Download Scapular region

Scapular region
OBJECTIVES …
 To list scapular muscles
 To describe axillary gateways
 To describe scapular anastomosis
 To follow main nerves in the region
The scapula articulates:
-By its glenoid with the humeral head
-By its acromion with the clavicle
Surface localization:
-Scapula extends from T2-T7 vertebral
level
-Costal level is the same as the vertebral
level
-Scapular spine: T3
-Inferior scapular angle: T7
Scapular movements:
 Elevation
 Depression
 Protraction
 Retraction
 Medial rotation
 Lateral rotation
Muscles connecting the scapula to the axial skeleton
Muscle
Origin
•
Trapezius •
•
Back of skull
Insertion
•
spine of the scapula
Ligamentum nuchae •
Lateral 1/3 of
Spines of C7-T12
clavicle
Innervation
Spinal
Function
•
accessory n •
Scapular elevator
Lateral rotator
Muscle
Origin
Insertion
Innervation
Function
Levator Transverse processes of superior angle to root
scapulae
Rhomboid
minor
Rhomboid
major
C3-C6 vertebrae
Elevator of scapula
of spine of the scapula
Medial border of
Spines of C7 & T1
scapula at the spine Dorsal scapular
root
Medial border of
Spines T2-T5
scapula below the
spine root
nerve
•
Scapular elevator
•
Retractor
Muscles connecting the scapula to the humerus
Muscle
Origin
•
Deltoid •
•
Scapular spine
Acromion
Lateral 1/3 clavicle
Insertion
Deltoid tuberosity of
humerus
Innervation
Function
•
Shoulder abductor
Axillary nerve •
Flexor (anterior F)
•
Extensor (post F)
Muscle
Origin
Subscapularis Subscapular fossa
Insertion
Innervation
Function
Lesser tuberosity of
Upper & lower •
Medial rotator
humerus
subscapular n •
Rotator cuff
Muscle
Origin
Supraspinatus Supraspinous fossa
Insertion
Innervation
Function
Greater tuberosity
•
Initiates abduction
(upper facet)
•
Rotator cuff
Greater tuberosity
•
Lateral rotator
(middle facet)
•
Rotator cuff
Suprascapular n
Infraspinatus
Infraspinous fossa
Muscle
Teres minor
Teres Major
Origin
Insertion
Axillary border of
Greater tuberosity
scapula
(lower facet)
Oval area beside
Medial lip of bicepital
infraspinous fossa
groove
Innervation
Axillary n
Lower
Function
•
Lateral rotator
•
Rotator cuff
•
Medial rotator
subscapular n •
Extensor
Rotator cuff:
These four muscles play important role
in stabilizing the shoulder joint in
position by:
1- Fusing with its capsule
2-
Approximating
surfaces
the
two
articular
Muscles connecting the trunk to the humerus
Muscle
Latissimus
dorsi
Origin
•
Spines of T7-12
•
Iliac crest
•
Lower 4 ribs
Insertion
Intertubercular groove
Innervation
Thoracodorsal
n
Function
•
Shoulder adductor
•
Extensor
•
Medial rotator
Communication with the axilla (axillary gateways):
1- Quadrangular space
2- Triangular space
3- Triangular interval
Quadrangular space:
Boundaries:
1- Teres major
2- Teres minor
3- Triceps long head
4- Humerus
Structures:
1- Axillary nerve
2- Posterior CHA
Triangular space:
Boundaries:
1- Teres major
2- Teres minor
3- Triceps long head
Structures:
Circumflex scapular n
Triangular interval:
Boundaries:
1- Teres major
2- Humerus
3- Triceps long head
Structures:
1- Radial n
2- Profundal brachii artery
Nerves:
1- Suprascapular n (C5 & 6):
- Branch of upper trunk of BP
- Descends to the region to pass in the
scapular
notch
underneath
the
transverse scapular ligament
- Enters supraspinatus
- Hooks
around
scapular
spine
&
reaches the infraspinatus to supply it
2- Dorsal scapular n (C5):
- Arises from BP roots
- Descends deep to levator scapulae &
rhomboids supplying them
3- Thoracodorsal n (C5, 6 &7):
-
Branch of posterior cord of BP
-
Descends
on
subscapularis
accompanied
by
the
subscapular artery
-
Enters latissimus dorsi near
its insertion to supply it
Arteries:
1- Suprascapular artery:
- Branch of 1st part of subclavian a
- Passes in the neck then descends
with its accompanying nerve
- Shares the same course of the nerve
but it passes above the ligament
- Shares in scapular anastomosis
2- Dorsal scapular artery:
- Arises from subclavian artery or from
its transverse cervical branch
- Descends deep to levator scapulae &
rhomboids supplying them
- Shares in scapular anastomosis
3- Subscapular artery:
-
Branch of 3rd
part of axillary
artery
-
Descends
on
subscapularis
accompanied by thoracodorsal
nerve
-
Gives the circumflex scapular
branch to the back muscles
-
Shares in scapular anastomosis
Scapular anastomosis
Connects the 1st part of
subclavian to the 3rd part
of axillary arteries