GROSS ANATOMY

Deltoid M (arm abduction /anteversion) Teres minor m (arm lateral rotation) All extensor compartment mm in arm + forearm **PLUS: Brachioradialus M (One of 4 flexors of forearm) Supinator m (One of 2 supinators of forearm) NERVES BRACHIAL PLEXUS (#17) C5, 6 Axillary ɳ C5 Radial ɳ (C5, 6, 7, 8) C5, 6 C6 All flexor compartment mm in arm **EXCEPT: Brachioradialus m (One of 4 flexors of forearm) (C5, 6, 7) musculocutaneous ɳ Radial ɳ, C5, 6

INJURIES TO NERVE OF BRACHIAL PLEXUS ASSOCIATE SYMPTOMS WITH PART OF PLEXUS 1st "Winged scapula" (Accentuated when pushing against wall) Anesthesia of lateral upper portion of arm; partial or complete loss of abduction of arm Partial loss of abilities to: depress shoulder, adduct and extend arm Extensive & variable paralysis of shoulder and upper limb; "waiter's tip" included in constellation of signs; variable anesthesia of upper back & upper limb "waiter's tip" sign: Long Thoracic n Serratus Anterior m C5, 6, 7 (can be caused by carrying very heavy load on shoulder; crushing n between 1st rib & clavicle Axillary n Deltoid m C5, 6 (also Teres minor m C5, a lateral (Can result from rotator of arm) shoulder dislocation) Thoracodorsal n Latissimus dorsi m C7, 8 (vulnerable to injury during surgery of the axilla, such as in removal of axillary lymph nodes during breast CA surgery) Superior trunk of brachial plexus C5, 6 Nerves most affected: musculocutaneous n C5, 6, 7 axillary n C5, 6 radial n C5, 6, 7, 8) Arm hangs down: (loss of abduction) Arm hangs straight: (loss of flexion of forearm) Arm rotated medially: (loss of lateral rotation of arm) axillary n: suprascapular n musculocutaneous n: radial n: axillary n: suprascapular n: deltoid m C5, 6 supraspinatus m C6 biceps & brachialis mm C5, 6 Coracobrachialis m C6, 7 Brachioradialis m, C5, 6 teres minor m C5 infraspinatus m C5, 6 Straight hand adducted: (loss of hand extension) radial n: extensor carpi radialis longus m C6, 7 extensor carpi radialis brevis m C6-8 extensor carpi ulnaris m C6-8 (most major upper brachial plexus injuries result from motorcycle accidents; may also result from a fall on the shoulder in a sport such as football; also may result from violent stretching of infant's neck during delivery, or from stab or bullet wounds to the neck) impairment of wrist flexion and of digital movements; anesthesia medial side of arm, forearm & hand lower brachial plexus C8, T1 nerve roots, both dorsal & ventral ulnar n C8, T1 flexor carpi ulnaris m C8, T1 (hand flexor) C8, T1 of radial, median & ulnar nn: (various effectors of digital movements)

"wrist drop" & loss of triceps reflex "wrist drop" radial n: (loss of hand extension) Loss of triceps reflex: radial n: (no forearm extension strength) "wrist drop" alone, radial n normal triceps strength, as isolated disability radial n C5, 6, 7, 8 ulnar n C8, T1 extensor carpi radialis longus m C6, 7 extensor carpi radialis brevis m C6-8 extensor carpi ulnaris m C6-8 triceps & anconeus mm C7, 8 extensor carpi radialis longus m C6, 7 extensor carpi radialis brevis m C6-8 extensor carpi ulnaris m C6-8 (this is radial n entrapment; most common site is compression of radial n in middle of arm; often from sleeping on arm, especially intoxicated: "Saturday night palsy") "claw hand" ulnar n C8, T1 no flexion of 4th & 5th fingers apothenar atrophy (as it passes posteriorly to medial condyle of elbow, it is often damaged when elbow is traumatized and medial epicondyle of humerus is fractured) numbness & tingling only in medial side of ulnar n C8, T1 palm (side opposite thumb), and in 4th & 5th finger (this is ulnar nerve entrapment; compression at the elbow is common) no thumb opposition & thenar atrophy, no median n C6, 7, 8, T1 flexion thumb, index & middle finger median n often cut proximal to flexor retinaculum at wrist from suicide attempts by wrist slashing with a razor blade pain & tenderness in proximal portion of median n C6, 7, 8, T1 anterior forearm, often following repetitive elbow movements ("The Pronator Syndrome"; median n is entrapped near elbow between the two heads of the pronator teres m, due to trauma or repetitive motion injury) loss of elbow flexion & musculocutaneous n C5, 6, 7 forearm supination; biceps & brachialism mm C5,6 loss of biceps reflex, as isolated set of sx's. coracobrachialis m C6, 7 (this occurs when the musculocutaneous n is severed in the axilla, before it has innervated any of the muscles in the arm for flexing & supinating the forearm) temporary numbness & inferior or trunk brachial plexus tingling upper limb; temp impairment motor function upper limb sensory & motor portions of ulnar, radial & median nn; esp: medial antebrachial cutaneous n C8, T1 medical brachial cutaneous n T1 (characteristic of thoracic outlet syndromes or cervical rib syndromes, where temporary compression of inferior trunk occurs while carrying a weight with arm hanging, such as when carrying a suitcase, or while performing a repetitive motion with an arm in a raised position)

ANATOMY 21. PERITONEAL LOCATION VS VISCERA Intraperitoneal viscera (within the peritoneum): Stomach Small intestine Transverse colon Spleen Liver Retroperitoneal viscera (outside the peritoneum): Aorta Vena cava Kidneys Pancreas Duodenum Ascending colon Descending colon 22. PECTINATE LINE Interior to pectinate line: Tissues of endoderm origin Visceral innervation, blood supply, lymphatic drainage Internal hemorrhoids Cancer: adenocarcina Exterior to pectinate line: Tissues of ectoderm origin Somatic innervation, blood supply, lumphatic drainage External hemorrhoids Cancer: Squamous cell carcinoma 23. LAYERS Layers of abdominal wall: 1. skin 2. superficial fascia--kemper's, Scarpa's 3. external oblique muscle 4. internal oblique muscle 5. transversus abdominus muscle 6. transversalis fascia 7. extraperitoneal fat 8. peritoneum Layers of scrotum: 1. skin 2. dartos muscle 3. Colle's fascia Layers of spermatic cord (also inner layers of scrotum covering): 1. external spermatic fascia 2. cremaster muscle 3. internal spermatic fascia 24. FOUR SIMPLE LOSSES OF FUNCTION IN LOWER LIMB Loss of dorsiflexion, causing foot drop Loss of plantar flexion Loss of knee jerk response Loss of hip adduction common peroneal nerve tibial nerve femoral nerve obturator nerve