Joint of the upper limb

Question 1

What are the main joints of the upper limb?

Answer 1

-Sternoclavicular joint(SCJ)
-Acromio-clavicular joint(ACJ)
-Gleno-Humeral joint(GHJ)(Shoulder Joint)
-Scapulo-thoracic joint(STJ)
-Elbow joint
Wrist Joint
Numerous joints in the hand

Question 2

Describe the sternoclavicular joint?

Answer 2

• attatchment of the upper limb to the trunk and is one of the PECTORAL GIRDLE joints
• It is a saddle type synovial joint (however it is more complex than synovial joints as its cavity is divided by a fibrous articular disc)
• It is capable of accomodating the elevation of the lateral end of the clavicle as well as its anterior and posterior movements
• It is stabilised by lots of ligaments that also prevent unwanted movement

Question 3

Describe the Acromio-clavicular Joint

Answer 3

• A plane synovial joint with an imcomplete particular disc between the lateral end (shoulder end) of the clavicle and the acromion process of the scapula
• Capable of limited movement
• Its rotation vertical and anterior posterior movements are associated with the movements of the scapular
• ligament and muscles limit the movements and stabilise the joint
• incomplete wedge of fibrocartilage in the joint cavity

Question 4

Describe the Scapulothoracic joint?

Answer 4

Not a true joint

Movements of the Scapula against the posterior and lateral thoracic wall (chest) are the scapulothoracic joint movements

Question 5

Describe the glenohumeral joint?

Answer 5

• shoulder joint
• ball and socket synovial joint (one of the most mobile joints in the body)
• the rounded humeral head(top of the humeral bone) articulates with the GLENOD FOSSA of the scalpa(socket)
• The glenoid fossa is shallow but slightly deepened by a rim of fibrocartilage, the glenoid labrum
• The head of the humerous is covered in HYALINE CARTILAGE
• Unstable due to the shape of the bones here but its is stabilised by lots of muscles that hold the head of the humerous against the glenoid fossa

Question 6

Describe the elbow joint?

Answer 6

• Synovial joint that involves two articulations and is closely asosiated with a third. The two main articulations are between the distal end of the humerus and the proximal ends of the radius and the ulna bones
• The distal humerous has 2 condyles: Capitulum and the trochlea
• The joint is limited to flexion and extension
• The third joint that the elbow joint is closely associated with is the PROXIMAL RADIOULNAR joint which is between the Proximal ends of the radius and ulna (some group this joint as the eblow joint whereas some consider it a distinct joint)
• At this third joint the raduis is rotated at its head so the shaft crosses the ulna, and the palm of the hand faces from anteriorly to posteriorly
• The elbow joint is configured so that flexion(bend forearm up) and extension(stretch out forearm so full arm is straight) can occur at any degree of pronation/supination

Question 7

What is a condyle?

Answer 7

The round prominence of the end of a bone

Question 8

What is Pronation and Supranation?

Answer 8

Pronation-palm facing back ‘

Supination-palm facing forwards

Question 9

What are the 2 fossa at the distil end of the humerous and what occupies them?

Answer 9

When the forearm is fully flexed the radial fossa- acommodates the head of the radius and the coronoid fossa which accomadates the ulnar coronoid process

Question 10

Which fossa is on the posterior aspect of the elbow joint ?

Answer 10

The Olecranon ossa- this accomadates the the olecranon process when the forearm is fully extended

Question 11

What limits extension of the forearm?

Answer 11

The way the bones fit together

Question 12

Describe the wrist joint?

Answer 12

Also known as the radiocarpal joint

• Its the articulation between the distal end of the radius and the 3 of the proximal row of the carpal bones
• The ilna does not strictly form part of the wrist joint but it articulates with the ARTICULAR DISC which in turn articulates with the carpals

Question 13

What are the names of the 3 carpal bones in the proximal row?

Answer 13

the scaphoid, lunate and triquetrum

Question 14

What id the fourth bone next the the carpals on the proximal bone?

Answer 14

Pisiform-this is not part of the wrist joint

Question 15

What do you see in an MRI and XRAY of the wrist?

Answer 15

there is a larger gap visible between the distal ulna and the bones of the wrist

This gap contains the articular disc which is not visible in the X-ray or MRI

Question 16

When do the distal ends of the radius and ulna articulate?

Answer 16

during pronation and supination

Question 17

Describe the distal radioulnar joint?

Answer 17

• A synovial pivot joint
• The margin of the disc like head of the ulna articulates with the notch at the distal end of the radius which pivots round the ulna

-The bones are connected by the fibrous particular disc which slides over the distal ulna during the pronation supination movements

Question 18

What are the 4 main sets of joints in the hand?

Answer 18

Intercarpal joints - articulation between the carpal bones and the proximal and distal rows and also between those within the rows

Carpometacarpal joints -articulation between the distal row of the carpal bones ad the basis of the metacarpals. These are synovial and mostlly palte joints apart from the first Capal Metacarpal joint which saddle joint that allows the grater mobility required of the thumb.

Metacarpophalangeal joints-articualtions between the metacarpals and the phalanges. These joints are usually visible as the knuckles.
They are Synovial condylar joints that allow a wide range of movement which is limited by ligaments

Interphalangeal joints - articulations between the phalanges
They are synovial hinge joints capable of flexion and extension only

Question 19

What type of ligament limit the movement of the interphalangeal joints?

Answer 19

tough ligaments particularly the COLLATERAL ligaments which connect the phalanges at the medial and lateral sites