Biceps Brachii (Proximal)
- attachments:
- short head to coracoid process
- long head runs into gleaned, over head of hum., inside inter tubercle groove where its fixed in place by transverse humerus ligament & surrounded by synovial membrane, attaches to supraglenoid tubercle
Biceps Brachii (Distal)
- attaches to tuberosity of the radius
* continues as bicipital aponeurosis
Bicipital Aponeurosis
- membranous band that runs from biceps tendon across cubital fossa & merges w/ ante brachial (deep) fascia on top of flex muscles in med. side of forearm
- functions to protect brachial a. and med.n in cubital fossa
- helps lessen pressure on biceps tendon on radial tuberosity during pronation & supination of forearm
Biceps Tendinitis
- tendon of long head of biceps (enclosed by synovial sheath) & lies in inter tubercular groove
- caused by repetitive micro trauma from certain motions (throwing/using racquet)
- symptoms- tenderness, crackling sound (credits) in region
- test- arm wrestle (pain)
Dislocation of Tendon
- may be caused by tendinitis & a traumatic separation of pro. epiphysis of hum.
- popping/catching sensation can be felt
Rupture of Tendon
- cause: wear and tear of an inflamed tendon, forceful flex. of the arm
- appearance: popeye deformity- detached muscle belly forms a ball near the center of the distal part of the ant. aspect of arm.
Fracture
*dislocation of prox. hum. epiphysis
Biceps Origin, Insert, Function & Innervation
ORIGIN: supraglenoid tubercle & coracoid process
INSERTION: tuberosity of radius
FUNCTION: flexes arm & forearm, supinate forearm when elbow at 90 degrees
INNERVATION: musculocutaneus n.
Brachialis
- lies deep to biceps
- from distal half of hum. to coronoid process & tuberosity
- major elbow flexor
Coracobrachialis
ORIGIN: coracoid process
INSERTION: mid 1/3 of humerus
FUNCTION: flexes & adducts arm
INNERVATION: median n. & humeral a. run deep
*stabilizes glenohumeral joint by resisting downward dislocation of head of humerus
Triceps Brachii
ORIGIN: infraglenoid tubercle
INSERTION: olecranon of ulna
FUNCTION: extend forearm, long head stabilizes adducted glenohumeral joint by preventing inf. displacement of head of humerus, help extend and adduct arm
INNERVATION: radial n.
Brachial Artery
- starts inf. border of t. major & ends in cubital fossa under bicipital aponeurosis
- divides into rad. & ulnar a.
- beginnig- runs med. to humerus, ant to triceps & brachial then turns ant. to hum
Deep Artery of Arm
*mos superior branch of brachial a. & accompanies radial n. through radial groove & divides (ant./ post.) descending branches
Cephalic Vein
- superficial vein
- location: along anterolateral surface of prox. forearm & arm
- visible through skin
- pass sup. between delt & pec major in deltopectoral groove
- pass through deltopectoral triangle where it empties into axillary v.
Basilica Vein
- pass on med. side of inf. part of arm, penetrate brachial fascia at junction of mid. & lower 1/3 of arm
- merge w/ veins accompanying brachial a. to form axillary vein
Median Cubital Vein
*basilica and cephalic anastomose in forearm & communicate in cubital fossa
Deep Vein
- runs with arteries
* anastomoses w/ each other freely & they all have valves- allow 1 direction blood flow
Musculocutaneuos Nerve
- comes from lat. cord of brachial plexus
- begins- inf. border of pec minor, pierces coracobrachialis, runs between biceps & brachial
- innervates all 3 ant. flexors of arm
- ends as a lat. cutaneous n. of forearm that supplies large area of forearm
Musculocutaneous Nerve Injury
- cause- weapons
- appearance- paralysis of coracobrachialis
- weakened forearm flexion & supination
- loss of sensation on lat. surface of forearm
Radial Nerve
- direct continuation of post. cord of brachial plexus
- enters arm ant. to long head of triceps to brachial a. med. to humerus
- descends w/deep a. of arm & passes around hum. in radial groove
- innervates triceps
- 2 branches at level of lat. epicondyle:
- deep branch: supplies forearm m. & elbow joint
- superficial branch: cutaneous, supplies skin of dorm of hand & digits
Injury to Radial Nerve
- before branches of triceps: paralysis of triceps, brachioradialis, supinator & extensor of wrist & digits
- loss of sensation in dorm hand & digits
- after branches of triceps (in radial groove): same symptoms as above except triceps may not be completely paralyzed
- writs drop sign: typical radial n. injury
- unable to extend at the metacarpophalangeal joints
Median Nerve
- comes from union of a lat. cord & a med. cord of BP
- runs together w/ but lat. to brachial a. until middle of arm
- crosses to medial side of brachial a. & descends to cubital fossa, where it runs under bicipital aponeurosis
- innervates elbow joint
- no branches in arm
Ulnar Nerve
- comes from med. cord of BP
- passes ant. to triceps, on med. side of brachial a.
- in middle of arm- pierces medial inter muscular septum w/ sup. ulnar collateral a. & descends between septum & med head of triceps
- crazy bone- when ulnar n. runs post. to epicondyle, superficial, easily palpable & vulnerable to injury
- innervates elbow joint
- no branches in arm
Cubital Fossa
- hollow area on ant. aspect of elbow
- boundaries:
- sup: imaginary line connecting med. & lat epicondyles
- medially: pronator teres
- laterally:brachioradialis
- floor: formed by brachial & supinator m. of forearm
- roof: formed by deep fascia & bicipital fossa aponeurosis
- contents: terminal part of brachial a. & branches, radial & ulnar a. accompanying deep v., biceps tendon, median n. radial n. branches
