Thoracic Flashcards
Lower Trapezius
Origin: spinous process of T5-T12
Insertion: lateral 1/3 of clavicle, acromion, spine of scapula
Innervation: motor - accessory nerve 11
Function: depression of scapula
Force couple: upward rotation with upper trap and serratus anterior
Lattisumus Dorsi
Origin: spinous process of T7-L5, sacrum, iliac crest, lower 8-9 ribs, thoracodorsal fascia
Insertion: intertubercular sulcus of humerus
Innervation: thoracodorsal nerve C6-C8
Function: shoulder extension, medial rotation, and adduction
Pectoralis Major
Origin: clavicle, sternum, first seven costal cartilages, aponeurosis of external oblique
Insertion: lateral lip of intertubercular sulcus of humerus
Innervation: medial and lateral pectoral nerves
Function: adduction, medial rotation, and flexion of shoulder
Pectoralis Minor
Origin: anterior surfaces of the third, fourth, and fifth ribs
Insertion: coracoid process of scapula
Innervation: medial pectoral nerves
Function: protracts scapula, respiration
Serratus Anterior
Origin: upper 8-9 ribs
Insertion: medial border of scapula
Innervation: long thoracic nerve (C5, C6, C7)
Function: protraction and upward rotation of the scapula; stabilizes medial border and inferior angle of scapula on thoracic wall
Serratus Posterior Superior
Origin: lower portion of ligamentum nuchae; spinous processes of CVII to TIII, and supraspinous ligaments
Insertion: upper border of ribs II to V just lateral to the angles
Innervation: anterior rami of upper thoracic nerves (T2-T5)
Function: elevates ribs II to V
Serratus Posterior Inferior
Origin: spinous processes of TXI to LIII and supraspinous ligaments
Insertion: lower border of ribs IX to XII just lateral to the angles
Innervation: anterior rami of lower thoracic nerves (T9-T12)
Function: depresses ribs IX to XII and may prevent lower ribs from being elevated when the diaphragm contracts
Diaphragm
Origin: margins of the inferior thoracic aperture including: xiphoid process of sternum, costal margin of thoracic wall, ends of ribs 11 and 12; vertebrae of lumbar region, and ligaments that span across structures of posterior abdominal wall
Insertion: central tendon of the diaphragm
Innervation: phrenic nerves C3, C4, and C5, with the major contribution coming from C4
Function: active during inspiration. Assists in increasing intrabdominal pressure
Iliocostalis
Origin:
cervicis - 3rd-6th ribs
Thoracis - 7th-12th ribs
Lumborun - sacrum, iliac crest, thoracolumbar fascia
Insertion:
Cervicis- transverse processes of C4-C6
Thoracis - 1st-6th ribs and transverse process of C7
Lumborun- 6th-12th ribs
Innervation: spinal nn. C8-L1
Function: extends neck (bilateral). Ipsilateral lateral flexion of the spine (unilaterally)
Longissimus
Origin:
Thoracis - blends with iliocostalis in lumbar region and is attached to transverse processes of lumbar vertebrae
Cervicis - transverse process of upper 4 or 5 thoracic vertebrae
Capitis - transverse progress of upper 4 or 5 thoracic vertebrae and articular processes of lower 3 or 4 cervical vertebrae
Insertion:
Thoracis - transverse process of thoracic vertebrae
Cervicis - C2-C6 transverse vertebrae
Capitis - posterior margin of mastoid process
Innervation: spinal nn. C1-L5 posterior rami, lateral branches
Function:
Thoracis/cervicus - extends the spine (bilateral), ipsilateral flexion of the spine (unilaterally)
Capitis - extends the head (bilaterally),!laterally flexes and rotates the head (unilaterally)
Spinalis
Origin:
Thoracis - spinous processes of T10/T11-L2
Cervicus - lower part of ligamentum nuchae and spinous process of CVII (sometimes TI-TII)
Capitis - blends with semispinalis capitis
Insertion:
Thoracis - spinous processes of T1-T8
Cervicis - spinous processes of CII (axis)
Capitis - with semispinalis capitis
Innervation: spinal nn. (Posterior rami)
Function: extends cervical and thoracic spine (bilateral). Laterally flexes cervical and thoracic spine to same side (unilateral)
