Pectoral and Axilla I

Question 1

The medial end of the clavicle is what shape and why?

Answer 1

It is expanded for articulation with the manubrium and first costal cartilage

Question 2

The distal end of the clavicle is what shape and why?

Answer 2

flattened for articulation with acromion process

Question 3

What are the origin, insertion, and innervation of the trapezius muscle?

Answer 3

origin: superior nuchal line, external occipital protuberance, nuchal ligament, and vertebrae C7-T12.
insertion: lateral 1/3 of clavicle, acromion, and spine of scapula
innervation: cranial nerve 11: the accessory nerve

Question 4

What are the origin, insertion, and innervation of the latissimus dorsi?

Answer 4

Origin: T6-L5, sacrum, iliac crest, and ribs 10-12
Insertion: intertubercular groove
Innervation: Thoracodorsal

Question 5

What is the action of latissimus dorsi?

Answer 5

extends, adducts, and medially rotates

Question 6

What are the origin, insertion, innervation, and action of the levator scapulae?

Answer 6

Origin: Transverse processes of C1-4
Insertion: Superior angle of scapula
Innervation: Dorsal scapular nerve
Elevates and rotates scapula

Question 7

What are the origin, insertion, innervation, and action of the rhomboid major and minor?

Answer 7

Origin: Spinous processes of C7-T5
Insertion: Medial border of scapula. Minor is superior to the spine, major is inferior
Innervation: Dorsal scapular nerve
Retracts, elevates, and rotates scapula

Question 8

What are the origin, insertion, innervation, and action of the deltoid?

Answer 8

Origin: Lateral 1/3 of clavicle, acromion, spine of scapula
Insertion: Deltoid tuberosity of humerous
Innervation: Axillary nerve
Abduction, flexion, extension, and medial or lateral rotation

Question 9

What are the origin, insertion, innervation, and action of the supraspinatus?

Answer 9

Origin: Supraspinous fossa
Insertion: Superior facet of greater tubercule of humerus
Innervation: Suprascapular nerve
Abduction of arm

Question 10

What are the origin, insertion, innervation, and action of the infraspinatus?

Answer 10

Origin: Infraspinous fossa
Insertion: Middle facet of greater tubercule of humerus
Innervation: Suprascapular nerve
Lateral rotation of arm

Question 11

What are the origin, insertion, innervation, and action of the teres major?

Answer 11

Origin: Lateral border of scapula
Insertion: Medial lip of intertubercular groove
Innervation: Lower subscapular nerve
Medial rotation, adduction, extends a flexed arm

Question 12

What are the origin, insertion, innervation, and action of the teres minor?

Answer 12

Origin: Lateral scapular border
Insertion: Inferior facet of greater tubercule of humerus
Innervation: Axillary nerve
Lateral rotation of arm

Question 13

What are the origin, insertion, innervation, and action of the long head triceps?

Answer 13

Origin: infraglenoid tubercule of scapula
Insertion: Olecranon process of posterior ulna via common tendon
Innervation: Radial nerve
Extends forearm

Question 14

What are the origin, insertion, innervation, and action of the subscapularis?

Answer 14

Origin: Subscapular fossa
Insertion: Lesser tubercule of humerus
Innervation: Upper and lower subscapular nerve
Medial rotation of the arm

Question 15

What are the origin, insertion, innervation, and action of the pectoralis major?

Answer 15

Origin: Medial 1/2 of clavicle, anterior surface of sternum
Insertion: Lateral lip of intertubercular groove
Innervation: Lateral and medial pectoral nerves
Flexion, adduction, and medial rotation

Question 16

What goes through the clavipectoral triangle?

Answer 16

Cephalic vein

Question 17

What are the origin, insertion, innervation, and action of the pectoralis minor?

Answer 17

Origin: Ribs 3-5
Insertion: Coracoid process
Innervation: Medial pectoral nerve
Pulls tip of shoulder down, protracts scapula

Question 18

What are the origin, insertion, innervation, and action of the subclavius?

Answer 18

Origin: First rib
Insertion: Inferior surface of clavicle
Innervation: subclavian
Pulls tip of shoulder down, pulls clavicle medially to stabilize sternoclavicular joint

Question 19

What are the origin, insertion, innervation, and action of the serratus anterior?

Answer 19

Origin: Lateral surface of ribs 1-8/9
Insertion: Costal (rib) surface of medial scapular border
Innervation: Long thoracic nerve.
Protraction, depression, and rotation of scapula

Question 20

What makes up the apex of the axilla and why is it important?

Answer 20

It’s the inlet for the axillary vessels and the brachial plexus. It is bounded by the first rib, the medial edge of the coracoid process, and the posterior edge of the clavicle.

Question 21

What makes up the anterior wall of the axilla?

Answer 21

Pec major, pec minor, subclavius, and clavipectoral fascia

Question 22

What makes up the posterior wall of the axilla?

Answer 22

Subscapularis, latissimus dorsi, teres major

Question 23

What makes up the lateral border of the axilla?

Answer 23

Medial humerus. The anterior and posterior walls converge on the intertubercular groove

Question 24

What makes up the medial wall of the axilla?

Answer 24

The first four ribs with their external intercostal muscles, and the superior portion of the serratus anterior muscle

Question 25

What makes up the floor of the axilla?

Answer 25

Skin and axillary fascia. The base is convex superiorly, which makes the armpit concave