Lecture 8 - Humerus & Shoulder Joint

Question 1

What is the shoulder joint?

Answer 1

• also known as the glenohumeral joint; the joint created between the scapula & humerus
• it is the Glenoid of the scapula
• it is also the head of the humerus

Question 2

What is the articulation of the glenhumeral joint?

Answer 2

• functional classification: diarthrosis; freely moveable
• structural classification: synovial; ball & socket joint, multi-axial
• 1/3 of head of the humerus articulates with the glenoid fossa

Question 3

What are the movements associated with the glenohumeral joint?

Answer 3

• Flexion/ Extension
• Abduction/Adduction
• Internal/External Rotation
• Horizontal cross flexion/extension
• Circumduction

Question 4

What is the head of the humerus?

Answer 4

• it is a proximal land mark
• it is a large, round, smooth region that faces medially
• it articulates with the Glenoid cavity of the scapula to form the GH joint

Question 5

What is the surgical neck of the humerus?

Answer 5

• a proximal landmark
• it is located at the proximal end of the humerus & joins the shaft of the humerus
• common site for arm fractures

Question 6

What is the anatomical neck of the humerus?

Answer 6

• a proximal landmark
• it is the smooth area of the head of the humerus

Question 7

What is the grater tuberosity of the humerus?

Answer 7

• a proximal landmark
• located on the lateral side of the proximal humerus
• it is an expanded bony area that serves as an attachment point for muscles of the shoulder joint

Question 8

What is the lesser tuberosity of the humerus?

Answer 8

• a proximal landmark
• located on the anterior aspect of the humerus
• also acts as an attachment point for muscles for the shoulder joint

Question 9

What is the bicipital groove of the humerus?

Answer 9

• a proximal landmark
• also known as the intertubercular groove (sulcus)
• located between the greater/lesser tuberosity
• provides passage for a tendon of the biceps brachii

Question 10

What is the capitulum of the humerus ?

Answer 10

• a distal landmark
• located lateral of the Trochlea on the anterior surface of the distal humerus
• a small knob-like structure

Question 11

What is the Trochlea of the humerus?

Answer 11

• a distal landmark
• Trochlea = pulley
• it articulates with the ulna bone

Question 12

What is the coronoid fossa of the humerus?

Answer 12

• a distal landmark
• located superior to the Trochlea
• it receives the coronoid process of the ulna

Question 13

What is the radial fossa of the humerus ?

Answer 13

• a distal landmark
• located above the capitulum
• receives the head of the radius when the elbow is flexed

Question 14

What is the olecranon fossa of the humerus?

Answer 14

• a distal landmark
• a large depression that receives the olecranon process of the ulna when the forearm is fully extended

Question 15

What is the medial & lateral epicondyle of the humerus?

Answer 15

• the medial epicondyle is the prominent bony projection located on the medial side; allows powerful grasping for the muscles
• the lateral epicondyle is a smaller bony projection found on the lateral side; gives rise to the weaker muscles of the forearm
• attachment points for muscles of the forearm, wrist, & hand

Question 16

What is the deltoid tuberosity of the humerus?

Answer 16

• part of the shaft
• a roughened v-shape region located on the lateral side in the middle of the humerus shaft
• attachment point for the deltoid muscle

Question 17

What is the Glenoid fossa?

Answer 17

• forms the GH joint & humerus
• Pear-shaped (wider inferiorly)
• Faces anteriorly, laterally & inferiorly
• Shallow, concave

Question 18

What is the Glenoid labrum?

Answer 18

• provide stability & shock absorption
• Peripheral rim of fibrocartilage
• Functions to deepen the socket

Question 19

What is the glenohumeral ligament ?

Answer 19

• stabilizes the GH joint in adduction & external rotation
• composed of an anterior/superior, middle, & inferior ligament
• its the loosest capsule of any joint, meaning it is unstable
• has a tendency to dislocate; dependent on muscles for support

Question 20

What is the coracohumeral ligament?

Answer 20

• strengthens the upper part of the joint capsule of the shoulder joint
• Attaches from coracoid process to greater tubercle of humerus
• Remainder blends with capsule
• Taut on lateral rotation of shoulder

Question 21

What is the coracoacromial ligament?

Answer 21

• connects the acromion & coracoid process of the scapula
• forms a static restraint to superior humeral head displacement
• Creates the coracoacromial arch

Question 22

What is the transverse humeral ligament ?

Answer 22

• Crosses the bicipital groove of the humerus
• Holds the tendon of the biceps brachii against the floor of the bicipital groove
• Prevents “bowstringing”; Tendon would move in & out if we don’t have THL

Question 23

What are bursae sacs?

Answer 23

• small sacs filled with synovial fluid that reduce friction between moving parts in your joints

Question 24

What is subacromial bursitis?

Answer 24

• inflammation of the bursa sac that sits under the acromion process of the shoulder
• most common

Question 25

What is subdeltoid bursitis ?

Answer 25

• excessive use of the shoulder
• inflammation

Question 26

What is subcoracoid bursitis?

Answer 26

• inflammation of the bursae sac of the subscapularis & the coracoid process
• lateral or anterior shoulder pain