Anatomy Lab Quiz- thoracic and abdominal muscles

TIRE

- 4 abdominal muscles transverse abdominis internal obliques rectus abdominus external obliques

external obliques

- diagonal direction of fibers - form mesh with internal obliques

linea alba

- line running down center of abdominals "white line" -connective tissue

internal oblique

- perpendicular to external obliques - forms mesh

serratus posterior

origin- T11 through L2 insertion- lower border of ribs 9-12 action- draws lower ribs backward and downward, rotation and extension of trunk

pectoralis major

origin- clavicle, sternum, ribs insertion- greater tubercle of humerus action- arm flexion, rotates arm medially, adducts arm, pulls rib cage upward

deltoid

origin- embraces insertion of trapezius, lateral third of clavicle, acromion and spine of scapula insertion- deltoid tuberosity of humerus action- abduction of arms, antagonist of pectoralis major and latissimus dorsi, flexion, medial rotation of the humerus, extension and lateral rotation

platysma

origin- fascia of chest (over pectoral muscles and deltoid) insertion- lower margin on mandible, skin ans muscle t corner of mouth action- mouth, pulls lip back and down, tenses skin of neck

quadratus lumborum

origin- fibers from iliolumbar ligament and adjacent portion of iliac crest insertion- lower border of last rib action- lateral flexion of vertebral column, depression pf thoracic cage

external intercostals

origin- inferior margins of ribs 1-11 insertion- superior margins of ribs 2-12 action- respiration

internal intercostals

origin- inferior margins of ribs 1-11 insertion- superior margins of ribs 2-12 action- respiration

internal abdominal oblique

origin- inguinal ligament, iliac crest, thoracolumbar fascia insertion- xiphoid process, linea alba, pubis, ribs 10-12 action- flexes waist (sit ups), flexes and rotates vertebral columns

transverse abdominis

origin- inguinal ligament, iliac crest, thoracolumnar fascia, costal cartilages 7-12 insertion- xiphoid process, linea alba, pubis, inguinal ligament action- compresses abdomen, increases intra abdominal pressure, flexes vertebral column

teres major

origin- lower 1/3 of lateral border of the scapula insertion- intertubercular groove of humerus action-adduction, internal rotation - more medial

rhomboid minor

origin- lower part of ligamentum nuchae, spinous process from C7, T1 insertion- medial border of scapula, acromion end action- adducts and rotates the scapula laterally, retracts scapula

sternocleidomastoid

origin- manubrium of sternum, medial portion of clavicle insertion- mastoid process of temporal bone and superior nuchal line of occipital bone action- head flexion, contraction of neck muscles, laterally flexes head

teres minor

origin- mid section of lateral border of scapula insertion- greater tuberosity of humerus action- external rotation adduction - more lateral

trapezius

origin- occipital bone, ligamentum nuchae and spines of C7 and all thoracic vertebra insertion- acromion and spine of scapula and lateral third of clavicle action- stabilizes, raises, retracts, elevates, depresses scapula

rectus abdominis

origin- pubis insertion- xiphoid process, costal cartilages action- stabilizes, protects, supports internal viscera "6 pack" actually 8 pack

iliocostalis

origin- rib insertion- rib action- extension, lateral flexion of vertebral column -erector spinae - "I Love Standing" - smallest muscle -lateral

pectoralis minor

origin- ribs 3, 4, 5 insertion- coracoid process of scapula action- pulls scapula forward and downward

external abdominal oblique

origin- ribs 5-12 insertion- xiphoid process, linea alba action- flexes waist (sit ups), flexes and rotates vertebral columns

serratus anterior

origin- ribs 8 and 9 insertion- anterior vertebral border of scapula action- pulls scapula forward and downward - looks like ribs, but not "boxer's muscle"

infraspinatus

origin- scapula below the spine insertion- greater tuberosity of humerus action- shoulder abduction, external rotation

latissimus dorsi

origin- spines of lower 6 thoracic vertebra, lumbar vertebra, lower 3 to 4 ribs, iliac crest insertion- intertubercular groove of humerus action- arm adduction, medially rotates arm, depresses scapula "swimmer's muscle" - helps with humerus, NOT BACK - sits between two dorsi majors

rhomboid major

origin- spinous process of T2- T5 insertion- medial border of the scapula action- retracts and rotates the scapula

subscapularis

origin- subscapular fossa insertion- medial border of scapula action- adducts, retracts and laterally rotates the scapula

supraspinatus

origin- supraspinous fossa insertion- greater tubercle of humerus action- abduction of shoulder joint

semispinalis

origin- transverse process insertion- spinous process action- extends vertebral column and head -erector spinae - "I Love Standing" - most medial

rotatores

origin- transverse process insertion- spinous process action- rotate vertebral column to opposite side

multifidus

origin- transverse process insertion- spinous process action- rotates vertebral column to opposite sides

Longissimus

origin- transverse process insertion- transverse process action- extension, lateral flexion of vertebral column -erector spinae - "I Love Standing" - longest muscle

levator scapulae

origin- transverse process of atlas and axis from the posterior tubercle to the transverse processes insertion- vertebral border of scapula action- elevates scapula

diaphragm

origin- xiphoid process, ribs 10-12, costal cartilages 5-9, lumbar vertebra insertion- central tendon action- inspiration, compresses abdominal viscera to aid in defecation, urination and childbirth exhale= relaxation inhale= contraction