ANATOMY: Shoulder, Arm and Elbow Part 1

Question 1

What are the functions of the upper limb?

Answer 1

Upper limb favours mobility over stability (as opposed to lower limb), e.g. easier to dislocate shoulder than hip
Wide range of motion is facilitated by bones
Upper limb is only attached by the clavicle to the trunk - aiding high mobility

Question 2

What are the parts of the upper limb?

Answer 2

• shoulder
  
  • scapula and glenohumeral joint (aka shoulder joint)
  • clavicle and trunk (shoulder girdle)
• arm
  
  • not the whole thing, just the upper part
  • humerus - long shaft
• forearm
  
  • ulnar and radius
• hand
  
  • carpal bones
  • metacarpals
  • phalanges

Question 3

Describe the scapula

Answer 3

• irregular bone, only connected to torso via muscles

Question 4

The scapula is kinda floating, what does this mean?

Answer 4

• we can retract and protract our scapula
• when you abduct your humerus, you’ll probably move it 90 degrees before the scapula kicks in - it starts having to rotate as well and become abducted
  You can do this as it is not fixed to ribs, it is floating on bed of muscle
  Lateral rotation of the scapula is esp important for the abduction of the arm at the shoulder joint

Question 5

What structure is represented by each of the numbers?

Answer 5

Question 6

Label this

Answer 6

• supraspinous and infraspinous fossa are going to be filled with muscle
• scapular spine ends in the acromion process

Question 7

Label this

Answer 7

• subscapular fossa - more muscles sit here
• glenoid fossa is site of glenohumeral joint
• scapular notch - important for some arteries to pass thru
• Coracoid process - muscular attachment joint

Question 8

Which joint connects the clavicle and scapula?

Answer 8

Clavicle and scapula connected by acromioclavicular joint. This doesn’t facilitate a great deal of movement, it is a plane joint - more so stability

Question 9

Label this

Answer 9

Question 10

Label this

Answer 10

Ligaments steady and support the joint

Question 11

Which joint connects the shoulder to the arm?

Answer 11

glenohumeral connects the shoulder and arm, it has high mobility and low stability

Question 12

Label this

Answer 12

Question 13

Label this

Answer 13

• intertubercular sulcus - where long tendon of biceps brachii runs
• deltoid tuberosity - where deltoid muscle attaches
• radial groove - radial nerve runs in this

Question 14

Label and describe the structures here

Answer 14

• glenoid labrum - fibrous structure which forms a lip - deepens the joint - give it extra support
• ball and socket joint. the head is too big for the socket, relies on musculature and ligaments TO HOLD IT IN PLACE

Question 15

Label this

Answer 15

there are three thickenings of the joint capsule called the glenohumeral ligaments in particular that are labelled here as the capsular ligaments
- capsular ligaments - helps to support unstable joint
- supraspinatus tendon - from rotator cuff muscles

Question 16

What are the anterior axio-appendicular muscles?

Answer 16

Question 17

What is pectoralis major? Describe the heads of pectoralis major and where they originate.

Answer 17

Adduct (bring in) and medially rotate humerus
- scapula - draws antero-inferiorly
- heads flex/extend humerus respectively, depending on the head that is being activated
The pectoralis major has: the clavicular head which originates from medial half of clavicle. Flexes arm
The sternocostal head originates from the anterior sternum, from 1-6 costal cartilages they attach external oblique. Extends arm

Question 18

Label this

Answer 18

Question 19

Describe the serratus anterior

Answer 19

Consists of several strips, which originate from the lateral aspects of ribs 1-8. they attach to the costal surface of the medial scapula border.
Function:rotates the scapula, allowing the arm to be raised over 90 degrees. It also holds the scapula against the ribcage.

Question 20

Describe pectoralis minor

Answer 20

Pec minor not connected to humerus - no action on the arm. Instead joins to scapula from ribs.
Function: Stabilises the scapula by drawing it anteroinferiorly against the thoracic wall.
- attachments: originates from the 3rd-5th ribs and inserts into the coracoid process of the scapula.

Question 21

Label this

Answer 21

Question 22

Describe the subclavius

Answer 22

Attachments: originates from the junction of the 1st rib and its costal cartilage. It inserts onto the inferior surface of the middle third of the clavicle.
Function: anchors and depresses the clavicle.

Question 23

Label the posterior axio-appendicular muscles on this diagram. What are these muscles innervated by?

Answer 23

All superficial muscles of the back are all innervated by ventral branches of spinal nerves
Dorsal branches supply deep muscles

Question 24

Describe the trapezius

Answer 24

Originates from the skull, nuchal ligament and the spinous processes of C7-T12. The fibres attach to the clavicle, acromion, and the scapula spine.
Actions: abduction of the upper limb at the shoulder (by rotating the scapula). The upper fibres of trapezius also elevate the scapula, the middle fibres retract, and the lower fibres depress.

Question 25

Describe the latissimus dorsi

Answer 25

Attachments: has a broad origin – arising from the spinous processes of T6-T12, thoracolumbar fascia, iliac crest, and the inferior three ribs. The fibres converge on humerus - intertubercular groove Extends, adducts + medially rotates the upper limb.

Question 26

Describe the rhomboid minor

Answer 26

Originates from the spinous processes of C7-T1 vertebrae. Attaches to the medial border of the scapula, at the level of the spine of scapula. Actions: Retracts and rotates the scapula

Question 27

Describe the rhomboid major

Answer 27

Originates from the spinous processes of T2-T5 vertebrae. Attaches to the medial border of the scapula, between the scapula spine and inferior angle. Actions: retracts and rotates the scapula.

Question 28

Describe the levator scapulae

Answer 28

Attachments: originates from the transverse processes of the C1-C4 vertebrae and attaches to the medial border of the scapula Actions: elevates the scapula.

Question 29

The trapezius is split into 3 parts, describe these

Answer 29

Question 30

Label this

Answer 30

Question 31

Label this

Answer 31

Question 32

Which muscles run from the scapula to the humerus?

Answer 32

Question 33

What are the attachments of the deltoid

Answer 33

attachments: Originates from the lateral third of the clavicle, the acromion and the spine of the scapula. It attaches to the deltoid tuberosity on the lateral aspect of the humerus.

Question 34

What are the actions of the deltoid muscle fibres

Answer 34

Actions: Anterior fibres – flexion and medial rotation at the shoulder Posterior fibres – extension and lateral rotation at the shoulder Middle fibres – abduction at the shoulder (takes over from the supraspinatus, which abducts the first 15 degrees).

Question 35

Label this

Answer 35

Question 36

What does this arrow point to? Also what are the highlighted structures?

Answer 36

Question 37

What are the attachments and actions of teres major?

Answer 37

Attachments: originates from the posterior surface of the inferior angle of the scapula. It attaches to the medial lip of the intertubercular groove of the humerus. Actions: Adduction, extension and medial rotation of the upper limb at the shoulder.

Question 38

Label this

Answer 38

Question 39

What are the rotator cuff muscles?

Answer 39

- supraspinatus - infraspinatus - teres minor - subscapularis The rotator cuff muscles originate from the scapula and attach to the humeral head. Collectively, the resting tone of these muscles pulls the humeral head into the glenoid fossa, giving extra stability to glenohumeral joint

Question 40

Label this, and hihglight the rotator cuff muscles

Answer 40

Question 41

What is the function, origin and innervation of the suprasinatus and infraspinatus?

Answer 41

Supraspinatus: Abduction of arm. Originates from upraspinous fossa, attaches to greater tubercle of humerus. Innervation: Suprascapular nerve Infraspinatus: Laterally rotates arm. Originates from infraspinous fossa, attaches to greater tubercle of humerus. Innervation: Suprascapular nerve

Question 42

What is the function, origin and innervation of the teres minor and subscapularis?

Answer 42

Teres minor: Laterally rotates arm. Originates from lateral border of scapula, attaches to greater tubercle of humerus. Innervation: Axillary nerve Subscapularis: Medially rotates arm. Originates from subscapular fossa, attaches to lesser tubercle of the humerus. Innervation: Upper and lower subscapular nerves

Question 43

Label this

Answer 43

Question 44

Label

Answer 44

Question 45

What are bursa and what is their function?

Answer 45

Synovial joints have synovial cavities filled w synovial fluid Sometimes cavities have extra space/bubbles= bursa Function of bursa = reduce friction between moving parts in your body's joints. Bursa run underneath tendons and ligaments to reduce friction as they are lined internally by synovial membrane