Lesson 2: Muscles And Bones Of The Head And Pectoral Girdle

Question 1

Name the 3 actions for the trapezius. One each for the upper, middle and lower fibres.

Answer 1

Upper fibres - upward rotation and elevation of the scapula. Middle fibers - retraction of scapula. Lower fibers - upward rotation and depression of scapula.

Question 2

Name the 4 rotator cuffs in order of the most anterior, superior, posterior superior, posterior inferior.

Answer 2

Anterior - subscapularis Superior - supraspinatus Posterior superior - infraspinatus Posterior inferior - teres minor

Question 3

Name the bone and the following landmarks. 1, 2, 4, 5, 7, 10, 12

Answer 3

Humerus bone.

1: Greater tubercle
2: Lesser tubercle
4: head (epiphysis)
5: Neck
7: Deltoid tuberosity
10: medial epicondyle
12: lateral epicondyle

Question 4

Name the bone and the following landmarks. 1, 5, 6, 8, 9, 10, 11, 12, 14, 15, 16.

Answer 4

Scapula bone.

1&15: acromial process

5: subscapula fossa
6: medial border
8: Lateral border

9&16: Glenoid cavity

10: Supraspinous fossa
11: Spine
12: infraspinous fossa
14: Coracoid process

Question 5

The name, insertion, origin and action of the muscle in the picture?

Answer 5

Muscle is the sternocleidomastoid.

Insertion - Mmastoid process on the temporal bone

Origin - Manubrium and medial clavicle.

Action - By itself will rotate head to opposite side. Together will flex neck.

Question 6

Name the 2 muscles most medial (insertion scapula medial border) and their actions.

Answer 6

Muscles are the Rhomboid major (inferior) and rhomboid minor (superior).

Both muscles have the same action, retracting and stabilising the scapula.

Question 7

From superior to inferior name the 4 muscles along with their actions.

Answer 7

1. Supraspinatus - shoulder abduction (abduction of humerus).
2. Teres minor - Laterally rotates shoulder

Both these muscles are also part of the rotator cuff group that help to stabilise the shoulder joint.

3. Teres major (last little helper) - medically rotates, extends and addicts shoulder.
4. Serrated anterior - upward rotation and protraction of scapular. Also stabilises scapular.

Question 8

Name the muscle and it’s origins and insertions.

Answer 8

Muscle is the Deltoid muscle (posterior part shown).

As a whole it abducts the shoulder.

Deltoid anterior - flexes and horizontally flexes and medically rotates shoulder.

Deltoid posterior - extends, horizontally extends and laterally rotates shoulder.

Origin follows the bones - lateral clavicle to acromial process to spine of scapula.

Insertion is deltoid tuberosity.

Question 9

Name this muscle and its actions.

Answer 9

Muscle is the subscapularis.

Also part of the rotator cuff group.

Its actions are to medically rotate and stabilise the shoulder joint.