Upper limb 2 Flashcards
3 muscles of anterior/flexor compartment of arm
brachialis
biceps brachii
coracobrachialis
(BBC)
Biceps brachii heads
2 : long & short
Long= lateral
Short= medial
Arise from scapula:
long head-> supraglenoid tubercle
short head-> coracoid process
Both heads unite at distal 1/3 of upper arm and form tendon to insert into radial tuberosity
What joints does biceps brachii act on?
Shoulder
Elbow
Radio-ulnar
Which head of biceps arise from coracoid process along with coracobrachialis?
Short
Which part of the scaplua does the long head of biceps arise from and what does it run in
Supraglenoid tubercle
runs in bicipital groove of humerus
Where does the tendon of biceps attach distally
(biceps tendon= union of long and short heads)
Radial tuberosity
Action of biceps on glenohumeral joint and elbow joint
Flexion
Biceps action on superior radio-ulnar joint
Supinaton
Flexion
Nerve supply to biceps
Musculocutaneous nerve
(lateral cord -> C5-7)
Action of coracobrachialis on glenhumeral joint
Flexion
Adduction
Nerve supply to coracobrachialis
Musculocutaneous
(Lateral cord -> C5-7)
Brachialis origin and insertion
Shaft of humerus -> ulnar tuberosity
(ulnar tubrosity is in the picture)
Coracobrachialis origin and insertion
Coracoid process -> humeral shaft (medial)
Brachialis action on elbow joint
Flexion
Nerve supply to brachialis
Musculocutaneous
(lateral cord -> C5-7)
How does musculocutaneous nerve enter arm?
Perforate coracobrachialis
Descend between biceps and brachialis
Then gives off a Lateral Cutanoeous Nerve branch
Musculocutaneous nerve roots
C5-7
Why is nerve called musculocutaneous?
Innervates anterior muscles of arm
Cutansoueus sensation to lateral aspect of forearm
Does musculocutaneous nerve supply any muscles in forearm or hand?
No fucking way
Knife in axilla damages what nerve
Muscluocutaneous nerve damage causing:
Paralysis of BBC muscles loss & sensation on lateral aspect of arm
Deep artery of arm
Profundal brachii artery
Median nerve pathway
- Descends down: lateral side of axillary artery -> lateral side of brachial artery (upper part)
- Crosses over the medial side of brachial artrery
- Enters the cubital fossa
(does not branch in the axilla or arm)
Does median nerve supply any muscles in arm?
No fucking way
How does ulnar nerve enter posterior compartment?
(top right of picture)
Via the intermuscular septum
Then runs along medial head of triceps and medial epicondyle
(intermuscular septum= boundry between anterior and posterior compartment)
Does ulnar nerve innervate any muscles in arm?
Not a bloody chance
3 common sites of humerus and the assoaited nerve injuries
Surgical neck -> axillary
Medial epicondyle -> ulnar
Radial groove -> radial
What is the cubital fossa?
Triangular depression in front of elbow
Pulsation medial to tendon of biceps brachii
Brachial artery
Base (posterior border) of cubital fossa
Imaginary line between 2 epicondyles of humerus
medial border of cubital fossa
Protonator teres
lateral border of cubital fossa
Brachioradialis
Muscle of posterior compartment of arm
Triceps
(and anconeus)
Triceps origin and insertion
Origin
Infraglenoid tubercle -> long head (medial)
Humerus -> medial and lateral short heads
Insertion
Olecranon process
Olecranon process and coronoid process are on which bone?
Ulna
Main action of triceps on elbow joint
Extension
Anconeus function
Extension
Stabilisation
Triceps and anconeus innervation
Radial nerve
(posteior cord -> C5-T1)
Radial nerve innervates
Extensor compartment of arm and forearm
Radial nerve path
Enters arm anterior to long head of triceps
Runs with profunda brachial artery
Curves around radial groove
Radial nerve roots
C5-T1
(all of the brachial plecus baby)
Radial nerve injury sign
Wrist drop
Elbow joint type
Synovial hinge
Articulating parts of elbow
Capitulum
Tochlea
Radius
Ulna
Lateral side: capitulum -> radius
Medial side: trochlea -> ulna
Elbow ligaments
Ulnar & radial collateral
What ligament holds the head of radius?
Annular ligament
Flexors of elbow joint
BBC muscles
Extensors of elbow joint
Triceps
Anconeus
Olecranon bursitis is AKA
Students elbow
Radio-ulnar joint is a type of
Synovial pivot
Supination muscles of radioulnar joint
Supinator
Biceps brachii (most powerful)
Pronation muscles of radioulnar joint
Pronator teres (most powerful)
Pronator quadratus
What is the main flexor of the elbow joint
Brachialis
What are the 3 muscles that attach to the coracoid process
Short head of biceps
Coracobrachialis
Pectoralis minor
What tendon attaches into the cubital fossa
Biceps brachii tendon
What is the course of the axillary nerve
Posterior cord of BP
v
Posterior to axillary artery
v
Passes medially to the surgical neck of humeurs
v
Give off 3 terminal branches
