Upper Limb Anatomy Flashcards
Boundaries of the Axilla - Base, Anterior wall, Posterior wall, Medial wall & Lateral wall.
Base = Skin & Hair
Anterior wall = Pectoralis major, Pectoralis minor & Clavipectoral fascia.
Posterior wall = Latissimus dorsi, teres major, teres minor & subscapularis.
Medial wall = Serratus anterior and Ribcage
Lateral wall = intertubercular groove of humerus
Gateways in the Posterior wall of the Axilla
Quadrangular space, Triangular space & Triangular interval.
Quadrangular space
MADE BY:
- Inferior margin of the subscapularis muscle;
- Surgical neck of the humerus;
- Superior margin of the teres major muscle;
- Lateral margin of the long head of the triceps brachii muscle
It allows through: Axillary nerve & posterior circumflex humeral artery and vein.
Triangular space
MADE BY:
- Medial margin of the long head of the triceps brachii muscle
- Superior margin of the teres major muscle
- Inferior margin of the subscapularis muscle.
Passing through: Circumflex scapular artery and vein.
Triangular interval
MADE BY:
- Lateral margin of the long head of the triceps brachii muscle
- Shaft of the humerus
- Inferior margin of the teres major muscle
Passing through: Radial Nerve
Define Fascia
Fascia is made up of sheets of connective tissue that are found below the skin. These tissues attach, stabilize, impart strength, maintain vessel patency, separate muscles, and enclose different organs.
Contents of Axilla
- Passing through the axilla are:
Major vessels
Brachial plexus
Lymphatics of the upper limb. - Also contains:
Proximal parts of two muscles of the arm
Axillary process of the breast,
Lymph nodes draining the upper limb and chest wall.
(6) Branches of Axillary artery
Screw The Lawyer, Save A Patient
S: superior thoracic artery. T: thoracoacromial artery. L: lateral thoracic artery. S: subscapular artery. A: anterior humeral circumflex artery. P: posterior humeral circumflex artery.
Axillary vein
- Deep vein of the upper limb is formed by the union of the brachial and basilic veins.
- Starts at the lower border of the teres major muscle and ascends medially through the axilla towards the 1st rib, where it is continued by the subclavian vein.
- Along its course, the axillary vein lies anteromedial to the axillary artery, partially overlapping it.
Names of Axillary lymph nodes
- Pectoral nodes
- Subscapular nodes
- Lateral nodes (where most lymphatics of the upper limb drain into)
- Central nodes
- Apical nodes
Define Brachial plexus and how is it formed?
- Network of nerve fibers that supply the skin and musculature of the upper limb.
- Begins in the root of the neck, passes through the axilla, and runs through the entire upper extremity.
- Formed by the anterior rami (divisions) of C5, C6, C7, and C8, and T1
5 parts of the Brachial plexus
Mnemonic Read That Damn Cadaver Book
R- Roots T - Trunks D - Divisions C - Cords B - Branches
5 terminal branches of the Brachial plexus
- Musculocutaneous nerve
- Median nerve
- Ulnar nerve
- Axillary nerve
- Radial nerve
The Arm is the region _______
of the upper limb between the shoulder and the elbow.
The layout of the Arm
2 Septa: - Medial - Lateral 2 Compartments: - Anterior - Posterior
The lower end of the Humerus
- Trochlear, Capitellum, Medial epicondyle & Lateral epicondyle.
There are ___ muscles in total for the Anterior & Posterior compartments of the arm.
These are:
Anterior compartment = _____
Posterior compartment = ______
- 4
- Anterior compartment = Coracobrachialis, Biceps Brachii & Brachialis.
- Posterior compartment = Triceps brachii
OIAN long form
Origin, Insertion, Action & Nerve.
Triceps brachii (OIAN)
O = Long head: infraglenoid tubercle of the scapula
Lateral head: posterior surface of the humerus, superior to radial groove.
Medial head: posterior surface of the humerus, inferior to the radial groove.
I = Proximal end of the olecranon process of ulna and fascia of forearm
A = Chief extensor of forearm; long head steadies head of the abducted humerus
N = Radial Nerve
Coracobrachialis (OIAN)
O = Tip of coracoid process of scapula I = Middle third of the medial surface of the humerus A = Helps to flex and adduct the arm N = Musculocutaneous nerve
Biceps brachii (OIAN)
O = Short head: tip of coracoid process of scapula
Long head: supraglenoid tubercle of the scapula.
I = Tuberosity of radius and fascia of forearm via a bicipital aponeurosis.
A = Supinates forearm and, when it is supine, flexes forearm.
N = Musculocutaneous nerve
Brachialis (OIAN)
O = Anterior surface of the humerus I = Ulna tuberosity A = Flexes the forearm N = Musculocutaneous nerve
Name the nerves that pass through the arm
Radial nerve
Musculocutaneous nerve
Ulnar nerve
Median nerve
