pectoral girdle, elbow and shoulder

Question 1

pectoral girdle attachment

Answer 1

• attachment to axial
• only 1 p.o.a to the axial skeleton at the sternoclavicular joint- medial end of the clavicle articulates w manubrium of the sternum
• scapula doesn’t directly attach to the axial skeleton via joint but connects to back of the thorax by muscles- allows 4 large range of movement
• ligs provide stability and support to joints in pec girds

Question 2

what is pec gird

Answer 2

clavicle n scapula

Question 3

clavicle

Answer 3

• long bone
• lies horizontally between scapula n sternum
• 2 joint- ACJ (acromioclavular joint) and SCJ (sternoclaviculr joint)
• articulates medially with the sternum at SCJ
• articulates laterally with acromion at ACJ
• serves as muscular attachment point
• one of the most fractured bones in body

Question 4

scapula

Answer 4

• large, triangular flat bone that connects the trunk to the upper limb
• the posterior bone of pectoral girdle sitting across the back of the thoracic cage, superiorly
• major features= spine, coracoid process, acromion process and glenoid cavity
• got 3 borders n angles (it triangle): superior, medial n lateral and superior, inferior and lateral
• 3 fossas= supraspinous, infraspinous, subscapular
• has a suprascapular notch

Question 5

acromion process

Answer 5

a continuation of the scapula spine which passes laterally over the shoulder (Glenohumeral) joint
- ACROMION: of the scapula extends from the scapular spine to articulate with the clavicle to form the Acromio-clavicular joint

Question 6

spine of scapula

Answer 6

oblique ridge of bone that passes across the upper posterior part of the scapula

Question 7

coracoid process

Answer 7

small hook-like structure which points laterally forward, on the edge of the superior anterior portion of the scapula
- for muscle attachments

Question 8

glenoid cavity

Answer 8

• a very shallow articular surface that articulates with the humeral head

Question 9

sternoclavicular joint

Answer 9

• where pec girdle joins to the axial skeleton
• Strong synovial saddle joint
• Contains a fibrocartilaginous articular disc
• Robust ligamentous and muscular support
  -sternoclavicular ligament= reinforces the joint capsule and prevents forward/ backward movement
• costoclavicular ligament= connects the clavicle to the first rib and prevent elevation of clavicle
• interclavicular ligament= runs along top of sternum, connects the 2 clavicle to prervnt excessive downward movement

Question 10

Acromioclavicular joint

Answer 10

Small synovial plane joint

Allows scapula and clavicle to move together during arm movement

Strong ligamentous support

Can have a small fibrocartilaginous disc

Relatively prone to injury

• acromioclavicular ligament: keeps joint capsule together and connects acromion n clavicle together
• coracoclavicular ligament: connect coracoid process to the clavicle to prevent displacement

Question 11

labrum of the shoulder

Answer 11

labrum: fibrous cartilage and deepens the socket and provides additional stability = different movement allowed

Question 12

glenohumeral joint

Answer 12

• synovial joint of the shoulder has a fibrous articular capsule that completely encloses the joint and extends from the glenoid cavity to the neck of the humerus
• on surface, joint is lined with synovial membrane= provide synovial fluid= lubricates joint and reduce friction
• it has 5 ligaments, a glenoid labrum, and four bursae (act as cushions) to alleviate friction

Question 13

humerus

Answer 13

• largest and longest bone in upper limb
• articulates with scapula at glenohumeral joint + radius and ulna at the elbow joint

Question 14

major features of humerus

Answer 14

head:
- rounded part at the proximal end
- fits into the glenoid fossa of scapula
anatomical neck:
- separates the head of the humerus from the greater and lesser tubercles
tubercles (greater and lesser):
- greater is more lateral and larger
intertubercular groove:
- dep groove between tubercles
- houses the tendon of long head of bicep brachii, provides poa for major muscle groups of shoulder
surgical neck:
- site of fractures that require surgery
shaft:
- cylindrical at proximal end but becomes more triangular as it flattens and broadens at the distal end
- contains a central medullary cavity filled with bone marrow
deltoid tuberosity:
- attachment for deltoid muscles
- on posterior side there is radial groove that contain the radial nerve

Question 15

distal end of humerus

Answer 15

capitulum:
- rounded notch that articulates with radius at the elbow joint
trochlea:
- articulates with the ulna allowing for flexion and extension of elbow
median and lateral epicondyle:
- bony protrusions
- attachment point for muscles n ligaments
olecranon fossa:
- deep indentation on posterior aspect that accommodates the olecranon (bony prominence of the ulna when elbow is extended)
coronoid fossa:
- small indentation on anterior aspect that receives the coronoid process of the ulna during flexion
- large depression on back of humerus

Question 16

the elbow

Answer 16

Essential for bending the arm and rotating the forarm

3 points of articulation:

Humeroradial joint:
Capitulum with radial head

Humeroulnar joint:
Trochlear with trochlear notch

Proximal radioulnar joint:
Head of the radius with the radial notch

Question 17

ligaments of elbow joint

Answer 17

median collateral ligament:
- extends from the medial epicondyle of the humerus to the coronoid process and the olecranon of the ulna
- thick triangular ligament
lateral collateral ligament:
- strong triangular ligament
- extends from lateral epicondyle of the humerus to the annular ligament of the radius and the radial notch of the ulna
- annular ligament completely encircles the head of the radius and hold it into eh radial notch of the ulna

Question 18

ligaments of shoulder joint

Answer 18

5 ligaments:

Coracohumeral
(to greater tubercle)
- extends from coracoid process in scapula to greater tubercle of humerus= split into anterior and posterior divisions by the biceps tendon

S, M, I glenohumeral
(to lesser tubercle)
- mobile and least stable joint- commonly dislocated synovial joint
- extend from the glenoid cavity to the lesser tubercle and anatomical neck of humerus

Transverse humeral:
- connects greater to lesser tubercle
-keeps the tendon of the long head of the bicep in the bicipital groove

acromioclaviclaular ligament:
- connects acromion to clavicle

coracoclavilcuar ligament:
- connects coracoid process to clavicle

coracoacreomion ligament:
- connects coracoid to acromion

labrum:
- fibrous ring around the glenoid cavity

Question 19

muscles of shoulder

Answer 19

• there are superficial and deep muscles that connect the scapula and clavicle to the trunk
• also superficial and deep muscles connect the clavicle, scapula and trunk to the proximal end of the humerus
• four rotator cuff muscles which connect
  the scapula to the humerus (most important)

Question 20

muscles that connect the scapula and clavicle to the trunk

Answer 20

function by controlling the movement of the scapula and the humerus:

trapezius:
- superficial, flat and broad
- covers the upper back and part of neck and shoulders
- inserts on the lateral third of the clavicle, the acromion and scapula spine

levator scapulae:
- deep
- lies in posterior triangle of neck
- attaches to medial surface of the scapula and elevates

rhomboid (major and minor):
- deep
- attached to medial border of the scapula
- retract and stabilise the scapula, pulling it towards the spine

Question 21

muscles that connect the clavicle, scapula, and trunk to the proximal end of the humerus

Answer 21

3 superficial and 2 deep

superficial:
pectoralis major
deltoids
latissimus dorsi

deep:
pectoralis minor
teres major

Question 22

superficial muscles that connects c,s and t to proximal end of h

Answer 22

pectoralis major:
- provide movement and support in the anterior part of the shoulder
- 2 heads: originates from midline of clavicle and sternum
- inserts into humerus and ribs
- allow 4 shoulder flexion (horizontal, upward diag and downward diag

latissimus dorsi:
- originate from lumbar vertebrae and pelvis
- inserts into the Intertubercular groove groove of humerus
- allow 4 shoulder adduction and extension
- keeps the inferior angle of scapula against the chest

deltoid:
- provides the characteristic shape of the shoulder
- originates in 3 portions, anterior, middle, and posterior
- anterior portion originates from anterior superior surface of the clavicle
- middle from the acromion process
- posterior from the lower border of crest of spine of scapula
- these 3 insert into deltoid tuberosity of the humerus

Question 23

deep muscles that connect c,s and t to the proximal end of the h

Answer 23

pectoralis minor:
- small deep triangular muscle that passes as 3 muscular slips from the thoracic wall to the coracoid process
- draws scapula forwards and downwards and raises the ribs in inspiration (draw air in lungs)

teres major:
- originate from posterior surface of inferior angle of scapula
- attaches medial lip to the middle lip of the intertubercular groove
- extends and medially rotates the humerus

Question 24

rotator cuff muscles

Answer 24

• muscles that connect the scapula to the humerus
• muscles and associated tendons surround the shoulder joint and all originate from the scapula and attach either to the greater or lesser tubercle of the humerus
• stabilises point and allow 4 wide range of movement
• work together to keep head of humerus within the shoulder socket of the glenoid fossa
• rotator cuff tendons attach 2 deep rotator cuff muscles

Question 25

describe rotator cuff muscles

Answer 25

supraspinatus- originates in supraspinous fossa of scapula/ inserts on the superior facet of the greater tubercle of the humerus / initiates abduction of the arm and stabilises the joint while helping to hold head of humerus in place infraspinatus- originates and sits in the infraspinatus fossa of scapula (below spine of scapula) / inserts on middle facet of greater tubercle / externally rotates the arms and helps stabilise shoulder joint teres minor - originates from lateral border of the scapula / inserts into lower facet of the greater tubercle / externally rotates the arm / assists in adduction and stabilisation subscapularis- originates in subscapularis fossa of scapula (front surface of scapula) / inserts onto lesser tubercle / internally rotates the arm and help w stabilisation

Question 26

vascular supply to pectoral gridle summary

Answer 26

intricate network of blood vessels ensures that the shoulder girdle has the necessary blood flow for proper function and muscle activity Arteries: - blood supply to the shoulder girdle primarily comes from the subclavian and axillary arteries and their branches, which supply the bones, muscles, and joints of the shoulder Veins: - subclavian and axillary veins, along with their tributaries, drain the blood from the shoulder region back to the heart

Question 27

major arties of the shoulder

Answer 27

- oxygenated blood delivered via SUBCLAVIAN (primary source) - run under clavicle - becomes AXILLARY ARTERY AT THE OUTER BORDER OF THE FIRST RIB - continues until the lower border of the teres major muscle where it becomes the BRACHIAL ARTERY key branches of axillary artery that supply shoulder are: thoracoacromial artery, lateral thoracic artery, subscapular artery, circumflex scapular artery and the thoracodorsal artery

Question 28

major veins of the shoulder

Answer 28

veins of the shoulder follow the path of the arteries and drain into larger veins that eventually return blood to the heart. Subclavian Vein: - subclavian vein runs parallel to the subclavian artery, draining blood from the arm, shoulder, and neck - It joins the internal jugular vein to form the brachiocephalic vein, which drains into the superior vena cava. Axillary Vein: - primary vein draining the shoulder area - It is a continuation of the brachial vein, and it runs alongside the axillary artery. It receives blood from various tributaries, including: Cephalic vein, Basilic vein and branches from the circumflex humeral veins

Question 29

major arteries of the elbow summary

Answer 29

- provided mostly by the brachial artery (with branches), radial artery, and ulnar artery (forms extensive network of arteries around the joint) - blood vessels join together to ensure that the elbow joint receives an adequate blood supply during movement

Question 30

description of major artery of elbow

Answer 30

MEDIAL SIDE: - superior ulnar collateral artery from brachial artery joins with the posterior recurrent artery from the ulnar artery - inferior ulnar collateral artery joins with the anterior ulnar recurrent artery LATERAL SIDE: - radial collateral artery meets with radial recurrent - medial collateral artery joins with the interosseous recurrent artery

Question 31

major veins in elbow

Answer 31

return deoxygenated blood from elbow to heart & drain muscles, bones and other structures around the elbow joint & closely accompany the arteries SUPERFICIAL: - cephalic, basilic, median cubital - join superficial tissue of the elbow - visible under skin (cannulation) DEEP: - brachial, radial, ulnar and interosseous - join deeper structures - from primary root venous= drain back to the heart

Question 32

major innervation of the shoulder

Answer 32

BRACHIAL PLEXUS - supply motor and sensory function to the shoulder joint and surrounding structures (forearm and hand) - gives rise to 7 important nerves

Question 33

description of the major innervation of shoulder

Answer 33

- suprascapular innervates the supraspinatus and the infraspinatus - dorsal scapula innervates the rhomboids and levator scapulae - long thoracic nerve innervates the serratus anterior muscle - thoracodorsal nerve innervates the latissimus dorsi muscle, scapula nerves and the medial and lateral pectoral nerves - musculocutaneous nerve innervates the anterior compartment of the arms at the biceps and provides sensory info to the lateral forearm - axillary nerve innervates the deltoid - radial nerve innervates the extensor muscles - median nerve innervates most of the flexor muscles - ulnar nerve innervates some of the forearm muscles and most intrinsic hand muscles 2 provide sensation

Question 34

fat pads

Answer 34

- small protective cushions made of adipose tissue located within elbow joint - fibrous joint capsule at the side of your membrane - reduce friction and assist w smooth movement 3 fat pads in elbow: - anterior, located in coronoid fossa of humerus - posterior fat pad located in the olecranon - supinator fat pad located near the supine muscle in the lateral part of elbow

Question 35

shoulder- dislocation

Answer 35

- 90% of dislocations are anterior - Common sports injury - Causes lots of soft tissue injury - Lots of vulnerable structures nearby including main blood vessels and nerves

Question 36

shoulder- fracture

Answer 36

- can be caused by fall from height/ traffic accident - involves humeral head, the greater tuberosity and the lesser tubercle of the humeral shaft

Question 37

clavicle - fracture

Answer 37

- normally treated without surgery dependent on displacement - "cyclists" fracture

Question 38

calcific tendonitis

Answer 38

- calcium salts deposited in the tendons, most commonly in rotator cuff - causes pain and inflammation and can limit range of movement -

Question 39

labral tear

Answer 39

- labrum of glenoid cavity can have a tear - joint stability can be comprised - there are different classifications of labral tear: SLAP ; Bankart; Posterior MRI Arthrogram (contrast injected into the joint) to image the labrum and detect tears