Chapter Four: The Upper Limb Flashcards
The axilla
-space between the upper rib cage and the humerus
-the armpit
Inside the axilla
-blood vessels, nerves, and fat
Walls of the axilla
-lateral wall
-medial wall
-posterior wall
-anterior wall
Lateral wall of the axilla
-bicipital groove
Medial wall of the axilla
-serratus muscle (sits over ribs)
Posterior wall of the axilla
-subscapularis muscle
Anterior wall of the axilla
-2 pectoralis muscles
Labelling of axilla walls
Arteries of the Axilla
-arterial trunk passes downward through axilla and name changes as it goes through
-subclavian artery: while passing under clavicle
-axillary artery: sends 3 branches to main axillary walls and supplies deltoid muscle via the posterior humeral circumflex artery
-brachial artery: when blood vessel leaves the axilla
Branches of the axillary artery
-lateral thoracic artery (to medial wall)
-thoracoacromial artery (to anterior wall)
-subscapular artery (to posterior wall)
Axillary artery labelling
Veins and lymph nodes of the axilla
-venae comitantes (veins that accompany), empty in subclavian vein
-also several groups of interconnected lymph nodes (pathway in spread of cancer to upper limbs from the breast)
The brachial plexus number of roots, trunks etc..
-roots: 5
-trunks: 3
-divisions: 6
-cords: 3
-branches: 5
Brachial plexus roots
-c5, c6, c7, c8, t1
Brachial plexus trunks
-upper, middle, lower
Brachial plexus divisions
-strike and a spare
Brachial plexus cords
-lateral, posterior, medial
Brachial plexus branches (nerves)
-axillary
-radial
-musculocutaneous
-median
-ulnar
Brachial plexus labelling
Axillary nerve
-c5 and c6
-goes to top of arm (deltoid)
-abduction of shoulder
Musculocutaneous nerve
-c5, c6, c7
-goes to top muscles in the arm
Ulnar nerve
-c8 and t1
-goes to lower part of arm and hand
Median nerve
-c5-8 and t1 (all roots)
Radial nerve
-c5-8 and t1 (all roots)
-biggest one
Somatotopism
-upper, middle, and lower innervations usually stay consistent throughout whole arm
Dorsal scapular nerve (minor)
-c5
-to rhomboid major and minor
Suprascapular nerve (minor)
-c5 and c6
-to rotator cuff muscles
-abduction of shoulder
-suprapinatus
Upper and Lower subscapular nerve (minor)
-c5 and c6
-rotator cuff muscles
Lateral pectoral nerve (minor)
-c5, c6, and c7
-goes to pectoralis major
Long thoracic nerve
-c5, c6, and c7
-goes to serratus anterior
Thoracodorsal nerve (minor)
-c6, c7, and c8
-goes to latissimus dorsi
Medial pectoral nerve (minor)
-c8 and t1
-goes to pectoralis major and minor
Medial cutaneous nerve of the arm and forearm (minor)
-c8 and t1
-cutaneous sensation of the arm and forearm
The scapula position
-sits between t2 and t7
The scapula borders and angles
-superior border
-medial border
-lateral border
-superior angle
-inferior angle
-lateral angle
Glenoid fossa of scapula
-articulates with the head of the humerus
Suprascapular notch
-where blood vessels and nerves run through
Coracoid process
-in the lateral angle
Spine of the scapula
-posterior ridge
-turns into the acromion
Acromion
-forms the point of the shoulder
-forms acromioclavicular joint
Subscapular fossa
-anterior face (slightly concave)
-subscapularis muscle originates here
Infraspinous fossa
-below spine
-posterior face (slightly concave)
Supraspinous fossa
-depression above the spine
-posterior face (slightly concave)
Clavicle ends
-roundish end (articulates with sternum at sternoclavicular joint)
-flatish end (articulates with scapula at acromioclavicular joint)
-this connection is the only articular attachment of the upper limb to the axial skeleton
Proximal humerus head
-articulates with glenoid fossa forming the shoulder joint (glenohumeral joint)
Proximal humerus neck(s)
-anatomical neck: located right under the head
-surgical neck: located further down and is where most fractures occur
Proximal humerus labelling
Muscles attaching the axial skeleton to the scapula
-serratus anterior
-trapezius
-levator scapula
-the rhomboids (major and minor)
Serratus anterior
-origin: upper 9 ribs
-insertion: medial border of scapula
-protraction (pulls scapula forward) and upward rotation of glenoid fossa
-innervated by long thoracic nerve (c8 & t1)
Trapezius
-origin: occipital bone
-insertion: scapula (clavicle and acromion)
-there is an upper, middle and lower aspect
-upper and lower fibres elevate shoulder and rotate glenoid fossa upwards
-middle fibres depress shoulder and also rotate glenoid fossa upwards
-innervated by cranial nerve 9 (spinal accessory nerve)
Levator Scapula
-origin: transverse processes of c1-c4
-insertion: upper medial border of scapula
-elevation of scapula and depression of glenoid fossa
-innervated by branches of nerves c3 and c4
The rhomboids (major)
-origin: spinous processes of t2-t5
-insertion: lower third of medial scapular border
-elevate and retract the scapula and aid in depressing glenoid fossa
-innervated by dorsal scapular nerve (c5)
The rhomboids (minor)
-origin: ligamentum nuchae and spinous processes of c7 and t1
-insertion: middle of the medial border of the scapula
-elevate and retract the scapula and aid in depressing glenoid fossa
-innervated by dorsal scapular nerve (c5)
Muscles attaching the axial skeleton to the humerus
-latissimus dorsi
-pectoralis major
-pectoralis minor
Latissimus dorsi
-origin: ilium
-insertion: bicipital groove of the humerus
-powerful extensor, adductor and medial rotator
-innervated by thoracododorsal nerve
Pectoralis major
-origin: clavicular head (at clavicle) and costal head (at ribs)
-insertion: lateral lip of bicipital groove on humerus
-adducts, flexes and medially rotates the arm
-innervated by medial and lateral pectoral nerves
Pectoralis minor
-origin: ribs 3-5
-insertion: coracoid process of the scapula
-stabilize and pull upward and forward on the rib cage
-innervated by the medial pectoral nerve
Muscles attaching the girdle to the humerus
-deltoid
-teres major
-rotator cuff (subscapularis, supraspinatus, infraspinatus, teres minor)
Deltoid
-origin: on distal clavicle to acromion and spine of scapula
-insertion: deltoid tuberosity
-anterior fibres flex, middle fibres abduct and posterior fibres extend
-innervated by axillary nerve
Teres major
-origin: lower back
-insertion: medial lip of occipital groove
-extends, abducts and medially rotates the arm
-innervated by lower subscapular nerve
Rotator cuff muscles
-subscapularis
-infraspinatus
-supraspinatus
-teres minor
Subscapularis
-origin: subscapular fossa of scapula
-insertion: lesser tubercle of humerus
-medial rotator and adductor
-innervated by subscapular nerve
Supraspinatus
-origin: supraspinous fossa of scapula
-insertion: top facet of greater tubercle
-abduction
-innervated by suprascapular nerve