Thoracic Wall Muscles

Question 1

Diaphragm

Answer 1

I: phrenic nerve (C3-C5)
B: musculophrenic arteries, inferior phrenic arteries
A: p- costal margin, inferior border of ribs XI-XII, L3 (right crus), L2 (left crus)
d- Central Tendon
A: normal breathing at rest

Question 2

Extrinsic muscles

Answer 2

Diaphragm
Pec major/minor
Subclavius
Serratus anterior and posteriors

Question 3

Intrinsic muscles

Answer 3

Intercostal muscles (external, internal, innermost)
Transversus thoracis
Subcostal

Question 4

Pectoralis Major

Answer 4

I: lateral pectoral nerve (C5-T1), medial pectoral nerve (C8-T1)
B: pectoral branch of thoracoacromial trunk
A: p- medial 1/2 of the clavicle, sternum, costal head (rib VI,VII)
d- lateral lip of intertubercular crest/ dicipital groove of the humerus
A: GH joint - FLX vs. Ext, IR/ADD

Question 5

Pectoralis minor

Answer 5

I: medial pectoral nerve (C8, T1)
B: pectoral branch of thoracoacromial trunk
A: p- rib III-V
d- coracoid process of scapula
A: scapulothoracic articulation depression and anterior tilt of scapula

Question 6

Subclavius

Answer 6

Nerve to subclavius (C5, C6)
pectoral branch of thoracoacromial trunk
P- costal cartilage of rib I
D- under the surface of distal clavicle
A: depression of clavicle

Question 7

Serratus anterior

Answer 7

Long thoracic nerve (C5-C7)
Lateral thoracic and thoracodorsal arteries
P- rib 1-9
D- anterior medial border of the scapula
A: scapular protraction, holding scapula to the Thorax, upward rotation of scapula, elevation of ribs

Question 8

Intercostal muscles

Answer 8

External, internal, innermost

Question 9

External intercostal muscle

Answer 9

Oblique posterosuperior
Anteriorly stops at costal cartilage and continuous to external intercostal membrane

Question 10

Internal intercostal muscle

Answer 10

Oblique posterosuperior
Posteriorly stops at posterior intercostal membrane

Question 11

Innermost intercostal muscle

Answer 11

Same direction of internal intercostal muscle
Between the posterior and external intercostal membrane

Question 12

Transversus thoracis

Answer 12

Intercostal nerve
Anterior intercostal artery
P- posterior surface of lower sternum
D- internal surface of costal cartilage 2-6
A: depression of rib cage; expiration

Question 13

Inspiration muscles

Answer 13

Primary: external intercostal, membranous internal intercostal, serratus posterior superior
Anterolateral accessory: sternocleidomastoid, subclavian, pectoralis minor

Question 14

Expiration muscles

Answer 14

Primary: other internal intercostal muscles, innermost intercostal, serratus posterior inferior
Anterior accessory: abdomonals