Thoracic Limb Flashcards
Protractors of the thoracic limb
Brachiocephalicus (cleidomastoideus, cleidocervicalis, & cleidobrachialis); Trapezius (cervicis & thoracis); Omotransversarius
Cleidomastoideus
F: protractor; depresses head & neck
O: clavicular tendon
I: mastoid process of temporal bone
Cleidocervicalis
F: protractor; depresses head & neck
O: clavicular tendon
I: dorsal neck of fibrous raphe & nuchal occipital bone
Cleidobrachialis
F: protractor; extends shoulder
O: clavicular tendon
I: distal part of cranial humerus
Trapezius cervicis
F: protactor; elevates scapula & abducts limb
O: median fibrous raphe neck
I: (aponeurosis) cranial scapular spine
Trapezius thoracis
F: protractor; elevates scapula & abducts limb
O: supraspinous ligament
I: (aponeurosis) caudal scapular spine
Omotransversarius
F: protractor
O: caudal wing of atlas
I: distal part of scapular spine/ acromion process
Retractors of the thoracic limb
Latissimus dorsi; Rhomboideus (cervicis, capitis, & thoracis); Serratus ventralis (cervicis & thoracis); Superficial Pectoral (Pectoralis descendens & Pectoralis transversus); Deep Pectoral
Latissimus dorsi
F: retractor; flexes shoulder
O: (aponeurosis) thoraco-lumbar fascia/ last few ribs
I: teres major tuberosity
Rhomboideus cervicis
F: retractor; elevates scapula; abducts limb; draws scapula medially towards trunk
O: median fibrous raphe of the neck
I: medial dorsal border of scapula
Rhomboideus capitis
F: retractor; elevates scapula; abducts limbs
O: nuchal crest of occipital bone
I: medial to dorsal border of scapula
Rhomboideus thoracis
F: retractor; elevates scapula; abducts limb; draws scapula medially towards trunk
O: spinous process of thoracic vertebrae
I: medial to dorsal border of scapula
Serratus ventralis cervicis
F: retractor; “sling” muscle; depresses scapula
O: transverse process of cervical vertebrae
I: medial aspect of scapula; facies serrata
Serratus verntralis thoracis
F: retractor; “sling” muscle; depresses scapula
O: ribs
I: medial aspect of scapula; facies serrata
Pectoralis descendens
F: retractor; protracts & adducts limb; rotates humerus medially
O: manubrium sterni 2nd-3rd sternebrae
I: greater tubercle of humerus
Pectoralis transversus
F: retractor; adducts & rotates humerus medially
O: manubrium sterni 2nd-3rd sternebrae
I: greater tubercle of humerus
Deep pectoral
F: retractor; pulls trunk cranially; extends shoulder
O: ventral sternum
I: (aponeurosis) greater & lesser tubercle of humerus
Extensors of the shoulder
Supraspinatus, Infraspinatus, Subscapularis, & Corocobrachialis
Supraspinatus
F: extends shoulder; stabilizes shoulder joint
O: supraspinous fossa
I: greater & lesser tubercle of humerus
Infraspinatus
F: extends shoulder; abducts shoulder; rotates humerus; flexes shoulder (when non-weight bearing)
O: infraspinous fossa
I: greater tubercle of humerus
Subscapularis
F: extends shoulde; adducts shoulder; helps stabilize shoulder joint
O: subscapular fossa
I: lesser tubercle of humerus
Corocobrachialis
Capsular muscle
F: extends shoulder; adducts shoulder; helps stabilize shoulder joint
O: corocoid process of scapula
I: crest of lesser tubercle of humerus
Notes on Supraspinatus muscle tendons
splits to reach both insertion sites
tendons help compensate for weak collateral ligaments
Notes on Infraspinatus muscle tendons
bursa found underneath it
Flexors of the shoulder
Deltoideus (Acromion & Scapular parts); Teres major; Teres minor
Deltoideus acromion part
F: flexes shoulder
O: acromion process
I: deltoid tuberosity
Deltoideus scapualar part
F: flexes shoulder
O: (aponeurosis) scapular spine
I: deltoid tuberosity
Teres major
F: flexes shoulder; medially rotates humerus
O: proximal caudal border of scapula
I: teres major tuberosity
Teres minor
Capsular muscle
F: flexes shoulder; laterally rotates humerus
O: (aponeurosis) infraglenoid tubercle & distal caudal border of scapula
I: teres minor tuberosity