Scapular and Pectoral Regions Flashcards
MM of Pectoral Girdle
rotator cuff mm and assisting mm -Deltoid m= shoulder pads -Teres major m= lats little helper -Supraspinatus m= S -Infraspinatus m= I -Teres minor m= T -Subscapularis m= S (sternum is not part of girdle but some of its mms connect to sternum)
Deltoid m O and I
O: lateral clavicle acromion spine of scapula I: deltoid tuberosity of humerus
Deltoid m A
abducts humerus (1)
flexes
extends
rotates humerus (2)
Deltoid m S
axillary n
post circumflex humeral vessels
Teres Major m O and I
O:
inferior angle of scapula
I:
crest of lesser tubercle of humerus
Teres Major m A
adducts
extends
medially rotates humerus
Teres Major m S
lower subscapular n
subscapular vessels
Supraspinatus m O and I
O:
supraspinous fossa
I:
greater tubercle of humerus
Supraspinatus m A
abducts humerus (1st 15*)
Supraspinatus m S
suprascapular n/a/v
dorsal scapular vessels
Infraspinatus m O and I
O:
infraspinous fossa
I:
greater tubercle of humerus
Infraspinatus m A
lateral rotation of humerus
Infraspinatus m S
suprascapular n/a/v
subscapular vessels
Teres Minor m O and I
O:
lateral border of scapula
I:
greater tubercle of humerus
Teres Minor m A
lateral rotation of humerus
Teres Minor m S
axillary n
suprascapular vessels
subscapular vessels
Subscapularis m O and I
O:
subscapular fossa
I:
lesser tubercle of humerus
Subscapularis m A
medial rotation of humerus
Subscapularis m S
upper and lower subscapular nn/a/v
What mms protect the shoulder region?
deltoid m: provides outer muscular support
rotator cuff provides inner muscular suppoer
Subacrominal (Subdeltoid) Bursa
- membranous sac containing lubricating synovial fluid
- inferior to acromion and deltoid
- superior to supraspinatus m
- -does not communicate with jt capsule
- -becomes continuous with jt capsule due to attrition of supraspinatus tendon
Attrition of Supraspinatus tendon: tendon degenerates in ___________. Up to ___ of adults rupture tendon by ____. As it wears away, underlying jt capsule _____. When capsule _____, continuous with bursa, painful shoulder with _______ arm movement.
middle age 1/4 65 thins opens limited
Quadrangular Space contains
transmitting axillary n and posterior circumflex humeral a
Triangular Space contains
with circumflex scapular a deep to space
Triangular Interval contains
profunda brachii (deep brachial) a and radial n
Quadrangular Space mm
-teres minor m (sup)
-teres major m (inf)
-long head of triceps brachii m (med)
-surgical neck of humerus (lat)
contains- axillary n and pos circumflex humeral vessels
Triangular Space mm
-teres minor m (sup)
-teres major m (inf)
-long head of triceps brachii m (lateral)
contains- circumflex scapular vessel
Triangular interval mm
-teres major m (sup)
-long head of triceps brachii m (med)
-lateral head of triceps brachii m (lat)
contains- radial n and deep brachial a
Suprascapular n
ventral rami of C5-C6
-runs under superior transverse scapular lig thru suprascapular notch
along with a pass thru spinoglenoid notch to infraspinatus fossa and supply supraspinatus and infraspinatus mm
Suprascapular a
thyrocervical trunck
-runs over superior scapular lig above suprascapular notch
along with n pass thru spinoglenoid notch to infraspinatus fossa and supply supraspinatus and infraspinatus mm
Dorsal Scapular n
ventral ramus of C5
along with a runs parallel to vertebral border of scapula and supply levator scapulae and rhomboid mm
Dorsal Scapular a
subclavian a or transverse cervical a
along with n runs parallel to vertebral border of scapula and supply levator scapulae and rhomboid mm
Accessory n
brainstem (CN XI)
-descends thru neck and joins transverse cervical a
along with transverse cervical a supplies trap
Transverse Cervical a
thyrocervical trunk
-runs deep to trap m
along with accessory n supplies trap
Upper and Lower Subscapular nn
posterior cord of brachial plaxus
-ventral rami of C5-C6
supplies subscapularis m
lower subscapular n (along with subscapular a) supply teres major m
Subscapular a
axillary a
-splits to thoracodorsal a and circumflex scapular a
supplies subscapularis m
along with lower suscapular n supplies the teres major m
Collateral Circulation of Scapular Region:
- extensive
- ensures adequate blood supply to ______
- -in event of insufficient flow thru ________/temporary ligation
- -collateral circulation by ______ and ______
UL
axillary a
thyrocervical trunk
subscapular a
CCOSR: ligated axillary a:
- ligate btw __________ and ________
- blood flow in __________ reverses
- allows blood to flow to UL
- ligate anywhere ____ to ________ and blood cannot flow to UL
thyrocervical trunk subscapular a subscapular a distal subscapular a
Pectoralis Major m O and I
O: clavicle sternum ribs 2-6 I: crest of greater tubercle of humerus
Pectoralis Major m A
adducts
medially rotates humerus
Pectoralis Major m S
medial and lateral pectoral nn
thoracoacrominal vessels
Pectoralis Minor m O and I
O:
ribs 3-5
I:
coracoid process of scapula
Pectoralis Minor m A
protracts scapula
Pectoralis Minor m S
medial pectoral n
thoracoacomial vessels
Lateral Thoracic (mammary) a
branch of axillary a (deep to pec minor m)
- runs with LONG THORACIC n
- supplies:
- -lateral thorax
- -lateral pec region
- -lateral breast
Internal Thoracic (mammary) a
branch of subclavian a (inside thorax)
- descends across intercostal spaces lateral to sternum
- supplies:
- -anterior thorax
- -medial pec region
- -medial breast
Thoracoacromial a
branch of axillary a (under pec minor)
- 4 branches:
- -pectoral a
- -clavicular a
- -acromial a
- -deltoid a
Pectoral a
branch of Thoracoacromial a
-supplies upper pec region
Clavicular a
branch of Thoracoacromial a
-supplies clavicle region
Acromial a
branch of Thoracoacromial a
-supplies upper shoulder region
Deltoid a
branch of Thoracoacromial a
-supplies lower should region
Cutaneous nn of pec region
general sensation
- T1-T6
- lateral and anterior cutaneous branches of intercostal nn
Medial Pectoral n of pec region
medial cord of brachial plexus
- -derived from ventral rami (C8-T1)
- pierces pec minor to enter pec major
- -supplies both
Lateral Pectoral n of pec region
lateral cord of brachial plexus
- derived from ventral rami (C5-C7)
- -runs above pec minor to enter pec major
- supplies the remainder of pec major m
Long Thoracic n of pec region
derived from ventral rami (C5-C7)
-supplies serratus anterior m superficially
–damage can occur during mastectomy resulting in “winged scapula”
