Pectoral girdle and Axilla Flashcards
Anterior muscles in the axial skeleton to the pectoral girdle
Subclavius
Pectoralis minor
Serratus anterior
Posterior muscles in the axial skeleton to the pectoral girdle
Trapezius
Levator scapulae
Rhomboid minor
Rhomboid major
Anterior muscles in the axial skeleton to the humerus
Pectoralis minor
Posterior muscles in the axial skeleton the the humerus
Latisimus dorsi
Levator scapulae origin
Transverse processes of atlas and axis
Posterior tubercles of C4 + 5
Levator scapulae insertion
Superior angle and medial border of scapula
Levator scapulae innervation
Dorsal scapular nerve
Levator scapulae functions
Elevates scapula
Helps inferiorly rotate scapula
Rhomboid minor origin
Spinous processes of C7 and T1 vertebrae
Rhomboid major origin
Spinous processes of T2 - 5
Rhomboids insertion
Medial border of scapula
Rhomboids innervation
Dorsal scapular nerve
Rhomboids functions
Retract scapula
Help inferiorly rotate scapula
Latissimus dorsi origin
Spinous processes of T7 to L5
Latissimus dorsi insertion
Floor of intertubercular groove on the anterior humerus
Latissimus dorsi innervation
Thoracodorsal nerve
Latissimus dorsi functions
Adducts humerus
Internally rotates humerus
Depress scapula
Help inferiorly rotate scapula
Pectoralis major origin
Sternocostal head
Pectoralis major insertion
Lateral lip of intertubercular groove
Pectoralis major innervation
Lateral and medial pectoral nerves
Pectoralis major functions
Adducts humerus Internally rotates humerus Helps protract scapula Depresses scapula Inferiorly rotates scapula
Pectoralis minor origin
Ribs 3 - 5
Pectoralis minor insertion
Coracoid process
Pectoralis minor innervation
Medial pectoral nerve
Pectoralis minor functions
Depresses scapula
Helps protract scapula
Subclavius origin
Costal cartilage of 1st rib
Subclavius insertion
Clavicle
Subclavius innervation
C5
Subclavius functions
Braces clavicle
Weak depressor of scapula
Serratus anterior origin
Ribs 1 - 8/9
Serratus anterior insertion
Medial border of scapula
Serratus anterior innervation
Long thoracic nerve
Serratus anterior functions
Protracts scapula
Helps superiorly rotate scapula
Depresses scapula
Movements of scapula
Retraction + protraction
Elevation + depression
Superior + inferior rotation
3 angles of the scapula
Superior
Inferior
Glenoid fossa
3 borders of the scapula
Superior border
Medial border
Lateral border
3 protuberances of the scapula
Acromion
Coracoid process
Spine
3 surfaces of the scapula
Supraspinous fossa
Infraspinous fossa
Subscapula fossa
Scapula location
Covers postero-lateral surface of ribs 2 - 7
Clavicle strut location
Between manubrium and acromial process of scapula
Sternoclavicular joint
Saddle shaped joint
Between medial end of clavicle and sternum
Two cavities divided by fibrocartilagenous disc
Four ligaments of SC joint
Anterior sternoclavicular
Posterior sternoclavicular
Interclavicular
Costoclavicular
Costoclavicular joint importance
Fulcrum for clavicular movements
Chief stabiliser of SC joint
Acromioclavicular joint
Synovial
Between lateral end of clavicle and medial border of acromion
Wedge shaped fibrocartilagenous disc inside
Loose AC joint capsule, strengthened by strong coracoclavicular ligament
2 compartments of coracoclavicular ligament
Conoid + trapezoid
Trapezius origin
Head to bottom of thorax
Trapezius insertion
Anatomical horseshoe
Trapezius innervation
Accessory nerve CN XI
Trapezius functions
Retracts scapula
Superior trapezius function
Elevates scapula
Superior rotation of scapula
Inferior trapezius function
Depresses scapula
Superior rotation of scapula
Middle trapezius function
Retracts scapula
Axilla
Space between upper arm and side of upper chest
Truncated pyramid
Axilla apex borders
Medial: lateral border of first rib
Anterior: clavicle
Posterior: superior border of scapula
Axilla base borders
Medial: serratus anterior
Lateral: medial aspect of humerus
Posterior: Latissimus dorsi
Anterior: pectoralis major
Posterior axillary fold
Base (armpit) posterior border formed by latissimus dorsi
Posterior wall of axilla
Subscapularis
Anterior wall of axilla
Pectorals
Contents of axilla (6 main parts)
Brachial plexus (cords and branches) Axillary artery Axillary vein Lymph nodes Lymphatics Fat
5 groups of lymph nodes and their drainage
Brachial (arm)
Pectoral (breast)
Subscapular (upper part of trunk posteriorly)
Central (receive from other groups)
Apical (receive from other groups and drain into thoracic duct)
Brachial plexus formation
From ventral rami of spinal nerves arising from C5 to T1
Sections of brachial plexus
Roots Trunks Divisions Cords Branches
The trunks form:
Anterior and posterior divisions
Anterior division supplies:
Flexor compartment of limb
Posterior division supplies:
Extensor compartment of limb
The roots emerge from:
Between scalenus anterior and scalenus medius
The trunks lie in:
The lower part of the posterior triangle of the neck
The roots and trunks form:
The supraclavicular part of the plexus
The divisions lie behind:
The clavicle
The cords are formed:
At the outer border of the first rib
3 parts that enter the axilla apex together
Cords
Axillary artery
Axillary vein
The cords and their branches form:
The infraclavicular part of the plexus
The 3 cords
Medial
Lateral
Posterior
The cords are so named because:
Of their spatial relationship with the axillary artery
The 5 terminal branches
Musculocutaneous Axillary Radial Medial Ulnar
The medial cord gives rise to:
The median nerve with ulnar and medial heads
The lateral cord gives rise to:
The median nerve with musculocutaneous and lateral heads
The posterior cord gives rise to:
Axillary and radial nerves
Prefixed brachial plexus
C4 nerve contributes to the roots
Dorsal branch of T1 nerve is small
No ascending branch from T2 nerve
Postfixed brachial plexus
Branch from C4 nerve is absent
Dorsal branch of T1 nerve is large
T2 nerve supplies branch to plexus
The 3 nerves coming from the root of C5
Long thoracic nerve
Phrenic nerve
Dorsal scapular nerve
Nerve arising from superior trunk
Subclavian nerve
Nerve arising from most caudal division
Suprascapular nerve
3 nerves from posterior cord
Upper subscapular nerve
Thoracodorsal nerve
Lower subscapular nerve
Nerve arising from lateral cord
Lateral pectoral nerve
3 nerves arising from medial cord
Medial pectoral nerve (joined to lateral pectoral nerve)
Medial cutaneous nerve of arm
Medial cutaneous nerve of forearm
The brachial artery arises from the:
Axillary artery
The axillary artery arises from the:
Subclavian artery
Border where subclavian artery becomes axillary artery
First rib
Border where axillary artery becomes brachial artery
Teres major
1st division of axillary artery borders
First rib to superior border of pectoralis minor
2nd division of axillary artery borders
Superior border of pectoralis minor to inferior border of pectoralis minor
3rd division of axillary artery borders
Inferior border of pectoralis minor to teres major
Trunk arising from subclavian artery
Thyrocervical
Arteries arising from thyrocervical trunk
Dorsal scapular artery
Suprascapular artery
Artery arising from 1st division of axillary artery
Superior thoracic artery
Supplies medial wall of upper thorax
Arteries arising from 2nd division of axillary artery
Thoracoacromial artery - supplies anterior wall of thorax to acromion
Lateral thoracic artery - supplies medial wall of lower thorax`
3 branches from thoracoacromial artery
Deltoid
Acromial
Pectoral
Arteries arising from 3rd division of axillary artery
Subscapular artery - supplies posterior wall of thorax
Anterior and posterior circumflex humeral arteries - both supply lateral wall of thorax
2 key arteries arising from subscapular artery
Circumflex scapular artery
Thoracodorsal artery - supplies dorsal side of thorax
3 key arteries that connect to the posterior scapula
Suprascapular artery
Dorsal scapular artery
Circumflex scapular artery
3 key anterior muscles innervated by musculocutaneous nerve
Coracobrachialis
Biceps brachii
Brachialis
Median nerve arises from:
Lateral and medial cords of brachial plexus
Muscles of forearm innervated by median nerve
Most anterior muscles (lateral side) including: Pronator teres Flexor carpi radialis Palmaris longus Flexor digitorum superficialis Flexor digitorum profundus (radial side) Flexor pollicis longus Pronator quadratus Thenar muscles 1st and 2nd lumbricals
Muscles of forearm innervated by ulnar nerve
Anterior muscles not innervated by median nerve (medial side) including: Flexor carpi ulnaris Flexor digitorum profundus (ulnar side) Hypothenar muscles Deep head of flexor pollicis brevis Palmaris brevis All dorsal and palmar interossei 3rd and 4th lumbricals Adductor pollicis
Key muscles innervated by axillary nerve
Teres minor
Deltoid
Muscles innervated by radial nerve
All arm and forearm posterior muscles including: Triceps brachii Anconeus Brachioradialis All extensors Abductor pollicis longus Supinator