anatomy: shoulder and brachial plexus

Question 1

skeletal system is divided into two systems what are they and how many bones in each

Answer 1

• axial (80)
• appendicular (126)

Question 2

axial consist of what bones?

Answer 2

• skull
• neck
• spine
• ribcage

Question 3

appendicular consist of what bones?

Answer 3

• upper limbs
• lower limbs

Question 4

bone classifcation

Answer 4

• long bones : tubular
• short bones: cuboidal
• flat bones: two compact bone plates seperated by spongy bone (skull)
• irregular bones: bones with various shapes (face bones)
• sesamoid bones: round/oval develop in tendons

Question 5

1/2 general categories of joints

synovial joints

Answer 5

where the skeletal elements are separated by a cavity

Question 6

2/2 general categories of joints

solid joints

Answer 6

where there is no cavity and the components are held together by connective tissue

Question 7

synovial joints

condylar (ellipsoid) joints

Answer 7

allow movement around two axes that are at right angles to each other;
- permit flexion, extension, abduction, adduction, circumduction

wrist

Question 8

synovial joints

gliding (plane) joints

Answer 8

allow sliding or gliding movements when one bone moves across the surface of another

radio-ulnar

Question 8

synovial joints

hinge joints

Answer 8

allow movement around one axis that passes transversely through the joint; permit flexion and extension

elbow - humero-ulnar joint

Question 9

synovial joint

ball and socket joints

Answer 9

allow movement around multiple axes; permit flexion, extension, abduction, adduction, circumduction, and rotation

hip joint

Question 9

synovial joints

pivot joints

Answer 9

allow movement around one axis that passes longitudinally along the shaft of the bone; permit rotation

atlanto-axial joint

Question 10

synovial joint

saddle joints

Answer 10

allow movement around two axes that are at right angles to each other; the articular surface surfaces are saddle shaped; permit flexion, extension, abduction, adduction, and circumduction

carpometacarpal joint

Question 11

two categories under solid joints

Answer 11

• fibrous joints
• cartilaginous joints

Question 12

solid joints = fibrous joints

sutures

Answer 12

occur only in the skull where adjacent bones are linked by a thin layer of connective tissue termed a sutural ligament

Question 13

solid joints; fibrous joint

gomphosis

Answer 13

short collagen tissue fibers in the periodontal ligament run between the root of the tooth and the bony socket

Question 14

solid joints; fibrous joints

syndesmosis

Answer 14

joints in which two adjacent bones are linked by a ligament

Question 15

solid joints; cartilaginous joints

synchondrosis

Answer 15

occur where two ossification centers in a developing bone remain separated by a layer of cartilage

Question 16

solid joints; cartilaginous joints

symphysis

Answer 16

occur where two separate bones are interconnected by cartilage

Question 17

muscle attachements

define origin and insertion

Answer 17

origin- place is a bone that remains immobile for an action
insertion- place is on the bone that moves during the action

Question 18

brachial plexus

Answer 18

formed by the anterior rami of spinal nerves C5-T1
- surrounds the axillary artery

Question 19

mnemonic: real trucker drink cold nog(egg)

Answer 19

roots, trunks, divisions, cords, nerves (terminal)

Question 20

5 terminal nerves of the brachial plexus

Answer 20

1. musculocutaneus
2. axillary
3. median
4. radial
5. ulnar

Question 21

origin, function, spinal segments

musculocutaneous nerve

Answer 21

Question 22

origin, function, spinal segments

axillary nerve

Answer 22

Question 23

origin, function, spinal segments

radial nerve

Answer 23

Question 24

origin, function, spinal segments

median nerve

Answer 24

Question 25

origin, function, spinal segments

ulnar nerve

Answer 25

Question 26

clavicle

Answer 26

only bony attachment between the trunk and the upper limb

Question 27

scapula

Answer 27

large flat triangular bone

Question 28

humerus

Answer 28

Question 29

what are the shoulder joints

Answer 29

• sternoclavicular = saddle joint between the proximal clavicale and the manubrium of the sternum
• acromioclavicular= plane joint between distal clavicle and acromion of scapula
• glenohumeral= stabilized by lig/mus (glenohumeral lig, coracohumeral lig, transverse lig; 4 rotator cuff muscles)

Question 30

muscles of the shoulder: posterior

rotator cuff muscles

Answer 30

• supraspinatus
• infraspinatus
• tres minor
• subscapularis

Question 31

muscles of the shoulder: posterior

list the posterior muscles of the shoulder

Answer 31

• rotator cuff
• teres major
• latissimus dorsi

Question 32

infraspinatus

origin, insertion,innervation

Answer 32

Question 33

teres minor

origin, insertion,innervation

Answer 33

Question 34

subscapularis

origin, insertion,innervation

Answer 34

Question 35

teres major

origin, insertion,innervation

Answer 35

Question 36

latissimus dorsi

origin, insertion,innervation

Answer 36

Question 37

musculotendionous collar = rotator cuff muscles

of the glenohumeral joint

Answer 37

• anterior = subscapularis tendon
• superior = supraspinatus tendon
• posterior = infraspinatus tendon
• inferoposterior = teres minor

Question 38

major arteries

right subclavian artery

where are they located?

Answer 38

arises from the brachiocephalic trunk

Question 39

major arteries

left subclavian artery

where are they located

Answer 39

arises directly from the aortic arch

Question 40

major arteries

axillary artery

Answer 40

subclavian artery becomes the axillary artery as it passes the lateral border of the first rib
- axillary artery divided into 3 parts

supplies blood to axilla, shoulder joint, and surrounding muscles

Question 41

major arteries

circumflex arteries

Answer 41

wrap around the surgical neck of the humerus contributing to the vascular supply of the shoulder joint and the suround structures

Question 42

venous drainage

axillary vein

Answer 42

formed by the union of the brachial veins and the basilic vein

Question 43

venous drainage

subclavian vein

Answer 43

axillary vein becomes the subclavian vein as it passes the lateral border of the first rib

Question 44

venous drainage

how do the brachiocephalic vein and superior vena cava form

Answer 44

subclavian vein continues its path into the thorax eventually joining with the internal jugular vein to form the brachiocephalic vein, which then merge to create the superior vena cava

Question 45

nerves

axillary nerve

motor and sensory innervations

Answer 45

• passes inferiorly and laterally along the posterior wall of the axilla to exit thorugh the quadrangular . passes posteriorly around the surgical neck

motor: innervation to deltoid and teres minor
sensory: innervation skin of upper lateral part of the arm

Question 46

clinical correlations

proximal humerus fracture

Answer 46

• fractures occur around the surgical neck of the humerus
• axillary nerve and posterior circumflex humeral artery maybe damaged with this type of fracture

Question 47

clinical correlations

fractures of the clavicle

Answer 47

• only bony connection b/w upper limb and trunk
• typical site of fracture is the middle third

Question 48

clinical correlations

acromioclavicular dislocation

Answer 48

• minor injury: tear fibrous joint capsule and ligaments of the acromioclavicular joint
• severe trauma: disrupt conoid and trapezoid ligaments of the coracoclavicular ligament = elevation and upward subluxation of the clavicle

Question 49

clinical correlation

sternoclavicular dislocation

Answer 49

• injury at medial end of the clavicle is an anterior or posterior dislocation of the sternoclavicular joint
• posterior dislocation of the clavicle may impinge on the great vessels in the root of the neck and compress or disrupt them

Question 50

clinical correlation

dislocation of the glenohumeral joint

Answer 50

• anterior dislocation occurs more frequently, axillary nerve maybe injured by direct compression of the humeral head, “lengthening” of the radial nerve which is tightly bound within radial groove = radial nerve paralysis
• vessel occlusion = compression of the axillary artery
• posterior dislocation very rare

Question 51

clinical correlation

rotator cuff disorders

Answer 51

• impingement
• tendinopathy
  most commonly invovled is supraspinatus as it passes beneath the acromion and the acromioclavicular lig

Question 52

clinical correlations

subacromial bursitis

Answer 52

• b/w suprasinatus & deltoid muscles laterally and acromion medially
• patients who have injured shoulder or who have suprasinatus tendinopathy this bursa may become inflamed making movements of the glenohumeral joint painfulh

Question 53

clinical correlation

winging scapula

Answer 53

• long thoracic nerve (C5-7) roots of the brachial plexus
• serratus anterior muscle plays a key role in scapular stabilization and protraction
• LOF causes medial border and particular the inferior angle of the scapula to elevate away from the thoracic wall resulting in characteristic “winging” of the scapula

Question 54

clinical correlation

Erb Duchenne palsy (upper brachial plexus)

Answer 54

• C5-6 damage (superior trunk)
• loss of 3 nerves musculocutaneous, suprascapular, axillary
• limb of adduction and medial rotation
• extension of the elbow w/pronation of the forearm
• wrist is flexed due to the loss of C6 fibers of the radial nerve
• cutaneous loss on the lateral border of the forearm

Question 55

clinical correlation

klumpke palsy (lower brachial plexus)

Answer 55

• C8-T1 fibers (ulnar/median nerves)
• weakness of the intrinsic muscles of the hand (ulnar nerve)
• ulnar claw hand + ape hand
• cutaneous loss of the medial border of the forearm and hand