The Shoulder and Arms Flashcards
What are the articulations of the scapula?
- Gleno-humoral joint – humerus with glenoid cavity
- Acromio-clavicular joint - acromion of scapula with acromion end of clavicle
- Scapulo-thoracic joint – this is a “gliding” physiological joint with the thoracic wall (via serratus anterior)
At what spinal levels are the scapular angles?
- Superior angle – T2
- Medial end of scapula spine – T3
- Inferior angle – T7
How do you orientate the clavicle?
via the “flat” lateral end at the acromion of the scapula and the circular sternal end at the sternum/1st CC (superior smooth)
Which neck of the humerus is more commonly damaged?
surgical neck
How can you differentiate between left and right humerus?
head of the humerus needs to face medially:
- lesser tubercle is medial and anterior (greater tubercle is lateral and posterior)
- capitulum on left = left humerus
What are the compartments of the muscles?
- anterior pectoral girdle muscles
- posterior pectoral girdle muscles
- intrinsic shoulder muscles
- anterior compartment of the (upper) arm
- posterior compartment of the (upper) arm
What are the anterior pectoral girdle muscles?
- pectoralis major
- pectoralis minor
- subclavius
- serratus anterior (runs between posterior and anterior)
What are the attachments of pectoralis major?
What does pectoralis major do?
proximal attachments:
- medial 1/3 of clavicle
- sternum
- costal cartilages (6,7 and sometimes 8th region)
distal attachments:
lateral lip of intertubercular sulcus/groove
adducts and medially rotates the humerus
* lesser actions on scapula
What are the attachments of pectoralis minor?
What does pectoralis minor do?
proximal:
- finger like processes attach to 2nd, 3rd, 4th and 5th ribs
distal:
- coracoid process of scapula
helps stabilise the scapula
pulls the scapula forward onto the back of the thoracic wall
What are the attachments of the subclavius?
What does the subclavius do?
proximal:
- first rib
distal:
middle/slightly lateral part of the clavicle (groove in the clavicle)
anchors clavicle
What are the attachments of the serratus anterior muscle?
proximal:
- ribs 1-9
distal:
- medial edge of the scapula
What are the posterior muscles?
- trapezius
- latissimus dorsi
- levator scapulae
- rhomboids
What are the attachments of the trapezius?
What does the trapezius do?
proximal:
- spinal processes ( superior nuchal line - T12)
distal:
- spine of scapula
- lateral third of clavicle
major actions on scapula
- upper fibles can elevate scapula
- lower fibres depress
What are the attachments of the latissimus dorsi?
What does the latissimus dorsi do?
proximal:
- T8 - sacrum round to iliac crest
distal :
- fibres converge and twist slightly and attach to floor of intertercular groove
- extends, adducts, and rotates the humerus
- pulls body up to arms during climbing and important in rowing
What are the attachments of the rhomboids?
What do the rhomboids do?
proximal:
- nucal ligament and C7 (rhomboid minor)
- T2-T5 (major)
distal:
- medial border of scapula
retracts, rotates an fixes scapula
What are the attachments of the levator scpulae?
What does it do?
proximal:
- transverse processes of C1-C4
distal:
superior angle of scapula
elevates and rotates scapula
What innervates pectoralis major muscle?
dual motor innervation - medial and lateral pectoral nerve
What innervate pectoralis minor?
medial pectoral nerve
What innervates the suclavius muscle?
subclavian nerve
What is the nerve supply to the serratus anterior muscle?
long thoracic nerve
What innervates the trapezius?
accessory nerve (CN XI)
What innervates the lattisimus dorsi?
thoracdorsal nerve
What innervates the rhomboids?
dorsal scapular nerve
What are the intrinsic shoulder muscles?
What innervates each one?
deltoid - axillary nerve
rotator cuff:
supraspinatus - supracapular nerve (C5)
infraspinatus - supracapular nerve (C5-6)
teres minor - axillary (C5)
subscapularis - upper and lower subcapular nerve (C5-6)
Teres major - subscapular nerve
What are the attachment of the deltoid?
What does it do?
proximal:
- clavicle
- acromion
- spine of scapula
distal:
- deltoid tuberosity of humerus
abducts arm
What are the attachments of the rotator cuff?
What does it do?
scapula -> head of humerus
important in stabilisation of shoulder joint
*supraspinatus important in initiating abduction of arm for first 15 degrees then deltoid takes over
What are the attachments of teres major?
What does teres major do?
inferior angle of scapula -> floor of intertubercular sulcus of humerus
adducts and medially rotates arm
What are the muscles in the anterior compartment of the arm?
What nerve supplies them?
biceps
coracobrachialis
bracialis (deepest)
all supplied by musculocutaneous nerve
What are the attachements of the biceps?
long head - supraglenoid tubercle of scapula
short head - coracoid process of scapula
both merge to attach to radial tuberosity (cross the elbow joint)
- some fibres fan o forming a biceps aponeurosis
What are the attachment so the coracobracialis/
coracoid process of scapula - medial shaft of humerus
- adduction and a bit of flexion at humeral joint
What are the attachments of the bracialis?
anterior shaft of humerus -> coronoid process of ulna
- important flexor of elbow
What are the muscles in the posterior compartment of the arm?
What supplies them?
triceps and anconeus
supplied by radial nerve
What are the attachments of the triceps?
long head - infraglenoid tubercle of scapula
lateral head - shaft of humerus
medial head - shaft (deeper)
converge to form triceps tendon -. olecranon process of ulna
- extends elbow
What are the attachments of the anconeus?
lateral epicondyle of humerus -> upper part of shaft of ulna
- stabilises elbow joint during certain movement
What are the joints of this region?
sterno- clavicular
acromio - clavicular (acromion head of clavicle and acromion process of scapula)
gleno- humeral (glenoid fossa and head of humerus) - ball and socket joint
scapulo-thoracic (virtual/physiological)
elbow
What deepens the gleno-humeral joint?
glenoid labrum
*muscles required for join stability (rotator cuff)
Which muscles are used in movements of the shoulder joint ?
abduction: supraspinatus and deltoid
adduction: pectoralis major, teres major, latissimus dorsi, triceps long head
flexion: deltoid, pectoralis major, coracobracialis
extension: deltoid, teres major, latissimus dorsi, triceps long head
lateral rotation: deltoid, teres minor, infraspinatus
medial rotation: deltoid, pectoralis major, teres major, latissimus dorsi
What is contained in the axilla?
Arteries – axillary artery and its branches
Veins – axillary vein and its tributaries
Lymphatic vessels and lymph nodes (important!)
Nerves – the brachial plexus
What are the arteries in this region?
Subclavian artery passes over the first rib to become -> Axillary artery
at the lower border of teres major becomes the -> Brachial artery
Gives off a large branch in the arm – profunda brachii
Divides as the level of the elbow into -> Ulnar and Radial arteries
What are the superficial veins in this region?
In limbs, venous return is via superficial and deep vessels
Basilic vein runs up the medial border of arm
Basilic veins joins venae comitantes to form the axillary vein in the arm
Cephalic vein runs up lateral border of arm
Cephalic vein joins axillary vein in the axilla
Axillary vein becomes the subclavian vein at the level of the first rib
What are the lymph nodes in this region?
*Superficial and deep systems, run with veins
- Cubital lymph nodes
- Delto-pectoral lymph nodes
- Axillary lymph nodes
What are the parts of the brachial plexus?
What are the largest nerves of the brachial plexus?
roots (anterior rami) -> trunks -> divisions -. cords -> terminal branches (peripheral nerves)
Axillary nerve (C5-6) Musculocutaneous nerve (C5-7) Ulnar nerve (C8- T1) Median nerve (C6-T1) Radial nerve (C5-T1)
