The Axilla, Brachial Plexus and Arm Flashcards
The axilla is divided into 3 parts. What is the 1st branch of the axilla.
Superior thoracic artery
In the 2nd part of the axilla what are the 2 branches
Thoraco-acromial
Lateral thoracic artery
In the 3rd part of the axilla what are the 3 branches
subscapular artery
ant. circumflex humeral artery
post. circumflex humeral artery
List the 5 groups of spinal nerves
8 Cervical
12 Thoracic (T1-T12)
5 Lumbar (L1-L5)
5 Sacral (S1-S5)
1 Coccygeal (Co1)
What is the brachial plexus
network of nerves that controls muscle movements and sensations in the upper limb
What are the 5 components of the brachial plexus
Roots, Trunks, Cords, Divisions, Branches
Which spinal nerves form the brachial plexus
Brachial plexus is formed by the union of anterior rami C5, C6, C7, C8, T1
What structure is innervated by the dorsal scapular
rhomboids, occasionally supplies the levator scapulae
what structure is innervated by the long thoracic
serratus anterior
what structure is innervated by the suprascapular nerve
supraspinatus and infraspinatus
glenohumeral joint
what structure is innervated by the nerve to subclavius
subclavius and sternoclavicular joint
Origin of biceps brachii
short head - tip of the coracoid process of scapula
long head - supraglenoid tubercle of scapula
insertion of biceps brachii
radial tuberosity and fascia of forearm via bicipital aponeurosis
innervation of biceps brachii
Musculocutaneous
nerve
C5,C6,C7
action of biceps brachii
Supinates
forearm
* Flexes forearm
when supinated
* Short head
resists dislocation
of shoulder
origin of coraco-brachialis
tip of coracoid process
of scapula
insertion of caraco-brachialis
Middle third of medial
surface of humerus
innervation of coraco-brachialis
Musculocutaneous
nerve
C5,C6,C7
action of caraco-brachialis
Helps flex and
adduct the arm
* Resists
dislocation of arm
origin of brachialis
Distal half of anterior
surface of humerus
insertion of brachialis
Coronoid process and
tuberosity of ulna
innervation of brachialis
Musculocutaneous
nerve (C5,C6) and
radial nerve (C5,C7)
action of brachialis
Flexes forearm in
all positions
origin or triceps brachii
Long head- infraglenoid
tubercle of scapula
* Lateral head- posterior
surface of humerus, superior
to radial groove
* Medial head- posterior
surface of humerus, inferior
to radial groove
insertion of triceps brachii
Proximal end of
olecranon of ulna and
fascia of forearm
innervation of triceps brachii
Radial nerve
C6,C7,C8
action of triceps brachii
Chief extensor of
forearm
* Long head
resists
dislocation of
humerus
* Important during
adduction
origin of anconeus
Lateral epicondyle of humerus
insertion of anconeus
Lateral surface of
olecranon and superior
part of posterior surface
of ulnar
innervation of anconeus
Radial nerve
C7,C8,T1
action of anconeus
Assists triceps in
extending
forearm
* Stabilizes elbow
joint
* May abduct ulnar
during pronation
does injury to the axilla lead to complete loss of innervation to triceps
True
why is there incomplete loss of innervation to triceps when the radial nerve has been injured?
branch to the long head of the triceps is in the axilla
Origin of brachial artery
Direct continuation of axillary artery at lower border of teres major
end of the brachial artery
Neck of radius medial to biceps tendon where it divides into radial and ulnar arteries
what are the medial branches of the brachial artery?
profunda brachii
superior ulnar collateral artery
inferior ulnar collateral artery
What branches does the profunda brachii divide into?
middle and radial collateral arteries
Which arteries does the superior ulnar collateral artery anastomose with?
the posterior ulna recurrent artery and inferior
ulnar collateral artery
Which arteries does the inferior ulnar collateral artery anastomose with?
the anterior ulna recurrent artery
What is the lateral branches of the brachial artery
the humeral nutrient artery
What are the superficial veins of the arm?
Cephalic and basilic veins
What are the deep veins of the arm
Brachial vein begins at the elbow by union of the accompanying veins of the ulnar and radial arteries
* Ends by merging with the basilic vein to form the axillary vein
the injury of the upper trunk of the brachial plexus results in what disease
erb-duchenne paralysis
the injury of the lower trunk of the brachial plexus results in what disease
Klampke’s paralysis
is the skin over the deltoid muscle innervated by the branch of the axillary nerve
True
