Module 2: Pectoral, Axilla, Arm, & Cubital Fossa Flashcards
What are the attachments of the pectoralis major?
- clavicle, costal cartilages, sternum, and aponeurosis of external oblique
- lateral lip of intertubercular sulcus
What are the actions of pectoralis major?
- humeral adduction
- flexion + medial rotation
- (sternocostal portion assists in extension of flexed arm)
What nerve innervates the pectoralis major?
lateral + medial pectoralis nerves (C5-7: clavicular head, C8-T1: sternocostal head)
What are the attachment sites of pectoralis minor?
-outer surfaces of ribs 3-5
- coracoid process
What are the actions of pectoralis minor?
- anterior tilt of scapula
- assists with depression of the shoulder + forced inspiration
What nerve innervates pectoralis minor?
medial + lateral pectoral nerves (C5-T1)
What are the attachments of the deltoid?
- clavicle, acromion, + spine of scapula
- deltoid tuberosity of humerus
What are the actions of the deltoid?
-flexion + medial rotation
- abduction
- extension + lateral rotation, horizontal extension of humerus
What are the attachments of the subclavius?
- 1st rib + cartilage
- undersurface of the clavicle
What are the actions of the subclavius?
- depresses + stabilizes the clavicle
What nerve innervates the subclavius?
subclavian nerve (C5-6)
What is the superficial muscle of the pectoral region?
pectoralis major
What are the deep muscles of the pectoral region?
- pectoralis minor
- subclavius
What are the pectoral (shoulder) girdle joints?
- sternoclavicular
- acromioclavicular
- glenohumeral
- scapulothoracic
What is the classification of the sternoclavicular joint?
synovial - seller/saddle
What is the classification of the acromioclavicular joint?
synovial - plane/gliding
What is the classification of the glenohumeral joint?
synovial - ball & socket
What is the classification of the scapulothoracic joint?
psuedo-joint necessary for full glenohumeral function
What is the saddle mechanism of the sternoclavicular joint?
- clavicle = convex in superior - inferior
- manubrium = concave in superior -inferior
- clavicle = concave in anterior - posterior
- manubrium = convex in anterior - posterior
What is the function of the coracoclavicular ligament
stablize acromioclavicular joint limiting medial displacement, protraction, and elevation
What are the attachment sites of the coracoclavicular ligament (2 regions)
- Trapezoid - from coracoid process to trapezoid tubercle of clavicle
- Conoid - from coracoid process to conoid tubercle of clavicle
What is the function of the acromioclavicular ligament?
stablize acromioclavicular joint
What the attachments of the acromioclavicular ligament?
from superior aspect of acromial end of clavicle to adjacent acromion
What is the function of the coracoacromial joint?
prevents the superior displacement of the humeral head by forming coracoacromial notch
What are the attachments of the coracoacromial ligament?
from lateral border of coracoid process to acromion adjacent to clavicular articulaton
What is the function of the coracohumeral ligament?
reinforces superoanterior aspects of joint capsule
What are the attachments of the coracohumeral ligament?
from base of coracoid process to anterior aspect greater tubercle
What is the function of the costoclavicular ligament?
stabilizes sternoclavicular joint, limiting elevation of the clavicle
What are the attachments of the costoclavicular ligament?
from superior aspect of cartilage of 1st rib to undersurface of the clavicle
What is the function of the superior transverse scapular ligament?
close off suprascapular notch
What are the attachments of the superior transverse scapular ligament?
from base of the coracoid process to the medial edge of scapular notch
What are the attachments of the glenoid capsule ligament?
from circumference of glenoid cavity to anatomical neck of the humerus
What is the function of the glenohumeral ligament? (superior, middle, inferior)
stabilize glenohumeral articulation
What area of the skin is associated with C5 spinal nerve?
deltoid tuberosity (lateral arm)
What area of the skin is associated with C6 spinal nerve?
thumb (middle arm to thumb)
What area of the skin is associated with C7 spinal nerve?
index finger (digit 2- lateral half of 4)
What area of the skin is associated with C8 spinal nerve?
pinky (digit 5 and medial half of 4)
What area of the skin is associated with T1 spinal nerve?
medial epicondyle of humerus (medial arm and forearm)
What are the two compartments the brachial fascia is broken into?
Anterior + Posterior Compartment
What are the contents of the anterior compartment of the arm?
- biceps brachii
- coracobrachialis
- brachialis
What is the function of the anterior compartment of the arm?
shoulder + elbow flexion
What is the arterial supply of the anterior compartment of the arm?
brachial artery
What are the contents of the posterior compartment of the arm?
triceps brachii + anconeus
What is the function of the posterior compartment of the arm?
shoulder + elbow extension
What nerve innervates the anterior compartment of the arm?
musculocutaneous nerve
What nerve innervates the posterior compartment of the arm?
radial nerve
What is the arterial supply of the posterior compartment of the arm?
profunda brachii artery
What structures separate the two brachial fascia compartments?
medial + lateral intermuscular septum
What are the contents of the triangular space?
circumflex scapular artery
What structures border the triangular space?
- teres minor
- teres major
- LH triceps brachii
What are the contents of the triceps hiatus?
- radial nerve
- profunda brachii artery
What structures border the triceps hiatus?
- humerus
- LH triceps brachii
- teres major
How many spinal nerves are in the different regions of vertebrae?
- cervical = 8
- thoracic = 12
- lumbar = 5
- sacral = 5
- coccygeal = 1
= 31 total
How are spinal nerves named in the cervical region?
- cervical nerves exit above corresponding vertebrae
C6 nerve: C5-C6
How are spinal nerves named in the other vertebral regions that aren’t cervical?
- all others exit below their corresponding vertebrae
T7 nerve: T7-8
What are the boundaries of the axilla region?
- Apex = 1st rib, clavicle
- Base = skin of the armpit
- Anterior = pectoral muscle
- Posterior = scapula, subscapularis muscle
- Medial = thoracic wall, serratus anterior
- Lateral = humerus
What are the contents of the axilla region?
- axillary artery
- axillary vein
- axillary lymph nodes
- 3 cords of brachial plexus
What are the attachments of the anconeus?
from lateral epicondyle of humerus to lateral surface of olecranon process
What is the action of the anconeus?
extension of the elbow
What nerve innervates the anconeus?
radial nerve (C7-8)
What are the attachments of the biceps brachii?
- long head: from supraglenoid tubercle of scapula
- short head: from coracoid process of scapula
to radial tuberosity + deep ante brachial fascia (through bicipital aponeurosis)
What are the actions of biceps brachii?
flexion of the shoulder + elbow, supination of the forearm
What nerve innervates biceps brachii?
musculocutaneous nerve (C5-6)
What are the attachments of brachialis?
from distal anterior shaft of the humerus + lateral & medial intermuscular septa to coronoid process & ulnar tuberosity
What are the actions of brachialis?
flexion of the elbow
What nerve innervates brachialis?
musculocutaneous & small branch from radial nerve (C5-6)
What are the attachments of coracobrachialis?
from coracoid process to the proximal medial shaft of humerus
What are the actions of the coracobrachialis?
flexion & adduction of the shoulder
What nerve innervates the coracobrachialis?
musculocutaneous nere (C6-7)
What are the attachments of triceps brachii?
- long head: from infraglenoid tubercle of the scapula
- lateral head: proximal posterolateral shaft of humerus
- medial head: distal posteromedial shaft of humerus
to the olecranon process of the ulna
What are the actions of triceps brachii?
- long head: extension of shoulder
- long, lateral, + medial head: extension of the elbow
What nerve innervates triceps brachii?
radial nerve (C6-T1)
What does the clavicopectoral fascia surround?
subclavius + pectoralis minor muscles
What does the axillary sheath surround?
- axillary artery
- axillary vein
- cords of brachial plexus
(continuous with the prevertebral fascia of the neck)
What are the functions of sympathetic (pre/post) axons in the peripheral nerves of the brachial plexus?
innervate smooth muscle of the blood vessels
How many roots are in the brachial plexus?
5 (ventral rami, [C4] C5-T1)
How many trunks are in the brachial plexus?
3 (upper, middle, lower)
How many divisions are in the brachial plexus?
3 anterior, 3 posterior
How many cords are in the brachial plexus?
3 (medial, lateral, posterior)
How many nerves(terminal branches) are in the brachial plexus?
- 5 main
- 11 additional
= 16 total
What are the joints of the elbow and their synovial classifications?
- humeroulnar = hinge
- humeroradial = gliding
- proximal radioulnar = pivot (pronation/supination)
What are the attachments and functions of the radial collateral ligament?
- lateral epicondyle»_space; annular ligament
- resist cubital varus
What are the attachments and functions of the ulnar collateral ligament?
- medial epicondyle»_space; coronoid process and olecranon process
- resist cubital valgus
What are the attachments and functions of the annular ligament?
- anterior radial notch»_space; posterior radial notch
- stabilize proximal radioulnar joint
What are the attachments and functions of the interosseous membrane?
- interosseous border of radius»_space; interosseous border of ulna
- stablize radius and ulna in pro/supination
What is radial head subluxation?
- radial head slips out of annular ligament
- seen mostly in children because of radial head development
- when hanging or lifted
What is olecranon bursitis?
- excessive pressure on the olecranon causes overproduction of fluid of olecranon bursa
What are the contents, actions, and innervation of the anterior compartment of the forearm?
- flexors of elbow + wrist, pronators
- mostly median nerve innervation
What are the contents of the superficial anterior compartment of the forearm?
- pronator teres
- flexor carpi radialis
- palmaris longus
(median nerve - flexor carpi ulnaris
(ulnar nerve)
What are the contents of the intermediate anterior compartment of the forearm?
- flexor digitorum superficialis
(median n)
What are the contents of the deep anterior compartment of the forearm?
- flexor digitorum profundus
(median n = digit 2&3)
(ulnar n = digit 4&5)
What is the carrying angle of a male and female?
male = 5-10 deg
female = 15-20 deg
What are the attachments, actions, and innervation of flexor carpi radialis
attach: medial epicondyle»_space; palmar aspect of 2nd metacarpal
action: flex + abduct hand at wrist, pronation of forearm, elbow flexion
innervation: median n (C6-8)
What are the attachments, actions, and innervation of flexor carpi ulnaris?
attach: medial epicondyle & proximal ulnar shaft»_space; pisiform
action: flex + abduct hand at wrist, elbow flexion
innervation: ulnar nerve (C7-T1)
What are the attachments, actions, and innervation of flexor digitorum superficialis?
attach: medial epicondyle»_space; sides of middle phalanges of digits 2-5
action: flexion of digits + hand
innervation: median nerve (C7-T1)
What are the attachments, actions, and innervation of the flexor digitorum profundus?
attach: ant prox 2/3 of ulna + interosseous membrane»_space; base of distal phalanges of digits 2-5
action: flex digits 2-5, flex hand and wrist
innervation: median = digits 2+3, ulnar = digits 4+5 (C7-T1)
What are the attachments actions, and innervation of flexor pollicis longus?
attach: ant surface of radius»_space; base of distal phalanx of the thumb
action: flex thumb
innervation: median n (C7-T1)
What are the attachments, actions, and innervation of palmaris longus?
attach: medial epicondyle»_space; palmar aponeurosis
action: flex hand and wrist, tenses palmar fascia
innervation: median n (C7-8)
What are the attachments, actions, and innervation of pronator quadratus?
attach: ant surface of distal ulna»_space; ant surface of radius
action: pronate forearm
innervation: median nerve (C8-T1)
What are the attachments, actions, and innervation of the pronator teres?
attach: medial epicondyle»_space; ulnar coronoid process»_space; lat radius
action: pronate + flex forearm
innervation: median nerve (C6-7)
What are the bursa of the elbow?
- subcutaneous bursa of med epicondyle
- subcutaneous bursa of lat epicondyle
- bursa of anconeus
- bursa at origin of ext carpi radialis brevis
- olecranon bursa (subtendinous, infratendinous, subcutaneous)
What is the spinal cord segment and function of the lateral pectoral nerve?
(C5-7)
- sensory, post gang symp, motor innervation of pec major (clavicular head) and minor
What are the spinal cord segments and functions of the musculocutaneous nerve?
C5-7
- sensory, postgang symp, and motor innervation of biceps brachii, coracobrachialis, and brachialis
- sensory and postgang symp innervation of skin overlying lateral aspect of forearm
What are the spinal cord segments and functions of the median nerve?
C5-T1
- sensory, postgang, and motor innervation of ant forearm muscles
- sensory and postgang symp of radial palm
What are the spinal cord segments and functions of the medial pectoral nerve?
C8-T1
- sensory, postgang symp, and motor innervation of pectoralis major(SC head) and minor
What are the spinal cord segments and functions of the ulnar nerve?
C7-T1
- sensory, postgang symp, motor innervation of flexor carpi ulnaris and flexor digitorum profundus
- sensory of ulnar palm
What are the spinal cord segments and functions of the upper subscap nerve?
C5-6
- sensory, postgang symp, and motor innervation of subscapularis
What are the spinal cord segments and functions of the thoracodorsal nerve?
C6-8
- S, PGS, M of latissimus dorsi
What are the spinal cord segments and functions of the lower subscapular nerve?
C5-6
- S, PGS, M of subscapularis and teres major
What are the spinal cord segments and functions of the axillary nerve?
C5-6
- S, PGS, M of deltoid and teres minor
- S, PGS of superior lateral aspect of arm
What are the spinal cord segments and functions of the radial nerve?
C5-T1
- S, PGS, M of triceps brachii and brachialis
- S, PGS, M of extensor muscles of forearm
S, PGS of radial dorsal of hand, and posterior aspect of forearm
What are the spinal cord segments and functions of the subclavian nerve?
C5-6
- S, PGS, M of subclavius
What are the spinal cord segments and functions of the dorsal scapular nerve?
C4-5
- PGS and M of levator scapulae and rhomboid
What are the spinal cord segments and functions of the suprascapular nerve?
C4-6
- S, PGS, M of supraspinatus and infraspinatus
What are the spinal cord segments and functions of the long thoracic nerve?
C5-7
- S, PGS, M of serratus ant
What are the spinal cord segments and functions of the medial cut nerves of the arm and forearm?
C8-T1
- S and PGS of skin overlying medial aspect of arm and forearm
What neurovascular structures would be injured from a fracture of the surgical neck of the humerus?
posterior humeral circumflex artery and axillary nerve
What neurovascular structures would be injured from a fracture of the radial groove of the humerus?
radial nerve and profunda brachii artery
What neurovascular structures would be injured if a medial epicondyle fracture?
ulnar nerve and anterior ulnar recurrent artery