Anatomy of the Upper Limbs

Question 1

How many bones and muscles are there in the Upper Limb?

• main innervation structure

Answer 1

• 32 bones
• 57 muscles
• the brachial plexus

Question 2

What makes up the Pectoral girdle?

Answer 2

• the scapula and the clavicle

Question 3

Label this diagram - scapula humerus

Answer 3

• the dotted lines indicate the anatomical (superior) and surgical (inferior) neck of the
  
  • the anatomical neck is at the glenoid fossa
  • the surgical neck is more prone to injury/breaks

Question 4

Label this diagram - radius ulna

Answer 4

Question 5

What is the difference between tubercles and tuberosities?

Answer 5

• tuberosity are rough larger protrusions from the bone
• tubercles are smaller rounder and often sit at the head of the bone

Question 6

What are the joints of the upper limb and what movement can they do?

(7)

Answer 6

• Glenohumeral
  
  • extension/ flexion
  • abduction/ adduction
  • circumduction
  • lateral and medial rotation
• Elbow
  
  • flexion/ extension
  • pronation and supination
• Radiocarpal joint
  
  • abduction/adduction (radial and ulnar deviation)
  • circumduction
• Midcarpal (not much movement)
• Carpometacarpal (saddle joint) - lots of movement
• Metacarpophalangeal
  
  • abduction/ adduction (spreading your fingers)
  • flexion/extension
• Interphalangeal
  
  • flexion extension

Question 7

What are the functional compartments of the upper limb?

Answer 7

• Flexor compartments - on the anterior
• Extensor compartments - on the posterior

Question 8

What are the attachment muscles of the upper limb to the trunk

Answer 8

• Pectoralis major/ minor
• Serratus anterior
• Trapezius
• Latissmus dorsi

Question 9

OrIn of the Serratus anterior

• movement

Answer 9

• protractor, and stabilises the shoulder
• ​Origin: the upper 8 ribs
• Insertion: Medial edge of the scapula

Question 10

OrIn of the Deltoid

• movement

Answer 10

• abduction, anterior part: flexion, medial rotation, posterior part: extension lateral rotation
• ​Origin: Spine of the scapula, the Acromion, lateral part of the Clavicle
• Insertion: Deltoid tuberosity (this sits on the lateral side halfway down the humerus)

Question 11

OrIn of the Biceps Brachii

• movement

Answer 11

• flexor of humeral joint and flexor of the forearm at elbow joint
• ​Origin: Coracoid process (short head)
• Origin: above the Glenoid fossa (long head)
• Insertion:Radial tubersoity

Question 12

OrIn of the Brachialis

• movement

Answer 12

• flexor of the forearm at the elbow joint
• ​Origin: Distal end of the humerus
• Insertion: Ulna tuberosity

Question 13

OrIn of the Triceps brachii

• movement

Answer 13

• extension
• ​Origin: Glenoid fossa (long head)
• Origin: Lateral side of the humerus (lateral)
• Origin: Medial side of he humerus (medial)
• Insertion: Olecranon (back of the elbow)

Question 14

OrIn of the Brachioradialis

• movement

Answer 14

• flexion of the forearm at the elbow when you are half pronated (moves glass towards your mouth)
• ​Origin: lateral side of the Humerus
• Insertion: Radial Styloid process

Question 15

OrIn of the Coracoidbrachialis

• movement

Answer 15

• flex arm at the glenohumeral joint
• ​Origin: Corachoid proces
• Insertion: Proximal part of the shaft of the humerus

Question 16

What muscles in the forearm largely cause flexion and extension of the wrist and digits?

Answer 16

• the Medial epicondyle is the origin of the muscles in the anterior part of the forearm that cause flexion
• the Lateral epicondyle is the origin of the muscles in the posterior part of the forearm that cause extension

Question 17

OrIn of the Pectoralis major & Minor

• movement

Answer 17

Major- adductor, flexor, medial rotator of the glenohumeral joint

• ​Origin: the sternum and the medial portion of the clavicle, and the costal cartilages,
• Insertion: the lateral lip of the bicipital groove (intertubercular sulcus) sits between the greater and lesser tubercle of the humerus

Minor- protractor

• Origin: Ribs 3,4,5
• Insertion: Coracoid process of the scapula

Question 18

What are the muscles of the thumb and the pinkie finger that cause?

Answer 18

• Thenar muscles (thumb)
• Hypothenar muscles (pinkie)

Question 19

What are the curvatures of the vertebral column?

• what are their significance?

Answer 19

• Kyphoses - primary curvatures (fetal)
  
  • thoracic and sacral
• Lordoses - secondary curvatures (childhood)
  
  • cervical
  • lumbar
• they allow bipedalism, provide shock absorption and flexibility

Question 20

What conditions are associated with the curvatures of the lumbar region?

Answer 20

• Scoliosis - when the vertebral column is curved laterally
• Hyperkyphoses - humpback
• Hyper excessive lumbar lordoses - seen in osteoporosis

Question 21

What are the ligaments of the vertebral column?

• what is their significance?

Answer 21

• Anterior longitudinal ligaments - prevent hyperextension
  
  • this can be torn if whiplash is experienced
• Posterior longitudinal ligaments and ligamentum flava prevent hyperflexion
  
  • also have the supraspinous ligaments and interspinal ligaments that resist hyperflexion
• they reinforce and stabilize joints

Question 22

What are the intervertebral joints and discs

• what is clinical relevant about the discs

Answer 22

• Intervertebral joints are for weight-bearing and for strength
  
  • these are secondary cartilaginous joints - joint surfaces are separated by fibrocartilage –> the intervertebral discs
• the discs are important for shock absorption
  
  • disc thickness increases as you move down the vertebral column
• they have a semi-fluid core: nucleus pulposus this absorbs compression
• the nucleus pulposus is surrounded by rings of fibre cartilage - annulus fibrosus
  
  • ​the annulus fibrosis binds each of the body’s vertebrae together
• these discs can protrude or you can have nucleus pulposus herniation (from lifting heavy objects) –> impinge on nerves

Question 23

Explain the various facet joints of the vertebral column and explain the movement they allow

• clinical relevance

Answer 23

these are synovial joints

• Cervical : flexion/ extension/ rotation
  
  • slight slope
• Thoracic: rotation only
  
  • near-vertical
• Lumbar: flexion-extension only
  
  • wrapped
• back pain may be caused by degeneration of these joints

Question 24

Explain the general division of the back muscles

Answer 24

• Extrinsic muscles: they move the upper limbs/ribs
  
  • superficial and intermediate
• Intrinsic muscles: postural/move the vertebral column
  
  • Deep
• they are separated by the thoracolumbar fascia

Question 25

What are the Superficial muscles of the back?

Answer 25

* Trapezius: rotates the scapula * Latissmus dorsi: adducts/ extends/ medial rotation of the arm * Levator scapulae: elevates the scapula * Rhomboids (minor and major: retracts the scapula

Question 26

OrIn of the Trapezius - movement

Answer 26

* movement and rotation the scapula. can be separated into * Upper fibres: elevation of the scapula * Middle fibres: retraction (draws scapula backwards) * Lower fibres: depression of the scapula * ​Origin: the cervical and thoracic spinous processes * Insertion: spine of the scapular acromion and the lateral portion of the clavicle

Question 27

OrIn of the Latissmus dorsi - movement

Answer 27

- **_adducts_**/extends/ medial rotation of the arm * ​Origin: thoracolumbar fascia * Insertion: bicipital groove (the intertubercular sulcus that sits between the greater and lesser tubercles of your humerus)

Question 28

OrIn of the Levator Scapulae - movement

Answer 28

- elevates the scapula * ​Origin: upper cervical vertebrae * Insertion: superior angle of the scapula

Question 29

OrIn of the Rhomboids - movement

Answer 29

- retracts the scapula * ​Origin: lower cervical C7 - T5 * Insertion: medial border of the scapula

Question 30

What are the Deep muscles of the back?

Answer 30

- they are involved with posture and movement of the vertebral column, they sit within a groove either side of the spinous processes * Splenius - most superficial mainly in the neck muscles​ * Erector spinae - main group​ * Multifidus - very deep

Question 31

Explain the following about eh Erector spinae muscles - location - it's 3 muscle blocks - OrIn - movements

Answer 31

- sits within the grooves between the spinous processes and angles of the ribs - produces extension/ lateral flexion /rotation of the vert. column Made up of the medial to lateral : **Spinales, Longissmus, Iliocastalis** * ​Origin: Erector spinae aponeurosis * Insertion: S - spinous processes, L- transverse process, I - the ribs

Question 32

OrIn of the Multifidus - movement

Answer 32

- extension/ rotation/ _stabilizes the vertebral column_ * ​Origin: Sacrum, Erctor spinae aponeurosis * Insertion: Spinous process

Question 33

What is the nerve supply of the Extrinsic muscles?

Answer 33

Anterior primary ramus _- mainly from the cervical rami_ ***_apart from the trapezius which i ssupplied by the accessory nerve (CNXI)_***

Question 34

What is the nerve supply of the Intrinsic muscles?

Answer 34

Posterior primary ramus

Question 35

Which arteries supply the upper limbs? - where do they branch from?

Answer 35

the Subclavian arteries - Right subclavian artery form the brachiocephalic trunk - Left subclavian artery from the aorta

Question 36

Describe the journey of the subclavian artery and describe its divisions

Answer 36

* passes over the first rib through the scalene triangle formed by the rib and the scalene muscles * divided into three parts by the **scalenus anterior** * **​1st division medial to the muscle** * **​**Vertebral artery * Thyrocervical trunk (to thyroid cervical and scapular) * **2nd division is behind the muscle** * **​**Dorsal scapular artery * **3rd division is lateral to the muscle** * **​**Dorsal scapular artery

Question 37

Label this diagram

Answer 37

* the thyrocervical trunk also gives off a suprascapular artery which forms part of the anastomeses to the scapula

Question 38

Describe the journey of the Axillary artery and its divisions - when does it become the axillary artery?

Answer 38

* Axillary artery begins when the subclavian artery crosses the outer border of the first rib * It's divided into three parts by pectoralis minor * **1st Medial to muscle** * **2nd Behind muscle** * **​**the first and second parts are closely associated with the brachial plexus * **3rd Lateral to muscle** * Ends at the lower border of the **teres major**, where it becomes the brachial artery

Question 39

What are the branches of the third part of the Axillary artery? - label the diagram - what is the clinical relevance

Answer 39

* the ant/post circumflex humeral arteries are at risk of rupture if the humerus is fractured

Question 40

Describe the journey of the brachial artery and its divisions

Answer 40

* remains superficial through the arm * supplies the flexor muscles * has a large branch - **Profunda brachii artery** * **​**passes posterior to the humerus through the *_spiral/radial groove_* * _this supplies the extensor muscles of the (triceps)_ * contributes to anastomosis around the elbow * Divides in the **_cubital fossa_** into the * Radial artery * Ulnar artery

Question 41

# Profunda brachii artery Label this diagram

Answer 41

Question 42

Describe the journey of the Radial artery

Answer 42

* comes from the brachial artery at the **cubital fossa** and travels on the _lateral side of the forearm_ * it's the smaller of the two terminal brachial branches * covered by the brachioradialis muscle * it travels to the hand where it forms a **deep palmer arch** deep relative to the long flexor tendons * at the wrist it winds around the dorsum of the hand * ​travels through anatomical snuff box * pierces through the 1st dorsal interosseous muscle (allows abduction - spread the index finger) * travels to the palmer aspect of the hand where it forms the deep arch and anastomoses with the ulnar artery on the medial side of the hand

Question 43

Describe the journey of the Ulnar artery

Answer 43

* comes from the brachial artery at the **cubital fossa** and travels on the medial _side of the forearm_ * it's the larger of the two terminal brachial branches * covered by the **_flexor carpi ulnaris muscle_** * It has a deep branch: **common interosseous artery** anterior and posterior branch which site either side of the interosseous membrane which hold the ulnar and radius together * it travels to the hand where it forms a **superficial** **palmer arch** relative to the long flexor tendons * eventually anastomoses with the radial artery​

Question 44

Give an overview of venous return in upper limbs

Answer 44

* it's variable but all drain into the axillary vein into the subclavian vein * can be dived into the deep and superficial veins * **Deep:** paired veins- follows the arteries- venae comitantes * **Superficial:** * _Cephalic vein_ which travels on the lateral aspect of the arm/ forearm * _Basilic vein_ which travels on the medial aspect of the arm/ forearm

Question 45

Label this diagram

Answer 45

Question 46

Give an overview of the lymphatic drainage of the upper limb

Answer 46

* relatively few lymph nodes in the upper limb * Cubital nodes (sits next to the basilic vein) * Deltopectoral node (sits next to the cephalic vein) * **Axillary nodes** (sits next to the axillary vein) * ​this is where they drain to

Question 47

What is the nerve supply of the upper limb?

Answer 47

Brachial plexus - carriers motor, sensory and sympatheric axons

Question 48

What are the overall divisions of the brachial plexus?

Answer 48

- Roots --\> Trunks --\> Divsions --\> Cords --\> Terminal branches

Question 49

What are the Roots of the brachial plexus?

Answer 49

* they are ventral primary rami of C5- T1 * they exit between the intervertebral discs * they supply motor innervation

Question 50

What are the motor functions/innervations from the motor axons in the Brachial plexus Roots?

Answer 50

* **C5** - Arm abductor (Deltoid) * **C6** - Forearm flexors (Biceps) * **C7** - Forearm extensors (Triceps)/ Wrist flexors/extensors (curling fingers) * **C8** - Digit flexors/extensors * **T1** - Intrinsic hand muscles (spreading fingers)

Question 51

What are the Trunks of the Brachial plexus

Answer 51

* Roots form trunks * Superior: C5 + C6 * Middle: C7 * Inferior trunk: C8 + T1 * Trunks pass through the scalene triangle * formed from the first rib and the anterior and middle scalene muscles * These trunks form divisions as they pass over they leave the scalene triangle

Question 52

What are the Divisions of the Brachial plexus - which cords do they go on to form

Answer 52

- Divsions are the trunks dividing into anterior and posterior divisions * Anterior: axons to **flexor compartments** * forms lateral and medial cords * Posterior: axons to **extensor compartments** * forms posterior cord

Question 53

What are the Cords of the Brachial plexus? - location - terminations

Answer 53

* Cords formed from Divisions of the brachial plexus * Lateral Cord - from the anterior division * terminates as the **Musculocutaneous nerve** which is the * Posterior Cord - from the posterior division * terminates as the **Radial nerve** and **Axillary nerve** * Medial Cord - from the anterior division * terminates as the **Ulnar nerve** * the medial cord and lateral cord form the **Median nerve** which has lateral and medial sides respectively * they lie beneath the **pectoralis minor** * *cords named in relation to the axillary artery*

Question 54

What is the Musculocutenous nerve? - function

Answer 54

* the lateral part of the Median nerve formed from the median cord * pierces through the Coracobrachialis muscle and sits between the brachialis and the biceps brachii muscle (supplies these muscles) * **Motor supply: Anterior muscles of the arm** * **Sensory supply - Lateral skin of forearm** * moves out from under the biceps to the lateral side of the elbow and _changes_ to become the **lateral cutaneous nerve to the forearm** (hence the name first it innervates muscles then it becomes a cutaneous nerve)

Question 55

What is the journey of the Median nerve? - innervation/action

Answer 55

* formed from the medial and lateral cords * travels down the medial side of the arm along with the brachial arteries * passes into the forearm through the _cubital fossa_ and goes into the anterior flexor compartment between the flexor muscles * _innervates all the flexor muscles apart from_ **flexor carpi ulnaris** and the two medial bellies of **flexor digitorum profundus** * through the carpal tunnel to give motor and sensory innervation to the hand. * **Motor – Anterior forearm and lateral hand (the intrinsic muscles mainly the thumb)** * **Sensory – Skin on the lateral palm hand, d1,2, 3 + half d4**

Question 56

What is the Ulnar nerve? - innervation/action

Answer 56

* formed from the medial cord * travels behind the elbow through the **cubital tunnel** and travels along the medial side and sits **flexor carpi ulnaris muscle** and the **ulnar artery** * **​**it innervates the _flexor carpi ulnaris muscle_ and the medial two bellies of the **_flexor digitorum profundus_** * _does not pass through the carpal tunnel_ * **Motor – Medial side of the anterior forearm and hand** * **Sensory – Medial hand + half d4 + d5**

Question 57

What is the journey of the Radial nerve? - innervation/action

Answer 57

* formed from the posterior cord * travels through the **spiral groove of the humerus** * It innervates the extensor compartment muscles in the arms - **triceps** * divides into a **Deep branch** (motor supply) and a **Superficial branch** (sensory supply) * deep branch goes into the posterior part of the forearm where it innervates the **extensor muscles** * superficial branch travels under the brachioradialis muscle to the hand * **Motor – Posterior side of the forearm and arm** * **Sensory – Posterior arm and forearm + lateral dorsum of the hand**

Question 58

Label this Diagram

Answer 58

Question 59

What is the Axiallry nerve? - journey - innervation/action

Answer 59

* formed from the posterior cord * travels through the quadrangular space * Motor supply: deltoid and trees minor * Sensory: Lateral aspect of the arm (military badge area of the arm)

Question 60

Label this diagram - what are they collectively know as?

Answer 60

Terminal branches of the Brachial plexus

Question 61

What are the dermatome regions for the upper limb and the cutaneous innervation by terminal branches? - what is the clinical significance of these regions?

Answer 61

* Altered sensation in the region of a dermatome indicates damage to _specific spinal nerve of spinal cord segment_ (i.e. _proximal nerve injury_) * Altered sensation in one of the cutaneous areas indicates damage to a more _distal nerve segment_ (i.e. _distal nerve injury_)

Question 62

What are the branches of the Lateral cord? - terminates as?

Answer 62

* has one branch the **Lateral pectoral nerve** * terminates as the **Musculocutaneous nerve** and the lateral part of the **Median nerve**

Question 63

What are the branches of the Medial cord? - terminates as

Answer 63

* **medial pectoral nerve, cutanous nerves** to the medial side of the arm and forearm * terminates as the medial part of the **median nerve** and the **ulnar nerve**

Question 64

What are the branches of the Posterior Cord/ where do they innervate? - terminates as?

Answer 64

* has three branches that innervate the posterior axillar * terminates as the **Radial nerve** and the **Axillary nerve**

Question 65

What are the skeletal components of the clavicle? - what are the two joints? - clinical significance?

Answer 65

* _Clavicle_ * _Scapula_ * Humerus - _form the pectoral girdle_ * Glenohumeral joint * Acromioclavicular joint * synovial plain joint that can be easily dislocated

Question 66

Label this diagram

Answer 66

Question 67

Label this diagram

Answer 67

Question 68

Describe the location and function of the Coraclavicular and Coracoacromial ligaments - clinical significance?

Answer 68

* Coracoclavicular * Two parts * Major stabilizing ligament * Coracoacromial * Forms arch - forms a space for the head of the humerus * *the tendon of the supraspinatus muscle runs below this arch - this can become trapped* * Provides support for head of humerus * Prevents superior dislocation

Question 69

Describe the location and function of the Glenohumeral joint

Answer 69

* Highly mobile ball and socket joint * Abduction/Adduction * Flexion/Extension * Circumduction * Lateral/Medial rotation

Question 70

What muscle produces abduction of the arm? - nerve supply?

Answer 70

* **Performed by Deltoid** * Origin: Spine of scapula + acromion + clavicle * Insert: Deltoid tuberosity * **Supplied by Axillary nerve** * Posterior fibres cause: * Extension + lateral rotation * Anterior fibres cause: * Flexion + medial rotation * when all the fibres contract they cause * Abduction

Question 71

What muscle(s) produce adduction of the arm?

Answer 71

* Latissimus dorsi, * Pectoralis major - gravity as well

Question 72

What additional role does the scapula have in the abduction and adduction of the arm?

Answer 72

* rotation of the scapula increases the range of movement past what the glenohumeral joint can facilitate * Abduction after 90 degrees: scapula is rotated by * **Upper + lower fibres of the trapezius** * **Serratus anterior** * Adduction: scapula is rotated by * **Levator scapulae** and **Rhomboids**

Question 73

Label this diagram

Answer 73

Question 74

What muscle(s) are involved in the flexion of the arm?

Answer 74

* Biceps brachii * Coracobrachialis * the anterior fibres of the deltoid

Question 75

Label this diagram

Answer 75

Question 76

What muscle(s) produce extension in the arm?

Answer 76

* Long head of the Triceps * Posterior fibres of the deltoid * Latissimus dorsi

Question 77

What factors increase stability in the Glenohumeral joint? - clinical significance? (5)

Answer 77

1. Coracoacromial arch: **_prevents superior dislocation_** 2. Glenohumeral ligaments: **_support anterior of joint_** 3. Deepening of glenoid fossa by the **glenoid labrum** 4. Long heads of biceps (above) and triceps (below): 5. Tendons of rotator cuff muscles * the glenohumeral joint is the most frequently dislocated joint * anterior dislocation is common- the humeral head descends inferiorly and ends up anterior

Question 78

Label this diagram

Answer 78

Question 79

How do the long head of the biceps and triceps stabilise the glenohumeral joint?

Answer 79

* the origin of the long head of the biceps is the **supraglenoid tubercle** * **​**held in place by the transeverse humeral ligament which goes across eh greater and lesser tubercles * the origin of the long head of the triceps is the **infraglenoid tubercle** **-** this forms a **Splint joint** above and below the joint holding the head of the humerus against the glenoid fossa

Question 80

What are the muscles of the rotator cuff muscles and what is their action? - clinical significance?

Answer 80

* ****_S_**upraspinatus, **_I_**nfraspinatus, **_T_**eres minor, **_S_**ubscapularis** * they insert on the humerus close to the glenohumeral joint * the tendons of the muscles fuse with the joint capsule and * forms a cuff which ***_SITS_*** around the joint on all sides _except inferiorly_ * _​_hence why anterior dislocation is the most common - as the humerus is pulled in front of the joint

Question 81

Label this diagram

Answer 81

Question 82

What are the origins of the rotator cuff muscles?

Answer 82

* Supraspinatus: * supraspinous fossa of the scapula * Infraspinatus: * infraspinous fossa of the scapula * Teres minor: * lateral border of the scapula * Subscapularis * subscapular fossa of the scapula (the anterior aspect fo the scapula)

Question 83

Label this diagram

Answer 83

Question 84

What are the insertions of the rotator cuff muscles?

Answer 84

* Supraspinatus, Infraspinatus,Teres minor: * greater tubercle * Subscapularis * lesser tubercle

Question 85

What is the function of the rotator cuff muscles?

Answer 85

- _together they stabilise the humeral head on to the glenoid fossa - **concavity compression**_ * Supraspinatus: * initiates abduction * Infraspinatus: * lateral rotation * Teres minor: * lateral rotation * Subscapularis * medial rotation

Question 86

What is the significance of Teres Major with the rotator cuff muscles? - OrIn?

Answer 86

* Performs medial rotation * Stabilises the head of the humerus onto the glenoid fossa during abduction * called **_eccentric contraction_** * Origin: inferior angle of the scapula * Insertion: Medial lip of the bicipital groove of the intertubercular sulcus

Question 87

What injuries can happen to the rotator cuff?

Answer 87

* Supraspinatus impingement- due to repetitive overhead activities * common in athletes - throwers * Supraspinatus most commonly injured * due to limited space for tendon under the coracoacromial arch * ultrasound is taken to identify the condition

Question 88

What is the blood supply of the shoulder region?

Answer 88

* Supplied from the **Scapula anastomosis** * tributaries from the **subclavian** and **axillary** arteries

Question 89

Label this diagram

Answer 89

Question 90

What is the nerve supply of the shoulder?

Answer 90

* from the **brachial plexus** * the ***Suprascapular nerve*** (from the superior trunk of the brachial plexus) innervates the * _Supraspinatus_ and _Infraspinatus_ ( rotator cuff muscles) * the ***Posterior cord*** * ***Upper/ lower subscapular nerves-*** _Subscapularis, Teres major_ * ***Thoracodorsal nerve**-* _Latissmus dorsi_ * ***Axillary nerve***- _Deltoid and teres minor_ * ***Radial nerve-*** _Triceps brachii_

Question 91

What muscles do the branches and terminals of the Posterior cord innervate in the shoulder?

Answer 91

* Upper/ lower subscapular nerves- **Subscapularis, Teres major** * Thoracodorsal nerve (the middle branch) - **Latissmus dorsi** * Axillary nerve (travels through the quadrangular space)- **Deltoid and teres minor** * Radial nerve- **Triceps brachii**

Question 92

Label this diagram - what do these structures form?

Answer 92

Quadrangular space

Question 93

What is the Quadrangular space - what is the clinical significance?

Answer 93

* formed by * _long head of the triceps_ - medial border * _teres minor_ - superiorly * _teres major_ - inferiorly * _humerus_ - lateral border * the axillary nerve and posterior circumflex humeral artery travel through there * axillary nerve innervates the deltoid, there minor and the badge area * if the surgical neck of the humerus is fractured it can damage these structures * they will struggle to abduct their arm as the axillary nerve is damaged and their deltoid won't be innervated * sensation will also be lost in that badge area

Question 94

What are the branches and terminals of the Medial Cord? - innervations in the arm?

Answer 94

* Median nerve * Ulnar nerve * Medial pectoral nerve - **P_ectoralis major/ minor_** * Medial cutaneous nerves to arm and forearm

Question 95

What are the branches and terminals of the Lateral Cord? - innervations in the arm?

Answer 95

* Musculocutaneous nerve - **_Arm flexors_** * Median nerve - * Lateral pectoral nerve - **P_ectoralis major_**

Question 96

Label this diagram

Answer 96

Question 97

Label this diagram? - what does it show?

Answer 97

shows * the Synovial hinge joint (elbow joint) * Synovial pivot joint (proximal radioulnar joint)

Question 98

What range of motion does the Synovial Hinge Joint allow? - where is it

Answer 98

* the elbow joint * flexion and extension of the forearm

Question 99

What range of motion does the Synovial Pivot Joint allow? - where is this joint?

Answer 99

* it is the proximal radioulnar joint * it allows supination and pronation of the forearm

Question 100

Label this diagram - what do these structures do?

Answer 100

* Ligaments stabilise and strengthen the joint

Question 101

What are the two compartments of the forearm?

Answer 101

* Anterior/ flexor compartment * contains mainly flexor muscles * has superficial, intermediate and deep muscles * Posterior/ extensor compartment * contains mainly extensor muscles * has superficial and deep muscles

Question 102

What are the different layers of the anterior/flexor compartment of the forearm? - what actions do each layer create?

Answer 102

* Superficial muscles: * 3 Flexors of wrist (carpi) * 1 Pronator * Intermediate muscles: * 1 Flexor of digits 2-5 (digitorum) * Deep muscles: * 1 Flexor of digits 2-5 (digitorum) * 1 Flexor of thumb (pollicis) * 1 Pronator

Question 103

What are the muscles of the Superficial layer of the Anterior compartment forearm? - what is there action - what is the clinical relevance of the origin of these muscles?

Answer 103

- Pronator teres - Flexor carpi radialis - inserts on the 2 and 3rd metacarpal - Palmaris longus - Flexor carpi ulnaris- inserts on the 5th metacarpal * theses muscles flex our wrist * ***Golfers elbows/ Medial Epicondylitis*** is caused by inflammation at common flexor origin due to overuse/ excessive gripping

Question 104

Label this diagram - where are these muscles found?

Answer 104

* the superficial layer of the anterior compartment of the forearm

Question 105

What are the muscles of the Intermediate layer of the anterior compartment of the forearm - which structures does its action impact?

Answer 105

- Flexor digitorum superficialis acts on **digits 2-5** * causes flexion * in digits the carpus * the middle metacarpal phalangeal joints (nuckles) * the proximal interphalangeal joints

Question 106

What are the muscles of the Deep layer of the anterior compartment of the forearm - which structures does its action impact?

Answer 106

- Flexor pollicis longus - digits 1 * inserts on the distal phalanx of the thumb - pronator quadratus - Flexor digitorum profundus * cause flexion * the distal phalanx * flex our wrist * the metacarpal joints of 2-5 * flex the proximal and distal interphalangeal joints

Question 107

Label this diagram? - where are these muscles, what are their action?

Answer 107

* muscles of the deep layer of the anterior compartment of the forearm * flexion in the distal phalanges digits 1-5

Question 108

What are the different layers of the posterior/extensor compartment of the forearm? - what actions do each layer create?

Answer 108

- mainly extonsor muscles * Superficial muscles: * 3 Extensors of wrist (carpi) * 1 Extensor of digits 2-5 (digitorum) * 1 Accessory extensor to digit 5 (digiti minimi) * Brachioradialis and anconeus * Deep muscles: * 2 Extensors of thumb (pollicis) * 1 Abductor of thumb (pollicis) * 1 Accessory extensor to digit 2 (indicis) * 1 Supinator

Question 109

What are the muscles of the superficial layer of the posterior compartment of the forearm? - which structures does its action impact? - what is the clinical significance of the muscle origin

Answer 109

- Extensor Carpi radialis longus/ brevis * origin of the supracondylar ridge * brevis from the CEO * inserts on the 2nd metacarpal * brevis on the 3rd metacarpal - Extensor digitorum * inserts on the wrist causing extension * inserts on digits 2-5 on the middle and distal phalanx - Extensor digiti minimi (accesory to extensor digitorum) - digit 5 - Extensor carpi ulnaris - extends our wrist * **Brachioradialis -** flexor when half pronated * **Anconeus**- stabilises the elbow * causes extension of the metacarpals, middle phalanges and distal phalanges * ***Tennis elbow/ lateral epicondylitis*** - inflammation of the tendons at the Common Extensor Origin due to overuse/ forceful extension

Question 110

Label this diagram - where are these muscles found, what do they do?

Answer 110

* found in the superficial layer of the posterior compartment of the forearm * they cause flexion at the metacarpals, middle and distal phalanges

Question 111

Label this diagram - what is the action of the muscles?

Answer 111

* **Brachioradialis** acts as a flexor when half pronated * **Anconeus** stabilises the elbow

Question 112

What are the muscles of the Deep layer of the Posterior compartment of the forearm? - which structures does its action impact?

Answer 112

- Supinator - Abductor pollicis longus \* * inserts on digit 1 metacarpal - Extensor pollicic brevis and longus \* * brevis on proximal phalanx * longus on distal phalanx \* part of the anatomical snuff box - Extensor indicis (accessory to extensor digitorum) * cause extension in distal phalanx digits 2

Question 113

Label this diagram - where are these muscles found, what is their action?

Answer 113

* found in the deep layer of the posterior compartment of the forearm * causes extension in the first metacarpal the proximal and distal phalanx of digits 1-2

Question 114

Which muscles perform wrist abduction and adduction?

Answer 114

Performed by the carpi muscles * _Abduction (radial deviation):_ * Flexor carpi radialis * Extensor carpi radialis (longus + brevis) * _Adduction (ulnar deviation):_ * Flexor carpi ulnaris * Extensor carpi ulnaris Together muscles splint the wrist to allow fine movements of the hand

Question 115

What muscles are involved in pronation and supination of the forearm?

Answer 115

_Supination_ * Biceps brachii * Supinator teres - superficial/ deep the radius and ulnar are parallel _Pronation_ * pronator teres * pronator quadratus - the radius rotates over the ulnar

Question 116

Review the structures within the carpal tunnel and the flexor retinaculum - what is the purpose of the flexor retinaculum?

Answer 116

* prevents bowing of tendons * \* the median nerve is the only nerve that passes through the carpal tunnel

Question 117

Review the Extensor retinaculum - what is its purpose?

Answer 117

* prevents bowing of tendons * separates tendons into compartments * which are covered by a synovial sheath keeping the tendons lubricated

Question 118

Where do the long tendons insert in the hand?

Answer 118

* they are tendons for digits 2-5 * **Flexor digitorum profundus** into the _distal phalanx_ * **Flexor digitorum superficialis** into the _middle phalanx_ * **Extensor profundus** into the _middle + distal phalanx_ the superficial splits allowing the profundus tendon to pass through to the distal phalanx

Question 119

Label this diagram - what is the name of the area?

Answer 119

- the cubital fossa

Question 120

Label this image and give the clinical significance of these structures.

Answer 120

* clinically significant in venepuncture

Question 121

How does the brachial artery divide at the cubital fossa? - where do the divisions travel?

Answer 121

divides into the * **Radial artery** * Under brachioradialis * **Ulnar artery** * Under flexor carpi ulnaris * Gives off common interosseous these anastomoses around the elbow joint

Question 122

Label this diagram

Answer 122

Question 123

Label this diagram, what does it show?

Answer 123

- shows divisions of the ulnar artery

Question 124

Label this diagram- what is the journey of this structure?

Answer 124

- the radial artery winds to the dorsum of the hand

Question 125

What is the clinical significance of the Median nerve? - supply?

Answer 125

* it causes carpal tunnel syndrome when the nerve is compressed * due to increased pressure in the carpal tunnel usually associated with trauma, obesity and pregnancy Motor: Anterior compartment muscles, except FCU/medial part of FDP, and the medial two bellies of flexor digitorum profundus Sensory: Lateral palm, including d1, d2, d3, ½ d4

Question 126

What is the clinical significance of the Ulnar nerve? - supply?

Answer 126

* when compressed causes Cubital tunnel syndrome. causes pain in the sensory areas Motor: FCU and medial part FDP, and intrinsic muscles of hand Sensory: Medial side of hand, including ½ d4 + d5

Question 127

Give an overview of the Radial nerves journey - branches and their journey

Answer 127

Enters forearm on lateral side under brachioradialis and divides into two branches: * **Superficial branch (sensory)** * Under brachioradialis * Winds round to dorsum of hand * **Deep branch - posterior interosseous nerve (motor)** * Passes through supinator muscle * Enters extensor compartment

Question 128

Label this diagram, what is the clinical significance of the main structure? - supply?

Answer 128

* the damage to the radial nerve can cause wrist drop, can't extend wrists Motor: Deep branch supplies posterior extensor compartment muscles Sensory: Superficial branch supplies dorsolateral aspect of the hand

Question 129

Label this diagram and what is the clinical significance?

Answer 129

Altered sensation in one of the above areas indicates damage to a more distal nerve segment

Question 130

Label this diagram - what is it showing? - clinical significance?

Answer 130

- the carpal bones - The scaphoid bone is most commonly fractured carpal bone - takes a long time for the bone to heal as there is poor blood supply to the proximal ends of the bone

Question 131

What are the joints in the hand? | (6)

Answer 131

Question 132

Give an overview of the Radiocarpal (wrist) joint - structure - action

Answer 132

* it's between the radius, disc and the first carpal row * it's a synovial joint * it's reinforced by ligaments * Ulnar and radial collateral ligaments (limits abduction/adduction) * Ligaments on the palmar/dorsal surfaces (limits extension/flexion * allows, flexion/extension, abduction/ adduction, circumduction

Question 133

Label this diagram

Answer 133

Question 134

Give an overview of the Carpometacarpal joint - structure - action

Answer 134

* they are plane joints with limited movement except for the **saddle joint** * saddle joint is between the trapezium and metacarpal of d1 * it enables _opposition_ of the thumb

Question 135

Give an overview of the Metacarpophalangeal joints - structure/ type of joint - action

Answer 135

* It is a _condylar joints_ * formed by deep transverse metacarpal ligaments * holds metacarpals together * apart from between digit 1 and 2 * allows flexion/ extension, abduction/ adduction

Question 136

Give an overview of the Interphalangeal joints - structure - actions

Answer 136

* it is a hinge joint * there are proximal and distal and interphalangeal joints * there are also between the proximal and middle phalangeal joints (dips and pips) * allows flexion and extension

Question 137

What is the Palmar aponeurosis - structure - clinical significance

Answer 137

* thickened deep fascia continuous with palmaris longus * triangular: formed of longitudinal fibres and transverse fibres * ***Dupuytren's contracture:*** caused by shortening or fibrosis of the longitudinal fibres * you can't straighten D4, D5 * heredetary, seen in older males

Question 138

Which digits do the long flexor tendons correspond to? (3) - what other structures are important as they go into the hand (3)

Answer 138

Question 139

Label this diagram - what is it showing?

Answer 139

* the long flexor tendons

Question 140

Review how the flexor tendons insert onto the digits - the fibrous digital sheath - clinical relevance

Answer 140

* the tendons enter the _fibrous digital sheath_ as they move into the palm of the hand (still held within a synovial sheath) * formed of alternating annular and cruciate ligaments all the way to the distal phalanx * the _annular ligaments_ are referred to as the pullies * tendons can become stuck/ trapped underneath these pullies * the _vinculae_ hold the main tendons up against the phalanges

Question 141

Match the extensor muscles of the posterior compartment to their attaching digits (6)

Answer 141

_Digits 2-5_ * Extensor digitorum * Extensor indicis * Extensor digit minimi _Digit 1_ * Extensor pollicis longus * Extensor pollicis brevis * Abductor pollicis longus

Question 142

Which structures form the Anatomical snuff box? (5)

Answer 142

* Abductor pollicis longus - inserts to the base of the first metacarpal * Extensor pollicis brevis - inserts to the base of the proximal phalanx * Extensor pollicis longus - inserts to the base of the distal phalanx * Scaphoid bone + Trapezium makeup the floor of the snuff box

Question 143

What structures are found in the Anatomical snuff box? - what is the clinical significance of the snuff box?

Answer 143

found on the floor * scaphoid: can be palpated if they have a scaphoid fracture - would experience tenderness * radial artery- can be used to feel the radial pulse

Question 144

What muscles insert on the extensor hoods? (2)

Answer 144

* lumbrical muscle * interosseous muscle

Question 145

What is the role of the Lumbricals muscle - what is its structure

Answer 145

* originate from tendons and insert on tendons * links the flexor to the extensor tendons * flexor digitoriu profundus tendons to the extensor hood * _Extends the interphalangeal joints_ and * Flexes MCP joints * digits 2-5 - it's on the radial side of their respective digits * aids in precision grip (hold pen/pinch)

Question 146

Which nerves innervate the Lumbricals muscles

Answer 146

* _Median nerve_ innervates muscles on d2+ medial side of d3 * _Ulnar nerve_ innervates muscles between d3-d4 and d4-5

Question 147

What is the role of Palmar Interossei muscles? - describe location/structure

Answer 147

* they sit between the metacarpals - unipennate muscles * attaches the metacarpals to the extensor hoods on d2,d4,d5 * facilitates _palmar adduction at the MCP joint_ * this is relative to d3 (they adduct towards the middle finger) * There is no palmar interossei for D1 or D3 * ​adduction in D1 is performed by the adductor pollicis muscle * _PAD-_ palmer adduction

Question 148

What is the role of Dorsal Interossei muscles - their location/ structure

Answer 148

* they sit between the metacarpals - bipennate muscles * attaches the metacarpals to the extensor hoods on d2,d3 (on either side),d4 * facilitates _dorsal abduction at the MCP joint_ * this is relative to d3 (they adduct towards the middle finger) * There is no dorsal interossei for D1 or D5 * ​abduction in D1 + D5 is performed by the _thenar_ and _hypothenar_ muscles * _DAB-_ dorsal abduction

Question 149

Label this diagram - what is the relevance of these structures?

Answer 149

* Flexor retinaculum is the origin of the thenar and hypothenar muscles * Thenar muscles - fine movement of the thumb * Hypothenar muscle - fine movement of the little finger

Question 150

Describe the structure of the Thenar muscle**_s_** (3) - what are their actions?

Answer 150

all originate from the flexor retinaculum * Opponens pollicis (deepest) * ​inserts into the first metacarpal * Abductor pollicis brevis\* * Flexor pollicis brevis\* * \* both insert into the proximal phalanx * allow _opposition_, _abduction_ and _flexion_ of the thumb respectively

Question 151

Describe the structure of the Hypothenar muscle**_s_** - what is their action?

Answer 151

all originate from the flexor retinaculum * Opponens digiti minimi (deepest) * ​inserts into the 5th metacarpal * Abductor digiti minimi\* * Flexor digiti minimi\* * \* both insert into the proximal phalanx of the 5th digit * allow opposition, abduction and flexion of the pinkie respectively

Question 152

What structure facilitates the adduction of the thumb? - describe its structure/ location

Answer 152

* **_Adductor pollicis_** * it is deep to the thenar muscles * it has an _oblique head_ * originates from the base of the 2nd and 3rd metacarpal + carpal bone * and a _transverse head_ * originates from the 3rd metacarpal - both heads insert onto the _proximal phalanx_ of digit 5

Question 153

Which arteries supply the hand?

Answer 153

* Radial and Ulnar artery * form a complex anastomosis around the hand

Question 154

What are 3 key blood structures in the hand?

Answer 154

* the **radial artery** found in the _anatomical snuffbox_ this forms the deep palmar arch * *mainly supplies D1 and 1/2D2* * the **deep palmar arch** which is _below the long flexor tendons_ * the **superficial palmar arch** which is _above the long flexor tendons_ * *ulnar artery mainly supplies 1/2D2 to D5*

Question 155

Label this diagram - where do these structures supply?

Answer 155

* 1/2 of D2 to D5

Question 156

Label this diagram - where do these structures supply?

Answer 156

* D1 and 1/2 of D2

Question 157

Label this diagram - what structure is this and what is the clinical significance? - where do these structures supply?

Answer 157

* Median nerve * **Recurrent branch** - thenar muscles * **Digital nerves** - * _lateral 2 lumbricals (d2 + d3)_ * _and sensory of D1 - 1/2 D4_ * passes through the carpal tunnel. if it is compressed can cause pain, pins and needles, numbness and tingling in the hand * _carpal tunnel syndrome_ * _the palmar branch is spared in carpal tunnel syndrome_ * so symptoms aren't felt on the palm

Question 158

Label this diagram - what structure is this and what is the clinical significance? - where do these structures supply?

Answer 158

* **Ulnar nerve:** passes through the _pisiform born and the hook of the hamate_ instead of the carpal tunnel * **Deep branch** * hypothenar muscles * interossei * medial 2 lumbricals * adductor pollicis * **Superficial branch**- * sensory 1/2 of D4 and D5 * Clawed hand due to ulnar damage at the wrist * D4 +D5 MCP joint extension, interphalangeal joint flexion is seen * this isn't seen if the ulnar nerve is injured at the cubbital tunnel as the medial two bellies of flexion digitorum profundus is not innervated so you don't see flexion of the digits

Question 159

What are structures in the hand are innervated by the Deep branch of the Ulnar nerve?

Answer 159

* hypothenar muscles * interossei muscles * medial 2 lumbricals (d3/d4 + d4/d5) * adductor pollicis

Question 160

Explain what causes a clawed hand and any variations you would see

Answer 160

* Clawed hand is due to ulnar damage at the wrist * it effects D4 and D5 * the medial two lumbricals are no loner innervated * so usually perform _flexion of the MCP joints and extension of the interphalangeal joints_ the * instead, we see MCP joint _extension_, interphalangeal joint _flexion_ is seen * due to the action of flexor digitourm profundus - flexion into our palm giving the clawed appearance * this isn't seen if the ulnar nerve is injured at the _cubital tunnel_ as the medial two bellies of flexion digitorum profundus are also not innervated as well as the intrinsic hand muscles * so you don't see flexion of the digits