Axilla, Arm and Elbow Arthrology Flashcards
cranial nerve roots
C5-T1
where do the roots originate from
anterior rami of C5-T1
what does the anterior rami innervate
extremities
trunks
superior
middle
inferior
where is the clavicle located
placed b/w the trunks and the divisions
superior trunk
C5-C6
what nerves originate off the superior trunk
dorsal scapular nerve
suprascapular nerve
subclavius nerve
phrenic nerve
middle trunk
continuation of C7
inferior trunk
C8 - T1
divisions
posterior
anterior
what do the divisions do
reorganize
posterior division
superior and inferior trunks connecting onto the middle trunk
anterior division
connects the superior and middle trunks (opposite of posterior)
Cords
named in relation to its location around the axillary artery
lateral
posterior
medial
lateral cord
from the anterior division
what nerve originates off of the lateral cord
lateral pectoral nerve
posterior cord
comes from the posterior division
what nerves come off of the posterior cord
lower subscapular nerve
thoracodorsal nerve
upper subscapular nerve
medial cord
extension of the inferior trunk
what nerves come off of the medial cord
medial antebrachial cutaneous nerve
medial brachial cutaneous nerve
medial pectoral nerve
branches
come out b/w anterior scalenes
musculocutaneous nerve
axillary nerve
radial nerve
ulnar nerve
median nerve
musculocutaneous nerve
off lateral cord
innervates the anterior compartment
pierces coracoid brachialis on the way to the brachialis and the biceps brachii
axillary nerve
off posterior cord
innervates the deltoid and the teres minor
radial nerve
off posterior cord
innervates the posterior forearm and posterior arm (posterior compartment)
ulnar nerve
off medial cord
heads towards the hand and the forearm
median nerve
connection of lateral cord and medial cord
travels to the forearm and the hand through the arm
ASIA scale
asses motor points and sensory point
checks the cranial nerves
sensory point
check if the nerve is in tact and functioning
C5 sensory point
lateral elbow
C6 sensory point
dorsal side of the 1st digit
C7 sensory point
dorsal side of the 3rd digit
C8 sensory point
dorsal side of the 5th digit
T1 sensory point
medial elbow
motor function to check C5
elbow flexion
motor function to check C6
wrist extension
motor function to check C7
elbow extension
motor function to check C8
finger flexors
motor function to check T1
finger abductors
arm organization
brachial fascia
compartments
compartments of the arm
anterior
posterior
anterior compartment
innervated by musculocutaneous nerve
elbow flexors
supinators
posterior compartment
innervated by radial nerve
elbow extensors
distal end of the humerus
largest bone in the upper limb
articulations of humerus
radius and ulna @ elbow joint
surfaces and landmarks of distal humerus
lateral supracondyle
medial supracondyle
condyle
condyle of distal humerus
lateral and medial epicondyles
capitulum
radial fossa
trochlea
coronoid fossa
olecranon fossa
why is the medial epicondyle more prominent
the ulnar nerve runs underneath
ulna
the stabilizing bone of the forearm
medial and longer of the two forearm bones
ulnar articulations
radius and humerus @ elbow joint
distal and proximal radioulnar joints
does not articulate directly with carpal bones (separated by fibrocartilaginous articular disc)
surfaces and landmarks of the proximal end of the ulna
olecranon
trochlear notch
coronoid process
tuberosity
radial notch
supinator crest
supinator fossa
surfaces and landmarks of the body of the ulna
anterior border
posterior border
interosseous border
anterior surface
medial surface
posterior surface
surfaces and landmarks of the distal end of the ulna
head
styloid process
radius
lateral and shorter of the two forearm muscles
radial articulations
ulna and humerus at elbow joint
proximal/distal radioulnar joint
surfaces and landmarks of the proximal end of the radius
head
neck
radial tuberosity
surfaces and landmarks of the body of the radius
anterior border
posterior border
interosseous border
anterior surface
lateral surface
posterior surface
surfaces and landmarks of the distal end of the radius
ulnar notch
styloid process
dorsal tubercle (Lister’s tubercle)
Colle’s Fracture
falling out on an outstretched hand/wrist/arm (FOOSH/FOOSA)
causes distal end of radius to go more dorsal (dorsally)
looks like the back of a dinner fork
fractures both radius and ulna
very common
Smith’s fracture
fracture at the distal end of the radius
not as common
land on the arm w/ the wrist in a flexed position
wrists goes more palmar
presentation is like a shovel
muscles in the anterior compartment
biceps brachii
brachialis
coracobrachialis
biceps brachii
2 headed fusiform muscle
origin of the biceps brachii
long head O: supraglenoid tubercle of scapula
short head O: coracoid process of scapula
why is the long head considered the long head
named on the length of the tendon not the length of the muscle
insertion of biceps brachii
I: radius (radial tuberosity, bicipital aponeurosis)
bicipital aponeurosis changes the direction of pull which allows for supination
innervation of biceps brachii
musculocutaneous nerve (C5-C6)
actions of biceps brachii
elbow flexion and supination
shoulder flexion
humeral stabilization during deltoid contraction, IR and ABD
brachialis
strong muscle that is immediately deep to biceps brachii
wide muscle belly
origin of brachialis
O: humerus (distal half of anterior surface)
insertion of brachialis
I: ulnar tuberosity
innervation of brachialis
musculocutaneous nerve (C5-C6)
radial nerve (C7, minorly)
brachialis action
elbow flexion
coracobrachialis
small, cylindrical muscle
coracobrachialis origin
coracoid process of scapula
coracobrachialis insertion
humerus (in line with crest of lesser tuberosity)
coracobrachialis innervation
musculocutaneous nerve (C5-C6)
coracobrachialis actions
shoulder flexion, ADD, IR
what muscle are within the posterior compartment
triceps brachii
anconeus
triceps brachii
large fleshy muscle
3 heads (long, lateral, medial)
long head origin triceps brachii
O: infraglenoid tubercle of scapula
lateral head origin triceps brachii
O: posterior humerus (distal to radial groove), lateral intermuscular septum
medial head origin triceps brachii
O: posterior humerus (distal to radial groove), medial intermuscular septum
triceps brachii insertion
I: olecranon of ulna
innervation of triceps brachii
radial nerve (C6-C8)
actions of triceps brachii
elbow flexion
long head: shoulder extension and ADD
anconeus
short triangular muscle
anconeus origin
O: lateral epicondyle of humerus
anconeus insertion
I: olecranon of ulna
innervation of anconeus
radial nerve (C7-C8, T1)
actions of anconeus
assists triceps in elbow extension
stabilized elbow joint
ABD ulna during forearm pronation
artery origin (vascular element) of arm
axillary artery –> brachial artery
after it crosses lower border of teres major
course of the brachial artery
found in the anterior compartment
terminates just distal to the elbow joint
divides into radial and ulnar arteries
branches from lateral aspect of arm
unnamed muscular branches
humeral nutrient
branches from medial aspect of arm
profunda brachii artery (ascending branch, medial collateral, lateral collateral)
superior ulnar collateral
inferior ulnar collateral
superficial veins of arm
cephalic
basilic
deep veins of arm
brachial vein
neural elements of arm
intercostobrachial (T2)
musculocutaneous
median
ulnar
medial brachial cutaneous
medial antebrachial cutaneous
axillary
radial
intercostobrachial
T2
branch of intercostal nerve
contributes innervation of skin on medial surface of the arm
medial brachial cutaneous nerve
branches off of the medial cord
innervates the skin over the medial aspect of the arm
medial antebrachial cutaneous nerve
branches off the medial cord
innervates the skin of the medial aspect of the forearm
triangular interval
space
boundaries of the triangular interval
superior: teres major
lateral: lateral head of the triceps brachii
medial: long head of the triceps brachii
contents of the triangular interval
radial nerve
profunda brachii artery
cubital fossa
3-D space
boundaries of cubital fossa
roof: skin, subcutaneous tissue, brachial fascia, bicipital aponeurosis
superior: (imaginary) line connecting medial and lateral epicondyles of the humerus
medial: pronator teres
lateral: brachioradialis
floor: brachialis and supinator
contents of cubital fossa
veins (cephalic, basilic, median cubital)
biceps brachii tendon
brachial artery
median nerve
elbow joint
complex joint involving three separate articulations
share a common synovial joint cavity
articulations of elbow joint
3 principal articulations
- trochlear notch of the ulna and the trochlear of the humerus
- b/w head of the radius and capitulum of the humerus (primarily involved with hinge like flexion, extension of the forearm)
- joint b/w the head of the radius and the radial notch of the ulna and proximal radio-ulna joint (involved with pronation and supination of the forearm)
articular capsule of the elbow joint
fibrous membrane of the joint capsule
overlies the synovial membrane
encloses the joint
attaches the medial epicondyle and the margins of the olecranon, coranoid and radial fossa
medial and lateral sides are thickens (collateral ligaments)
collateral ligaments of elbow joint
support flexion and extension movements
loose in the direction of movements (posterior and anterior sides)
radial collateral ligament
extends from the lateral epicondyle of the humerus
reduces movement laterally
anular ligament of radius
encircles and holds the head of the humerus in the radial notch of the ulna
can have radial subluxation (nursemaid’s elbow –> pronated arm while the arm is pulled)
ulnar collateral ligament
extends from the medial epicondyle of the humerus to coronoid process of the ulna
3 parts
reduces movement medially
often injured in overhead athletes –> Tommy john surgery –> take palmaris longus and restructure UCL
3 parts of the UCL
- anterior cord-like band is the strongest
- posterior fan-like band is the weakest
3.slender oblique band deepens the socket for the trochlear of the humerus
elbow flexors
brachialis and biceps brachii
elbow extensor
triceps brachii
carrying angle
the long axis of the fully extended ulna
makes angle of approx 170 degrees with the long axis of the humerus
allows space b/w the object being carried and the body w/o banging into the legs
vascular supply to elbow joint
through a network of vessels derived from collateral and recurrent branches of the brachial, profunda brachii, radial, and ulnar arteries
ulnar side vascular supply of elbow joint
superior ulnar collateral artery will anastomose with the posterior ulna recurrent artery
inferior ulnar collateral artery will anastomose with the anterior ulna recurrent artery
radial side vascular supply of elbow joint
radial collateral artery will anastomose with the anterior ulna recurrent artery
middle collateral artery will anastomose with the interosseous recurrent artery
innervation of elbow joint
branches of the musculocutaneous and radial nerves
some innervation by branches of the ulnar and median nerves
olecranon bursae
intratendinous olecranon bursa
subtendinous olecranon bursa
subcutaneous olecranon bursa
intratendinous olecranon bursa
sometimes present on the tendon of the triceps brachii
subtendinous olecranon bursa
located b/w the olecranon and the triceps tendon (proximal to its attachment to the olecranon)
subcutaneous olecranon bursa
located in the subcutaneous connective tissue over the olecranon
bicipitoradial bursa
seperated the biceps tendon from the anterior part of the radial tuberosity
reduces abrasion against the anterior part of the radial tuberosity