Deep Muscles of the Back & Muscles of the Shoulder and Arm
What innervates the deep muscles of the back? (No exceptions?)
dorsal rami
deep muscles = erector spinae and some others
O I A INN of pectoralis minor
O anterior surface of ribs 3-5
I corocoid process of scapula
A protracts scapula, elevates ribs when scapula is stationary to assist in inhalation
Inn medial pectoral n. (C8-T1)
O I A Inn of triceps brachii?
O Long Head: infraglenoid tubercle of scapula
Lateral Head: posterior surface of humerus superior to radial groove
Medial Head: posterior surface of humerus inferior to radial groove
I olecranon process of ulna
A extends forearm - long head resists dislocation of the humerus and extends shoulder joint
Inn radial n (C6-C8)
What are the posterior muscles from the axial skeleton to the pectoral girdle?
trapezius, levator scapulae, rhomboid major, rhomboid minor
O I A INN of trapezius
O superior nuchal line, external occipital protuberance, ligamentum nuchae, spinous process C7 and T1-T12 vertebrae
I lateral 1/3rd of the clavical, acromion, and spine of scapula
A Descending(upper) - Elevates scapula
Middle - Retracts scapula
•Ascending(lower) - Depresses scapula
Inn motor - accessory n (CN XI)
pain and proprioception - C3, C4 spinal nerves
Where is the superior nuchal line located?
On the skull, just superior to the external occipital protuberance
What is the nuchal ligament?
The nuchal ligament extends from the external occipital protuberance on the skull and median nuchal line to the spinous process of the seventh cervical vertebra in the lower part of the neck
O I A INN of levator scapulae
O transverse process of C1-C4 vertebrae
I vertebral (medial) border of scapula near superior angle
A elevates scapula
INN dorsal scapular n
Rhomboid major O I A INN
O spinous processes of T2-T5 vertebrae
I medial border of the scapula from the level of the spine to the inferior angle
A retract scapula and rotate it to depress the glenoid cavity; fix scapula to thoracic wall
Inn dorsal scapular nerve C4 C5
O I A INN of infraspinatus
O infraspinous fossa of the scapula
I middle facet of greater tubercle of the humerus
A laterally rotates the arm/shoulder; helps hold humeral head in glenoid cavity
Inn suprascapular n (C4-C6)
What are the anterior muscles from the axial skeleton to pectroal girdle?
serratus anterior and pectoralis minor
O I A INN of serratus anterior
O lateral surface of ribs 1-8
I anterior surface of medial (vertebral) border of scapula
A protracts scapula, holds scapula against thoracic wall, and rotates scapula
Inn long thoracic n (C5-C7)
O I A INN of pectoralis minor
O anterior surface of ribs 3-5
I corocoid process of scapula
A protracts scapula, elevates ribs when scapula is stationary to assist in inhalation
Inn medial pectoral n. (C8-T1)
What is the result of a paralyzed serratus anterior?
"winging of the scapula"
scapula is not held to the thoracic wall
What muscles are from the axial skeleton to the humerus?
pectoralis major and latissimus dorsi
O I A Inn of pectoralis major?
O clavicular head: anterior surface of medial half of clavicle
sternalcostal head: anterior surface of sternum superior six costal cartilages, aponeurosis of external oblique muscles
I lateral lip of intertubercular sulcus of humerus
A adducts arm, medially rotates arm. draws scapula anterior and inferior. acting alone, clavicular head flexes shoulder joint and sternocostal head extends it from flexed position.
Inn medial pectoral n (C8-T1) and lateral pectoral n (C5-C7)
Which muscle could be referred to as the "boxer's muscle" as it protacts the scapula and rotates the scapula?
serratus anterior
O I A Inn of triceps brachii?
O Long Head: infraglenoid tubercle of scapula
Lateral Head: posterior surface of humerus superior to radial groove
Medial Head: posterior surface of humerus inferior to radial groove
I olecranon process of ulna
A extends forearm - long head resists dislocation of the humerus
Inn radial n (C5-T1)
Which muscle could be called the handcuff muscle, as making the motion to be handcuffed required adduction of the arm, medial rotation of the arm, and extension of the arm?
latissimus dorsi
O I A INN of deltoid
O lateral 1/3 of clavicle, acromion, and spine of scapula
I deltoid tuberosity of humerus
A anterior part: flexes arm and medially rotates arm
middle part: abducts arm
posterior part: extends and laterally rotates arm
Inn axillary n (C5-C6)
What are the rotator cuff muscles?
subscapularis, supraspinatus, infraspinatus, and teres minor
O I A INN of subscapularis
O subscapular fossa of scapula
I lesser tubercle of humerus
A medially rotates arms, adducts shoulder joint and holds humerus in glenoid cavity
INN upper subscapular n (C5) and lower subscapular n (C6)
O I A INN of supraspinatus
O supraspinous fossa of the scapula
I superior facet og greater tubercle of the humerus
A abducts shoulder - initates before deltoid takes over
Inn suprascapular n (C4-C6)
O I A INN of infraspinatus
O infraspinous fossa of the scapula
I middle facet of greater tubercle of the humerus
A laterally rotates the arm/shoulder; helps hold humeral head in glenoid cavity
Inn suprascapular n (C4-C6)
Which muscle initiates abduction (moves the arm for the first 15 degrees)
supraspinatus muscle
After the first fifteen degrees of abduction which muscle takes over from supraspinatus?
the deltoids
O I A INN of teres minor
O lateral border of the scapula
I inferior facet of greater tubercle of the humerus
A laterally rotates the shoulder; helps hold humerus in glenoid cavity
Inn axillary n (C5-C6)
O I A INN of teres major
dorsal surface of inferior angle of scapula
crest of lesser tubercle of humerus
Adducts arm, extends arm, medially rotates arm
lower subscapular n (C6)
O I A INN of teres minor
O lateral border of the scapula
I inferior facet of greater tubercle of the humerus
A laterally rotates the shoulder; helps hold humerus in glenoid cavity
Inn axillary n (C5-C6)
what are the muscles of the anterior compartment of the arm?
coracobrachialis
biceps brachii (long head and short head)
brachialis
In the biceps brachii, which is more lateral, short or long head?
long head
O I A INN of biceps brachii
O short head: corocoid process of scapula
long head: supraglenoid tubercle of scapula
I radial tuberosity and deep fascia of forearm via bicipetal aponeurosis
A flexes forearm when forearm is supinated, supinates forearm, and slight arm flexion. short head resists dislocation of shoulder.
Inn musculocutaneous n (C5-C7)
O I A INN of the coracobrachialis
O coracoid process of the scapula
I medial surface of the middle of the humerus
A flexes arm, adducts arm; resists dislocation of shoulder
Inn musculocutaneous n.
O I A Inn of brachialis
O distal half of anterior surface of humerus
I ulnar tuberosity and coranoid process
A flexes forearm in all positions
Inn musculocutaneous n (C5-C7)
Which muscle can flex the elbow joint whether the hand is pronated or supinated?
brachialis
O I A INN of subscapularis
O subscapular fossa of scapula
I lesser tubercle of humerus
A medially rotates arms, adducts shoulder joint and holds humerus in glenoid cavity
INN upper subscapular n (C5) and lower subscapular n (C6)
O I A Inn of triceps brachii?
O Long Head: infraglenoid tubercle of scapula
Lateral Head: posterior surface of humerus superior to radial groove
Medial Head: posterior surface of humerus inferior to radial groove
I olecranon process of ulna
A extends forearm - long head resists dislocation of the humerus
Inn radial n
O of triceps brachii?
O Long Head: infraglenoid tubercle of scapula
Lateral Head: posterior surface of humerus superior to radial groove
Medial Head: posterior surface of humerus inferior to radial groove
During pronation and supination, which bone moves and which bone remains stationary?
radius moves. ulna remains stationary.
A muscle attaching to the ulna can flex forearm when hand is supinated, pronated, or both?
both - example is brachialis
O I A INN of subclavius m.
O junction of first rib and its costal cartilage
I inferior surface of middle third of clavicle
A anchors and depresses clavicle
Inn subclavian n.
O I A INN of anconeous m
O lateral epicondyle of humerus
I lateral surface of olecranon and superior part of posterior surface of ulna
A assists triceps in extending elbow joint and abducts ulna during pronation
Inn radial n (C5-T1)
Rhomboid minor O I A INN
O nuchal ligament spinous processes C7 and T1
I triangular area at the medial end of the scapular spine
A retract scapula and rotate it to depress glenoid cavity. fix scapula to thoracic wall
Inn dorsal scapular nerve (C4,C5)
Rhomboid major O I A INN
O spinous processes of T2-T5 vertebrae
I medial border of the scapula from the level of the spine to the inferior angle
A retract scapula and rotate it to depress the glenoid cavity; fix scapula to thoracic wall
latissimus dorsi O I A IN
O spinous processes of T6-T12, thoracolumba fascia, iliac crest, ribs 8 or 9 - 12
I floor of intertubercular sulcus of humerus
A extension, adduction, and medial rotation of humerus. raises body toward arms when climbing
In thoracodorsal n (C6-C8)