Anterior and Posterior Axio-Appendicular Muscles (Quiz 1) Flashcards
Which ribs attach to the pectoralis major?
potential test q
ribs 1-6
What ribs attach to the pectoralis minor?
potential test q
ribs 3-5
What ribs attach to the subclavius?
potential test q
rib 1 only
What ribs attach to the serratus anterior?
potential test q
ribs 1-8
What are the 4 muscles that make up the anterior axio-appendicular muscles?
-pectoralis major
-pectoralis minor
-subclavius
-serratus anterior
What is the origin/proximal attachment for the pectoralis major?
2 head attachments
-clavicular head (anterior surface of the medial half of clavicle)
-sternocostal head (anterior surface of sternum)
superior 6 costal cartilages (ribs 1-6)
aponeurosis of external oblique muscle
What is the insertion/distal attachment of the pectoralis major?
lateral lip of the inter-tubercular sulcus of the humerus
What are the innervation points of the pectoralis major?
-lateral and medial pectoral nerves (at the clavicular head and sternocostal head)
What are the main actions of the pectoralis major?
-adducts and medially rotates the humerus
-draws scapula anteriorly and inferiorly
ACTING ALONE:
-the clavicular head flexes the humerus
-the sternocostal head extends it from the flexed position
-note: these 2 heads are opposites of each other when acting alone
What muscle’s inferior border forms the anterior axillary fold?
pectoralis major
The pectoralis major and deltoid form the deltopectoral groove for what vein?
cephalic vein
What are the 2 muscle tests for the pectoralis major?
1) clavicular head- abduct arm 90 degrees and move it anteriorly against resistance
2) sternocostal head- abduct 60 degrees and adduct against resistance
What is the origin/proximal attachment for the pectoralis minor?
ribs 3-5 costal cartilage
What is the insertion/distal attachment for the pectoralis minor?
medial border and superior surface of the coracoid process of the scapula
What innervates the pectoralis minor?
medial pectoral n.
What is the main action of the pectoralis minor?
stabilizes scapula by drawing it inferiorly and anteriorly against the thoracic wall
What muscle stabilizes the scapula when outstretching the upper limb (ex: to touch something out of reach)?
pectoralis minor
What muscle elevates the ribs for deep inspiration when pectoral girdle is fixed or elevated?
pectoralis minor
What muscle forms a bridge with the clavicle for neurovascular vessels in the arm?
pectoralis minor
What is the origin/proximal attachment for the subclavius?
rib 1 junction and its costal cartilage
What is the insertion/distal attachment for the subclavius?
inferior surface of the middle third of the clavicle (at the clavicular groove)
What innervates the subclavius?
potential test q!
nerve to subclavius
What is the main action of the subclavius?
anchors and depresses the clavicle
What muscle is known as the “boxer’s muscle”?
potential test q
serratus anterior
What is the origin/proximal attachment of the serratus anterior?
external surfaces of the lateral aspects of ribs 1-8
What is the insertion/distal attachment of the serratus anterior?
anterior surface of the medial border of the scapula
What innervates the serratus anterior?
long thoracic n.
What are the main actions of the serratus anterior?
-protects scapula and holds it against the thoracic wall
-rotates scapula
What muscle is a strong protractor muscle and is used when punching or reaching anteriorly, push-ups or pushing against resistance?
serratus anterior
What muscle normally holds the scapula against the thoracic wall, but paralysis to this muscle would cause a winged scapula?
serratus anterior
What is the muscle test for the serratus anterior?
outstretched hand pushed against a wall
What is another name for posterior axio-appendicular muscles?
extrinsic shoulder muscles
What do posterior axio-appendicular (extrinsic shoulder) muscles do?
-connect axial skeleton (vertebral column) to superior appendicular skeleton (pectoral girdle and humerus)
-produce and control limb movements
What are the 2 superficial posterior axio-appendicular (extrinsic shoulder) muscles?
1) trapezius
2) latissimus dorsi
What are the origins/proximal attachments for the trapezius?
-medial third of superior nuchal line
-external occipital protuberance (EOP)
-nuchal ligament
-SP of C7-T12 vertebrae
What are the insertion/distal attachments for the trapezius?
-lateral third of clavicle
-acromion and spine of scapula
What innervates the trapezius?
-spinal accessory nerve (CN XI) motor fibers
-spinal nerves (pain and proprioception fibers)
What are the actions of the trapezius?
-descending part elevates the scapula
-ascending part depresses the scapula
-middle part (or all parts together) retracts the scapula
descending and ascending parts act together to rotate the glenoid cavity superiorly
What muscle that is weak will cause drooping of shoulders?
trapezius
What are the origin/proximal attachments of the latissimus dorsi?
-SP of inferior 6 thoracic vertebrae (T7-T12)
-thoracolumbar fascia
-iliac crest
-inferior 3-4 ribs (ribs 10-12, or ribs 9-12)
What is the insertion/distal attachment for the latissimus dorsi?
floor of the inter-tubercular sulcus of the humerus (also known as the bicipital groove of the humerus)
What innervates the latissimus dorsi?
thoracodorsal n.
What are the main actions of the latissimus dorsi?
-extends, adducts, and medially rotates humerus
-raises body towards arms during climbing
What muscle is important for climbing, chin-ups, chopping wood, paddling canoe, or swimming?
latissimus dorsi
What are the 3 deep posterior axio-appendicular (extrinsic shoulder) muscles?
1) levator scapulae
2) rhomboid minor
3) rhomboid major
What is the origin/proximal attachment of the levator scapulae?
potential test q
posterior tubercles of TPs of C1-C4 vertebrae
What is the insertion/distal attachment of the levator scapulae?
potential test q
medial border of the scapula superior to the root of scapula spine
What 3 muscles are innervated by the dorsal scapular nerve?
potential test q
the deep posterior axio-appendicular muscles
-levator scapulae
-rhomboid major and minor
What innervates the levator scapulae?
potential test q
dorsal scapular n. and cervical nerves
What are the main actions of the levator scapulae?
potential test q
-elevates scapula and rotates its glenoid cavity inferiorly by rotating scapula
-bilaterally (tightened muscle) extends the neck
-unilaterally flexes the neck (lateral flexion)
What is the origin/proximal attachment of rhomboid minor?
potential test q
-nuchal ligament
-SP of C7 and T1
What is the insertion/distal attachment of rhomboid minor?
potential test q
smooth triangular area at the medial end of scapular spine (superior 3rd of scapular spine)
What innervates rhomboid major/minor?
potential test q
dorsal scapular n.
What are the main actions of rhomboid major/minor?
potential test q
-retract scapula and rotate its glenoid cavity inferiorly
-fix scapula to thoracic wall
What is the origin/proximal attachment of rhomboid major?
SP of T2 and T5 vertebrae
What is the insertion/distal attachment of rhomboid major?
medial border of scapula from the level of spine to the inferior angle
