Lecture 22 - Upper Limb 1 Flashcards
What gives rise to the ability to oppose the thumb?
The thumb is rotated 90 degrees with respect to the other fingers
What is the basic mammalian form of the bones inthe upper limb?
Limb girdle connected to the axial skeleton One proximal bone Two distal bone Pentadactyl hand - Thumb rotated 90 degrees
What is interesting about upper limb development?
It rotates, giving rise to the anatomical position
Big toe is medial
Thumb is lateral
What does the clavicle do?
Connects to the axial skeleton and the upper limb
What are the names of the two ends of the clavicle?
What are the cakes of the joints?
Acromial
Sacral
Acromial-clavicle
Sternal-clavicle
What is the role of the scapula?
Muscle attachments the shoulder joint
In what does the head of the humerus sit?
Glenoid fossa
Where does the clavicle normally fracture?
What happens after there is a fracture?
At the weakest point: biggest bend
At the Lateral 1/3
The lateral end and limb drops down
Describe the structure of the humerus and the pertinent features
Head
Tuberosities (greater, lesser, deltoid)
Neck (surgical and anatomical)
Epichondyles (medial and lateral)
What are tuberosities?
This is where muscle attaches to the bone
What is the difference between the anatomical and the surgical neck?
Surgical neck: much more frequently fractured
Anatomical: epiphyseal plate
What are the bones of the forearm?
How are they linked?
Ulna: medial
Radius: lateral
They are linked by the interosseus membrane
Where are the ulna and the radius each articulated?
Ulna: elbow
Radius: wrist
Describe rotation of the ulna and radius
What is the rotation called?
Ulna remains attaches at the elbow hinge joint to the humerus
The radius rotates around the ulna
Supernation and pronation
Describe the bones of the wrist
There are two rows (proximal and distal), each with four bones
What are the bones in the proximal row of the wrist?
Pisiform, triquetrum, lunate, scaphoid
What are the bones in the distal row of the wrist?
Trapezium, trapezoid, capitate, hamate
Where are common sites of fracture in the humerus?
Surgical neck
Mid shaft
Suprachondylar
What are common fractures of bones in the forearm?
What causes them
Colles fracture: fracture of the distal radius
Normally caused by falling on an outstretched arm
Parry fracture: shaft of the ulna
What can fracture of the scaphoid lead to?
Necrosis of the proximal end of the scaphoid –> blood comes to the distal end first
What are the features of stable joints?
Congruent
Limited range of movement
Tight capsule and strong ligaments
What are features of mobile joints?
Low stability
Low congruence
Susceptible to subluxation and dislocation
Rely on fixators and labra for stability
What are the joints of the upper limb?
Acromioclavicular
Sternlclavicular
Glenohumeral
Elbow
Wrist
What are some features of the glenohumeral joint?
Very instable due to the large range of movement
Coracoclavicular ligaments are the main stabilisers and prevent upwards rotation of the clavicle
Weak capsule
What are the features of the sternoclavicular joint?
Very strong capsule
Costoclavicular ligament
What is the name of the socket in which the head of the humerus sits?
Glenoid fossa
What is the name of the labrum in the glenohumeral joint?
Glenoid labrum
Which muscles and ligaments stabilise the glenohumeral joint?
Coraco-acromial
Head of biceps
Rotator cuff
What do the rotator cuff muscle do?
Pull the head of the humerus towards the glenoid
Fuse with the capsule
What are the names of the rotator cuff muscles?
- Supraspinatus
- Infraspinatus
- Subscapularis
What is the name of the bursa in the glenohumoral joint?
Where exactly is it?
It is called the subacromial bursa
It is located under the acromion process of the scapula
Shoulder abductioncan bring about …
Irritation of the sub acromial bursa
When is the shoulder most commonly dislocated?
In which direction is the shoulder normally dislocated?
What are some other features?
Most susceptible when abducted and externally rotated
Dislocated anterior and inferior
Joint capsule tears and shoulder appears less broad
Which ligaments stabilise the hinge joint of the elbow?
Where do they attach?
The collateral ligaments that attach to the epichondyles and runs down the sides of the limb
What is the other joint present in the forearm?
What sort of movement does this joint allow?
Radio-ulnar joint
Supination and pronation
Which bones are connected in the wrist?
Distal radius joins with the scaphoid and lunate
What sort of joints are present in the phalanges?
How are here joints stabilised?
Hinge joints
They are stabilised by collateral ligaments
