UCF Dow: Anatomy Exam 4

Fractures of the surgical neck of the humerus

Could lead to an injury to the Axillary nerve

fractures of the middle of the shaft of the humerus

may cause injury to the radial nerve = wrist drop

fracture to the distal head of the humerus

Could lead to injury to the Median nerve

Fractures to the medial epicondyle

Injury to the ulnar nerve.

FUNNY BONE

Proximal humerus fractures

Lesser trochanter

Greater trochanter

Anatomical neck

could break off

Four joints of the shoulder

sternoclavicular

acromioclavicular

glenohumeral (shoulder)

scapulothoracic

which shoulder joint is most prone to injury?

(Glenohumeral joint) because it is just a shallow joint

What kind of joint is the glenohumeral joint?

synovial joint

most movable joint and most fluid filled

rotator cuff muscles

supraspinatus, infraspinatus, teres minor, subscapularis

what do the rotator cuff muscles do?

helps to maintain stability of the shoulder joint

Supraspinatus

Abductor of the arm

Innervation: suprascapular nerve (C4- C6)

Infraspinatus

lateral rotator of the arm

Innervation: suprascapular nerve (C4-C6)

teres minor

lateral rotator of the arm

Innervation: axillary (circumflex) nerve (C5-C6)

Subscapularis

arm adduction and medial rotation

Innervation: Upper and lower subscapular nerves (C5, C6, C7)

Teres major

arm adduction and medial rotation

Innervation: lower subscapular nerve (C6- C7)

Latissimus dorsi

(coughing muscle)

adduction and medial rotation and extension of the arm

Innervation: thoracodorsal nerve (C6, C7, C8)

Trapezius

Descending, transverse, and ascending

Innervation: accessory nerve (CN XI) and cervical plexus (C3 and C4)

Levator scapulae, Rhomboid major, Rhomboid minor

Function: work to steady the scapula

Rhomboids: keep scapula on thoracic cage

Innervation: dorsal scapular nerve (C4-C5)

Deltoid

(shoulder cap)

Most important for abduction of the arm up to 90 degrees

Innervation: axillary nerve (C5-C6)

Anterior part: flexs (anteversion) the arm and medial rotation of the arm

Middle part: abducts the arm

Posterior part: extend (retroversion) + lateral rotation

Coracobrachialis

flexion (anteversion) and adduction of the arm

Innervation: musculocutaneous nerve (C5, C6, C7)

Pectoralis minor

lows and rotates the scapula

Innervation: medial pectoral nerve (C8-T1)

Pectoralis major

adduction and medial rotation of humerus

Innervation: lateral and medial pectoral nerve (C5-T1)

Serratus anterior

elevation of the arm over 90 degrees. Protracts the scapula and holds it against the thoracic wall and rotates the scapula laterally to elevate the arm

Innervation: long thoracic nerve (C5- C6- C7)

subscapularis

upper and lower subscapular nerves

Subclavius

pulls the clavicle towards the sternum

Innervation: nerve to the subclavius (C5-C6)

biceps brachii

Acts on two joints:

long head- abductor and medial rotator of the arm

Short head- adductor of the arm

Both heads flex (anteroversion) shoulder joint

On elbow joint: flexor and strong superinator of the forearm

Innervtion: musculocutaneous nerve (C5-C6)

Biceps jerk: (C5-C6)

Brachialis

powerful flexor of the elbow joint

Innervation: musculocutaneous nerve (C5- C6) and radial nerve to some of its lateral part

o Triceps brachii

Function: chief extensor of elbow joint

Long head acts on 2 joints: retroversion and adduction of the arm

Innervation: radial nerve (C6, C7, C8)

Triceps jerk: C7-C8

Aconeus

assists (extension of the elbow) triceps

Innervation: radial nerve (C7-C8)

Winged scapula

2 ways to get it: damage to the serratus anterior or the rhomboids

Nerves involved: long thoracic nerve, dorsal scapular nerve

How to determine winged scapula?

ask if injury is front or back, winged scapula will be popping, If they can lift their arm over their head (above 90 degrees) > rhomboid issue, dorsal scapular nerve

If they can lift to 90 degrees and cannot go anymore> serratus anterior muscle, the long thoracic nerve (disruption in neural communication)

venipuncture

procedure used to puncture a vein with a needle to remove blood, instill a medication, or start an intravenous infusion

Which veins are utilized during a venipuncture?

Veins of the cubital fossa are frequently used when drawing blood

Use the median cubital vein b/c it is easy, superficial, not painful, easy to get to

Why do we not use arteries for venipuncture?

arteries have too much pressure and it will be careful

Veins are more palpable and visible

What are the nerves of the brachial plexus?

C5-T1

Nerves coming directly off the spinal cord

Dorsal Scapular Nerve (C4-C5)

Suprascapular nerve (C4-C6)

Nerve to the subclavius (C5-C6)

Long Thoracic nerve (C5-C7)

distal branches

musculocutaneous, axillary, radial, median, ulnar

nerves coming off posterior cord

Upper subscapular nerve (C5-C6)

Thoracodorsal nerve (C6-C8)

Lower subscapular neve (C5-C6)

Axillary nerve (C5-C6)

Radial nerve (C5-T1)

Nerves coming off of medial cord

Medial pectoral nerve (C8-T1)

Median antebrachial cutaneous nerve (C8-T1)

Medial brachial cutaneous nerve (T1)

Ulnar Nerve (C7-T1)

Median nerve (C8-T1)

nerves coming off lateral cord

Lateral Pectoral nerve (C5-C7)

Musculocutaneous nerve (C6-C7)

Median nerve (C6-C7)

superior trunk of brachial plexus

C5-C6

Middle trunk of brachial plexus

C7

Inferior trunk of brachial plexus

C8-T1

What comes directly off C5, C6, and C7?

long thoracic nerve

What comes directly off C5 and C6?

nerve to subclavius

What comes directly off C5?

dorsal scapular nerve

what comes off the superior trunk?

suprascapular nerve

Upper Brachial plexus lesion

Erb-Duchenne or trauma to shoulder. No arm abduction, impaired elbow flexion, and there's medial rotation of arm

C5-C6

Erb- Duchenne Paralysis is caused by what

Cause by traction on arm at birth or falling on shoulder.

Erb-Duchenne paralysis signs

Deltoid and supraspinatus are paralyzed (no arm abduction)

Infraspinatus paralysis leads to medial rotation of the arm.

Biceps and Brachialis are also paralyzed, no elbow flexion

Loss of Biceps and supinator, weak supination)

Adductors of shoulder are mildly affected (pectoralis major and Latissimus dorsi)

Erb-Duchenne paralysis damages

C5-C6

Lower brachial plexus lesion

(C8-T1)

Not as common as upper plexus injuries.

Paralysis of the intrinsic muscle of hand (small muscles) with anesthesia.

Results from sudden upward pull of the shoulder.

Klumpke's paralysis

Injury to C8-T1 roots following forced abduction of the shoulder

Klumpke's paralysis signs

Atrophic paralysis of the forearm and small muscles of hand (Claw hand) and often a sympathetic palsy, i.e, Horner's syndrome

clinical features of Axillary nerve?

inability to abduct the arm because of the paralysis of deltoid and teres minor, muscle wasting (loss in contour over shoulder, sensory loss

Axillary nerve damage

Loss of deltoid contour and greater tuberosity prominent

What are the lymph node groups in the axillary region?

Peripheral, Central, Pectoral, Lateral (Humeral), posterior, apical

how are lymph nodes involved in lymph drainage of the breast?

Breast cancer may transport metastasis (from primary sight to secondary site) to the axillary lymph node (75% of breast's lymphatics drain here)

Colle's fracture

Fracture of the distal end of the radius, posterior displacement

falling on hand with extended arm (example: falling on ice)

May be accompanied by avulsion (complete separation) of ulnar styloid process

Anterior compartment innervated by

All except two are innervated by the median nerve

Pronator teres

Innervation: Median Nerve

Function: forearm pronation

Flexor carpi radialis

Innervation: Median Nerve

Function: flexion and abduction (radical deviation) of hand

Palmaris longus

Innervation: Median Nerve

Function: flexion tightens palmar aponeurosis

30% of the population does not have it

Flexor carpi ulnaris

Innervation: Ulnar nerve

Function: flexion and adduction (ulnar deviation) of hand

Flexor digitorum superficialis

Innervation: Median nerve (C8, T1)

Function: weak flexor, wrist, MCP, and PIP 2nd to 5th digits: flexion

Flexor digitorum profundus

Innervation: median nerve, ulnar nerve

Function" Wrist, MCP, PIP, DIP of 2nd to 5th digits: flexion

Flexor pollicis longus

Innervation: median nerve

Function: wrist: flexion and abduction (radial deviation) of hand Carpometacarpal of thumb: flexion MCP and IP of thumb: flexion

Pronator quadratus

Innervation: median nerve

Function: hand- pronation distal radioulnar joint- stabilization

Posterior compartment innervated by

radial nerve

Extensor digitorum

Innervation: radial nerve

Function: extension MCP, PIP, DIP of 2nd to 5th digits; extension/abduction of fingers

Extensor digiti minimi

Innervation: radial nerve

Function: wrist- extension, ulnar abduction of hand MCP, PIP, and DIP of 5th digit; extension and abduction of 5th digit

Extensor carpi ulnaris

Innervation: radial nerve

Function: wrist- extension, adduction (ulnar deviation) of hand

Supinator

Innervation: radial nerve

Function: Radioulnar joints- supination

Abductor pollicis longus

Innervation: radial nerve

Function: Radiocarpal joint- abduction of the hand

Carpometacarpal joint of thumb- abduction

Extensor pollicis brevis

Innervation: radial nerve

Function: Radiocarpal joint- abduction (radial deviation of the hand) Carpometacarpal and MCP of thumb- extension

Extensor pollicis longus

Innervation: radial nerve

Function: wrist- extension and abduction (radial deviation) of hand Carpometacarpal of thumb: adduction MCP and IP of thumb: extension

Extensor indicis

Innervation: radial nerve Function: wrist- extension MCP, PIP, and DIP of 2nd digit- extension

Brachioradialis

Innervation: radial nerve

Function: elbow- flexion, forearm- semi pronation

Extensor carpi radialis longus

Innervation: radial nerve

Function: Elbow: weak flexion, wrist: extension and abduction

Extensor carpi radialis brevis

Innervation: radial nerve

Extends wrist and abducts hand

Flexor Retinaculum

Double layer of membrane covering the carpal groove anteriorly and produces the carpal tunnel for transmission of flexor muscles and median nerve

Points of insertion of flexor retinaculum

o Tubercle of scaphoid, pisiform, tubercle of Trapezium and hook of Hamate

Carpal Tunnel Syndrome

Compression to the median nerve in the tunnel

Carpal Tunnel Syndrome causes

due to hypothyroidism, rheumatoid arthritis, pregnancy, and amyloidosis, Repetitive movementt

Structures passing into the tunnel

o Flexor digitorum superficialis and profundus

o Flexor pollicis longus

o Median nerve

the Clinical significance of scaphoid fractures

Scaphoid is the most frequent carpal to fracture

· generally occurring at the narrowed waist between the proximal and distal poles (A, right scaphoid)

Because blood supply to the scaphoid is transmitted via the distal segment, fractures at the waist can compromise the supply to the proximal segment

What can a scaphoid fracture lead to?

often resulting in nonunion and avascular necrosis- if broke it and did not go to get it fixed

most common dislocated carpal bone

lunate

Adductor pollicis

Innervation: Ulnar Nerve

Function: CMC joint of thumb: adduction MCP joint of thumb: flexion

Abductor pollicis brevis

Innervation: Median Nerve

Function: abduction

Flexor pollicis brevis

Innervation: Superficial head of the median nerve and deep head of the ulnar nerve

Function: flexion

Opponens pollicis

Innervation: Median nerve

Function: opposition

Can take thumb and pinky and touch them

Opponens digiti minimi

Innervation: Ulnar nerve

Function: draws metacarpal in palmar direction (opposition)

Flexor digiti minimi

Innervation: Ulnar nerve

Function: MCP joint of little finger: flexion

Abductor digiti minimi

Innervation: Ulnar nerve

Function: MCP joint of little finger: flexion and abduction of little finger PIP and DIP joints of little finger: extension

Palmaris brevis

Innervation: Ulnar nerve

Function: tightens the palmar aponeurosis (protective function)

snuffbox

When I have scaphoid fracture, it will displace and push into the snuffbox areait will be pushed out and you can see it

Radial artery enters the "Snuffbox" and branches to produce the dorsal arterial arch of the hand

Principal artery of the thumb

deep palmar arch

Snuffbox Borders:

Tendon of extensor pollicis longus (superior), tendons of the extensor pollicis brevis, and abductor pollicis longus (inferiorly)

Contents of snuffbox

Radial artery and Superficial radial nerve