ANATOMY: Shoulder, Arm and Elbow Part 2

Question 1

What are the shoulder spaces? Why are they important and give examples

Answer 1

Shoulder spaces= triangular and quadrangular space
They’re important bc mucho arteries start in the axilla; they need to get round to supply the back of the shoulder, through these shoulder spaces
Eg: circumflex scapular artery goes thru the triangular space
Axillary nerve, posterior circumflex humeral artery and vein goes thru the quadrangular space
Axillary nerve innervates deltoid, if we lose it, we lose a lot of mobility

Question 2

Label this

Answer 2

Question 3

Label this

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Question 4

Label this and distingish between the different axillary boundaries

Answer 4

Question 5

Describe the borders of the axilla

Answer 5

Superior: cervico axillary canal. Bound by 1st rib, clavicle, and scapula
Base: Subcutaneous tissue/deep fascia of the armpit
Medial wall: Thoracic wall (ribs 1-4) and overlying intercostal and serratus anterior muscles
Lateral wall: Narrow bony wall. The intertubercular groove of the humerus
Anterior wall: pec major and minor
Posterior wall: superiorly the scapula/subscapularis. Inferiorly the latissimus dorsi and Teres major

Question 6

What are the 3 elbow joints?

Answer 6

Humeroulnar: hinge joint
Humeroradial: limited ball and socket joint, functions as a hinge joint with humeroulnar, while allowing rotation for proximal radioulnar joint
Proximal radioulnar joint: pivot joint

Question 7

What are the 2 different parts on the distal end of the humerus?

Answer 7

There are two different parts on its articular surface:
Trochlea-forms a hook-like joint with the trochlear notch of the ulnar
Capitulum - against head of radius

Question 8

Label and describe this

Answer 8

Fat pads - act as reinforcement + support
Anular ligament of radius is for proximal radialulnar joint - allows radius to pivot against the ulnar

Question 9

What is the joint capsule relating to the radius and ulna?

Answer 9

Joint capsule has two distinct enlargements
- radial collateral ligament
- ulnar collateral ligament
- (also anular ligament of radius)
They stop the elbow from dislocating laterally

Question 10

Label this

Answer 10

Question 11

Label this

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Question 12

Label this

Answer 12

Question 13

What is the olecranon process, what attaches to it?
Also, describe what the biceps bracii and brachialis attach to

Answer 13

When u feel ur elbow, it is the olecranon process that ur feeling

Triceps attaches to the olecranon process
Brachialis attaches to the coronoid process
Biceps bracii attaches to the radial tuberosity

Question 14

What are the muscle compartments of the arm?

Answer 14

The flexor compartment - anterior
The extensor compartment - posterior
Bound in deep fascia - separates musculature from skin.
The lateral intermuscular septum is where the fascia goes inwards and joins onto the bone

Question 15

Label

Answer 15

Question 16

Which muscles are located in the anterior compartment of the upper arm?

Answer 16

3 muscles in theanterior compartment of upper arm – biceps brachii, coracobrachialis and brachialis. They are all innervated by themusculocutaneous nerve

Arterial supply to the anterior compartment of the upper arm is via muscular branches of thebrachial artery.

Question 17

Describe biceps brachii and its function

Answer 17

Biceps brachii: short head comes from the coracoid process of the scapula, long head from the supraglenoid tubercle.
Both heads converge to insert into the radial tuberosity, with part also attaching to the forearm fascia via the bicipital aponeurosis. Innervated by the musculocutaneous nerve

Action: supinates the forearm, and, when the forearm is in a supinated position, it flexes the forearm at the elbow joint

Question 18

Answer 18

Question 19

Describe the brachialis

Answer 19

• Attachments:Originates from the medial and lateral surfaces of the humeral shaft and inserts into theulnar tuberosity,just distal to the elbow joint.
• Function:Flexionat the elbow.

Question 20

Answer 20

Question 21

Describe the corobrachialis

Answer 21

• Attachments:Originates from the coracoid process of the scapula. The muscle passes through theaxilla and attaches the medial side of the humeral shaft, at the level of the deltoid tubercle.
• Function:Flexionof the arm at the shoulder, and weak adduction.

Question 22

Answer 22

Question 23

The posterior comparatment of the arm contains the triceps. Describe the attachments of this

Answer 23

Attachments
Long head – originates from the infraglenoid tubercle.
Lateral head – originates from thehumerus, superior to the radial groove.
Medial head – originates from the humerus, inferior to the radial groove.
Distally, the heads converge onto one tendon and insert into the olecranon of theulna

Question 24

Answer 24

Question 25

What is the function of the triceps?

Answer 25

Function:Extension of the arm at the elbow. Additionally, as the long head crosses the glenohumeral joint, it has some action in the shoulder joint. It mainly resists dislocation, especially if the arm is in the abducted position. It has a small role in adduction and extension, but mostly to prevent dislocation

Question 26

Answer 26

Question 27

Describe the anterior posterior and lateral walls of the axilla

Answer 27

Anterior wall of your axilla is mostly made up of the pectoralis major
The back of it is made up of lattisimus dorsi
Lateral wall is just where intertubercular groove is
Arteries + nerves are contained in a layer of fascia called the axillary sheath
Axillary sheath contains:
- axillary nerve
- axillary artery
- brachial plexus

Question 28

Describe the axillary artery

Answer 28

Axillary artery starts as subclavian artery
On the LHS, subclavian branches off directly from the arch of aorta
On the RHS, subclavian branches off the brachiocephalic trunk
We go from subclavian artery to the axillary artery at the lateral margin of rib I
It runs through axilla until it reaches the bottom border of axilla marked by inferior border of teres major
From then on, it is in the axilla, so is called brachial artery

Question 29

The axillary artery is divided into…

Answer 29

Axillary artery divided into three parts
- before pec major (1st part)
- behind pec major (2nd part)
- after pec major (3rd part)

Question 30

Answer 30

Question 31

What comes off the axillary?

Answer 31

Coming off the axillary:
Thoracoacromial artery - clavicular branch, goes up the clavicle
Pectoral branch - supplies pecs
Deltoid branch - supply deltoid muscle
Acromial branch - supplies all tissue in acromial area
Circumflex arteries - wrap around head of humerus

Question 32

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Question 33

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Question 34

Describe the brachial veins

Answer 34

Brachial veins are usually not a single vein, rather they are 2-3 smaller veins running around the brachial artery.
They join with the basilic vein –> axillary vein
Basilic and brachial vein have a communicating vein in the elbow crook (median cubital fossa). This superficial point is good for taking blood

Question 35

Answer 35

Question 36

The brachial plexus wraps around the brachial artery. Describe the brachial plexus

Answer 36

Sections are named after the relation of themselves to the brachial artery
The lateral and medial chord are in front of the brachial artery
Posterior chord runs behind the brachial artery

Question 37

Draw out the brachial plexus

Answer 37

Question 38

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Question 39

What do these nerves supply?

Answer 39

Musculocutaneous supplies anterior compartment of the arm
Median supplies most of anterior compartment of forearm
Ulnar supplies some parts of both the anterior and posterior compartments of the forearm, on the ulnar (medial) side

Question 40

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Question 41

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Question 42

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Question 43

What does the axillary and radial nerve supply?

Answer 43

Axillary supplies deltoid and teres minor
Radial supplies posterior compartment of arm and most of the posterior compartment of the forearm

Question 44

Where do all of the lymph nodes drain into?

Answer 44

Humeral/pectoral/scapular lymph nodes all drain into the central lymph node. This drains into the apical, which drains into the subclavicular. This predictable pattern of drainage is important for the spread of cancer, particularly breast cancer