Musculoskeletal Flashcards
The pectoral girdle (shoulder girdle) is made up of ?
Scapula
Clavicle
All muscles attached to these (rhomboids, trapezius, subclavian, pec minor, elevator scapularis)
Latissimus dorsi
The rounded contour of the shoulder is made by what muscle and bone?
Deltoid and upper end of humerus
Name the 5 muscles of the back
Latissimus dorsi Levator scapulae Trapezius Rhomboid minor Rhomboid major
Name the 4 muscles which arise from the back of the scapula
supra-spinatus
infra-spinatus
teres minor
teres major
What joint attaches the scapula to the humerus?
glenohumeral joint
Do most clavicular fractures occur in the lateral end, middle or medial end of the clavicle?
What nerve can be damaged by a fractured clavicle and what would the patient experience?
Middle commonly due to a fall onto the shoulder or a fall onto an outstretched hand
Supraclavicular nerves can be damaged in surgery resulting in a numb patch over the upper chest and shoulder
What 3 muscles attach to the coracoid process of the scapula?
- Pectoralis minor
- Corcacobrachialis
- Short head of the biceps brachii
In ‘winging of the scapula’ what nerve is damaged and why does it cause the winged appearance?
Winging of the scapula occurs when the long thoracic nerve which innervates serratus anterior is damaged. As serratus anterior inserts onto the costal surface of the scapula, it usually pulls the scapula against the rib cage.
What does the distal end of the humerus articulate with?
head of radius
trochlear notch of ulnar
Name the 4 rotator cuff muscles and where do they attach on the humerus? (SITS)
Supraspinatus - greater tubercle of humerus
Infraspinatus - greater tubercle of humerus
Teres minor - greater tubercle of humerus
Subscapularis - lesser tubercle of humerus
What muscle runs through the inter tubercular sulcus of the humerus? What is found on either side of the inter tubercular sulcus and what muscles attach onto them?
Long head of biceps
Edges are known as lips and pec major and teres major insert onto the lips of the inter tubercular sulcus.
If a patient falls on an outstretched hand and fractures the surgical neck of the humerus, what key neuromuscular structures might be damaged?
What symptoms would a patient present with if the. nerve is damaged?
Axillary nerve
Posterior circumflex artery
Damage to axillary nerve would cause paralysis of deltoid and teres minor muscles so they would have trouble abducting the affected limb. The nerve also innervates skin over deltoid so sensation in the. regimental badge area would be impaired.
The radial groove runs diagonally down the posterior surface of the humerus, which nerve runs in this groove?
Radial nerve
A mid shaft fracture risks damage to which nerve?
What signs would a patient present with if this nerve was damaged?
Radial
The radial nerve innervates the extensors of the wrist and therefore, damage will result in paralysis of the extensors (unopposed flexion of the wrist ‘wrist droop’) - there might also be sensory loss over posterior surface of the hand
Where do the forearm extensor muscles originate from?
- medial supraepicondylar ridge
- lateral supraepicondylar ridge
- medial epicondyle
- lateral epicondyle
- lateral supraepicondyle ridge is where forearm extensor muscles originate from
Which nerve passes in a groove on the posterior aspect of the medial epicondyle?
Ulnar nerve
What is the purpose of the bursa around the shoulder joint?
Reduce friction in the joint and cushions between tendons and other structures
Where does the deltoid muscle originate and insert?
Originates from clavicle, acromion and spine of scapula and inserts onto deltoid tuberosity at the middle of the humerus
Which nerve innervates deltoid? How can this nerve be damaged? What symptoms would the patient experience?
Axillary nerve
Damaged by posterior dislocation of the shoulder.
- Paralysis of deltoid
- patch of numb skin on lateral arm
Contraction of supraspinatus muscle causes what?
Abduction of the arm
What nerve supplies the extensors of the posterior arm?
Radial nerve
What nerve supplies the extensors of the posterior forearm?
Radial
What nerve supplies the anterior flexors of the arm?
musculocutaneous nerve
what nerves supply the anterior flexors of the forearm?
flexor carpi ulnaris and medial half of flexor digitorum profundus = ulnar nerve
All the other flexors in the forearm = median
What nerves supply the muscles of the hand?
LLOAF = median nerve
All the other muscles = ulnar
Describe what happens in a ‘frozen shoulder’ to cause pain
Tendon of supraspinatus passes through a tight junction between acromion and humerus and if the tendon becomes inflamed, it can cause pain as it passes through the tight space.
Typically a patient will be able to lift their arm to a certain point and then feel pain as the inflamed tendon passes through the tight space and then the pain goes away once the tendon is through and the arm is raised. It is described as a ‘painful arc’.
Which nerve runs in the spiral groove directly against the humerus which can easily be damaged by a fracture of the humerus or pressure on the humerus (sleeping with arm hooked over sofa)
Radial nerve - radial nerve palsy
When someone hits their ‘funny bone’ what nerve have they hit?
Ulna nerve which runs behind the medial epicondyle of the humerus
What is the innervation to trapezius muscle?
CN XI
What is the action of elevator scapulae?
Elevate the scapula
What is the action of rhomboid minor and major?
Adduct scapula and perform downward rotation
What is the action of latissimus dorsi?
extension, adduction and medial rotation at the shoulder
What are the boundaries of the axilla? (anterior, posterior, lateral, medial, apex and base)
- Anterior wall - pectoralis major and pectoralis minor muscles
- Posterior wall - subscapularis, teres major and latissimus dorsi muscles
- Lateral wall - upper end of the humerus with the biceps brachii and coracobrachialis muscles
- Medial wall - serratus anterior muscle covering ribs and intercostal spaces
- Apex - formed by the first rib medially with the clavicle infront and the scapula behind.
- Base - skin and fascia extending between chest wall and the arm
What does the axilla contain?
- fat and lymph
- axillary artery
- axillary vein
- brachial plexus
- all of the above
All of them
- Fat and lymph nodes
- Axillary artery which is the major artery supplying the upper limb
- Axillary vein which is the major vein draining the arm
- Brachial plexus which is the nerve plexus supplying the limb
Lymph nodes in the axilla drain what part of the body? Which cancer is commonly involved in spread to the axillary lymph nodes?
Upper limb, chest wall and abdominal wall as far as the umbilicus
Breast cancer commonly spread to axillary lymph nodes
What are the 5 divisions of the brachial plexus?
read that damn cadaver book Roots Trunk Divisions Cords Branches
Which spinal nerves make up the brachial plexus?
C5, 6, 7, 8, T1
Are the roots of the brachial plexus made up of the anterior or posterior rami of the spinal cord nerves?
Anterior
Posterior innervates skin and intrinsic muscles of the back