Brachium and Cubital Fossa Flashcards
brachial fascia?
continuous with fascia of shoulder muscles above, attached to humeral epicondyles and olecranon process
continuous with the antebrachial fascia below
**encases are in cylindrical sheath
what separates arm into anterior and posterior compartments?
intermuscular septa
intermuscular septa?
two laminae that enclose the neurovascular compartment
neurovascular compartment of arm
brachial artery and veins, median nerve, and musculocutaneous and ulnar nerves superiorly
biceps brachii attachments?
origin:
long head - supraglenoid tubercle of scapula
short head - coracoid process of scapula
insertion:
common tendon to radial tubersoity, also via bicipital aponeurosis to antebrachial fascia covering the flexor forearm muscles
biceps brachii action?
flexes forearm and supinates the hand
most powerful supinator above 90 degree flexion
long head also assists in flexion of arm
biceps brachii innervation?
musculocutaneous nerve
brachialis attachments?
origin:
half way up anterior surface of humerus
insertion:
coronoid process and tuberosity of ulna
brachialis action?
flexion of forearm
-most powerful of three primary forearm flexors
brachialis innervation?
musculocutaneous nerve
anterior compartment muscles?
biceps brachii, brachialis, and coracobrachialis
brachioradialis attachments?
origin:
lateral supercondylar ridge of humerus
insertion:
lateral radius at base of styloid process
brachioradialis action?
flexion of foerarm
-best mechanical advantage when hand is midway between supination and pronation (handshake)
brachioradialis innervation?
radial nerve
corachobrachialis attachments?
origin:
coracoid process of scapula
insertion:
middle third, medial surface of humerus
corachobrachialis actions?
flexion, adduction of humerus
corachobrachialis innervation?
musculocutaneous nerve
muscles of posterior compartment of arm?
triceps brachii and anconeus
triceps brachii attachments?
origin:
long head - infraglenoid tubercle of scapule
lateral head - posterior surface of humerus proximal to radial groove
medial head - posterior surface of humerus distal to radial groove
insertion:
posterior surface of olecranon process of ulna
triceps brachii actions?
all heads act to extend forearm
long head extends and adducts arm
triceps brachii innervation?
radial nerve
anconeus attachments?
origin:
poseterior surface lateral epicondyle of humerus
insertion:
lateral surface of olecranon and proximal posterior surface of ulna
anconeus actions?
assists triceps in extension of forearm
anconeus innervations?
radial nerve
three primary forearm flexors?
biceps brachii, brachialis, brachioradialis
beginning of brachial artery?
continuation of axillary once it passes inferior border of teres major
course of brachial artery?
courses within neurovascular compartment through medial brachium
end of brachial artery?
within cubital fossa when it divides to radial and ulnar arteries
deep brachial artery?
largest branch of brachial artery
- arises posteromedial aspect
- accompanies radial nerve
- ends when divides into middle and radial collateral arteries which anastamose with interosseus and radial recurrent arteries, respectively
superior ulnar collateral artery?
branch of medial mid brachial artery
-courses inferiorly with ulnar nerve and goes posterior to medial epicondyle
-anastomose with posterior ulnar recurrent
inferior ulnar collateral artery?
branch of medial distal brachial artery
-courses anterior to medial epicondyle and anastomose with anterior ulnar recurrent artery
cephalic vein
superficial vein
-arises on lateral dorsum of hand and goes superior through forearm and along anterolateral surface of bicep
courses between deltoid and pectoralis major to disappear within deltopectoral triangle where it will pierce costocoracoid membrane to join axillary vein
basilic vein
superficial vein
arises on medial dorsum of hand and goes posteriomedial aspect of forearm and medial surface of arm piercing brachial fascia at midportion
median cubital vein
joins cephailc and basilic veins
anastomosis is variable
brachial vein
deep veins
formed by union of radial and ulnar veins
course parallel to brachial artery
-superficial basilic vein, after piercing brachial fascia, runs parallel to brachial veins
where does basilic vein join brachial vein?
at approximately the inferior border of teres major muscle
forms the axillary vein
median nerve
C6, C7, C8, T1
exits axilla anterior to brachial artery
-in neurovascular compartment becomes medial to artery
courses through cubital fossa deep to the bicipital aponeurosis
NO BRANCHES TO BRACHIUM
ulnar nerve
C8, T1
exits axilla medial to brachial artery in brachial neurovascular compartment
exits compartment with superior ulnar collateral midway in brachium by piercing the posterior lamina of medial intermuscular septum
travels inferiorly along posterior surface of septum to eventually exit arm between medial epicondyle of humerus and olecranon process of ulna
musculocutaneus nerve
C5, C6, C7
leaves axilla lateral to axillary artery and traverses corachobrachialis piercing it
runs inferiorly between biceps and brachialis
exits under lateral inferior edge of biceps to become lateral antebrachial cutaneous nerve
innervates corachobrachialis, biceps, brachialis (anterior compartment)
radial nerve
C5, C6, C7, C8, T1
exits axilla posterior to brachial artery and anterior to long head of triceps
courses between lateral and medial heads of triceps within radial groove with the deep brachial artery
after circumventing the humerus, nerve pierces the lateral intermuscular septumand comes to lie between the brachialis and brachioradialis muscles
at lateral epicondyle, divides into superficial and deep branches
pass via separate routes in forearm
in arm, radial nerve innervates triceps, and a portion of skin on posterior surface of arm
radial groove?
between medial and lateral head of triceps brachii
location of the radial nerve and deep brachial artery
boundaries of cubital fossa?
lateral - brachioradialis medial - pronator teres superior - line drawn through both humeral epicondyles roof - deep fascia floor - brachialis and supinator
contents of cubital fossa?
tendon, artery, nerve (lateral to medial)
biceps tendon
brachial artery divides to radial and ulnar
median nerve
structures associated with cubital fossa
superficial:
median cubital nerve and latera antebrachial cutaneous nerve (from musculocutaneous)
deep:
bifurcation of radial nerve into its superficial and deep branches
