1. Upper Limb, part I Shoulder, Arm, and Axilla.

2. Objectives: 1. Bones and joints of the shoulder 2
Objectives: 1. Bones and joints of the shoulder 2. Organization of the shoulder’s muscles Axilla - borders and contents 4. Organization of the brachial plexus
Corocoid process is only on front

3. Sternal clavicular joint
Which joint serves as the only bony attachment of
the upper limb to the axial skeleton?
Sternal clavicular joint
Start dissection on the posterior side
Supraspinous fossa
Infraspinous fossa
Subscapular fossa
Lesser and greater tubercles
Surgical neck: area of upper limb that breaks most often
Anterior view
Posterior view
Which of these bones is commonly fractured?
clavicle

4. } ORGANIZATION OF THE SHOULDER: MUSCLES AND INNERVATION rotator cuff
* Muscles (MM) ATTACH HUMERUS TO AXIAL SKELETON:
1. Latissimus Dorsi ( thoracodorsal n. C6-C8 )
2. Pectoralis Major ( lateral pectoral n. C5-C7, medial pectoral n. C8-Th1 )
- attaches to humerus
* MM ATTACH HUMERUS TO THE SCAPULA
1. Supraspinatus, Infraspinatus ( suprascapular n. C5-C6 )
2. Subscapularis ( upper C5 and lower C6 subscapular nn. )
3. Teres Minor ( axillary n. C5-C6 )
4. Teres Major ( lower subscapular n. C6 )
5. Deltoid ( axillary n. C5-C6 ) }
rotator cuff
Supraspinatus
.: Assists the deltoid in the initial abduction
Infraspinatus
.: Powerful lateral rotator of humerus
Teres minor
.: Helps rotate the arm laterally and assists in adduction (like infraspinatus). HOWEVER, it is innervated by the axillary nerve, while the infraspinatus is innervated by the suprascapular nerve
Subscapularis
.: It is the primary medial rotator (also adducts it)
.: Innervated by the subscapular nerve
Humerus (arm bone)
Levator scapulae is innervated by the dorsal scapular nerve. Why? It’s the most dorsal (superficial) muscle in that group around the scapula. However,
* MM ATTACH SCAPULA TO AXIAL SKELETON
1. Trapezius ( spinal accesory n. XI )
2. Levator Scapulae, Rhomboids ( dorsal scapular n. C5 )
3. Serratus Anterior ( long thoracic n. C5-C7 )
4. Pectoralis Minor ( medial pectoral n. C8-Th1 )

5. The deltopectoral triangle is also known as the “clavicopectoral triangle”. These two names tells me the exact borders.
What’s in the triangle?
Latissimus dorsi and teres major have similar actions and run in similar directions
Trapezius innervation: CN XI (Accessory)
Deltoid innervation: Axiliary nerve
Infraspinatus: Suprascapular
Supraspinatus: Suprascapular
Levator scapulae: dorsal scapular
Rhomboid major: Dorsal scapular
Rhomboad minor: dorsal scapular
Teres Major: Suprascapular
Splenius capitis:
Teres Minor: Axiliary
The cephalic vein

6. Which structures lie in the deltopectoral triangle?
Cephalic vein
Cut away the breast, not concerned with it
Look for the cephalic vein (lateral side of arm)
- lies between deltoid and pectoralis major
- Pretty superficial

7. Lateral rotation (away from body)
Medial rotation (towards the body)
Subscapularis medially rotates
Teres minor and infraspinatus rotate laterally
The rotator cuff muscles work as a group in holding the head of the humerus in the glenoid cavity. They give protection and stability to the shoulder joint.

8. Rotator cuff
S I T S
subscapularis
Rotator cuff is formed by the tendons of: Supraspinatus , Infraspinatus, Teres minor and Subscapularis fuses with the joint capsule.
What is the tendonitis of the rotator cuff? inflammation

9. Axilla (the armpit)
Apex – cervicoaxillary canal, the passageway between
the neck and the axilla. Lies between the 1st rib, clavicle
and upper border of the scapula.
Base - formed by the skin, subcutaneous tissue and axillary
fascia
3. Four walls:
* anterior wall - pectoralis major and minor mm, pectoral and clavicopectoral fascia.
Anterior axillary fold -> pectoralis major!
* posterior wall - scapula , subscapularis m., latissimus dorsi m., teres major m.
Posterior axillary fold -> latissimus dorsi and teres major!
What forms the fold?
What forms the wall?
At which point do we find the cervico-axillary canal?
What is contained in the cervico-axillary canal?
* medial wall - thoracic wall and serratus anterior m.
* lateral wall - intertubercular groove of the humerus.
Fun note: Axillary fossa = armpit

10. What passes through the cervico-axillary cannel?
.: Arteries, veins, lymphatics and nerves to and from the arm
What mainly forms the posterior wall?
.: Scapula

12. Contents of the axilla:
axillary artery and its branches
axillary vein and its tributaries
brachial plexus
axillary lymph vessels and lymph nodes
3 muscles: long/short head of biceps brachii m.
and coracobrachialis m.
The axillary artery and vein, and the cords of brachial plexus
(neurovascular bundle) are enveloped in the thin fascial sheath - axillary sheath.
Cord of the brachial plexus, axillary artery and vein in the axilla are called… neurovascular bundle
What is the neurovascular bundle wrapped in? Axillary sheath

13. AXILLA ROOTS AND TRUNKS CORDS AXILLARY ARTERY NEUROVASCULAR BUNDLE
CLAVICLE

14. Axillary artery – three parts
First part - one branch – superior thoracic a.
Second part - two branches – thoracoacromial a.
– lateral thoracic a.
Third part - three branches – subscapular a.
– anterior circumflex humeral a.
– posterior circumflex humeral a.
Screw the lawyer, save the patient
Superior thoracic
Thoracodorsal
Lateral thoracic
Subscapular
Anterior circumflex humeral
Posterior circumflex humeral
Screw the lawyer, save the patient
Superior thoracic
Thoracodorsal
Lateral thoracic
Subscapular
Anterior circumflex humeral
Posterior circumflex humeral

15. The thoracoacromial artery will further branch off in 4 directions, named after parts of the body.
Mnemonic: Cadavers Are Dead People
Clavicular
Acromial
Deltoid
Pectoral

16. Screw the lawyer, save a patient
Superior thoracic
Thoracoacromial
Lateral thoracic
Subscapular
Anterior circumflex humeral
Posterior circumflex humeral

17. posterior circumflex
humeral a. (3rd part)
superior thoracic a.
(1st part)
anterior circumflex
humeral a. (3rd part)
thoracoacromial a.
(2nd part)
subscapular a.
(3rd part)
circumflex scapular a.
lateral thoracic a.
(2nd part)
thoracodorsal a.

18. Arterial anastomoses around the scapula
.: Thoracoacromial artery
Cadavers are dead people
1. clavicular
-2. acromial
-3. deltoid
-4. pectoral
Humeral loop:
anterior circumflex humeral posterior circumflex humeral
profunda brachii
thyrocervical trunk
subscapular a.
axillary a.
anterior circumflex humeral a.
deep branch of
transverse cervical a.
*(dorsal scapular)
posterior circumflex humeral a.
circumflex scapular a.
Humeral loop:
Anterior circumflex humeral
Posterior circumflex humeral
Profunda brachii
Scapular loop:
Suprascapular
Dorsal scapular
Subscapular
Scapular loop:
Suprascapular
Dorsal scapular
Subscapular
profunda brachii a.

19. Arterial anastomoses form loops
Think about where the loops are located. That’s where they get the name. The anterior circumflex humeral, posterior circumflex humeral and profunda brachii are all wrapping around in the humerus
The same goes for the scapular loop, which contains the suprascapular, dorsal scapular and subscapular ateries

20. Axillary lymph nodes Five principal groups:
1. Pectoral( anterior) nodes receive lymph mainly from anterior thoracic wall and the breast and abdominal wall.
2. Subscapular (posterior) nodes receives lymph from posterior thoracic wall and scapular region.
3. Humeral (lateral) nodes
receive lymph from upper limb.
4. Central nodes (base of axilla)
receive lymph from anterior, posterior and lateral nodes.
Drain into apical nodes.
5. Apical nodes (apex of axilla)
Receive lymph from all the other nodes. Drain into the subclavian trunks.
Axillary lymph nodes
What we need to know about the arteries; don’t need to study the material. Just used to display what’s going on here.

21. PLAN OF BRACHIAL PLEXUS = Ventral Rami C5 to T1
ROOTS
(5)
TRUNKS
(3) C5
DIVISIONS
(3/3) C6
CORDS
(3)
SUPERIOR
TERMINALS
(5) C7 A C8
MIDDLE
MUSCULOCUTANEOUS
LATERAL T1 P
INFERIOR
POSTERIOR A
RADIAL
Terminal branch: nerve going to the branches
MEDIAL
DIVISIONS = ANTERIOR AND POSTERIOR
AXILLARY
MEDIAN
ULNAR
Which spinal nerves form the brachial plexus? C5, C6, C7 C8 and T1

22. The roots of brachial plexus unite to form three trunks:
Brachial plexus is formed by the union of the anterior (ventral) primary rami of C5 – T1 nerves that constitute roots of brachial plexus.
The roots of brachial plexus unite to form three trunks:
* superior trunk (C5-C6)
* middle trunk (C7)
* inferior trunk (C8-T1)
Each trunk divides into anterior and posterior divisions of brachial plexus.
The divisions of the trunks form three cords of brachial plexus:
* posterior cord - posterior divisions of all three trunks
* lateral cord – anterior divisions of superior and middle trunk
* medial cord – anterior division of the inferior trunk
The cords of brachial plexus give rise to most of the named peripheral nerves (branches) that result from the plexus formation.

23. Basic Anatomy of the Brachial Plexus
Axillary nerve
Radial nerve
Ulnar nerve
Musculocutaneous nerve
Median nerve 5
Ventral rami or
roots
Posterior cord
Medial cord
Lateral cord 6
Trunk
Posterior divisions
Anterior divisions 7 8 1

24. Roots, Trunks and Cords:
BRACHIAL PLEXUS
Roots, Trunks and Cords:
Motor Distribution to Anterior and Posterior Shoulder
Terminal Branches:
Motor Distribution to Arm, Forearm and Hand
My Aunt Raped My Uncle
Musculocutaneous; Axillary; Radial; Medial; Ulnar

25. CORDS OF BRACHAL PLEXUS - TERMINAL BRANCHES
I. LATERAL CORD:
1. musculocutaneous n.(C5-C7):
 anterior group of arm (muscles of anterior arm are innervated; biceps, brachialis and coracobrachialis)
2. lateral root of median n.(C6-C7) :
 anterior group of forearm (except flexor carpi ulnaris, medial half of flexor digitorum profundum)
 thenar muscles and first two lumbricals
What does the musculocutaneous innervate?
- brachialis, biceps (muscles of anterior arm)
What does the lateral root of the median nerve innervate?
- anterior group of forearm (except for flexor carpi ulnaris and medial half of flexor digitorum profundum
- Thenar muscles and first two lumbricals

26. Musculocutaneous nerve (C5,6,7)
Lateral cord of brachial plexus
Coracobrachialis muscle
Ulnar nerve
Biceps brachii muscle
Cutaneous innervation
( skin of lateral forearm)
Brachialis muscle
Lateral cutaneous nerve of forearm
Note the name: musculocutaneous
It innervates the muscles in the arm and the cutaneous layer (skin) of the forearm
What cord does this nerve spring from? The lateral cord.
This is a pretty good way to remember what part of the forearm the musculocutaneous nerve innervates.
Lateral anterior
Musculocutaneous nerve: C5, C6, C7
Innervates:
-Coracobrachialis
-Biceps brachii
-Brachialis

27. CORDS OF BRACHAL PLEXUS - TERMINAL BRANCHES
II. MEDIAL CORD:
1. medial root of median n. (C8-T1):
 anterior group of forearm (except flexor carpi ulnaris, medial half of flexor digitorum profundum)
 thenar muscles and first two lumbricals
2. ulnar n. (C8-T1):
 flexor carpi ulnaris
 medial half of flexor digitorum profundum
 all the small muscles of the hand (except thenar and two first lumbricals)

28. What did the lateral root of the median nerve innervate?
.: thenar muscles, first two lumbricals, and anterior group of forearm except for flexor carpi ulnaris and medial half of flexor digitorum profundum
Does the medial root of the median nerve innervate these exceptions?
.: No, in fact it does the same thing as the lateral root (these cords join together to form the median nerve
So what does innervate the flexor carpi ulnaris and the medial half of flexor digitorum profundum?
.: ulnar nerve
Anything else?
.: All the small muscles of the hand except for the thenar and the first two lumbricals, which is what the median nerve takes care of.

29. Median nerve (C5,6,7,8,T1) Medial cord of brachial plexus
Note that the median nerve only cutaneously innervates the anterior part of the hand, and the back of the fingertips, not the rest of the back of the hand.
The pimp hand is felt with the radial nerve and the ulnar, I believe.
Medial cord of brachial plexus
Median nerve (C5,6,7,8,T1)
Lateral cord of brachial plexus
Muscles of forearm
Flexors of forearm except fl.carp.ulnaris and medial flexor dig. profundus
Cutaneous innervation
Palmar branch of median nerve
Median nerve innervates thumbs and index and middle fingers with some ring finger
Ignore except for flexor/extensors
Muscles of hand (thenar group and two first lumbricals)
Common & proper digital nerves

30. Note: Only muscles innervated by ulnar nerve shown
Ulnar nerve (C7,8,T1)
Medial epicondyle
Flexor dig. profundus (medial part)
Cutaneous innervation
Flexor carpi ulnaris muscle
Dorsal branch of ulnar nerve
Deep & superficial branch of ulnar nerve
Muscles of the hand
(excluding thenar and
two lumbrical muscles)
Proper palmar digital nerves

31. CORDS OF BRACHAL PLEXUS - TERMINAL BRANCHES
III. POSTERIOR CORD:
1. axillary n. (C5-C6):
 deltoid,
 teres minor
2. radial n. (C5-T1):
 posterior group of arm and forearm

32. In what situations the axillary nerve may be damaged (injured)?
Fracture of the surgical neck
Dislocation of the glenohumeral joint
Compression from the incorrect use of crutches
What’s in the quadrangular space?
- axillary nerve
- posterior circumflex artery/vein
What is the quadrangular space bordered by? -

33. Radial nerve(C5,6,7,8) a Superficial and deep branch of radial nerve
Posterior interosseous nerve (continuation of deep branch of Radial nerve)
Superficial branch of radial nerve
The radial nerve has both superficial and deep branches. It will later split into the posterior interosseous nerve. The superficial branch will turn into the dorsal digital nerves. These aid in feeling the sting when exercising your pimp hand.
Dorsal digital nerves

34. BRACHIAL PLEXUS – branches of ROOTS, TRUNKS AND CORDS
DORSAL SCAPULAR C5
RHOMBOID MM AND LEVATOR SCAPULE
ROOTS
SUPRASCAPULAR C5,6
SUPRASPINATUS M
INFRASPINATUS M C5
N. TO SUBCLAVIUS C5,6
SUBCLAVIUS C6
LATERAL PECTORAL C5-C7
PECTORAL MM C7
ROOTS
TRUNKS C8
THORACODORSAL C6-C8
LATISSIMUS DORSI M T1
CORDS
LONG THORACIC C5-C7
SERRATUS ANTERIOR M
Posterior cords are involved in medial rotation
MEDIAL PECTORAL C8,T1
PECTORAL MM
SUBSCAPULAR NN C5,6
SUBSCAPULARIS M
TERES MAJOR M

35. ARM muscles - action on shoulder and elbow
Flexors (anterior compartment):
* biceps brachii (both joints) - supination and flexion of forearm
- flexion of arm
* coracobrachialis (shoulder joint) - flexion and add. of arm
* brachialis (elbow joint) - flexion of forearm in all position
Extensors (posterior compartment):
* triceps brachii (both joints) - extension of forearm
- extension of arm (long h.)
2 groups: anterior and posterior compartments

36. Anterior ( flexor) compartment
Posterior (extensors) compartment
Teres minor
Quadrangular
Surgical neck of Humerus
Long head of tricep
Teres major

37. Important spaces of the shoulder region
Deltopectoral triangle – bounded by the clavicle superiorly, deltoid
laterally and the pectoralis major (clavicular head) medially.
Cephalic vein and deltoid branch of thoracoacromial artery.
Quadrangular space – bounded superiorly by the teres minor and subscapularis, inferiorly by the teres major, medially by the long head of the triceps and laterally by the surgical neck of the humerus.
Axillary nerve and posterior circumflex humeral artery and vein.
Triangular space – superiorly by the teres minor, inferiorly by the teres major and laterally by the long head of triceps.
Circumflex scapular vessels.
Triangular interval - between the two heads of the triceps muscle, inferior to the teres major.
Deep brachial artery and radial nerve.

38. 1 – triangular space, 2 – quadrangular space, 3 – triangular interval

39. Brachial plexus injuries
Injuries to the brachial plexus affect movements (paralysis) and
cutaneous sensation (anesthesia). Signs and symptoms depend on the
part of the plexus involved.
Erb-Duchenne palsy is a paralysis of the arm caused by injury to the upper group of the
arm's main nerves (specifically, spinal roots C5-C7), almost always occurring during
birth. Depending on the nature of the damage, the paralysis can either resolve on its own
over a period of months, necessitate physical therapy or require surgery.
Dejerine-Klumpke (Klumpkes) palsy refers to paralysis of the lower brachial plexus.
A rare condition where a lower spine lesion causes paralysis of the forearm and hand muscles. The lesion may occur during birth or as a result of infection, tumor or trauma.

40. Questions of the day!
Which muscle is the primary supinator of the forearm?
Biceps brachii
Which muscle serves as the prime extensor of the forearm?
Triceps
If a tumor grows into the quadrangular space of the axillary region, which structures would be in danger? (Axillary nerve, posterior circumflex humeral)
Humeral loop
Brachial plexus
****Which artery may be damaged during the fracture of the shaft of the humerus?
Posterior circumflex humeral artery