MSK 1.1 - Pectoral Region, Axilla And Brachial Plexus

Question 1

What are the 5 origin points of the pectoralis major?

Answer 1

• Medial half of clavicle
• Manubrium
• Body of sternum
• Costal cartilage of ribs 1-6
• Anterior layer of rectus sheath

Question 2

Where is the insertion point of the pectoralis major?

Answer 2

Crest of greater tubercule of humerus

Question 3

What is the nerve supply of the pectoralis major?

Answer 3

• Medial and lateral pectoral nerves

- Brachial plexus (C5, T1)

Question 4

What are the actions of the pectoralis major?

Answer 4

Adduction, medial rotation and Flexion of the humerus

Question 5

What is the shape and size of the pectoralis minor?

Answer 5

Small and triangular

Question 6

What are the origin points of the pectoralis minor?

Answer 6

Ribs 3,4 and 5

Question 7

What is the insertion point of the pectoralis minor?

Answer 7

Coracoid process of the scapula

Question 8

What is the nerve supply of the pectoralis minor?

Answer 8

Medial and lateral pectoral nerves (C6, T1)

Question 9

What is the action of the pectoralis minor?

Answer 9

Pulls scapula medially, forwards and downwards

Question 10

What is the shape and size of the serratus anterior?

Answer 10

Fan shaped and small

Question 11

What are the origin points of the serratus anterior?

Answer 11

• Superior section = 1st and 2nd ribs
• Intermediate section = 2nd and 3rd ribs
• Inferior section = 4th and 9th ribs

Question 12

What is the insertion point of the serratus anterior?

Answer 12

Medial margin of the costal surface of scapula

Question 13

What is the nerve supply of the serratus anterior?

Answer 13

• Long thoraic nerve

- Brachial plexus (C5-C7)

Question 14

What are the actions of the serratus anterior?

Answer 14

• Superior external rotation of scapula which moves scapula internally and forward therefore lowering the arm
• Lifts ribs

Question 15

What is the axilla and where is it located?

Answer 15

• Pyramidal shaped space

- Underneath shoulder and between thorax and upper limb

Question 16

What makes up the medial border of the axilla?

Answer 16

• Rib

- Serratus Anterior

Question 17

What makes up the anterior border of the axilla?

Answer 17

• Pectoralis major

- Pectoralis minor

Question 18

What makes up the lateral border of the axilla?

Answer 18

Intertubecular grooves of humerus

Question 19

What makes up the posterior border of the axilla?

Answer 19

• Scapula
• Subscapularis
• Latissimus Dorsi
• Teres major

Question 20

What does the axilla contain? (6)

Answer 20

• Cords of brachial plexus
• Axillary vein and artery
• Short head of biceps brachi
• Coracobrachialis
• Tendons of muscles attaching to scapula
• Axillary lymph nodes

Question 21

What is the order of sections in the brachial plexus?

Answer 21

• Branches
• Cords
• Divisions
• Trunks
• Roots

(BIG COCKS DO TOUCH RIGHT)

Question 22

What is the order of nerves in the brachial plexus?

Answer 22

• Musculocutaneous
• Axillary
• Radial (behind median)
• Median
• Ulnar

MARMU

Question 23

Where does the Musculocutaneous nerve originate?

Answer 23

C5, C6, C7 (cervical)

Question 24

Where does the Axillary nerve originate?

Answer 24

C5, C6 (cervical)

Question 25

Where does the median nerve originate?

Answer 25

C5 - T1 (cervical to thoraco)

Question 26

Where does the radial nerve originate?

Answer 26

C5 - T1 (cervical to thoraco)

Question 27

Where does the ulnar nerve originate?

Answer 27

C8, T1 (cervical, thoraco)

Question 28

What does the Musculocutaneous nerve innervate? (3)

Answer 28

- Biceps brachi - Brachialis - Coracobrachialis (The BBC)

Question 29

What does the Axillary nerve innervate? (2)

Answer 29

- Deltoid | - Regimental badge (area of skin)

Question 30

What does the median nerve innervate? (1)

Answer 30

Lumbricals of the hand

Question 31

What does the radial nerve innervate? (4)

Answer 31

- Skin in posterior forearm - Dorsal surface of lateral palm - Triceps brachi - Majority of extensor muscles

Question 32

What does the ulnar nerve innervate? (1)

Answer 32

The muscles of the hand

Question 33

What are the three sections of the cords?

Answer 33

- Lateral - Posterior - Medial

Question 34

Which nerves branch from the lateral section of the cords?

Answer 34

- medial and lateral pectoral nerves

Question 35

Which nerves branch from the posterior section of the cords?

Answer 35

There are three: - middle = thoracodorsal nerve - outer = upper and lower subscapular nerves

Question 36

What are the nerves that branch from the medial section of the cords?

Answer 36

There are three, read right to left: - medial and lateral pectoral nerves - medial cutaneous nerve of the arm - medial cutaneous nerve of the forearm

Question 37

What are the three sections of the trunks of the brachial plexus?

Answer 37

- superior (C5 and C6) - middle (C7) - inferior (C8 and T1)

Question 38

Which nerves branch of the superior section of the trunks?

Answer 38

- Suprascapular | - Nerve to subclavius

Question 39

What is Erb's Palsy and how is it caused?

Answer 39

- Damage to roots C5 and C6 due to too big of an angle increase between neck and shoulder - Upper brachial plexus injury

Question 40

What are the effects of Erb's palsy?

Answer 40

- 'Waiter's tip' | - Loss of sensation on anterior arm

Question 41

What is klumpke's palsy and how is it caused?

Answer 41

- Damage to nerves from T1 root upwards due to excessive abduction - Lower brachial plexus injury

Question 42

What are the effects of klumpke's palsy?

Answer 42

- Paralysis of small muscles in hand | - Sensory loss on medial side of arm

Question 43

What is the shape of the pectoralis major?

Answer 43

Large and triangular