Axilla

Question 1

Osteology of pectoral region

Answer 1

Question 2

Acromioclavicular joint:
Joint type: ?
What does it connect:

Answer 2

Plane-type synovial joint connects clavicle + scapula

Question 3

Sternoclavicular joint:
Joint type: ?
What does it connect:

Answer 3

Saddle-type synovial joint functions as a
ball & socket (scapula movement); connects clavicle + thorax

Question 4

Identify this muscle

Answer 4

Pectoralis Major

Question 5

Pectoralis Major
Origin:
Insertion:
Action:
Innervation

Answer 5

Origin: medial surface of clavicle + sternum + ribs

Insertion: lateral lip on intertubercular sulcus

Innervation: lateral (C5-C7) + medial pectoral nerve (C8-T1)

Action: adduction, medial rotation of humerus, flexes humerus, extension from a flexed position

Question 6

Identify this muscle:

Answer 6

Pectoralis Minor

Question 7

Pectoralis Minor
Origin:
Insertion:
Action:
Innervation

Answer 7

Origin: ribs 3-5

Insertion: coracoid process

Innervation: medial pectoral nerve (C8-T1)

Action: stabilizes scapula by drawing it inferiorly and against thoracic wall

Question 8

Identify this muscle

Answer 8

subclavius

Question 9

Subclavius
Origin:
Insertion:
Action:
Innervation

Answer 9

Origin: junction of the 1st rib and the costal cartilage

Insertion: inferior, middle clavicle

Innervation: Nerve to subclavius (C5-C6)

Action: anchors and depresses the clavicle

Question 10

Identify this muscle

Answer 10

Serratus anterior

Question 11

Boundaries of the Axilla:
Base

Answer 11

Skin, subq tissue, axillary fascia

Question 12

Boundaries of the Axilla:
Apex

Answer 12

Space between 1st rib + clavicle; cervico-axillary canal

Question 13

Boundaries of the Axilla:
Anterior

Answer 13

Pectoralis major, pectoralis minor, pectoral and clavipectoral fascia

Question 13

Boundaries of the Axilla: Posterior

Answer 13

Superiorly via the scapula and subscapularis
Inferiorly via teres major and latissimus dorsi

Question 14

Boundaries of the Axilla: Lateral

Answer 14

Intertubercular groove of the humerus

Question 15

Boundaries of the Axilla: Medial

Answer 15

Thoracic wall + serratus anterior

Question 16

What is located within the axillary sheath?

Answer 16

axillary arteries & branches, axillary vein and tributaries; brachial plexus

Question 17

What is located OUTSIDE of the axillary sheath

Answer 17

axillary lymph nodes, lymphatic vessels, axillary fat

Question 18

Fascia of the Pectoral Region: Deltoid Fascia

Answer 18

Descends from clavicle, acromion, and scapular spine; Continuous w. the pectoral fascia anteriorly, infraspinous fascia inferiorly.

Question 19

Fascia of the Pectoral Region: Axillary Fascia

Answer 19

Continuation of the pectoral fascia; Forms floor of the axilla.

Question 20

Fascia of the Pectoral Region: Pectoral Fascia

Answer 20

Descends from the clavicle + sternum, investing the pectoralis major. Becomes the axillary fascia laterally

Question 21

Fascia of the Pectoral Region: Claviopectoral Fascia

Answer 21

Descends from clavicle, encloses the subclavius and pectoralis minor; continuous w. axillary fascia.

Question 22

Cephalic vein location:
subq vein of the (lateral/medial) aspect of the upper limb; Travels thru the deltopectoral groove & feeds INTO the _____ vein

Answer 22

Superficial, subq vein of the lateral aspect of the upper limb; Travels thru the deltopectoral groove & feeds into the axillary vein

Question 23

Axillary Vein: formed by the ____ and ____ veins and becomes the _____ vein at the lateral border of the ____ rib.

Answer 23

formed by the brachial and basilic veins and becomes the subclavian vein at the lateral border of the 1st rib

Question 24

Basilic Vein Location: travels along the _____ aspect of the arm

Answer 24

travels along the **medial aspect** of the arm

Question 25

1st part of the axillary artery (Hint: located between the first rib and medial border of pectorals minor

Answer 25

1. Superior thoracic artery

Question 26

2nd part of the axillary artery (Hint: lies posterior to pectoralis minor)

Answer 26

1. Thoracoacromial artery: Clavicular, Acromial, Deltoid, Pectoral 2. Lateral Thoracic Artery

Question 27

3rd part of the axillary artery (Hint: from the lateral border of pectorals minor to inferior border of teres major)

Answer 27

1. Subscalpular --> Circumflex scapular artery + Thoracodorsal artery 2. Anterior circumflex humeral artery 3. Posterior circumflex humeral artery

Question 28

Axillary artery becomes the brachial artery.. when?

Answer 28

after the inferior border of teres major

Question 29

Subclavian artery branches (Hint: VIT C & D)

Answer 29

1. Vertebral Artery 2. Internal Thoracic Artery 3. Thyrocervical Trunk --> transverse cervical artery + supra scapular 4. Costocervical Artery 5. Dorsal Scapular Artery

Question 30

Serratus anterior Origin: Insertion: Innervation: Action:

Answer 30

Origin: lateral parts of the 1st - 8th ribs Insertion: anterior surface of the medial border of scapula Innervation Long thoracic nerve (C5-C7) Action: protraction and superior rotation of scapula

Question 31

Cause of clavicle fracture:

Answer 31

direct fall on the shoulder; indirect due to the transmission of force from arm and forearm to shoulder during a fall on an outstretched hand

Question 32

Presentation of clavicle of fracture:

Answer 32

Medial fragment is elevated d/t SCM; Lateral fragment is depressed d/t weight of arm and adducted and pulled medially d/t pectoralis major.