Upper Limb: Brachial Plexus and Axillary Artery

Question 1

Axilla

Answer 1

• pyramidal space inferior to glenohumeral joint aka shoulder joint (when adducted, the space isn’t noticeable)
• passageway for neurovascular and muscular structures to enter and leave the upper limb)

Question 2

What are the boundaries of the Axilla? (this provides context to what space looks like but won’t be tested)

Answer 2

1. apex (1st rib and clavicle)
2. Base (skin and subcutaneous tissue)
3. Anterior (pectoralis major and minor)
4. Posterior (scapula and subscapularis)
5. Medial (Thoracic wall and serratus anterior)
6. Lateral (Humerus)

Question 3

What are the contents of the Axilla?

Answer 3

1. Axillary artery and its branches
2. Axillary vein and tributaries (vessel that empties into the main vessel kinda like a river)
3. Axillary lymph nodes (drain upper limp and chest wall/boobies)
4. Brachial plexus

Question 4

What does the overall 3D shape of the axilla look like?

Answer 4

a pyramid. It consists of four sides, an open apex and base.

Question 5

What is the Brachial Plexus

Answer 5

Major nerve network supplying the upper limb

Question 6

What is the Brachial Plexus formed by?

Answer 6

Union of C5-C8 and T1 nerve roots

Question 7

What are the 5 anterior rami roots of the brachial plexus?

Answer 7

C5 - T1

Question 8

What are the 3 trunks of the brachial plexus?

Answer 8

superior, middle, and inferior

Question 9

Toward the _____ root of the neck of the brachial plexus, the roots unite to form trunks

Answer 9

inferior

Question 10

where do the trunks of the brachial plexus pass through?

Answer 10

anterior and middle scalene muscles

Question 11

What are the components of the Brachial Plexus?

Answer 11

1. Roots (C5- C8 and then T1)
2. Trunks (Upper, Middle and Lower)
3. Divisions (Anterior and Posterior)
4. Cords (Posterior, Medial and Lateral) 5. Branches (5 total)

Question 12

What are the branches from the roots of the Brachial Plexus?

Answer 12

1. Dorsal scapular nerve (C5) - Rhomboids and levator scapulae
2. Long thoracic nerve (C5 -C7) - Serratus anterior
3. un-named muscular branches to deep cervical muscles

Question 13

What do the roots combine to form?

Answer 13

3 Trunks

Question 14

What are the 3 trunks of the Brachial Plexus?

Answer 14

1. Superior (upper) trunk: C5 and C6
2. Middle trunk: C7
3. Inferior (lower) trunk: C8 and T1

Question 15

What are the Branches of the Trunks of the Brachial Plexus?

Answer 15

1. Suprascapular (C5 - C6)
   - supr - and infraspinatus muscles
2. Nerve to subclavius (C5 and C6)
   - Subclavius muscle

Question 16

What does each trunk divide into?

Answer 16

An anterior and posterior division

Question 17

What do the anterior divisions of the trunk supply?

Answer 17

supply the anterior (flexor) compartment

Question 18

What do the posterior divisions of the trunk supply?

Answer 18

supply the posterior (extensor) compartment

Question 19

Anterior divisions of the upper and middle trunks unite to form the ________________

Answer 19

lateral cord

Question 20

Anterior division of the lower trunk continues as the _________________

Answer 20

medial cord

Question 21

Posterior divisions of all three trunks unite to form the __________

Answer 21

posterior cord

Question 22

Look at structure

Question 23

Cords are named in relation to their position to what structure?

Answer 23

Axillary Artery

Question 24

What are the branches from the posterior cord?

Answer 24

–Upper subscapular nerve-motor to subscapularis

–Lower subscapular nerve-motor to subscapularis and teres major

–Thoracodorsal nerve-motor to latissimus dorsi

Question 25

What are the branches from the Medial cord?

Answer 25

–Medial cutaneous nerve of the arm-sensory to medial arm –Medial cutaneous nerve of the forearm-sensory to medial forearm –Medial pectoral nerve-motor to pec major and minor

Question 26

What are the branches from the Lateral cord?

Answer 26

–Lateral pectoral nerve-motor to pec major

Question 27

What is the role of the 5 terminal braches of the brachial plexus?

Answer 27

provide motor and sensory distribution to the upper limb 1. Median nerve (M) - main trajectory are the muscles of the flexor compartment of forearm and part of the hands 2. Muscultaneous - Later aspect of the M, supplying the flexor muscles of the arm 3. Axillary nerve - comes off posterior curve and supplies deltoid and teres minor muscles 4. Ulnar nerve - supplies some muscles in the flexor compartment of the nerve 5. Radial nerve - comes off of posterior cord and takes care of extensor compartment of arm and forearm

Question 28

What does the supra-infraclavivular parts of the Brachial Plexus include?

Answer 28

–Roots, trunks and divisions of the brachial plexus –Dorsal scapular, long thoracic nerve, nerve to subclavius and suprascapular nerve

Question 29

What does the »Infraclavicular parts of the Brachial Plexus include?

Answer 29

–Cords and terminal branches of the brachial plexus –Lateral cord: 1 branch; Medial and Posterior Cords: 3 branches each –5 terminal branches (ulnar, median, radial, musculocutaneous, axillary)

Question 30

What are common locations of injury for the axillary nerve?

Answer 30

Surgical neck of humerus

Question 31

What are common locations of injury for the radial nerve?

Answer 31

spiral fracture along the distal third of humerus improper use of crutches

Question 32

Whats a common location of injury for the ulnar nerve?

Answer 32

Medial epicondyle, hitting the funny bone

Question 33

\_\_\_\_\_\_\_\_\_ is a network of nerve fibers that supplies the skin and musculature of the upper limb

Answer 33

brachial plexus

Question 34

The roots of the brachial plexus converge to form three trunks. What trunk is the combination of C8 and T1 roots?

Answer 34

inferior trunk

Question 35

The lateral cord of the brachial plexus is formed by:

Answer 35

anterior division of the superior and middle trunks

Question 36

Which of the following muscles does the axillary nerve innervate?

Answer 36

deltoid

Question 37

What is the axillary artery a continuation of?

Answer 37

subclavian artery (once it reaches its first rib, it becomes axillary artery

Question 38

Where is the 1st part of the axillary artery located?

Answer 38

Located between the lateral border of the 1st rib and the medial border of pec minor

Question 39

The axillary artery can be classified by its position relative to which muscle?

Answer 39

pectoralis minor

Question 40

The second part of main branches of the axillary artery includes:

Answer 40

thoracoacromial trunk and lateral thoracic artery

Question 41

The ___________ or shoulder blade is the bone that connects the clavicle to the humerus. The scapula forms the posterior aspect of the shoulder girdle.

Answer 41

scapula

Question 42

The _______ is the shallow depression of the scapula found on the lateral angle.

Answer 42

glenoid fossa

Question 43

The \_\_\_\_\_\_\_\_\_is a small projection of the scapula that extends anteriorly from the spine of the scapula.

Answer 43

acromiom

Question 44

The ______ originates from the superolateral surface of the costal scapula. It is a hook-like projection, which lies just underneath the clavicle.

Answer 44

coracoid process.

Question 45

The costal surface contains a large concave depression over most of its surface called \_\_\_\_\_\_\_\_\_\_\_\_\_.

Answer 45

subscapular fossa

Question 46

What does the proximal aspect of the humerus articulate with to form the glenohumeral joint?

Answer 46

glenoid fossa of the scapula

Question 47

The \_\_\_\_\_\_\_\_\_\_is located laterally on the humerus and has anterior and posterior surfaces.

Answer 47

greater tubercle

Question 48

The \_\_\_\_\_\_\_\_is a shallow depression that runs diagonally down the posterior surface of the humerus, parallel to the deltoid tuberosity.

Answer 48

radial groove

Question 49

What innervates the supraspinatous and infraspinatous

Answer 49

Suprascapular nerve

Question 50

The _____________ are a group of four muscles that originate from the scapula and attach to the humeral head.

Answer 50

rotator cuff muscles

Question 51

teres minor + infraspinatus =

Answer 51

lateral rotation

Question 52

What does the infraspinatous do to the humerus?

Answer 52

abducts

Question 53

What are the 3 heads of the triceps?

Answer 53

1. lateral head 2. medial head 3. long head

Question 54

Which space has the following anatomic borders; the teres minor the teres major muscle, the long head of the triceps brachii muscle, and the humeral surgical neck.

Answer 54

quadrangular space

Question 55

The posterior humeral circumflex artery is a vessel arising from the axillary artery at the ________ part of the arm.

Answer 55

proximal

Question 56

The _________ is a depression in the lateral part of the superior border of the scapula, which runs medial to the coracoid process

Answer 56

suprascapular notch

Question 57

The suprascapular nerve travels\_\_\_\_\_\_\_ the suprascapular ligament

Answer 57

under

Question 58

The axillary sheath contains the brachial plexus nerves and the \_\_\_\_\_\_\_\_\_.

Answer 58

axillary artery

Question 59

The _________ is a network of nerve fibers that supplies the skin and musculature of the upper limb. It begins in the root of the neck, passes through the axilla, and runs through the entire upper extremity.

Answer 59

brachial plexus

Question 60

T or F? Once the anterior and posterior divisions have entered the axilla, they combine together to form three cords, named by their position relative to the axillary artery.

Answer 60

True

Question 61

What are the terminal braches of the Brachial Plexus?

Answer 61

1. Musculocutaneous Nerve 2. Axillary Nerve 3. Median Nerve 4. Radial Nerve 5. Ulnar Nerve

Question 62

The radial and axillary nerves arise from the ________ of the brachial plexus

Answer 62

posterior cord