scapula
- appearance
- surfaces
large flat triangular bone
surfaces
-costal (anterior or ventral) surface
-dorsal surface
scapula dorsal surface
- divided into _____ and _____ by _____
- acromion has a _____ for atriculation with _____
divided into supraspinous and infraspinous fossae by spine
acromion has a facet for articulation with the clavicle
spinoglenoid notch
- other name
- location
great scapular notch
lateral extent of dorsal surface of scapula before acromion
scapular spine
- where does it begin?
- what is the acromial angle?
from lateral end a forward projecting acromion (his words)
acromial angle is where the spine bends at the spinoglenoid notch
scapula borders
-locations
lateral border -from inferior angle to glenoid cavity medial border (vertebral) -from inferior angle to superior angle superior border -superior angle to suprascapular notch
infraglenoid tubercle
- location
- what is it
on lateral border of scapula
widening as you move superiorly on the lateral border
suprascapular notch purpose
traveling path for suprascapular artery and nerve
scapula angles
-location of each
inferior angle -overlies 7th intercostal space (rib) superior angle -medial to superior border lateral angle (head) medial angle -sometimes described along the medial border at the end of the spine
lateral angle of the scapula
-contains…
glenoid cavity glenohumeral joint supraglenoid tubercle infraglenoid tubercle anatomical neck (constriction around the glenoid cavity) surgical neck that is ill-defined
coracoid process
-location
from top of head of scapula (lateral to suprascapular notch)
points laterally and anteriorly
clavicle
- articulates with…
- parts and description of each
articulates with the manubrium of the sternum and the acromion of the scapula
acromial end
-flattened for articulation with acromion
sternal end
-enlarged for articulation with the manubrium of sternum and 1st costal cartilage
shaft
-medial 2/3 convex anteriorly
-lateral 1/3 concave anteriorly
jugular notch
- other name
- location
suprasternal notch
location
-midsagitally
-between the paired articulation of the clavicles
parts of the humerus
head body trochlea capitulum coronoid fossa olecranon fossa supracondylar ridges
head of the humerus
- articuates with…
- creates what joint
- two ridges called…
- ridges separated by…
articulates with the glenoid cavity of the scapula
creates glenohumeral joint
ridges
-greater and lesser tubercles
separated by intertubercular groove (sulcus; also known as bicipital groove)
body of the humerus
- name of distal expansions of the bone
- 2 landmarks and purpose
expansions are medial and lateral epicondyles
deltoid tuberosity
-anterolateral “bump” indicating insertion of deltoid muscle
radial groove
-spiral groove
-posterior aspect
-position of the radial nerve
trochlea
- articulates with…
- lateral to trochlea is…
- -purpose
articulates with ulna
lateral to trochlea is a deep groove (sulcus for ulnar nerve)
-“funny bone”
capitulum
-articulates with…
radius
joints of the shoulder
acromioclavicular joint
shoulder (glenohumeral) joint
acromioclavicular joint
-ligaments
acromioclavicular ligament
coracoclavicular ligament
coracoclavicular ligament
-what are the parts?
conoid (more medial) ligament
trapezoid ligament
glenohumeral joint
- ligaments and capsules supported by…
- glenoid cavity enlarged/deepened by…
- where is the weakest part of the articular capsule and why?
ligaments and capsules supported by rotator cuff
-supraspinatus, infraspinatus, teres minor, subscapularis
glenoid cavity enlarged by fibrocartilaginous labrum (may be dense CT instead)
weakest part of articular capsule is posterior part because it is not supported by any ligaments
glenohumeral joint ligaments
intrinsic ligaments of the capsule glenohumeral ligaments transverse humeral ligament coracohumeral ligament coracoacromial arch
glenohumeral ligaments
- names
- where do they travel?
names -superior -middle -inferior supraglenoid tubercle of scapule to neck and lesser tubercle of humeruss
transverse humeral ligament
-location
covers intertubercular groove
coracohumeral ligament
-function
strengthens superior part of capsule
coracoacromial arch
- what is it formed by
- function
formed by -coracoid process -coracoacromial ligament -acromion prevents superior displacement of humerus
triangles and spaces
-what are their names (4)
triangular space
quadrangular space
triangular interval
triangle of auscultation
triangular space
- what is the lateral border
- space contains…
lateral border
-tendon of the long head of the triceps as it separates the bellies of the teres minor (and subscapularis) and teres major lateral to their muscular origin on the lateral border of the scapula
contains the circumflex scapular arteries
quadrangular space
- medial and lateral borders
- contains…
medial border -long head of the triceps separating the lateral extension of the teres minor (and subscap) and teres major muscles lateral border -humerus contains -posterior circumflex humeral vessels -axillary nerve
triangular interval
- continuous inferiorly from…
- what is it bordered by (3)?
- deep in the groove you can identify…
continuous inferiorly from the quadrangular space
borders
-between long and lateral head of the triceps
-below teres major
deep in the groove
-posterior shaft of humerus
-lying on the bone are the deep brachial artery and radial nerve
the deep brachial artery and the radial nerve lie in the…
radial groove
triangle of auscultation
-borders
borders
- inferolateral edge of trapezius (lower fibers)
- dorsomedial edge of lat
- medial border of scapula (or medial edge of rhomboid major)
triangle of auscultation
- what enlarges this area
- enlarging the area causes what to occur
crossing the arm in front of the body enlarges the area
as a result, the underlying intercostal spaces 6 and 7 become subcutaneous
this allows for a relatively unobstructed access to respiratory sounds
what arteries form the anastomotic blood supply to the scapular region and muscles on the anterior body wall
subclavian artery
-all bronches
axillary artery
-continuation of subclavian past first rib
subclavian artery
- where does it originate?
- what are it’s 3 parts
origination
-right: brachiocephalic trunk
-left: aortic arch
parts
-from origin to medial border of anterior scalene muscle
-portion situated behind anterior scalene
-from anterior scalene’s lateral border to outer border of the 1st rib
subclavian artery branches
vertebral artery
internal thoracic artery (mammary artery)
thyrocervical trunk
dorsal scapular artery
vertebral artery
- function
- where is it located after branching from subclavian?
- where is it identified?
blood supply to CNS
located in the transverse foraminae of cervical vertebrae
identified in the floor of the suboccipital triangle
internal thoracic artery
-functions
blood to the diaphragm
anastomosis with intercostal arteries
thyrocervical trunk
- location
- branches into…
usually from 1st part of the subclavian branches -inferior thyroid artery -suprascapular artery -transverse cervical artery -superficial scapular artery
dorsal scapular artery
- arises from…
- may also arise from
arises from the 3rd (sometimes 2nd) part of the subclavian
may also arise from brance of the thyrocervical trunk
what is the dorsal scapular artery called if it arises from the thyrocervical trunk
transverse cervical artery
axillary artery
- lateral extension of…
- parts…
lateral extension of subclavian artery past lateral border of 1st rib
parts
-lateral border of 1st rib to medial boder of pectoralis minor
-portion situated posterior to pectoralis minor
-pectoralis minor’s lateral border to inferior border of teres major (becomes brachial artery)
axillary artery main branches
troracoacromial artery (trunk) lateral thoracic artery subscapular artery anterior circumflex humeral artery posterior circumflex humeral artery
thoracoacromial artery (trunk)
- location
- branches
from 2nd part of axillary artery branches -pectoral -acromial -clavicular -deltoid
lateral thoracic artery
-why is it larger in females?
runs with lateral mammary branches to mammary gland
subscapular artery
- arises from…
- size
- branches into ____ via…
- continues as _____ after that point
arises from 2nd part of axillary
largest branch of axillary
branches into circumflex scaplar artery through triangular space
continues as thoracodorsal artery
anterior circumflex humeral artery
-location
from lateral side of axillary
-2nd to 3rd part
posterior circumflex humeral artery
-location
from 3rd part posteriorly
goes around the posterior side of humerus through quadrangular space to anastomose with anterior circumflex humeral artery
from where do the intercostal arteries arise?
segmental branches off of the descending aorta
what are the anastomoses of the scapula and humerus called?
scapular anastomosis
anastomosis around the head of the humerus
scapular anastomosis
-involved arteries
dorsal scapular suprascapular subscapular circumflex scapular (branch of subscapular) intercostal branches
head of humerus anastomosis
-involved arteries
anterior and posterior circumflex humeral arteries
lymphatic drainage
- location
- lymph from UE, back, and anterior surface of thorax and abdomen drain to…
location
-parallels venous drainage through the axilla
lymph travels down to the umbilicus
lymphatic drainage
- how are the nodes divided?
- how do these nodes drain?
- how does this drainage enter the venous system?
divided into groups
-brachial (lateral)
-subscapular (posterior)
-pectoral (anterior)
these groups drain into a set of central nodes
-central nodes drain through an apical group of nodes
drainage enters venous system through thoracic duct
lymphatic drainage
- constant or variable
- pectoral nodes continuous with…
- result of blockage of a node or lymph vessel
variable -lymph from the breast does not have to enter the anterior group prior to getting into the central or apical group pectoral nerves continuous with -supraclavicular nodes -cervical nodes blockage of node -can alter flow pattern -spread of metastatic cells takes place in this fashion
nerve supply for shoulder
-formed from
formed from branches of the brachial plexus
brachial plexus
- organization
- innervates which muscles outside of shoulder?
similar to the lumbar and sacral plexuses
nerves are formed by a mixing of primary ventral rami of lower cervical and first thoracic spinal nerves
innervates
-trapezius
-sternocleidomastoid
-these also receive from spinal accessory nerve
why are ventral rami of the brachial plexus involved in trap and SCM innervation?
provide sensory innervation for the purpose of transmitting proprioceptive information about the muscle back to the CNS
required since CN 11 does not have a sensory component
winged scapula
- due to…
- results in..
due to -damage to long thoracic nerve OR -ventral rami that eventually form long thoracic result -paralysis of serratus anterior
serratus anterior
- function
- what happens if it is paralyzed due to long thoracic damage?
function
-assists in fixing scapula to thoracic wall
-upward rotation
result
-patient unable to abduct arm above horizontal
-patient unable to push with the arm since scapula is limited in superior rotation
axillary nerve damage
-leads to…
atrophy of deltoid muscle
weakness in shoulder abduction against resistance
absence or roundness of shoulder
thoracodorsal nerve damage
- inability to…
- what becomes paralyzed?
- how does this lead to the inability
inability to do “chin-ups”
paralyzes latissimus dorsi
lat extends humerus
in a closed chain with humerus fixes (as in during chin-ups), the lat pulls the body towards the humerus
rotator cuff
- function
- what muscles reinforce the superior, posterior, and anterior aspects of the joint?
main dynamic stability of glenohumeral joint superior -supraspinatus posterior -teres minor -infraspinatus anterior -subscapularis
GH joint
- what structures provide static stabilization
- where is the weakest support dynamically and why?
static -ligaments supporting the articular capsule weakest dynamic support -inferiorly -lack of supporting tendons
