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Question 1

What are axio-humeral muscles and how many are there?

Answer 1

Large muscles anchored to the axial skeleton acting on the glenohumeral joint/ humerus. There are 2: Pectoralis major and latissimus dorsi

Question 2

Describe the pectoralis major? Flex, add, med rot (clavicular)

Answer 2

clavicular portion: Origin run inferiorly and lateral from the medial portion of the clavicle.

Action: flexion, horizontal adduction and medial rotation

Insertion: greater tubercle of the anterior humerus

Peripheral Innervation: lateral pectoral

segmental Innervation: 5, 6 ,7

Question 3

Describe the pectoralis major? (sternal)

Answer 3

sternocostal: run medial to lateral in a horizontal line (frontal) from sternum and cartilage of ribs

Action: Shoulder depression and oblique adduction

Insertion: greater tubercle of the anterior humerus

Peripheral innervation: lateral and medial pectoral

Segmental innervation: 5 ,6, 7, 8, T1

Question 4

What is the latissimus dorsi muscle?

Answer 4

Origin: T7-L5 spinous processes, inferior angle of scapula, ilium and sacrum
Insertion: intertubercular groove of anterior humerus
Action: extends, adducts and medially rotates (respiratory muscle)
Peripheral innervation: thoracodorsal
Segmental Innervation: 5, 6, 7

Question 5

What are the muscles of the scapulohumeral joint?

Answer 5

Deltoid, teres major and rotator cuff muscles.

Question 6

What are the deltoid muscles?

Answer 6

Origin:
anterior: acromion and clavicle
middle: acromion
posterior:scapular spin

Insertion: Deltoid tuberosity
Action: Main Action is ABDUCTION
Anterior: flex and medially rotate
middle: abduction
posterior: lateral rotation and horizontal abduction
Peripheral innervation: axillary
Segmental Innervation: 5,6

Question 7

What is the teres major muscle? (same action as?)

Answer 7

Origin: inferior border of the scapula
Insertion: lesser tubercle crest of the anterior humerus
Action: med rot,, adducts and extends humerus stabilizes humerus in glenoid cavity
Peripheral innervation: upper and lower subscapular
Segmental Innervation: 5,6,7

Question 8

What are the 4 rotator cuff muscles and what is their action?

Answer 8

They are rotate the humerus except the supraspinatus m.
Infraspinatus
Subscapularis
Teres minor

Question 9

What is the supraspinatus muscle?

Answer 9

Origin: supraspinatus fossa of the scapula
Insertion: greater tubercle of the proximal humerus
Action: abducts humerus and stabilizes head of humerus in glenoid cavity
Peripheral: suprascapular
Segmental: 4,5,6

Question 10

what is the infraspinatus muscle?

Answer 10

Origin: infraspinatus fossa of the scapula
Insertion: greater tubercle of the proximal humerus
Action: lateral rotation and stabilizes head of the humerus in glenoid cavity
Peripheral: suprascapular
Segmental: 4,5,6

Question 11

What the subscapularis muscle?

Answer 11

Origin: the subscapular fossa of the scapula
Insertion: lesser tubercle of the proximal humerus
Action: medial rotation and stabilizes head of the humerus in glenoid cavity
Peripheral: upper and Lower subscapular
Segmental: 5,6,7

Question 12

What is the teres minor muscle?

Answer 12

Origin: dorsal and lateral scapula
Insertion: inferior greater tubercle of the humerus
Action: lateral rotation stabilizes head of the humerus in glenoid cavity and internally rotates scapula
Peripheral: axillary
Segmental: 5,6

Question 13

What are the scapulothoracic muscles?

Answer 13

The muscles anchored to the thorax/axial skeleton that act on the scapula 6 muscles

• pectoralis minor
• serratus anterior
• trapezius
• rhomboids
• levator scapula
• subclavius

Question 14

What is the pectoralis minor muscle?

Answer 14

Origin: 3rd, 4th, 5th ribs
Insertion: coracoid process of scapula
Action: anteriorly tilts scapula + assists in inspiration
Peripheral Innervation: medial pectoral
Segmental Innervation: 6,7,8,T1

Question 15

What is the serratus anterior muscle?

Answer 15

Origin: outer surface of 8/9ribs
Insertion:anterior and medial boarder of scapula
Action: Upward rotator, abducts scapula, prevents scapula winging via external rotation
Peripheral Innervation: long thoracic
Segmental Innervation: 5,6,7,8

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Question 16

what is the trapezius?

Answer 16

Origin:
Upper: occipital bone
Middle: T1-5 spinous processes
Lower: T6-T-12
Insertion: clavicle and acromion process
and scapula spine
Action:
Upper: elevation, upward rotation of scapula
Middle: adduction of scapula
Lower: depression of scapula and upward rotation of scapula
Peripheral Innervation: spinal portion of cranial nerve (accessory) and ventral ramus
Segmental Innervation: C2,3,4

Question 17

What is the rhomboid minor muscle?

Answer 17

Origin: C7-T1
Insertion: anterior and medial boarder of scapula
Action: adduct scapula Externally and Downwardly Rotate scapula
Peripheral Innervation: Dorsal Scapula
Segmental Innervation: C4,5

Question 18

What is the rhomboid major muscle?

Answer 18

Origin: Spinous processes of T2-T5 vertebrae
Insertion: medial border of scapula
Action: adduct scapula and Externally and Downwardly rotate scapula
Peripheral Innervation: dorsal scapula
Segmental Innervation: C4,5

Question 19

What is the levator scapulae muscle?

Answer 19

Origin: transverse process of the C1-4 vertebrae
Insertion: anterior medial border of scapula
Action: elevates scapula, downward rotation, extend rotate and sidebend cervical spine
Peripheral Innervation: dorsal scapula and cervical spine
Segmental Innervation: C4,5 - C3,4

Question 20

What is the subclavius muscle?

Answer 20

Origin: 1st rib
Insertion:under the surface of the clavicle
Action:draws clavicle down, stabilizes sternoclavicular joint
Peripheral Innervation: subclavian
Segmental Innervation: C5,6

Answer 21

Origin:
Insertion:
Action:
Peripheral Innervation:
Segmental Innervation:

Answer 22

Origin:
Insertion:
Action:
Peripheral Innervation:
Segmental Innervation: