Lecture-7 Axilla & Arm

Question 1

Pectoralis Major

Answer 1

2 heads: -Clavicular head
-Sternocostal Head
Inserts: crest if greater tubercle of humerus/lateral lip of intertubercular sulcus
Innervation: lateral/medial pectoral nerves
Action: -adducts, medial rotation, flex humerus, scapula protraction
-enclosed in pwctoral fascia

Question 2

Pectoralis Minor

Answer 2

Origin: ribs 3-5
Inserts: -coracoid process
Innervation: - medial pectoral nerve
Action: -Stabilizes scapula against thorax wall by drawing it anteriorly and inferiorly

Question 3

Subclavius

Answer 3

-Attaches clavicle to 1st rib
-Innervation: subclavian nerve
Action: depresses scapula

Question 4

Serratus Anterior

Answer 4

Inserts: attaches to medial scapular border
Innervation: long thoracic nerve
Action: -protraction, upward rotation of scapula

Question 5

Axila

Answer 5

• pyramidal shaped region at junction of upper extremity/thorax
• transmits nerves/vessels between neck/thorax proximally and the upper extremity distally

Question 6

Axillary contents

Answer 6

• axillary artery + branches
• axillary vein +tributaries
• axillary lymph nodes +lymph vessels
• Parts of brachial plexus
• axillary sheath of fascia

Question 7

Borders of Axilla

Answer 7

Apex: formed by convergence of clavicle, scapula, and 1st rib
Base: formed by axillary fascia
Anterior wall: pec major and minor + fascia
Posterior wall: anterior part of scapula and scapular muscles
Lateral wall: intertubercular groove of humerus, tendon of long head of biceps braccii traverses the intertubercular groove

Question 8

Axillary Artery

Answer 8

-begins at lateral border of 1st rib, ends at inferior border of teres major
-divided into 3 parts by pec minor
First part: -medial to pec minor -one branch: superior thoracic artery
Second part: -posterior to pec minor - 2 branches: -Thoracoacromial artery
(4 branches: pectoral, clavicular, deltoid, acromial)
-Lateral thoracic artery
Third part: -lateral to pec minor -3 branches: -subscapular -anterior circumflex -posterior circumflex

Question 9

Axillary Vein

Answer 9

• A continuation of basilic vein
• at inferior border of teres minor
• turns to subclavian at lateral broder of 1st rib
• cephalic vein pierces costocoracoid membrane to enter medial part of axillary vein

Question 10

Brachial plexus

Answer 10

-goes inferior and deep to clavicle
-has region superior to claavicle and distal to clavicle
C5-T1
Primarily responsible for motor and sensory
-thoracoappendicular and appendicular muscles

Question 11

Musculocutaneous

Answer 11

• Terminal Branch
• C5,6,7
• provides innervation to anterior arm
• becomes lateral cutaneous nerve of forearm

Question 12

Median

Answer 12

• Terminal Branch
• C6-T1
• Innervates anterior compoartment of forearm -except flexor carpi ulnaris and part of flexor digitorum profundus
• innervates thenar muscls and lateral 2 lumbricals in hand

Question 13

Ulnar

Answer 13

-Terminal Branch
-C8-T1
Innervates 2 and a half muscles

Question 14

Radial

Answer 14

• Terminal Branch
• From posterior cord
• C5-T1
• innervates posterior aspect of upper extremity

Question 15

Axillary

Answer 15

-Terminal Branch
From posterior cord
-C5,6
-innervates deltoid, teres minor, long head of triceps

Question 16

Dorsal Scapular

Answer 16

• From root level

- C5

Question 17

Suprascapular

Answer 17

-From trunk
level
-C5,6
-to supraspinatus and infraspinatus

Question 18

Nerve to subclavius

Answer 18

• From trunk level

- C5

Question 19

Lateral/medial pectoral

Answer 19

• From cord level
• C5,6,7 / C8,T1
• To pec majorm medial nerve also supplies pec minor

Question 20

Upper subscapular

Answer 20

• From cord level
• C5,6
• to subscapularis

Question 21

middle subscapular/thoraco dorsal

Answer 21

• From cord level
• C6,7,8
• To lat. dorsi

Question 22

lower subscapular

Answer 22

• From cord level
• C6,7,8
• to subscapularis and teres major

Question 23

Long thoracic

Answer 23

• From root level

- C5,6,7

Question 24

Lesion types

Answer 24

Avulsion: nerve torn from spine, can’t heal
Rupture: nerve is torn but not at spinal attachment
Neuroma: nerve torn and healed, but scar tissue puts pressure on injured nerve and prevents it from conducting signals to muscles
Neuropraxia: - damaged but not torn

Question 25

Biceps Brachii

Answer 25

Distal Attachment: Radial tuberosity and fascia of forearm Proximal Attachment: short head: tip of coracoid long head: supraglenoid tubercle of scapula Innervation: Musculocutaneous nerve (C5,6) Action: Supinates forearm, flexes forearm

Question 26

Brachialis

Answer 26

Distal Attachment: Coronoid process and ulnnar tuberosity Proximal Attachment: Distal half of anterior surface of humerus Innervation: Musculocutaneous nerve (C5,6) Action:Flexes forearm in all positions

Question 27

Coracobrachialis

Answer 27

Distal Attachment: Middle third of medial surface of humerus Proximal Attachment: Tip of coracoid process Innervation: Musculocutaneous nerve (C5,6,7) Action: flex and adduct arm

Question 28

Musculocutaneous nerve

Answer 28

innervates: -coracobrachialis -biceps brachii -brachialis | - gives rise to lateral cutaneous nerve of forearm

Question 29

Median nerve

Answer 29

-travels distally behind biceps entering forearm in cubital fossa -no innervation of arm

Question 30

Ulnar nerve

Answer 30

- most medial, passes to forearm posterior to medial epicondyle - no innervation of arm

Question 31

Radial nerve

Answer 31

- innervates triceps brachii - descends posterior to humerus along radial groove - ccourses anteriorly at distal humerus and crosses anterior to lateral condyle

Question 32

Brachial Artery

Answer 32

- Deep artery of arm (profunda brachii) - muscular branches - middle collateral - radial collateral - humeral nutrient branch - superior ulnar collateral - inferior ulnar collateral - muscular branches

Question 33

Triangular space

Answer 33

Made by: -long head of triceps brachii -teres minor -teres major passage to posterior arm for: -circumflex scapular artery

Question 34

Quadrangular space

Answer 34

Made by: -long head of triceps brachii -teres major -teres minor -neck of humerus passage to posterior arm for: -posterior circumflex humeral artery -axillary nerve

Question 35

Triangle interval

Answer 35

Made by: - teres major -long head of triceps brachii -shaft of humerus passage to posterior arm for: -radial nerve -deep artery of the arm