Upper Limb - Muscles (1) Flashcards Preview

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Flashcards in Upper Limb - Muscles (1) Deck (44)
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1
Q

In the muscles of the upper arm, what separates the anterior compartment from the posterior compartment? Describe this structure.

A

The intermuscular septum, which is continuous with the deep fascia of the upper arm, which surrounds all the muscles of the upper arm. The lateral intermuscular septum is separated from the medial intermuscular septum by the humerus bone.

2
Q

Name the three muscles in the anterior comparment of the upper arm. How are these muscles innervated?

A

Biceps brachii. Coracobrachialis. Brachialis muscle. All innervated by the musculocutaneous nerve.

3
Q

Describe the attachments of the biceps brachii.

A

The long head of biceps originates from the supraglenoid tubercle of the scapula, then runs down through the intertubercular groove of the humerus. The short head of biceps originates from the coracoid process of the scapula. The biceps then inserts mostly as the bicipital aponeurosis onto the fascia of the forearm, but also as the radial tuberosity.

4
Q

Describe the attachments of the coracobrachialis. What lies superficially to the coracobrachialis?

A

The coracobrachialis originates from the **coracoid process **of the scapula, and inserts at the mid-shaft of the humerus. The coracobrachialis lies deep to the biceps brachii.

5
Q

Describe the attachments of the brachialis muscle.

A

The brachialis originates from the mid-shaft of the humerus and inserts at the ulnar tuberosity.

6
Q

Describe the muscles of the posterior compartment of the arm, including attachments.

A

There is just the triceps brachii. The long head originates from the infraglenoid tuberosity of the scapula, the lateral head originates from the upper shaft of the humerus, and the medial head lies just deep to this, originating just a little more distally. All three heads converge to form the triceps tendon, which inserts onto the olecranon process of the ulna.

7
Q

What is the innervation to the triceps brachii?

A

The Radial Nerve.

8
Q

What is meant by the mnemonic “The Lady between two Majors”

A

The insertion of the Latissimus dorsi is on the intertubercular groove of the humerus, in between the insertion sites of the Teres Major and the Pectoralis Major.

9
Q

Name the origins of the pectoralis major.

A

Medial half of clavicle, Anterior surface of sternum, Aponeurosis of external oblique.

10
Q

Name the distal attachment of pectoralis major.

A

Lateral lip of intertubercular groove of humerus.

11
Q

Name the origins of the pectoralis minor.

A

3rd-5th ribs, near their costal cartilages.

12
Q

Name the distal attachment of the pectoralis minor. Which muscle overlies the pectoralis minor?

A

Coracoid process of scapula. Pectoralis major overlies it.

13
Q

What causes a winged scapula?

A

Injury to the long thoracic nerve, causing paralysis of the serratus anterior muscle.

14
Q

What are the proximal attachments (origins) of the trapezius muscle?

A

Nuchal ligament, Spinous processes of C7-T12 vertebrae.

15
Q

What are the distal attachments of the trapezius muscle?

A

Lateral third of clavicle, Spine of scapula.

16
Q

Name two major adductors of the humerus.

A

Latissimus dorsi. Teres major.

17
Q

What are the technical terms for these movements of the scapula:

  1. Shrug
  2. Hug
  3. Star jumps
A
  1. Elevation/Depression
  2. Protraction/Retraction
  3. Upward rotation / Downward rotation
18
Q

Name the deep muscles that retract the scapulae.

A

Rhomboids.

19
Q

Name the deep muscles that allow you to shrug your shoulders.

A

Levator scapulae.

20
Q

During the first 15 degrees of abduction of the arm, which muscle is required to assist the deltoid?

A

Supraspinatus.

21
Q

The deltoid muscle is innervated by the _______ nerve.

A

Axillary.

22
Q

Name the muscles of the following walls of the axilla:

  1. Medial wall
  2. Anterior wall
  3. Posterior wall

What is the bony structure making up the lateral wall?

A
  1. Serratus anterior
  2. Pectoralis major and minor
  3. Subscapularis

The intertubercular groove of the humerus.

23
Q

What holds the tendon of the long head of biceps in the intertubercular groove?

A

The transverse humeral ligament.

24
Q

What is the anconeus muscle?

A

A small, triangular muscle on the posterolateral aspect of the elbow.

25
Q

What is the main flexor of the elbow?

A

Brachialis.

26
Q

What are the names of the two compartments of the forearm, and where are the situated?

A

Flexor-pronator compartment (positioned antero-medially), and Extensor-supinator compartment (positioned postero-laterally)

27
Q

Name the four muscles in the superficial layer of the flexor-pronator muscles of the forearm.

A

From lateral to medial: Pronator teres, Flexor carpi radialis, Palmaris longus, Flexor carpi ulnaris.

28
Q

What is the common flexor attachment?

A

This is the proximal attachment of all four muscles in the superficial layer of the flexor-pronator muscles of the forearm, as well as the flexor digitorum superficialis (of the intermediate layer), and it is at the medial epicondyle.

29
Q

Name the muscles of the intermediate layer of the flexor-pronator muscles of the forearm.

A

One muscle: flexor digitorum superficialis

30
Q

Name the muscles of the deep layer of the flexor-pronator muscles of the forearm.

A

Flexor digitorum profundus, Flexor pollicis longus, Pronator quadratus.

31
Q

Which nerve supplies most of the muscles of the anterior compartment of the forearm? Which nerve supplies the minority of these muscles?

A

Most by the median nerve. The ulnar nerve supplies flexor carpi ulnaris, and the medial half of flexor digitorum profundus.

32
Q

Which flexor muscle of the forearm is absent in approximately 14% of people?

A

Palmaris longus

33
Q

What is the only muscle that can flex the distal interphalangeal joints of the fingers?

A

Flexor Digitorum Profundus.

34
Q

Which tendons of the forearm are ensheathed in synovial tendon sheaths, and why?

A

The extensor tendons as they pass over the dorsum of the wrist, the synovial tendon sheaths reduce friction.

35
Q

Where is the common extensor origin?

A

Lateral epicondyle of humerus.

36
Q

Name the muscles of the superficial layer of the extensor compartment of the forearm.

A

From lateral to medial: Brachioradialis, Extensor carpi radialis longus, Extensor carpi radialis brevis, Extensor digitorum, Extensor digiti minimi, Extensor carpi ulnaris.

37
Q

Name the five muscles of the deep layer of the posterior compartment of the forearm.

A

In order of their origins, from proximal to distal: Supinator, Abductor pollicis longus, Extensor pollicis longus, Extensor pollicis brevis, Extensor indicis.

38
Q

Which two tendons form the borders of the anatomical snuff box?

A

Laterally: Extensor Pollicis Brevis.

Medially: Extensor Pollicis Longus.

39
Q

Which artery lies in the floor of the anatomical snuff box?

A

Radial artery.

40
Q

Which nerve gives off the posterior interosseous nerve? Where does this happen? Which muscle does it penetrate? What is the name for this nerve before it has penetrated this muscle?

A

Radial nerve. At the cubital fossa. Penetrates the supinator muscle. Called the deep branch of the radial nerve until it penetrates the supinator, at which point it becomes named the posterior interosseous nerve

41
Q

Which is more medial, the short head of biceps or the long head of biceps?

A

The short head.

42
Q

Name the two heads of the flexor digitorum superficialis, and their origins.

A

Humeroulnar head: Medial epicondyle (common flexor origin) and coronoid process of ulna.

Radial head: Anterior surface, just below the tuberosity.

43
Q

What is the bicipital aponeurosis?

A

It is part of the distal attachment of the biceps brachii.

44
Q

Where does the extensor pollicis longus insert? Where does the extensor pollicis brevis insert?

A

Longus: base of distal phalynx.

Brevis: base of proximal phalynx.

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