Shoulder and Brachial Regions

Question 1

Name the regions of the forelimb appendicular skeleton and the relative bones.

Answer 1

1. Shoulder: Scapula, shoulder joint.
2. Arm (Brachium): Humerus.
3. Forearm (Antebrachium): Radius, ulna.
4. Manus (Hand): Carpus, metacarpus, phalanges.

Question 2

Name key features of the scapula and label these on the lateral aspect.

Answer 2

Spine, supraspinous fossa, infraspinous fossa, glenoid cavity, acromion.
Look at notes

Question 3

What is the function of the brachiocephalic muscle?

Answer 3

Protractor - acts across shoulder.

Question 4

Where does the brachiocephalic muscle originate/insert?

Answer 4

• Origin = cervico-thoracic fascia
• Insertion= humerus (aponeurosis)

Question 5

Name extrinsic shoulder muscles, origin, and insertion.

Answer 5

1. Trapezius: Midline → Spine of scapula.
2. Latissimus dorsi: Thoracolumbar fascia → Humerus.
3. Rhomboideus: Dorsal midline → Scapula.
4. Serratus ventralis: Ribs/cervical vertebrae → Scapula.

Question 6

Name scapular ossification centers.

Answer 6

Primary: Scapular body.
Secondary: Supraglenoid tubercle.

Question 7

What are abductors?

Answer 7

Move limb away from midline.

Question 8

What are adductors?

Answer 8

Move limb towards midline.

Question 9

Where are the centres of ossification in the humerus?

Answer 9

• Proximal epiphyses
• Body
• Medial epichondyle
• Medial half of the condyle
• Lateral half of the condyle

Question 10

What are the major features of the proximal end of the humerus?

Answer 10

• Head of the humerus: Spherical shape; articulates with the glenoid cavity of the scapula to form the shoulder joint.
• Greater tubercle: Large prominence on the lateral side for muscle attachment.
• Lesser tubercle: Smaller prominence on the medial side for muscle attachment.
• Intertubercular groove: A groove between the greater and lesser tubercles for the biceps brachii tendon.

Question 11

What features are found at the distal end of the humerus?

Answer 11

1. Condyle: The distal part of the humerus, which articulates with the radius and ulna at the elbow joint.
2. Medial epicondyle: Located on the inner side of the condyle; attachment for flexor muscles of the forelimb.
3. Lateral epicondyle: Located on the outer side of the condyle; attachment for extensor muscles of the forelimb.
4. Trochlea: Medial portion of the condyle, articulates with the ulna.
5. Capitulum: Lateral portion of the condyle, articulates with the radius.