorsal extensor expansion; bases of proximal phalanges of lateral four toes Flexor digitorum longus tendon Flexor hallucis longus tendon Third Layer nerve Assists flexor digitorum longus in flexing lateral four toes First lumbrical: medial plantar nerve; remainder: lateral plantar nerve Extends toes at interphalangeal joints Flexor hallucis brevis Cuboid, lateral cuneiform, tibialis posterior insertion Medial tendon into medial side of base of proximal phalanx of big toe; lateral tendon into lateral side of base of proximal phalanx of big toe Adductor hallucis Oblique head bases of second, third, and fourth metatarsal bones; transverse head from plantar ligaments Lateral side of base of proximal phalanx of big toe Flexor digiti minimi brevis Base of fifth metatarsal bone Lateral side of base of proximal phalanx of little toe l plantar nerve Flexes phalangeal joint of big toe; medial longitudinal arch Deep branch lateral plantar nerve Flexes metatarsophalangeal joint of big toe; holds together metatarsal bones plantar nerve Flexes alangeal joint of little toe Fourth Layer Interossei Dorsal (4) Adjacent sides of metatarsal bones Bases of proximal phalanges first: medial side of second toe; remainder: lateral sides of second, third, and fourth toes also dorsal extensor expansion ar nerve Abduction of toes; arsophalangeal joints and nterphalangeal joints Plantar (3) Inferior surfaces of third, fourth, and fifth metatarsal bones Medial side of bases of proximal phalanges of lateral three toes ar nerve Adduction of toes; arsophalangeal joints and nterphalangeal joints Peroneus longus tendon Tibialis posterior tendon Muscle of the Dorsum of the Foot Muscle Extensor Origin Anterior part of upper Insertion Nerve Supply Action By four tendons Extends toes 15 digitorum brevis surface of the calcaneum and from the inferior extensor retinaculum proximal phalanx of big toe and long extensor tendons to second, third, and fourth toes nerve Branches of the Sacral Plexus and Their Distribution Branches Superior gluteal nerve Gluteus me latae mus Inferior gluteal nerve Gluteus ma Nerve to piriformis Piriformis m Nerve to obturator internus Obturator i Nerve to quadratus femoris Quadratus Perforating cutaneous nerve Skin over m Posterior cutaneous nerve of thigh Skin over p over lower Sciatic nerve (L4, 5; S1, 2, 3) Tibial portion Common peroneal portion Pudendal nerve Ham add plan flex bra on Bic bra digi bre The and of le Mu mu of p Branches of the Lumbar Plexus and Their Distribution Branches Iliohypogastric nerve abdominal Ilioinguinal nerve External ob muscles o aspect of th pubis and l Lateral cutaneous nerve of the thigh Skin of ant Genitofemoral nerve (L1, 2) Cremaster of thigh; ne Femoral nerve (L2, 3, 4) Iliacus, pec intermediat surface of t medial side knee joints Obturator nerve (L2, 3, 4) Gracilis, ad pectineus, medial surf Segmental branches Quadratus Ext mus 16 Muscles Connecting the Upper limb to the Vertebral Column/ Superficial (Appendicular) Group of Back Muscles *Trapezius *Latissimus Dorsi *Levator Scapulae *Rhomboid Major *Rhomboid Minor Intermediate (Respiratory) Group of Back Muscles Muscle Origin Insertion Serratus Posterior Superior Lower portion of ligamentum nuchae, spinous process of C7 to T3 and supraspinous ligaments Upper border of ribs 2 to 5 just lateral to their angles Serratus Posterior Inferior Spinous process of T11 to L3 and supraspinous ligaments Lower border of ribs 9 to 12 just lateral to their angles Innervation Action Anterior rami of upper thoracic nerves (T2 to T5) Elevates ribs 2 to 5 Anterior rami of lower thoracic nerves (T9 to T12) Depresses ribs 9 to 12 and may prevent lower ribs from being elevated when the diaphragm contracts Back Deep Group of Back Muscles SpinoTransversales Muscles Muscle Origin Insertion Innervation Action Splenius Capitis Lower half of ligamentum nuchae, spinous processes of C7 to T4 Mastoid process, skull below lateral 1/3 of superior nuchal line Posterior rami middle cervical nerves Togetherdraw head backwards extending neck; individuallydraw and rotate head to one side (turn face to same side) Spinous processes of T3 to T6 Transverse processes of C1 to C3 Posterior rami middle cervical nerves Togetherextend neck; individually draw and rotate head to one side (turn face to same side) Splenius Cervicis Erector Spinae Group of Back Muscles Muscle Origin Insertion Iliocostalis Lumborum Sacrum, spinous process of lumbar and lower two thoracic vertebrae and their supraspinous ligaments and the iliac crest Angles of the lower 6 or 7 ribs Iliocostalis Thoracis Angles of the lower 6 ribs Angles of the upper 6 ribs and the transverse process of C7 Iliocostalis Cervicis Angles of ribs 3 to 6 Transverse processes of C4 to C6 Longissimus Thoracis Blends with iliocostalis in lumbar region and is attached to transverse processes of lumbar vertebrae Transverse processes of all thoracic vertebrae and just lateral to the tubercles of the lower 9 or 10 ribs Longissimus Cervicis Transverse processes of upper 4 or 5 thoracic vertebrae Transverse processes of C2 to C6 Spinalis Cervicis Longissimus Capitis Spinalis Thoracis Transverse processes of upper 4 or 5 thoracic vertebrae and articular processes of lower three Spinalis Capitis four cervical vertebrae Spinous processes of T1 or T11 to L2 Lower part of ligamentum nuchae and spinous processes of C7 (sometimes T1 to T2) Usually blends with semispinalis capitis Transversospinales Group of Back Muscles Muscle Semispinalis Thoracis vertebrae Origin Transverse processes of to T10 Suboccipital Gorup of Back Muscles Muscle Semispinalis Cervicis Transverse processes of upper 5 or 6 thoracic vertebrae Semispinalis Capitis Transverse processes of to T6 (or T7) and C7 and articular processes of C4 Rectus Capitis C6 Posterior Minor Multifidus Sacrum, origin of erector spinae, PSIS, mammillar processes of lumbar vertebrae, transverse processes of thoracic vertebrae and articular processes of lo four cervical vertebrae Rotatores Lumborum Mammillary processes of lumbar vertebrae Rotatores Thoracis Transverse processes of thoracic vertebrae Rotatores Cervicis Articular processes of cervical vertebrae Rectus Capitis Posterior Major Origin Insertion In Spinous process of axis (C2) Lateral portion of occipital bone below inferior nuchal line Po ram Posterior tubercle of atlas (C1) Medial portion of occipital bone below inferior Po of 17 nuchal line Segmental Back Muscles Muscle Origin Levatores Costarum Short paired muscles arising from transverse processes of C7 to T11 Interspinales Intertransversarii Short paired muscles attached to the spinous process of contiguous vertebrae, one on each side of the interspinous ligament Small muscles between the transverse processes of contiguous In Obliquus Capitis The rib Superior vertebra near tu Transverse process of atlas (C1) Occipital bone between superior and inferior nuchal lines Po of Obliquus Capitis Inferior Spinous process of axis (C2) Transverse process of atlas (C1) Po of Thorax 18 Muscles Connecting the Upper Limb to the Thoracic Wall/ Muscles of the Pectoral Region (except Serratus Anterior) *Pectoralis Major *Subclavius *Pectoralis Minor Muscles of the Thorax/ Thoracic Wall Muscle Origin Insertion Innervation Function External Intercostal Inferior margin of rib above Superior surface f rib below Intercostal nerves; T1-T11 Most active during inspiration; supports intercostals space; moves ribs superiorly Internal Intercostal Lateral edge of costal groove of rib above Superior surface of rib below deep to the attachment of the related external intercostal Intercostal nerves; T1-T11 Most active during expiration; supports intercostals space; moves ribs inferiorly Innermost Intercostal Medial edge of costal groove of rib above Internal aspect of superior surface of rib below Intercostal nerves; T1-T11 Acts with internal intercostals muscles Subcostales Internal surface (near angle) of lower ribs Internal surface of 2nd to 3rd rib below Related intercostal nerves Transversus Thoracis Lower margins and internal surfaces of cocostal cartilages of 2nd to 6th ribs Inferior aspect of deep surface of body of sternum, xiphoid process and costal cartilages ribs 4-7 Diaphragm (most important muscle of respiration) Xiphoid process; lower six costal cartilages, first three lumbar vertebrae Levatores Costarum (12) Tip of transverse process of C7 and T1-11 May depress ribs Related intercostals nerves Depresses costal cartilages Central tendon Phrenic nerve Very important muscle of inspiration; increases vertical diameter of thorax by pulling central tendon downward; assists in raising lower ribs. Also used in abdominal straining and weight lifting Rib below Posterior rami of thoracic spinal nerves Raises ribs and therefore inspiratory vertebrae Serratus Posterior Superior Serratus Posterior Inferior 19 (see Intermediate (Respiratory) Group of Back Muscles) muscles
