Shoulder Arthrology and Axilla Flashcards
Sternoclavicular (SC) joint
-only articulation b/w upper limb and axial skeleton
-saddle type joint
-extremely strong joint
SC joint is a _______ joint but acts as a ______ joint
-saddle joint
-functions as a ball and socket joint
SC joint being extremely strong leads to
-rare dislocations
-rather, fractures in the clavicle are common
articulations of SC joint
-it is divided into 2 compartments by an articular disc
ligaments of the SC joint
-anterior sternoclavicular ligament
-posterior sternoclavicular ligament
-interclavicular ligament
-costoclavicular ligament
costoclavicular ligament
-anchors the inferior surface of the sternal end of the clavicle to the first rib (limits elevation of the pectoral girdle)
-primary stabilizer
movements of the SC joint
elevation, rotation, anterior, posterior
what type of joint is the acromioclavicular (AC) joint
plane type synovial joint
articulations of the AC joint
acromial end of the clavicle articulates with the acromion of the scapula
ligaments of the AC joint
-acromioclavicular ligament
-coracoclavicular ligament
acromioclavicular ligament
-supports the superior portion of the joint
coracoclavicular ligament
-strong pair of bands that unite the coracoid process of the scap to the clavicle
-critical for maintaining the integrity of the AC joint
-contains 2 ligaments
what are the 2 ligaments of the coracoclavicular ligament
-conoid ligament (attachment at the conoid tubercle)
-trapezoid ligament (attachment at the trapezoid line)
movements of the AC joint
-acromion of the scap rotates on the acromion end of the clavicle
is the scapulothoracic joint a “true joint”
-no
-conceptual joint involving muscles
what is the scapulothoracic joint
-conceptual joint involving muscles
-space b/w the muscles considered to be “in the joint”
whatre the muscles of the scapulothoracic joint
subscapularis and the serratus anterior
what movement does the scapulothoracic joint allow
allows for an increase in shoulder elevation
what is the glenohumeral joint
-the shoulder joint
-ball and socket type of synovial joint
-mobility makes this joint relatively unstable
-most dislocated joint in adults
articulations of the GH joint
-round humeral head articulates w/ shallow glenoid cavity
-like a golf ball sitting in a tee –> the tee can hold the ball in place but is built to allow for a lot of movement
glenoid labrum
-fibrocartilage ring that surrounds the outer rim of the glenoid cavity
-used to create a little more depth and stability to the glenoid cavity @ the GH joint
articular capsule of GH joint
loose fibrous layer of the joint capsule
ligaments of the GH joint
-glenohumeral ligaments
-coracohumeral ligaments
-transverse humeral ligament
-coracoacromial ligament
transverse humeral ligament
-goes across the bicipital groove (tuberosity to tuberosity)
-helps keep the bicep head in place
GH joint movements
-has more freedom of movement than any other joint in the body
-flex/ext
-abd/add
-rotation of the humerus
-circumduction
blood supply of the GH joint
-anterior circumflex humeral artery
-posterior circumflex humeral artery
neural elements of the GH joint
-suprascapular nerve
-axillary nerve
-lateral pectoral nerve
what is a bursa
flattened fibrous sac lined by a synovial membrane and filled with synovial fluid
what is the function of a bursa
lubricate and reduce friction
locations of bursa
-where tendons rub against each other, bone, skin and ligaments
-b/w muscle and bone
-b/w skin and bone
bursa can become ________
inflamed
where is the subscapular bursa
located b/w the tendon of the subscapularis and the neck of the scap
where is the subacromial bursa
-b/w the acromion, coracoacromial ligament and deltoid superiorly
-supraspinatus tendon and the joint capsule of teh GH joint inferiorly
what is the axilla
-gateway to the upper limb
-irregularly shaped pyramidal space
-all structures that pass through the upper limb pass through the axilla
what is the axilla formed by
-clavicle
-scapula
-upper thoracic wall
-humerus
-related muscles
axillary fascia
-axillary sheath and clavipectoral fascia
what does the axillary sheath surround
-arteries
-veins
-nerves
-lymphatics
clavipectoral fascia
-thick sheet of connective tissue
-connects the clavicle to the floor of the axilla
-encloses the subclavius and pectoralis
minor muscles
- spans the gap b/w them
boundaries of the axilla
-apex
-base
-anterior
-posterior
-medial
-lateral
apex and base boundaries of the axilla
-apex –> lateral margin of 1st rib, clavicle, superior margin of the subscapularis
-base –> skin of the armpit, subcutaneous tissue, axillary fascia
ant/post boundaries of axilla
-anterior –> pectoralis major and minor muscles
-posterior –> subscapularis, teres major, latissimus dorsi
medial/lateral boundaries of the axilla
-medial –> upper thoracic wall
-lateral –> bicipital groove
contents of the axilla
-lymphatic vessels and lymph nodes
-axillary artery
-axillary vein
-brachial plexus
lymphatic vessels and lymph nodes of the axilla
-all the lymphatics from the upper limb drain into lymph nodes of the axilla
pathway of drainage (lymphatic) for the axilla
apical node collects from –> central nodes which collects from –> humeral (lateral) nodes, pectoral (anterior) nodes and subscapular (posterior) nodes
humeral, pectoral, subscap –> central –> apical
origin of the axillary artery
subclavian artery
when does the subclavian artery become the axillary artery
when it passes the lateral margin of the first rib
course of the axillary artery
-passes through the axilla
-becomes the brachial artery @ the inferior margin of the teres major
branches of the axillary artery
-separated into 3 parts by the pectoralis minor muscle
-proximal to pectoralis minor
-posterior to pec minor
-distal to pec minor
proximal to pec minor branch of the axillary artery
-superior thoracic artery
what does the superior thoracic artery supply
-superior intercostal space
-superior part of the serratus anterior
posterior to pec minor branch of the axillary artery branch
-thoraco-acromial artery
-lateral thoracic artery
what branches does the thoraco-acromial artery split into
-“PACD”
-pectoral
-acromial
-clavicular
-deltoid
what does the lateral thoracic artery supply
-runs along the thoracic nerve
-supplies serratus anterior
distal to pectoralis minor branch of the axillary artery
-subscapular artery
-anterior circumflex humeral artery
-posterior circumflex humeral artery
what are the 2 branches of the subscapular artery
-circumflex scapular branch (comes through the triangular space)
-thoracodorsal branch (runs along the thoracodorsal nerve, supplies the latissimus dorsi)
anterior circumflex humeral artery
wraps around humerus and anastomoses with the posterior circumflex humeral artery
posterior circumflex humeral artery
wraps around the humerus and anastomoses with the anterior circumflex humeral artery
axillary vein
-formed by the brachial and cephalic veins
-drains the arm
how does the axillary brain drain (deep veins)
brachial vein –> axillary –> subclavian vein
how does the axillary drain (superficial veins)
cephalic vein and basilic vein –> axillary vein
-don’t have accompanying arteries
parts of the brachial plexus
-Robert Taylor Drinks Cold Beer
-roots
trunks
-divisions
-cords
-branches (terminal)
roots of the brachial plexus
-from the anterior rami of C5-T1
-comes out b/w anterior and middle scalene muscles
-C5 and C6 connect
-C7 continues
-C8 and T1 connect
what nerves come off of the superior trunk
suprascapular nerve and nerve to subclavius
trunks of the brachial plexus
-superior
-middle
-inferior
divisions of the brachial plexus
posterior division and anterior division
posterior division of the brachial plexus
superior and inferior trunks connecting (onto the middle trunk)
anterior division of the brachial plexus
connects the superior and middle trunks (opposite direction of posterior division)
cords of the brachial plexus
-named in relation to the position of the axillary artery
-lateral (from the anterior division)
-posterior (from the posterior division)
-medial (extension of the inferior trunk)
what nerves come off of the lateral cord
lateral pectoral nerve
what nerves come off of the posterior cord
-upper subscapular
-thoracodorsal
-lower subscapular
what nerves come off of the medial cord
-medial pectoral nerve
-medial brachial cutaneous nerve
-medial antebrachial cutaneous nerve
branches of the branchial plexus
-musculocutaneous nerve (from lateral cord)
-median nerve (from the lateral and medial cords)
-axillary nerve (from the posterior cord)
-radial nerve (from the posterior cord)
-ulnar nerve (from the medial cord)
what is special about the medial pectoral nerve
pierces through the pec minor in order to get to the pec major
