Lab Manual 5 pt.1 brachial plexus and muscles of the glenohumeral joint, arm

what is the roots of the C5-T1 Ventral Rami?

• Dorsal Scapular nerve (C5)

• Long thoracic nerve (C5-C7)

what does Dorsal Scapular nerve (C5) innervate?

rhomboid and levator scapulae muscles

what does Long thoracic nerve (C5-C7) innervate?

serratus anterior muscle

what is the trunks of brachial plexus?

• superior trunk

• middle trunk

• inferior trunk

whats inside of the superior trunk?

• union of the C5 and C6 roots

• nerve to subclavius (C5)

• suprascapular nerve (C5-C6)

what does nerve to subclavius innervate?

subclavius muscle

what oes suprascapular nerve (C5-C6) innervate?

supraspinatus and infraspinatus

what is the middle trunk of brachial plexus?

a continuation of the C7 foot

what is the inferior trunk of brachial plexus?

formed from the union of C8 and T1 roots

what is the divisions of the bracial plexus?

• anterior divisions (x3)

• posterior divisions (x3)

what does the anterior divisions innervate?

the anterior (flexor) compartments of the arm an forearm

what does the posterior divisions innervate?

the posterior (extensor) compartments of the arm an forearm

what are cords of brachial plexus ?

• lateral cord

• medial cord

• posterior cord

where is lateral cord located and which nerve resides inside of it?

• Located lateral to the axillary artery; gives rise of the following:

  • lateral pectoral nerve (C5-C7)

what does the lateral pectoral nerve (C5-C7) innervate?

pectoralis major

where is medial cord located and which nerve resides inside of it?

• Located medial to the axillary artery; gives rise to the following:

  • medial pectoral nerve (C8-T1)

  • medial cutaneous nerve of the arm (C8-T1)

  • medial cutaneous nerve of the forearmarm (C8-T1)

what does medial pectoral nerve (C8-T1) innervate?

pectoralis major and pectoralis minor

what does medial cutaneous nerve of the arm (C8-T1) innervate?

cutaneous innervation to the medial surface of the arm

what does medial cutaneous nerve of the forearm (C8-T1) innervate?

cutaneous innervation to the medial surface of the forearm

where is posterior cord located and which nerve resides inside of it?

• located posterior to the axillary aartery gives rise to the following:

  • upper subscapular nerve (C5-C6)

  • Thoracodorsal (middle subscapular) nerve (C6-C8)

  • Lower Subscapular nerve (C5-C6)

what does upper subscapular nerve (C5-C6) innervate?

subscapularis muscle

what does Thoracodorsal (middle subscapular) nerve (C6-C8) innervate?

latissimus dorsi muscle

what does Lower Subscapular nerve (C5-C6) innervate?

subscapularis and teres major muscle

what are the terminal branches of the brachial plexus?

• musculocutaneous nerve (C5-C7)

• median nerve (C6-T1)

• Ulnar nerve (C8-T1)

• Radial Nerve (C5-T1)

• Axillary nerve (C5-C6)

what does motor musculocutaneous nerve (C5-C7) innervate?

anterior compartment arm muslces

what does sensory musculocutaneous nerve (C5-C7) innervate?

cutaneous innervation to the lateral forearm

what does motor median nerve (C6-T1) innervate?

• anterior compartment forearm muscles

• hand muscles (thenar and lumbricals 1-2)

what does sensory median nerve (C6-T1) innervate?

• cutaneous innervation to the palmar surface of digits 1 through 3 and half of digit 4

• the lateral palm is supplied by the palmar cutaneous branch of the median nerve

what does motor Ulnar nerve (C8-T1) innervate?

• flexor carpi ulnaris and the ulnar half of the flexor digitorum profundus muscle in the anterior compartment of the forearm

• hand muscles

what does sensory Ulnar nerve (C8-T1) innervate?

cutaneous innervation of the medial half of the palm, digit 5 and mdial region of digit 4

what does the motor Radial nerve (C5-T1) innervate?

posterior compartment arm (triceps muscle) and forearm (wrist, thumb, and forearm extensors)

what does the sensory Radial nerve (C5-T1) innervate?

• cutaneous innervation to the posterior arm, posterior forearm

• dorsum of the hand and the dorsum of digits 1 through 3 and half of digit 4

what does the motor axillary nerve (C5-C6) ?

deltoid and the teres minor muscles

what does the sensory axillary nerve (C5-C6) ?

cutaneous innervation to the lateral region of the shoulder

What is the anterior muscles?

• pectoralis major clavicular head

• pectoralis major sternocostal head

• subscapularis

• coracobrachialis

• deltoid anterior fibers

• deltoid middle fibers

what is the origin of the pectoralis major clavicular head?

medial half of clavicle

what is the insertion of the pectoralis major clavicular head?

lateral lip of intertubercular groove

what is the action of the pectoralis major clavicular head?

• interal rotation horizontal adduction

• diagnal adduction

• flexion

• abduction

what is the innervation of the pectoralis major clavicular head?

lateral pectoral nerve (C5,C6,C7)

what is the origin of pectoralis major sternocostal head?

costal cartialges of first six ribs, and sternum

what is the insertion of pectoralis major sternocostal head?

lateral lip of intertubercular groove

what is the action of pectoralis major sternocostal head?

• internal rotation

• horziontal adduction

• diagnoal adduction

• extension from flexed position

• adduction

what is the innervation of pectoralis major sternocostal head?

medial pecoral nerve (C8,T1)

what is the origin of the subscapularis ?

subscapular fossa

what is the insertion of the subscapularis ?

lesser tubercle of humerus

what is the action of the subscapularis ?

• internal rotation

• adduction

• extension

what is the innervation of the subscapularis ?

upper and lower subscapular nerve (C5,C6)

what is the origin of the coracobrachialis?

coracoid process of scapula

what is the insertion of the coracobrachialis?

middle of medial border of humeral shaft

what is the action of the coracobrachialis?

• flexion

• adduction

what is the innervation of the coracobrachialis?

musculotaneous nerve(C5,C6,C7)

what is the origin of the deltoid anterior fibers?

lateral third of clavicle

what is the insertion of the deltoid anterior fibers?

deltoid tuberosity on lateral humerus

what is the action of the deltoid anterior fibers?

• abduction

• flexion

• horizontal adduction

• internal rotation

• diagnoal adduction

what is the innervation of the deltoid anterior fibers?

axillary nerve (C5, C6)

what is the origin of the deltoid middle fibers?

acromion

what is the insertion of the deltoid middle fibers?

deltoid tuberosity on lateral humerus

what is the action of the deltoid middle fibers?

• abduction

• horizontal abduction

what is the insertion of the deltoid middle fibers?

axillary nerve (C5, C6)

what is the origin of the supraspinatus ?

supraspinous fossa

what is the insertion of the supraspinatus ?

greater tubercle of humerus

what is the action of the supraspinatus ?

abduction

what is the innervation of the supraspinatus ?

suprascapular nerve (C5)

what is the posterior muscles?

• latissimus dorsi

• teres major

• infraspinatus

• teres minor

what is the origin of the latissimus dorsi ? (4)

• veretebral part: spinous processes of vertebrae T7-T12, Thoracolumbar fascia

• iliac part: posterior crest of ilium

• costal part: Ribs 9-12

• scapular part: inferior angle of scapula

what is the insertion of the latissimus dorsi ?

medial lip of intertubercular groove

what is the action of the latissimus dorsi ?

• extension

• adduction

• internal rotation

• horizontal abduction

what is the innervation of the latissimus dorsi ?

thoracodorsal (C6-C8)

what is the origin of the teres major?

lateral border of scapula

what is the insertion of the teres major?

medial lip of interubercular groove

what is the action of the teres major?

• extension

• adduction

• internal rotation

what is the innervation of the teres major?

lower subscapular nerve (C5,C6)

what is the origin of the infraspinatus ?

infraspinous fossa just below spine of scapula

what is the insertion of the infraspinatus ?

greater tubercle of humerus

what is the action of the infraspinatus ?

• external rotation

• horizontal abduction

• extension

• diagonal abduction

what is the innervation of the infraspinatus ?

suprascapular nerve (C5, C6)

what is the origin of the teres minor ?

posteriorly on upper and middle aspect of lateral border of scapula

what is the insertion of the teres minor ?

greater tubercle of humerus

what is the action of the teres minor ?

• external rotation

• horizontal abduction

• extension

• diagonal abduction

what is the innervation of the teres minor ?

axillary nerve (C5,C6)

whats in the anterior compartment of the arm?

• biceps brachii

• brachialis

• coracobrachilais

what is the origin of the biceps brachii?

• long head: supraglenoid tubercle

• short head: coracoid process

what is the insertion of the biceps brachii?

radial tuberosity

what is the action of the biceps brachii?

• flexion of shoulder

• flexion and supination of elbow

what is the innervation of the biceps brachii?

musculocutaneous n. (C5-C7)

what is origin of the brachialis ?

distal anterior surface of humerus

what is insertion of the brachialis ?

coronoid process of ulna

what is action of the brachialis ?

flexion of the elbow

what is innervation of the brachialis ?

musculocutaneous n. (C5-C7)

what is the origin of the coracobrachialis ?

coracoid process of scapula

what is the insertion of the coracobrachialis ?

medial midshaft surface of humerus

what is the action of the coracobrachialis ?

flexion of shoulder

what is the innervation of the coracobrachialis ?

musculocutaneous n. (C5-C7)

what is in the posterior compartment of the arm?

triceps brachii

what is the origin of the triceps brachii ?

• long head: infraglenoid tubercle

• lateral head: proximal posterior shaft of humerus

• medial head: distal posterior shaft of humers

what is the insertion of the triceps brachii ?

olecranon process of ulna

what is the action of the triceps brachii ?

extension of shoulder and elbow

what is the innervation of the triceps brachii ?

radial n. (C5-T1)