Upper limb anatomy

Question 1

If a patient has a problem in a limb, such as pain, limited movement of weakness, what could it be a problem with in terms of:
- bone
- muscles and tendons
- joints
- neurological

Answer 1

Bone- Fractures, dislocation, infections

Muscles and tendons- muscle disease, muscle weakness, muscle ischemia

Joints - degeneration or inflammation of the articular cartilage, excess fluid in the joint (causing pain and stiffness), infection, debris in the joint

Neurological- in relation to pathology of the brain, spinal cord, peripheral nerves, neuromuscular junction

Question 2

Which part of the upper limb is the pectoral girdle?

Answer 2

• The clavicle, scapula and muscles attach to these bones

Question 3

Which part of the upper limb is considered the arm? What is the bone of the arm called?

Answer 3

The region between the shoulder and elbow joints.
The bone of the arm is called the humerus
(contains anterior and posterior muscle compartments)

Question 4

Which part of the upper limb is considered the forearm? what are the bones of the forearm called?

Answer 4

The region between the elbow and wrist joints.
The bones of the forearm are the radius and ulna.
(contains anterior and posterior muscle compartments)

Question 5

Which part of the upper limb is considered the hand? What are the 2 surfaces of the hand?

Answer 5

• The area distal to the wrist
• The palm and the dorsum

(it contains many small muscles)

Question 6

What is the glenohumeral joint of the upper limb? What type of joint is it? What does it articulate? is it mobile?

Answer 6

• The shoulder join. It is a ball and socket joint formed by the articulation between the scapula and proximal humerus.
• It is highly mobile

Question 7

What type of joint is the elbow joint? What does it articulate?

Answer 7

• It is a synovial hinge joint formed by the articulation of the distal humerus with the ulna and radius

Question 8

What type of joints are the proximal and distal radioulnar joints? What actions do they allow?

Answer 8

• They are pivot joints
• They allow supination and pronation of the forearm and hand

Question 9

What is the radiocarpal joint? What type of joint is it? What does it articulate with?

Answer 9

• It is the wrist joint
• It is a condylar joint
• It articulates with the distal radius and 2 carpal bones
• It allows for flexion, extension, abduction and adduction

Question 10

What does the clavicle articulate with and what are the joints called?

Answer 10

• It articulates with the sternum medially (sternoclavicular joint) and it articulates with the acromion of the scapula laterally (acromioclavicular joint)

Question 11

What is the glenoid fossa? Is it a good or poor fit?

Answer 11

It is located at the lateral aspect of the scapula

It articulates with the proximal humerus to form the glenohumeral joint.

It is actually a poor fit for the humerus but stability is compromised in return for an increased range of motion

Question 12

What is located superior and inferior to the glenoid fossa?

Answer 12

The supraglenoid tubercle and infraglenoid tubercle

Question 13

What is the anatomical neck of the humerus?

Answer 13

• A groove in the head of the humerus

Question 14

State 2 ways in which the axillary nerve may be injured

Answer 14

• Dislocation of the humeral head
• Fracture of the surgical neck

Question 15

What is the part of the humerus just distal to the lesser tubercle of the humerus? What is its significance? What could result from a fracture of it or dislocation of the humerus?

Answer 15

Just distal to the tubercles, the bone of the humerus narrows and becomes continuous with the shaft- this is called the surgical neck of the humerus

This is clinically important because it is commonly fractured (especially in the elderly as the result of a fall)

Should the surgical neck be fractured or the humeral head be dislocated, the axillary nerve running close to this region can be injured. Axillary nerve innervates the deltoid muscle and teres minor.

Question 16

What is the protuberance in the upper lateral aspect of the humeral shaft called? What is its function?

Answer 16

• The deltoid tuberosity
• The site of attachment for the deltoid muscle

Question 17

Where is the radial groove located and what does it mark the path of?

Answer 17

• Located on the posterior humerus, inferior to the deltoid tuberosity
• It marks the path of the radial nerve. As the radial nerve runs very close to the humeral here, it can be injured if there are midshaft humeral fractures.

Question 18

What is the coracoid process?

Answer 18

• A hook like structure on the lateral edge of the superior portion of the scapula. It works with the acromion to stabilise the shoulder joint.

Question 19

What are the movements of the scapula?

Answer 19

Protraction- pushing a door
Retraction- squaring your shoulders
Elevation- Shrugging
Depression- lowering your shoulders
Rotation- The glenoid fossa tilts cranially to aid in the elevation of the upper limb. When raising your arm above your head, for every 2 degrees of abduction of your shoulder, the scapula rotates 1 degree.

Question 20

What are the 5 muscles of the pectoral girdle? Which are anterior/posterior?

Answer 20

• The pectoralis major, minor and serratus anterior (anterior)
• The trapezius and latissimus dorsi are posterior

Question 21

What do the posterior muscles of the pectoral girdle connect to?

Answer 21

• They connect extensively to the vertebral column (trapezius connects to the skull)
• Latissimus dorsi attaches to the anterior aspect of the proximal humerus.

Question 22

What muscles attach the medial border of the scapula to the vertebral column?

Answer 22

• Levator scapulae
• Rhomboid minor
• Rhomboid major

Question 23

Which muscles move the scapular, and specifically which actions do these muscles help with?

Answer 23

Trapezius; upper part- elevation, lower part, depresses. middle part, retracts. also rotates the scapula

Levator scapulae- elevates
Rhomboid major- retracts
Rhomboid minor- retracts

Question 24

Which muscles move the scapular, and specifically which actions do these muscles help with?

Answer 24

Trapezius; upper part- elevation, lower part, depresses. middle part, retracts. also rotates the scapula

Levator scapulae- elevates
Rhomboid major- retracts
Rhomboid minor- retracts

Question 25

What does the latissimus dorsi attach to and what action does it create?

Answer 25

• It is attached to the anterior proximal humerus. It extends, adducts and medially rotates the humerus

Question 26

What are the origins and insertions of the
Trapezius
Latissimus dorsi
Levator scapulae
Rhomboid minor
Rhomboid major?

Answer 26

Trapezius—- skull, cervical and thoracic vertebrae —- clavicle and scapula

Latissimus dorsi—- lower thoracic vertebrae —- humerus upper anterior

Levator scapulae– upper cervical vertebrae — scapula medial border

Romboid minor— C7 and T1 – Scapula medial border

Rhomboid major- Thoracic vertebrae —scapula medial border

Question 27

Most of the muscles of the posterior pectoral region are innervated by the brachial plexus. What is the trapezius and latissimus dorsi innervated by?

Answer 27

• The trapezius is innervated by the spinal root of CN XI (accessory nerve)
• The latissimus dosi is innervated by the thoracodorsal nerve

Question 28

What are the 6 muscles that attach the scapula to the humerus? Where are they found?

Answer 28

deltoid
supraspinatus
infraspinatus
subscapularis
teres minor
teres major

Apart from the deltoid, they are all found deep to the posterior scapula muscles.

Question 29

What muscles make up the rotator cuff and what is the purpose of the rotator cuff?

Answer 29

supraspinatus
infraspinatus
subscapularis
teres minor

The rotator cuff provides stability to the shoulder joint.

Question 30

What does the deltoid attach? Where does it insert on the humerus? Can the deltoid initiate abduction of the shoulder joint?

Answer 30

It attaches the humerus to the lateral part of the clavicle and to the spine of the scapula.

It inserts to the deltoid tuberosity on the humerus

The deltoid cannot initiate abduction of the shoulder joint, another muscle abducts the first 20 degrees before the deltoid muscle takes over

Question 31

What is the deltoid innervated by?
What happens if the axillary nerve is injured?

Answer 31

• The axillary nerve
• It can lead to atrophy and weakness of the deltoid

Question 32

What is the action of the deltoid at the shoulder joint? What is its origin? What is its insertion point?

Answer 32

• It abducts the shoulder beyond 20 degrees
• Its origin is the spine and acromion
• its insertion point is the deltoid tuberosity

Question 33

What is the action of the teres major at the shoulder joint? What is its origin? What is its insertion point?

Answer 33

• Medial rotation and adduction of the shoulders
• Origin is posterior surface of the scapula, on the inferior part of the lateral border
• Its insertion point is the anterior aspect of the humerus

Question 34

What is the action of the supraspinatus at the shoulder joint? What is its origin? What is its insertion point?

Answer 34

• Abducts the shoulder for the first 20 degrees
• originates in the supraspinous fossa on the posterior border of the scapula
• its insertion point is the greater tubercle of the humerus (superior facet)

Question 35

What is the action of the infraspinatus at the shoulder joint? What is its origin? What is its insertion point?

Answer 35

• It laterally rotates the shoulders
• It originates from the infraspinous fossa on the posterior border of the scapula
• Its insertion point is the greater tubercle of the humerus (middle facet)

Question 36

What is the action of the teres minor at the shoulder joint? What is its origin? What is its insertion point?

Answer 36

• It laterally rotates the shoulders
• It originates from the posterior surface and lateral border of the scapula
• Its insertion point is the greater tubercle of the humerus (inferior facet)

Question 37

What is the action of the subscapularis at the shoulder joint? What is its origin? What is its insertion point?

Answer 37

• It medially rotates the shoulders
• It originates from the subscapular fossa on the anterior surface of the scapula
• Its insertion point is the lesser tubercle of the scapula

Question 38

What is the quadrilateral space bordered by? What is the significance of this?

Answer 38

• superiorly - teres major
• Inferiorly - teres minor
• Laterally- surgical neck of the humerus
• Medially- long head of the tricpes
• The axillary nerve passes through this to enter the posterior scapula region to innervate the deltoid and teres minor.

Question 39

What is impingement?

Answer 39

As the supraspinatus travels from the supraspinous fossa to the greater tubercle, it travels under the acromion.

The tendon can become inflamed and pinched between the acromion and humerus during movements of the shoulder.

Question 40

What are 2 other things that contribute to shoulder joint stability?

Answer 40

• Glenoid labrum- rim of fibrocartilage around the margin of glenoid fossa that deepens the shallow fossa to aid stability
• The capsule of the shoulder joint is reinforced with ligaments

Question 41

What separates the anterior and posterior compartments of the arm?

Answer 41

• Intermuscular septa

Question 42

Where does the triceps brachii originate from and where does it attach to? What happens when it contracts?

Answer 42

• It is found in the posterior compartment of the arm
• It has 3 muscle heads which converge via a common tendon on the olecranon of the ulna
• The muscle crosses the posterior aspect of the elbow joint, therefore when it contracts, the elbow extends.

Question 43

Where does the triceps brachii originate from and where does it attach to? What happens when it contracts?

Answer 43

• It is found in the posterior compartment of the arm
• It has 3 muscle heads which converge via a common tendon on the olecranon of the ulna
• The muscle crosses the posterior aspect of the elbow joint, therefore when it contracts, the elbow extends.

Question 44

What are the 3 heads of the triceps and where do they originate? What nerve are they innervated by?

Answer 44

Long head: infraglenoid tubercle of the scapula (most medial part of triceps)

Lateral head: posterior humerus, proximal to the radial groove

Medial head: posterior humerus, distal to the radial groove

They are all innervated by the radial nerve.

Question 45

Where does the long thoracic nerve originate and what does it supply?
How can it be damaged?

Answer 45

• It arises directly from the roots of the brachial plexus (C5, C6, C7)
• It supplies the serratus anterior
• it can be damaged via surgery, radiotherapy or disease of the axilla

Question 46

What are the 6 boundaries of the axilla?

Answer 46

Anterior wall - Pectoralis major and pectoralis minor
Posterior wall - Subscapularis, teres major and latissimus dorsi
Lateral wall - upper humerus
Medial wall - serratus anterior and chest wall
Apex- first rib, clavicle and scapula (passage between the neck and the axilla)
Base - skin and fascia between the chest wall and arm

Question 47

Tell me about the axillary artery (what is it a branch of, how many branches does it branch into, what does it continue to become?)

Answer 47

It is a branch of the subclavian artery
The axillary artery gives rise to several branches. 1 above pectoralis minor, 2 behind it and 3 below it.
The axillary artery continues into the arm as the brachial artery

Question 48

Tell me about the axillary vein (what does it drain, where does it drain into, what is the union that forms it)

Answer 48

It is a large vein which drains the upper limb and is continuous with the subclavian vein
It travels alongside the axillary artery
It is formed by the union of the deep veins of the arm and the basilic vein.

If either the axillary artery or vein is punctured or injured, it can cause life threatening bleeding.

Question 49

What is the brachial plexus?

Answer 49

It is the network of nerves that provide motor and sensory innervation to the upper limb

Question 50

Where do the spinal nerves of the brachial plexus arise? And what are the 5 segments of the brachial plexus?

Answer 50

The spinal nerves arise from the lower cervical and upper thoracic vertebrae C5-8 and T1.

The 5 segments are: roots, trunks, divisions, cords and branches

Question 51

What are the roots of the brachial plexus?

Answer 51

The 5 spinal nerves exiting the spinal cord and collectively giving rise to the brachial plexus

Question 52

What are the trunks of the brachial plexus?

Answer 52

C5 and C6 combine to form the superior trunk
C7 continues as the middle trunk
C8 and T1 combine to form the inferior trunk

Question 53

What are the divisions of the brachial plexus?

Answer 53

Each trunk divides into an anterior and posterior division under the clavicle

Question 54

What are the cords of the brachial plexus?

Answer 54

Anterior divisions of the superior and middle trunk combine to form the lateral cord
Posterior divisions of all trunks combine to form the posterior cord
Anterior divisions of the inferior trunk continues as the medial cord

Question 55

Draw the brachial plexus

Answer 55

see diagram

Question 56

What are the branches of the brachial plexus?

Answer 56

Musculocutaneous - branch from the lateral cord
Axillary - branch from the posterior cord
Median - formed by branches of the lateral and medial cords
Radial - branch of the posterior cord
Ulna - branch from the medial cord

Question 57

Tell me about the axillary nerve in relation to motor and sensory innervation and position in the brachial plexus (which cord and spinal fibres). How is it vulnerable to injury? How would you test for injuries with the axillary nerve? (motor and sensory)

Answer 57

Teres minor and deltoid
Skin over the upper lateral arm (inferior portion of deltoid- sergeant badge area）
Posterior cord
C5 and C6
Fracture of the surgical neck or a dislocation of the humeral head
Abduction of shoulders (raising them up)
No sensation in the skin over the upper lateral arm (above the deltoid)

Question 58

Tell me about the radial nerve in relation to motor and sensory innervation and position in the brachial plexus (which cord and spinal fibres). How is it vulnerable to injury? How would you test for injuries with the radial nerve? (motor and sensory)

Answer 58

Triceps brachii and all muscles in the posterior compartment of the forearm (extensors of wrist and digits)
Skin on the medial part of the dorsum of the hand. Skin over posterior arm and forearm
Posterior cord
C5 - T1
Fracture of the midshaft of the humerus.
Extension of elbows. Movement and sensation of wrist may also be impaired
No sensation in the skin on the dorsum of the thumb.

Question 59

Tell me about the musculocutaneous nerve in relation to motor and sensory innervation and position in the brachial plexus (which cord and spinal fibres). How is it vulnerable to injury? How would you test for injuries with the musculocutaneous nerve? (motor and sensory)

Answer 59

Three anterior muscles of the arm: Biceps brachii, brachialis, coracobrachialis
Region of skin over the lateral half of anterior forearm
Lateral cord
C5 - C7
Not in a place that is frequently injured

Question 60

Tell me about the median nerve in relation to motor and sensory innervation and position in the brachial plexus (which cord and spinal fibres). How is it vulnerable to injury? How would you test for injuries with the median nerve? (motor and sensory)

Answer 60

Muscles in the anterior forearm (flexors of wrist and digits), innervates small muscles of the thumb
Skin over the lateral aspect of the palm of the hand and palmar surface of lateral digits
Lateral and medial cord
C6 - T1
Crosses anterior aspect of elbow in the cubital fossa - so fracture of the humerus or damage at the wrist due to carpal tunnel syndrome
Weakness or paralysis of thumb
No sensation in the skin of the lateral aspect of palm or lateral digits

Question 61

Tell me about the ulnar nerve in relation to motor and sensory innervation and position in the brachial plexus (which cord and spinal fibres). How is it vulnerable to injury? How would you test for injuries with the ulnar nerve? (motor and sensory)

Answer 61

Most of the small muscles in the hand (vital for fine movements of digits)
Skin over the medial aspect of the hand and palmar surface of medial digits
Medial cord
C8 - T1
Most injuries occur behind the medial epicondyle (being superficial in that region)
Loss of coordination of fingers
No sensation in the medial aspect of the palm of the hand or the medial digits

Question 62

What is the most catastrophic type of brachial injury?

Answer 62

When the 5 roots of the brachial plexus are injured as it effectively denervates the whole upper limb.

Question 63

Where does the biceps brachii lie? Where do its heads attach? Where do the heads converge?

Answer 63

It lies most superficially in the anterior arm.
It has 2 heads. The long head attaches to the supraglenoid tubercle and the short head to the coracoid process.
The two heads converge via a single tendon onto the radial tuberosity of the radius. The tendon of the long head pierces the capsule of the shoulder joint and helps to stabilise the shoulder joint.

Question 64

Is the biceps a flexor or extensor? What of. Does it help with supination or pronation of the arm when the elbow is flexed?

Answer 64

It is a flexor of the elbow (also contributes to flexion of the shoulder)
It aids with supination of the arm when the elbow is flexed (turning screwdriver)

Question 65

Where does the brachealis lie? What is it attached to? Is the brachealis a flexor or extensor? What of

Answer 65

It lies deep to the biceps brachii.
Proximally, it is attached to the anterior aspect of the lower half of the shaft of the humerus. Distally, it crosses the elbow joint to insert on the ulna tuberosity.
It is a flexor of the elbow joint. (means it crosses the elbow joint)

Question 66

Where is the coracobrachialis found? What is it attached to? Is it a flexor or extensor? What of.

Answer 66

In between the brachialis and the medial head of the triceps.
It attaches proximally to the coracoid process of the scapula and distally to the medial aspect of the middle part of the humerus.
It is a weak flexor of the shoulder joint

Question 67

What is the cubital fossa and what are the 3 borders?

Answer 67

It is the region anterior to the elbow joint.
It is triangular shaped with 3 borders
Lateral border: Brachioradialis (posterior forearm muscle)
Medial border: pronator teres (anterior forearm muscle)
Superior border: (imaginary line) drawn between the medial and lateral epicondyles.
Apex is just the most distal.

Question 68

What can be found in the cubital fossa?

Answer 68

The tendon of the biceps brachii
Bicipital aponeurosis
Brachial artery
Median and radial nerve
Superficial veins

Question 69

What is the bicep tendon?

Answer 69

It is the tendon that is palpable in the cubital fossa
A bicep hammer can be used to examine bicep reflex

Question 70

What is a bicipital aponeurosis? What is its function?

Answer 70

A fascial extension of the biceps tendon. It functions to separate the superficial veins from the brachial artery and the median nerve.

Question 71

Where does the brachial artery lie in regards to the bicep tendon? How does the brachial artery flow e.g. what is the path of it since subclavian artery becomes axillary artery which becomes brachial artery.

Answer 71

The brachial artery lies medial to the bicep tendon in the cubital fossa
It is easily palpable and it bifurcates to form the radial and ulnar arteries
It is possible for the brachial artery to be punctured during cannulation and venepuncture (so extra care must be taken)

Question 72

Where does the median nerve lie, what is it medial to? Does it innervate the muscles of the arm, forearm or hand?

Answer 72

It lies medial to the brachial artery
It does not innervate muscles of the arm but travels through the anterior compartment of the arm and the cubital fossa to get to the anterior forearm and hand.

Question 73

Where does the radial nerve pass?

Answer 73

It passes through the lateral aspect of the cubital fossa and lies deep to brachioradialis.