Lesson 7C - Muscles of the superficial back & pectoral region

which muscle, origin, insertion, innervation, and action is this

NAME; External Intercostals

ORIGIN; inferior border of rib above

INSERTION; superior border of rib below

ACTION; Contraction creates inhalation by elevating ribs; relaxation depresses the ribs resulting in exhalation

INNERVATION; intercostal nerves

which muscle, origin, insertion, innervation, and action is this

NAME; Internal Intercostals

ORIGIN; superior border of rib below

INSERTION; inferior border of rib above

ACTION; contraction draws adjacent ribs together during forced exhalation

INNERVATION; intercostal nerves

which muscle, origin, insertion, innervation, and action is this

NAME; external oblique

ORIGIN; inferior 8 ribs

INSERTION; iliac crest and linea alba

ACTION; together: Compress abdomen and flex vertebral column - Singly: Laterally flex and rotate vertebral column to the opposite side

INNERVATION; intercostal nerve

which muscle, origin, insertion, innervation, and action is this

NAME; internal oblique

ORIGIN; iliac crest, inguinal ligament and thoracolumbar fascia

INSERTION; cartilage of last four ribs and linea alba

ACTION; Together: Compress abdomen and flex vertebral column Singly: Laterally flex and rotate vertebral column to the same side

INNERVATION; intercostal nerves

which muscle, origin, insertion, innervation, and action is this

NAME; transverse abdominus

ORIGIN; iliac crest, inguinal ligament, lumber fascia, and cartilages of inferior 6 ribs

INSERTION; xiphoid process, linea alba, and pubis

ACTION; compress abdomen

INNERVATION; intercostal nerves

which muscle, origin, insertion, innervation, and action is this

NAME; Rectus Abdominus

ORIGIN; Pubic crest and pubic symphysis

INSERTION; Cartilage of 5th-7th ribs and xiphoid process

ACTION; Flexes trunk and compresses abdomen

INNERVATION; Intercostal Nerves

which muscle, origin, insertion, innervation, and action is this

NAME; Quadratus Lumborum

ORIGIN; Iliolumbar ligament and iliac crest

INSERTION; Inferior border of 12th rib and transverse processes of L1-L4

ACTION; Together: Pull the ribs inferior during forces exhalation, Extend vertebral column - Singly: Laterally flex vertebral column

INNERVATION; T12 thoracic nerve and nerves of L1- L3

which muscle, origin, insertion, innervation, and action is this

NAME; Diaphragm

ORIGIN; Xiphoid process, cartilage of the lower 6 ribs, and lumbar vertebrae

INSERTION; Central Tendon

ACTION; Contraction causes it to flatten and increase vertical dimension of thoracic cavity (inhalation); Relaxation causes it to move superiorly and decrease the vertical dimension of thoracic cavity (exhalation)

INNERVATION; Phrenic Nerve

which muscle, origin, insertion, innervation, and action is this

NAME; trapezius

ORIGIN; Superior nuchal line of occipital bone, ligamentum nuchae, and spines of C7 and T1–T12

INSERTION; Clavicle, acromion, and spine of scapula

ACTION; Upper trap: Elevate scapula, upwardly rotate the scapula and extend head Middle trap: Retract scapula Lower trap: Depress scapula and upwardly rotate the scapula

INNERVATION; Spinal accessory nerve

which muscle, origin, insertion, innervation, and action is this

NAME; Latissimus Dorsi

ORIGIN; Spines of T7–T12 and L1–L5, sacrum and ilium, inferior 4 ribs

INSERTION; Bicipital groove

ACTION; Extends, adducts, and internally rotates the arm at the shoulder joint; draws arm inferiorly and posteriorly

INNERVATION; Thoracodorsal nerve

which muscle, origin, insertion, innervation, and action is this

NAME; Rhomboid Major

ORIGIN; Spines of T2–T5

INSERTION; Medial border of scapula inferior to spine

ACTION; Elevation, retraction and downward rotation of the scapula

INNERVATION; Dorsal scapular nerve

which muscle, origin, insertion, innervation, and action is this

NAME; Rhomboid Minor

ORIGIN; Spines of C7–T1

INSERTION; Medial border of scapula superior to spine

ACTION; Elevation, retraction and downward rotation of the scapula

INNERVATION; Dorsal scapular nerve

which muscle, origin, insertion, innervation, and action is this

NAME; Levator Scapulae

ORIGIN; Transverse processes of C1–C4

INSERTION; Superior medial border of scapula

ACTION; Elevation and downward rotation of the inferior angle of scapula

INNERVATION; Dorsal scapular nerve

which muscle, origin, insertion, innervation, and action is this

NAME; Pectoralis Major

ORIGIN; Clavicle, sternum, and costal cartilages of ribs 2–6

INSERTION; Greater tuberosity and bicipital groove

ACTION; Shoulder adduction and internal rotation and assists with flexion

INNERVATION; Medial and lateral pectoral nerves

which muscle, origin, insertion, innervation, and action is this

NAME; Pectoralis Minor

ORIGIN; Ribs 2–5

INSERTION; Coracoid process

ACTION; Scapular protraction and downward rotation

INNERVATION; Medial pectoral nerve

which muscle, origin, insertion, innervation, and action is this

NAME; Serratus Anterior

ORIGIN; Superior 9 ribs

INSERTION; Medial border of scapula

ACTION; Protraction and upward rotation of the scapula

INNERVATION; Long thoracic nerve