Upper limb 1 Flashcards
Anterior wall
Posterior wall
Medial wall
Lateral wall
of axilla made up of what
Anterior wall - pec major and minor
Posterior wall - subscapularis
Medial wall - thoracic wall + serratus anterior
Lateral wall - intertubercular sulcus of humerus
Apex (axillary inlet) of axilla located at
Lateral border of 1st rib
Contents of axilla
Axillary artery Axillary vein Brachial plexus Axillary lymph nodes Tendons of short head of biceps brachii & coracobrachialis
Axillary artery is a continuation of what artery + what does axillary continue as
Subclavian
Brachial
What point does the subclavian become the axillary artery
Lateral border of 1st rib
What point does the axillary become the brachial artery
Inferior border of teres major
Brachial plexus is the ventral rami of
C5-T1
Brachial plexus:
5 roots –> 3 … –> 6 … –> 3 … –> 5 …
3 trunks - superior, middle, inferior
6 divisions - each trunk divides into anterior + posterior division
3 cords - different divisions combine to form lateral, posterior + medial cord (see other flashcard)
5 major branches - given off by the 3 cords
What nerve roots of the brachial plexus form the
- superior trunk
- middle trunk
- inferior trunk
Superior - C5 + C6
Middle - C7
Inferior - C8 + T1
What is erb’s point
Auscultation point for heart sounds + murmurs at the left sternal border 3rd intercostal space
What is erb’s palsy + what is the characteristic clinical sign
Injury to upper trunk (C5-6) of brachial plexus –> characteristic ‘waiter’s tip’ sign where
- shoulder is internally rotated
- elbow extended + pronated
- wrist flexed
Causes of erb’s palsy
Usually due to large size or shoulder dystocia (shoulders too wide) in neonates so too big to fit through birth canal
In adults - high impact injuries
What group of muscles are affected in erb’s palsy if it is the upper trunk of brachial plexus that is affected
C5 - elbow flexors (brachialis, biceps brachii, corachoradialis + brachioradialis)
C6 - wrist extensors (extensor carpi radialis longus (ECRL), extensor carpi radialis brevis (ECRB), extensor digitorum (ED), extensor digiti minimi (EDM), extensor carpi ulnaris (ECU), abductor pollicis longus (APL), extensor pollicis brevis (EPB), extensor pollicis longus (EPL), and extensor indicis (EI))
What is klumpke’s palsy (RARE)
Injury to the inferior trunk of the brachial plexus
What group of muscles are affected in klumpke’s palsy if it is the inferior trunk of brachial plexus that is affected
Intrinsic muscles of hand
Ulnar flexors of wrist + fingers
The cords (lateral/posterior/medial) of the brachial artery are named in relation to what structure
Axillary artery in the axilla
In the axilla and the proximal aspect of the upper limb, the three cords give rise to five major nerve branches - name these
Musculocutaneous Axillary Median Radial Ulnar
The lateral cord of the brachial plexus is formed by the combination of which divisions (2)
The anterior division of the superior trunk
The anterior division of the middle trunk
The posterior cord of the brachial plexus is formed by the combination of which divisions (3)
The posterior division of the superior trunk
The posterior division of the middle trunk
The posterior division of the inferior trunk
The medial cord of the brachial plexus is formed by which division
The anterior division of the inferior trunk
Main branches of
- lateral cord
- posterior cord
- medial cord
Lateral - musculocutaneous nerve, lateral root of median nerve
Posterior - axillary nerve, radial nerve
Medial - ulnar nerve, medial root of median nerve
Superficial veins of the upper limb
Dorsal venous arch
Cephalic vein
Basilic vein
Median cubital vein
What vein joins the cephalic and basilic vein + this vein shunts blood from cephalic to basilic or basilic to cephalic
Median cubital - shunts blood from cephalic to basilic
Dermatomes of upper limb
- regimental badge patch area
- thumb
- middle finger
- pinky
- axilla
C5 C6 C7 C8 T1
All lymphatics in the upper limb drain into which group of lymph nodes
Axillary
What 2 bones make up the pectoral girdle, connecting the upper limb to the axial skeleton
Scapula and clavicle
The upper limb and pectoral girdle articulate with the axial skeleton at one small joint - name this
Sternoclavicular
Clavicle has 2 ends - name them
Acromial end and sternal end
The conoid tubercle on the clavicle is the attachment point for what
Conoid ligament - which binds clavicle to coracoid process of scapula
Which part of the clavicle is the weakest
Junction between anterior 2/3 and outer 1/3, essentially the MIDDLE SHAFT (because thinnest)
What type of joint is the acromioclavicular joint
Synovial plane
What type of joint is the sternoclavicular joint
Synovial saddle
Abduction of the arm from the anatomical position occurs at the glenohumeral (shoulder) joint for the first 30 degrees but beyond that, for every 3 degrees of abduction, 2 degrees occurs at … joint and 1 degree at the … joint
2 degrees at the glenohumeral joint
1 degree at the scapulothoracic joint
What is the scapulothoracic joint
Not a true anatomical joint
It is just the movement on the scapula on the posterior thoracic wall
Name the 6 movements that occur at the scapula
Elevation Depression Protraction Retraction Lateral rotation Medial rotation
Name the muscles that
-elevate (2)
-depress (3)
the scapula
Elevate - upper fibres of trapezius, levator scapulae
Depress - pec major, lower fibres of trapezius, lattisimus dorsi, (gravity)
Name the muscles that
-protract (2)
-retract (3)
the scapula
Protract - serratus anterior (MAINLY), pec minor
Retract - middle fibres of trapezius, rhomboid major + minor
Name the muscles that
-laterally (upward) rotate (2)
-medially (downward) rotate (3)
the scapula
Laterally rotate - trapezius, serratus anterior
Medially rotate - levator scapulae, rhomboid major + minor
What are the 2 articular surfaces of the glenohumeral joint
Glenoid cavity of the scapula
+
Head of the humerus
What type of joint is the glenohumeral joint
Ball + socket
The rim of cartilage surrounding the glenoid cavity of the scapula is known as the
+ functions of this (2)
Glenoid labrum
Function - deepens the glenoid cavity, shock absorption
Name the ligaments associated with the glenohumeral joint
Coracohumeral
Coracoclavicular
Glenohumeral
Transverse humeral
Coracohumeral ligament strengthens which aspect of the joint capsule
Anterior
The coraco-acromial arch is made up of what 3 things
+ function
Acromion
Coracoid process
Coraco-acromial ligament
Prevents superior displacement of the humeral head from the glenoid cavity
Which part of the glenohumeral joint is the weakest
Inferior part because it’s not protected by muscles or ligaments
What are the 2 main bursa of the shoulder joint
+ which of these communicates with the joint cavity
Subacromial bursa
Subscapular bursa - communicates with joint cavity
Function of the subacromial bursa
Decreases friction beneath the deltoid and allows smooth motion of the rotator cuff tendons
Common cause of subacromial bursitis
Repeated minor trauma such as repetitive overhead motions, e.g. swimming
Name the 4 rotator cuff muscles
Subscapularis
Supraspinatus
Infraspinatus
Teres minor
Function of the rotator cuff muscles collectively
Resting tone of these muscles act to compress the humeral head into the glenoid cavity, so stabilising the GH joint
Function of deltoid
- anterior fibres
- middle fibres
- posterior fibres
Anterior fibres - flex + medially rotate arm at GH joint
Middle fibres - abduct arm at GH joint (MAJOR ABDUCTOR OF ARM)
Posterior fibres - extend + laterally rotate arm at GH joint
Innervation of deltoid
Axillary nerve
Clinical sign seen when long thoracic nerve damaged
Winged scapula
-as long thoracic nerve innervates serrates anterior which holds scapula against ribs
Functions of trapezius
- superior fibres
- middle fibres
- inferior fibres
Superior - elevate scapula
Middle - retract scapula
Inferior - depress scapula
Innervation of trapezius
CN XI
Actions of teres major (2)
Adduct + medially rotate arm at GH joint
Actions of latissimus dorsi on GH joint (3)
Extend
Adduct
Medially rotate
Muscles that flex GH joint (4)
Pec major
Anterior fibres of deltoid
Corachobrachialis
Biceps brachii (WEAKLY ASSISTS)
Muscles that extend GH joint (2)
Posterior fibres of deltoid
Latissimus dorsi
(Teres major)
(Teres minor)
Muscles that abduct at GH joint (4)
Supraspinatus - first 15 degrees
Middles fibres of deltoid - next 15-90 degrees
Trapezius + serratus anterior - past 90 degrees
Muscles that adduct at GH joint (3)
Pec major
Latissimus dorsi
Teres major
Muscles that internally/medially rotate at GH joint (5)
Subscapularis Pectoralis major Latissimus dorsi Teres major Anterior fibres of deltoid
Muscles that externally/laterally rotate at GH joint (2)
Infraspinatus
Teres minor
Actions of teres major (2)
Medial rotation + adduction of arm at GH
Function of coraco-acromial ligament
Prevent superior displacement of humeral head
