Lab 8 Spinal Nerves

What nerve innervates the Pectoralis minor

Medial Pectoral nerve

What nerve innervates the Pectoralis major?

• Medial Pectoral nerve

• Lateral Pectoral nerve

What nerve innervates the Subcalvius?

Subclavian nerve

What nerve innervates the Latissimus Dorsi

Thoracodorsal nerve

What nerve innervates the levator scapulae

dorsal scapular nerve

What nerve innervates the subscapularis

Upper and Lower subscapular nerves

What nerve innervates the rhomboid major

Dorsal scapular nerve

What nerve innervates the rhomboid minor?

Dorsal scapular nerve

What nerve innervates the Deltoid?

Axillary nerve

What nerve innervates the Supraspinatus?

Suprascapular nerve

This muscle is innervated via the medial pectoral nerve and acts to stabilize the scapula drawing it inferiorly?

Pectoralis minor

This muscle is innervated via the medial and lateral pectoral nerve and acts to adduct the shoulder

Pectoralis major

This muscle is innervated via the Subclavian nerve and acts to depress the clavicle

Subclavius

This muscle is innervated via the Long thoracic nerve and acts to protracts the scapula

Serratus anterior

This muscle is innervated via the Thoracodorsal nerve and acts to extend, adduct and medially rotate the humerus

Latissimus dorsi

This muscle is innervated via the Dorsal scapular nerve and elevates the scapula and rotates the glenoid cavity

Levator scapulae

This muscle is innervated by the Dorsal scapular nerve, retracts the scapula and is larger of the two muscle pair

Rhomboid major

This muscle is innervated by the Dorsal scapular nerve, retracts the scapula and is smaller of the two muscle pair.

Rhomboid minor

This muscle is innervated via the Axillary nerve and acts to abduct the arm

Deltoid

This muscle is innervated via the Axillary nerve and acts to laterally rotate the arm.

Teres minor

This muscle is innervated via the lower Subscapular nerve and adducts and medially rotates the arm.

Teres major

This muscle is innervated via the Suprascapular nerve and aids the deltoid in arm abduction

Supraspinatus

This muscle is innervated via the upper and lower Subscapular nerves and medially rotates the arm.

Subscapularis

This muscle is innervated via the Suprascapular nerve and laterally rotates the arm

Infraspinatus

Which muscle does not aid in internal rotation of the humerus

Infraspinatus

Which muscle doesn't aid in external rotation

Supraspinatus

Which muscle aids in shoulder abduction

Supraspinatus

Which muscle doesn't originate or insert on the ribs or associated cartilage

Levator scapulae

Which muscle does not originate or insert on the scapula

Pectoralis major

Which muscle doesn't originate or insert on the humerus

Pectoralis minor

OIAN Pectoralis Minor

• O = 3rd to 5th ribs near their costal cartilage
• I = medial border and superior surface of coracoid process of scapula
• N = medial pectoral (C8,T1)
• Action = Stabilizes scapula by drawing it inferiorly and anteriorly against thoracic wall

OIAN Pectoraliz Minor

O = Clavicular head: anterior surface of medial half of clavicle; Sternocostal head: anterior surface of sternum, superior six costal cartilages, aponeurosis of external oblique

I = lateral lip of intertubercular sulcus of humerus

N = medial and lateral pectoral (C5, C6), sternocostal head (C7,C8, T1)

Action = Adducts shoulder and medially rotates, draws scapula anteriorly and inferiorly; clavicular fibers - flexes shoulder; Sternocostal fibers - horizontal adduction and extend from flexed position when supine

Subclavius

• O = Junction of 1st rib and its costal cartilage

• I = inferior surface of middle third of clavicle

• N = Nerve to subclavius (C5, C6)

• Action = Anchors and depresses the clavicle

Serratus Anterior

• O = External surfaces of lateral parts of 1st-8th ribs
• I = Anterior surface of medial border of the scapula
• N = Long thoracic nerve (C5, C6, C7)
• Action = Protracts scapula and holds it against thoracic wall; upwardly rotates scapula

• O = Spinous processes of inferior 6 thoracic vertebrae,
thoracolumbar fascia, iliac crest, and inferior 3 or 4 ribs

• I = floor of intertubercular sulcus of humerus

• N = Thoracodorsal nerve (C6, C7, C8)

• Action = Extends, adducts, and medially rotates humerus.

Levator Scapulae

• O = Posterior tubercles of transverse processes of C1-C4 vertebrae
• I = Medial border of scapula superior to root of scapular spine
• N = Dorsal scapular (C4, C5) and cervical nerves (C3,C4)
• Action = Elevates scapula and rotates its glenoid cavity inferiorly by rotating scapula (aka downward rotation)

Rhomboid major

• O = Spinous process of T2-T5
• I = Medial border of scapula from level of spine to inferior angle
• N = dorsal scapular nerve (C4, C5)
• Action =Retracts scapula and rotate its glenoid cavity inferiorly; fix scapula to thoracic wall

Rhomboid minor

• O = nuchal ligament; spinous processes of C7 and T1 vertebrae
• I = smooth triangular area at medial end of scapular spine (base of the spine of the scapula)
• N = Dorsal scapular nerve (C4,C5)
• Action = Retract scapula and rotates its glenoid cavity inferiorly; fix scapula to thoracic wall

Deltoid

• O = Lateral third of clavicle; acromion and spine of scapula
• I = deltoid tuberosity
• N = axillary nerve (C5,C6)
• Action = clavicular portion = flexes and weak medial rotator;
Acromial = strongly abducts arm;
Scapula = extends and weak lateral rotator

Teres minor

• O = Middle part of lateral (axillary) border of scapula
• I = Inferior facet of greater tubercle of humerus
• N = Axillary nerve (C5,C6)
• Action = laterally rotates arm; and acts with rotator cuffs muscles.

Teres major

• O = posterior surface of inferior angle of scapula
• I = medial lip of intertubercular sulcus of humerus
• N = lower subscapular nerve (C5,C6)
• Action = adducts and medially rotates arm.

Supraspinatus

• O = Supraspinous fossa of scapula
• I = superior facet of greater tubercle of humerus
• N = suprascapular nerve (C4, C5, C6)
• Action = Initiates and assists deltoid in abduction of arm and acts with rotator cuff muscles.

Infraspinatus

• O = Infraspinous fossa of scapula
• I = middle facet of greater tubercle of humerus
• N = suprascapular nerve (C5, C6)
• Action = laterally rotates arm; and acts with rotator cuff muscles

Subscapularis

• O = subscapular fossa (most
anterior surface of scapula)
• I = lesser tubercle of humerus
• N = upper and lower subscapular nerves (C5,C6,C7)
• Action = Medially rotates arm; as part of rotator cuff, helps hold head of humerus in glenoid cavity.