Anatomical Areas

Question 1

Clinical link: Carpal tunnel syndrome

Mechanism and symptoms

Answer 1

Mechanism: Caused by entrapment or irritation of the median nerve within the carpal tunnel. Such as through thickening of the flexor retinaculum

Symptoms: Paresthesia in the median nerve distribution, wasting of the thenar muscles, reduced strength of grip, reduced thumb abduction; numbness in the thumb, middle and index fingers (not palm due to cutaneous branch).

Question 2

Clinical link: Blood supply of the hand - Allen’s Test

Answer 2

• Used to test the perfusion capability of the ulnar artery to the hand
• The both arteries and occluded. Pallour seen
• The ulnar artery is released.
• If perfusion is adequate then the hand will return to normal colour (flushing) in 5-15 seconds - positive
• If negative the radial artery should not be punctured for an arterial blood sample

Question 3

Palmar spaces and synoival sheaths: Describe the palmar spaces and synovial flexor sheaths of the hand.

Clinical relevance?

Answer 3

Infections may ‘jump’ between these spaces. Particularly important is the midpalmar space

☆Tenosynovial lining of flexor sheaths

Question 4

Elbow joint: Dislocation and annular joint subluxation

Answer 4

Dislocation: Commonly occurs in the posterior direction

Annular ligament: Surrounds the radius

• Function: Allows sliding of the ulnar on the radius and pivoting of the radius bone during supination and pronation
• Can be subluxed due to excessive force

Question 5

Fractures of the forearm: Describe Colle’s, Smith’s and Bennett’s fractures

Answer 5

Colle’s: Sees dorsal displacement of the distal fragment of the radius. Shortening and dorsal angulation seen

• FOOSH

Smith’s: Palmar displacement of the distal fragment of the radius. Shortening and volar angulation.

• Fall onto flexed wrist, direct blow to dorsal forearm

Bennett’s: Fracture of the carpometacarpal joint

• Forced abduction of the thumb

Question 6

Lower limb: Lateral compartment of the leg

Answer 6

Innervation: Superficial fibular nerve (L4-S3)

Muscles: Fibularis longus and brevis

Action: Eversion of the foot

Clinical relevance: Nerve injury may occur in neck of fibular fracture, sciatic nerve compression will also affect the compartment.

Inversion injuries can damage the muscle tendons and cause an avulsion injury of the 5th metatarsal

☆ The superficial fibular nerve and small saphenous vein pass posteriorly to the lateral malleolus

• Great saphenous vein passes anteriorly to the medial malleolus

Question 7

Scaphoid: Consequence of fractures and region for palpation

Answer 7

Fracture: Avascular necrosis may result as blood supply is provided in a distal to proximal fashion. A fracture in the middle of the scaphoid may disrupt this and avascularise the proximal portion

Palpation: The scaphoid bone can be palpated within the anatomical snuffbox

Question 8

Lower limb: Posterior compartment of the thigh

Answer 8

Innervation: Sciatic nerve (L4 - S3)

Muscles: Hamstring muscles (semimembranous, semitendinous and biceps femoris)

Action: Hip extension, knee flexion

Clinical relevance: The sciatic nerve may be impinged through vertebral disc herniation, at the sciatic notch, by piriformis

Ischial tuberosity avulsion fracture

Question 9

Upper limb: Dorsal scapular spaces

Answer 9

Quadrangular space: Axillary nerve

Triangular interval: Profunda brachii artery and radial nerve

Question 10

Pectoral girdle: Deltoid and pectoral muscles

Answer 10

Pectoralis major: Medial and lateral pectoral nerve

• Adducts, flexes and medially rotates the arm

Pectoralis minor: Medial pectoral nerve

Deltoid: Axillary nerve

• Abducts the arm (beyond the first 15 degrees of supraspinatus)

Question 11

Lower limb: Outline the landmarks of the pelvis

Answer 11

☆ The greater sciatic foramen is formed by the sacrospinous and sacrotuberous ligaments

☆ Piriformis muscle divides the greater sciatic foramen into an upper and lower region.

Upper sciatic foramen: Superior gluteal nerve, artery and vein

Lower sciatic foramen: All other vessels pass through this foramen

Question 12

Intervertebral foramen: Formation, patholgy

Answer 12

Formation: From the inferior vertebral notch of the superior vertebrae and the superior notch of the inferior vertebrae (of the pedicles)

Pathology: Narrowing of the intervertebral foramen

• Arthritis
• Spondylolisthesis
• Osteophyte growth (OA)

Question 13

Clinical link: Medial humeral epicondyle fracture and tunnel through which the associated nerve runs

Answer 13

• Can damage the ulnar nerve
• Cubital tunnel of the elbow
• Runs through Guyons Canal at the wrist

Question 14

Gluteal muscles

Answer 14

Gluteus maximus

Innervation: Inferior gluteal nerve (sacral plexus)

Action: Extends the thigh and lateral rotation

☆ Only active when force is required

Gluteus minimus and medius

Innervation: Superior gluteal nerve (sacral plexus)

Action: Abducts and medially rotates the thigh

Question 15

Lower limb: Sensory innervation

Answer 15

• Consider that the sensory innervation of the leg is suppled mostly by branches of the sciatic nerve

Question 16

Stability of the hip joint: Name the ligaments which contribute to the stabilty of the hip joint

Answer 16

• Iliofemoral
• Pubofermoral
• Ischiofemoral
• Ligamentum teres
  
  • Of the femoral head. Inserts into the fovea capitus. Important hip stabiliser.
  • Transmits a nutrient artery to the femoral head in infants

Question 17

Elbow joint: Name the ligaments of the elbow joint

Answer 17

• Radial collateral ligament
• Ulnar collaterol ligament
• Annular ligament

Question 18

Clinical link: Lumbar puncture - positon and surface marking

Answer 18

Position: Patient to lay on their side with their knees raised to their chect

Surface marking: The posterior iliac crest. Intersects the L4 spinous process

Structures passed through: Skin, superficial fascia, supraspinous ligament, intraspinous ligament, ligamentum flavum, epidural space, dura mater, arachnoid mater, subarachnoid space

Question 19

Pectoral girdle: Muscles of the anterior aspect

Answer 19

Suprascapular foramen: The suprascpaular nerve passes through this space

Subscapularis: Upper and lower subscapular nerves

Latissimus dorsi: Thoracodorsal nerve

Long and short heads of biceps brachi: Musculocutanous nerve

Bicipital aponeurosis: Seen at the sharp medial margin. Covers the brachial artery and the median nerve

Question 20

Upper limb: Posterior compartment of the arm

Answer 20

Innervation: Radial nerve

Muscles: Triceps brachii

Actions: Extension at the elbow joint

Clinical relevance: Radial nerve may be injured at the lateral epicondyle, tight watch/handcuffs, mid-shaft humeral fractures (radial groove), falling asleep with hand over the back of the chair, upper limb dislocation - becomes stretched (commonly anterior)

Question 21

The radiocarpal joint: Label the carpal bones

Answer 21

Scaphoid, lunate, triquestrum, pisiform (sesamoid bone), hamate, capitate, trapezoid, trapezium

Question 22

Outline the blood supply to the upper limb

• include areas of ‘transition’

Answer 22

Question 23

Lower limb: Medial compartment of the thigh

Answer 23

Innervation: Obturator nerve

Muscles: Adductor longus and brevis

Actions: Adducts the thigh

Clinical relevance: The obturator nerve may be damaged in birthing mothers and in sports (e.g. fencing)

Question 24

Quadratus lumborum: Action and innervation

Answer 24

Action: Extension and lateral flexion of the vertebral column

Innervation: Anterior rami of spinal nerves T12-L4

Question 25

**Erector Spinae Muscles:** Action and innervation

Answer 25

**Action:** Unilateral contraction: Lateral flexion Bilateral contraction: Supports the vertebral column and increases intra-abdominal pressure **Innervation:** Dorsal rami of spinal nerves

Question 26

**Clinical link:** Surgical neck and mid-shaft humerus fracture.

Answer 26

**Surgical neck:** * Can damage the **axillary nerve.** * Leads to loss of innervation to the deltoid muscle and teres minor * **Weakened abduction and lateral rotation** **Mid-shaft humerus fracture:** * Can damage the **radial nerve** * Leads to loss of innervation of the triceps branchii * Loss of extension of the elbow joint * Loss of innervation of the dorsal forearm * Sensory loss to dorsal forearm and hand

Question 27

Spinal nerves: Outline the 2 branches derived from spinal nerves

Answer 27

Spinal nerves (emerging from ventral rami) → **Large anterior rami:** Innervates most skeletal muscles and skin **Small posterior rami**: Innervates the intrinsic muscles of the back and narrow strip of associated skin

Question 28

Intervertbral disc herniation: Most common 'direction' and region

Answer 28

**Posterior:** Most common due to tapering of the posterior longitudinal ligament of the spine, weaker/less organised, flexion is much more common, nucleus becomes more posterior moving down the spine **Region:** Most commonly occurs in the lumbar region of the spine. This is due to the curvature of the spine and the large amount of pressure placed upon this region

Question 29

Muscles of the forearm: Outline the functions of the FDPs and FPS

Answer 29

Flex the digits at the IPJs, can flex the MCPJs

Question 30

Upper limb: anterior compartment of the forearm

Answer 30

**Innervation:** Median nerve (C5-T1) * Except medial half of FDP and FCU which are innervated by the ulnar nerve **Muscles:** FDS, FPL, pronator teres **Actions:** Flexion of the wrist and digits, pronation **Clinical relevance:** The median nerve may be damaged at the cubital fossa, brachial plexus lesions (upper or lower), supracondylar fracture of the humerus, damage at the wrist (e.g. self-harm)

Question 31

Intervertebral discs: Anatomy

Answer 31

**IV disc bodies:** Increase in size from rostral to caudal. Flexibility is sacrificed to allow stabilty. The amount of force apparent on the dics increases caudally. (shapes) **Central nucleus pulposus**: Derived from the notochord. Keeps the annulus fibrosus under constant tension. Contains proteoglycans with GAG side chains, type II collagen. Compression resistant. **Annulus fibrosus:** Layers of oliquely organised fibrocartilage. Less well organised posteriorly.

Question 32

Venous drainage of the upper limb: Name the deep and superficial vessels

Answer 32

**Superficial:** Basilic and cephalic veins **Deep:** Radial, ulnar and branchial veins

Question 33

Hip joint: Outline the relation of the hip joint to our centre of gravity when standing

Answer 33

The **hip joint** lies **anterior to** the **centre of gravity**. The knee joint is posterior to the centre of gravity. Allows us to **'lock' joints, reducing the muscular energy** required for standing.

Question 34

The axilla: Describe the boundaries of the axilla

Answer 34

**Inlet:** Lateral margin of rib I **Anterior wall:** Pectoralis major and minor muscles **Medial wall:** Upper thoracic wall, serratus anterior muscle **Posterior wall:** Subscapularis, teres major and latissimus dorsi **Lateral wall:** Intertubecular sulcus **Floor:** Skin of the armpit

Question 35

Outline the blood supply to the lower limb

Answer 35

Common iliac → Internal and external iliac Internal iliac → Superior and inferior gluteal, obturator External iliac → Femoral artery → \*Branch: Profunda Femoris→ medial and lateral circumflex \*→ Popliteal artery → anterior and posterior tibial Anterior tibial → dorsalis pedis Posterior tibial → Fibular, medial and lateral plantar

Question 36

Hip joint: Label the hip joint and describe the stabilty of the joint

Answer 36

The pelvis is formed by the ilium, ischium and pubic bones. The **acetabulum** of the pelvis and the **head of the femur** form the hip joint. **Acetabulum:** Fossa, notch and labrum * Large and cup shaped * Allows weight to be transferred to the femur The joint is **very stable**, to accomodate the large amount of force placed upon it. However, this is at the expense of movement. The acetabulum is large whilst the head of the femur is small.

Question 37

The axilla: Describe the contents of the axilla

Answer 37

**AX**illary artery and vein **I**nfraclavicular portion of the brachial plexus **L**ypmh nodes **L**ong thoracic nerve **A**dipose tissue

Question 38

Elbow joint: Epicondylitis

Answer 38

**Lateral** epicondylitis: (**tennis** elbow) Inflammation at the common **extensor origin** **Medial** epicodylitis: (**golfer's** elbow) Inflammation at the common **flexor origin**

Question 39

Forearm: Label the key anatomical regions of the forearm

Answer 39

Nerve: **Radial** * Loss leads to wrist drop * Can be injured at the lateral epicondyle and also by tight wrist watches/handcuffs **The interosseus membrane** * Provides attachment for muscles * Fibres orientated such that forces are transmitted from the hand to the humerous * Allow attachment of the radius and ulnar without restriction pro- and supination

Question 40

Subclavian vein: Relation to the subclavian artery and its approximate surface markings

Answer 40

* Both cross the first rib The **subclavian vein** crosses the **first rib** in the **midclavicular line,** extending to the **medial clavicular edge**.

Question 41

**Spinal nerves**: * At which vertebral level does the spinal cord end? * Define the cauda equina

Answer 41

**Spinal cord:** * Ends at L1 in adults and L2/L3 in children * Conus medullaris **Cauda equina:** Formed from the ventral and dorsal rootlets of spinal nerves **Clinical link:** The cauda equina may be compressed in vertebral disc prolapse. ☆ Red flag symptoms: Loss of anal tone, faecal and urine incontinence, paraesthesia in the saddle region

Question 42

Gleno-humeral joint: Decribe the anatomy of the gleno-humeral joint

Answer 42

* A synovial ball and socket joint * Formed from the head of the humerus inserting into the glenoid cavity, which has a surrounding glenoid labrum * The large head and small cavity cause the joint to be relatively unstable and therefore requires stabilisation by surrounding ligaments and muscles * The tendon of the long head of biceps is found near the joint * Blood supply: Medial and lateral circumflex arteries of the profunda brachii artery

Question 43

**Facet/Zygapophyseal Joints:** Formation, innervation, orientation and function

Answer 43

**Formation:** Formed by the **anterior and superior articular processes** of each vertebrae **Innervation:** Dorsal rami of spinal nerves **Orientation:** Move from a **horizontal to a vertical position** moving from superiorly to inferiorly. * This ↓ flexibility but ↑ stability **Function:** Guide and constrain motion of the vertebrae, faciliate load transmission

Question 44

Intrinsic muscles of the hand: Outline the actions of the dorsal and palmar interossei and the lumbricals

Answer 44

**Dorsal interossei:** Abduction **Palmar interossei:** Adduction **Lumbricals:** Flexion of the MCPs and extension of the IP joints. Crucial for movement of the fingers

Question 45

**Vertebral bodies:** Name the features of the vertebral bodies

Answer 45

Transverse processes Spinous process Pedicle Lamina Neural arch Body

Question 46

Palmar aponeurosis: Location and function

Answer 46

* A sheet of fascia with a central thickening covering the palmar surface of the hand * Function: Protection of the underlying tendons and forms the fibrous digital sheaths

Question 47

The carpal tunnel: Outline the contents of the carpal tunnel

Answer 47

* A bony canal formed by the carpal bones **Roof:** Flexor retinaculum **Contents:** Median nerve, FDP, FDS and **FPL** tendons

Question 48

**Dermatomes**: Label the dermatomes of the upper limb

Answer 48

Question 49

Upper limb: Anterior compartment of the arm

Answer 49

**Innervation:** Musculocutaneous (C5-C7) **Muscles:** Biceps brachii **Actions:** Flexion at the elbow joint **Clinical relevance:** The nerve may be damaged through stab wounds to upper arm or upper brachial plexus lesions

Question 50

Pectoral girdle: Muscles of the back

Answer 50

**Trapezius:** Accessory nerve * Movement of the scapula **Latissimus dorsi:** Thoracodorsal nerve * Extends, adducts and medially rotates the humerus **Levator scapulae:** Dorsal scapular nerve * Elevates scapula **Rhomboid minor and major:** Dorsal scapular nerve * Adducts and elevates the scapula

Question 51

Intrinsic muscles of the hand: Outline the innervation of the intrinsic muscles of the hand

Answer 51

**LOAF muscles (including thenar eminence)** supplied by the **median nerve** (recurrent branch): * Lateral 2 lumbricals * Opposens pollicis * Abductor pollicis brevis * Flexor pollicis brevis **All other intrinsic muscles, including the hypothenar eminence** of the hand are supplied by the **ulnar nerve.** * Enters the hand via Guyon's canal

Question 52

Clinical link: Outline the boundaries for IM injection of the gluteal muscles

Answer 52

* Vertical line from the posterior iliac crest to the ischial tuberosity * Horizontal line from the midpoint of this line * The left upper quadrant is the 'safe' area **Clinical relevance:** Failure to correctly recognise this site may lead to injury to the sciatic nerve ☆ REMEMBER ☆ The sciatic nerve ultimately innervates the leg and provides sensory innervation to the majority of the area

Question 53

Pronation and supination: Name the muscles which perform pronation and supination of the wrist

Answer 53

**Pronation:** Pronator teres and pronator quadratus (C7-C8) * Located in the anterior compartment * Pronator teres innervated by median nerve, quadratus by interroseous nerve **Supination:** Supinator and biceps brachii (C5-C6) * Biceps brachii innervated by musculocutaneous * Supinator innervated by the radial nerve

Question 54

Pectoral girdle: Muscles of the posterior aspect

Answer 54

**Supraspinatus:** Suprascapular nerve **Infraspinatus:** Suprascapular nerve **Teres minor:** Axillary nerve **Teres major:** Inferior subscapular nerve Long head of triceps brachii **Triangular space:** Circumflex scapular artery **Quadrangular space:** Axillary nerve, posterior circumflex arterty and vein **Triangular interval:** Radial nerveand profunda branchii artery

Question 55

Muscles of the forearm: Pronation and supination muscles, which movement is strongest

Answer 55

**Supination** is the **strongest** movement **Pronation:** Pronator teres and quadratus (C7-C8) **Supination:** Biceps brachii and supinator (C5-C6)

Question 56

Outline the borders and contents of the tarsal tunnel

Answer 56

Borders: Passes posteriorly to the medial malleolus, held in place by fibrous band (flexor retinaculum) Contents: Tibialis anterior, flexor digitorum longus, flexor digitorum brevis, posterior tibial artery, tibial nerve, posterior tibial vein

Question 57

**Spinal ligaments:** Name the ligaments of the spinal column

Answer 57

**Anterior and posterior longitudinal ligaments:** Support the vertebrae **Ligamentum flavum:** Resists separation of laminae **Inter- and supraspinatous ligaments:** Limit flexion **Ligamentum nuchae:** Supports the head, resists flexion, returns the head to anatomical postion * Attaches to the skull, extending down to the spinous process of cervical vertebrae VII

Question 58

Lower limb: Posterior compartment of the leg

Answer 58

**Innervation:** Tibial nerve (branch of sciatic nerve) (L4-S3) **Muscles:** Gastrocnemius, soleus, calcaneal tendon **Actions:** Plantarflexion, flexion of toes, inversion of the foot **Clinical relevance:** * Injury to the medial malleolus may sever the tibial nerve * The compartment may be affected by sciatic nerve damage * The calcaneal tendon may be injured by forceful plantarflexion

Question 59

Clinical link: Pathology of the subacromian space

Answer 59

* The subacromian space lies between the acromian and the head of the humerus * The **supraspinatus tendon** passes through the space * The tendon or bursa within the space may become inflammed causing impingement and subsequent pain * **Outcome:** * Overhead activities become painful * Inabilty to actively abduct the GHJ * Supraspinatus tendonitis generates a painful arc * Thickening of the coracoacromial ligament can also caused impingement of the tendon

Question 60

Elbow joint: Decribe the basic anatomy of the elbow joint

Answer 60

* A synovial hinge joint * Formed by articulation of the radial head on the capitulum of the humerus and articular of the ulnar head on the trochlea of the trochlea

Question 61

Osteology: Identify the key features of the humerus

Answer 61

**Anatomical and surgical necks** **Greater and less tubercles** **Bicipital groove:** The **tendon of the long head of biceps** passes through this groove. The tenosynovium enclosing the tendon may become inflammed - tenosynovitis. **Medial and lateral epicondyles** **Olecranon fossa** **Lateral epicondyle**

Question 62

Clinical link: Shoulder (GHJ) dislocation

Answer 62

Most likely to occur in the anterior direction Appearance: Externally rotated and abducted The **axillary nerve** is at risk in GHJ dislocation. Leads to loss of abduction and sensory loss over the regimental badge area. ☆Remember the axillary nerve passes through the quadrangular space and round the back of the humerus The radial nerve may also be damaged

Question 63

Outline the borders and contents of the cubital fossa

Answer 63

**Borders:** Pronator teres medially, brachioradialis laterally and between the lateral and medial epicondyles superiorly **Contents:** Median nerve, Brachial artery, Tendon of biceps brachii, Radial nerve

Question 64

Muscles of the forearm: Outline the function of the carpi muscles

Answer 64

Carpi = wrist **Extensor carpi** = extends and **abducts** the wrist **Flexor carpi** = flexes and **adducts** the wrist

Question 65

Lower limb: Knee Joint Formation, ligaments, menisci, bursa, clinical revelvance

Answer 65

**Synovial modified hinge joint** **Formed by:** The distal head of the femus articulating with the proximal head of the tibia and the patella (sesamoid bone) **Ligaments:** * **Anterior cruciate ligament:** Extends from the **tibia** (anterior part of the intercondylar area) to the **lateral** (wall of the intercondylar fossa of the) **femur**. Resists anterior displacement. * **Posterior cruciate ligamen**t: Extends from the **tibia** (posterior intercondylar area) to the **medial** (wall of the intercondylar fossa of the) **femur**. Resists posterior displacement. * **Lateral collaterol ligament:** **Lateral femur epicondyle** to the lateral surface of the **fibular head.** Resists varus forces. * **Medial collaterol ligament: Medial femur epicondyle** to the medial surface of the **tibial head.** Resists valgus forces. **Menisci:** Fibrocartilage, improve joint congruence, stabilty and provide proprioceptive feedback * **Medial meniscus:** ATTACHED to the joint capsule and medial collaterol ligament. **Clinical relevance:** This leaves the medial meniscus more vulnerable to damage. **Unhappy triad of knee injury:** Medial meniscus, ACL and medial collateral ligament **Bursa:** Fluid filled sacs that act to reduce friction between surfaces. Clinical relevance: A large joint effusion would typically be seen in the suprapatella pouch

Question 66

Lower limb: Anterior compartment of the thigh

Answer 66

**Innervation:** Femoral nerve (L2 -L4) ☆ Psoas innervated by anterior rami of L1-L3 * Injury within the femoral triangle, tumour * Consequence: Reduced hip flexion and knee extension, fuctional problems climbing stairs **Muscles:** Quadriceps (vastus medius), sartorius, rectus femoris **Actions:** Generally hip flexion (rectus femoris, psoas major and ilacus), knee extension **Clinical relevance:** Femoral stretch test (damage to the femoral nerve will cause reduced contraction of the quadriceps femoris)

Question 67

Venous drainage of the upper limb: Describe the route of the main venous vessels

Answer 67

**Basilic vein:** Travels from the dorsal venous network up the arm, on the medial/ulnar side. **Cephalic vein:** Travels from the dorsal venous network up the arm, on the lateral/radial side. **Median cubital veins:** Links the basilic and cephalic veins at the cubital fossa. Ideal for venepuncture **Brachial veins:** Deep paired veins which run alongside the brachial artery

Question 68

Intracapsular fracture of the femoral head: Outline the blood supply to the femoral head and the consequences of this event

Answer 68

**Blood supply:** Medial and lateral circumflex branches of the femoral artery, branch of the obturator and from the superior gluteal artery The blood supply of the femoral head **enters the capsule** of the joint **from below** the joint (distal to proximal) and hence can be **severed in fractures** of the femur. This can then leave the area without a blood supply, causing **avascular necrosis.** ☆ **Intracapsular fracture**

Question 69

Clinical link: Loss of serratus anterior innervation Innervation, function, observation and clinical test

Answer 69

**Innervation:** Long thoracic nerve (C5-C7) **Function:** Protraction and lateral rotation of the scapular **Observation:** Winging of the scapular (as the scapular is elevated away from the thoracic wall) **Clinical test:** Press-up against the wall

Question 70

Hip joint: Proximal femur

Answer 70

* Fovea * Head of the femur * Neck of femur * Greater trochanter * Lesser trochanter * Gluteal tuberosity

Question 71

The radio-carpal joint: Describe the articulation seen at the joint

Answer 71

* A synocial ellipsoid joint * The radius articulates with the carpal bones * The TFCC is seen between the ulnar bone and the carpals * Ulnar and radial styloid processes

Question 72

Muscles of the forearm: State the general function for muscles originating at the epicondyles

Answer 72

**Lateral epicondyles: Extensors** * Tennis elbow **Medial epicondyles: Flexors** * Golfer's elbow

Question 73

Upper limb: Posterior compartment of the forearm

Answer 73

**Innervation:** Radial nerve **Muscles:** EPL, EPB, EDL, supinator **Actions:** Extension of the wrist and digits, supination **Clinical relevance:** The radial nerve may be damage in **mid-humerus fractures** (winds around the **spiral groove**), at the lateral epicondyle, supra-epicondyle fractures, tight watch/handcuffs, falling asleep on arm, pressure of crutches

Question 74

Lower limb: Intrinsic muscles of the foot

Answer 74

☆ Plantar surface is separated in **4 layers**. The muscles **support the digits** during **standing and gait**. They also act as d**ynamic arch support.** **Plantar aponeurosis:** Deep fascia of the foot **Innervation:** Branches of the tibial nerve

Question 75

The axilla: Name the 5 lymph node groups of the axilla. Which areas which drain to these nodes and when may this be interrupted?

Answer 75

1. **C**entral 2. **H**umeral 3. **A**pical 4. **P**ectoral 5. **S**ubscapular All **upper limb** and **lateral breast lymphatics** drain into the axillary nodes. Drainage may be interrupted following **mastectomy** or s**urgical node clearance** (for breast cancer).

Question 76

Meninges: Outline the layers of the meninges

Answer 76

**Pia** Subarachnoid space: End at L3 vertebral level **Arachnoid** Subdural space: Only seen in pathology **Dura**

Question 77

Scapula: Name the vessels which contribute to the arterial anatomoses of the scapula. Outline the importance of this

Answer 77

1. **Suprascapular artery** 2. **Transverse cervical** 3. **Circumflex scapula** (of the axillary artery) 4. **Thoracodorsal** (of the axillary artery) 5. **Posterior intercostal** The anastomoses ensure that blood supply will not be prevented in the event of an occlusion to one of the vessels

Question 78

The extensor hood: Outline the formation and function of the extensor hood

Answer 78

**Formation:** Extensor tendons expand at the MCPJs, forming an extensor hood **Function:** As the lumbricals and interossei contract they pull on the extensor hood. MCPJs flex and IPJs extend.

Question 79

Lower limb: Ankle joints * Movements and ligaments

Answer 79

**Movement:** Plantar and dorsiflexion * Myotomes: Plantarflexion (S1-S2) * **Plantarflexion is unstable** due to the narrow area of talus in contact with the distal tibular. Mortise when more stable **Ligaments:** **Medially:** Anterior and posterior tibiotalar, tibionavicular and tibiocalcaneal, plantar calcaneonavicular ligament (spring) **Laterally:** Anterior and posterior talofibular, calcaneofibular ligaments

Question 80

Glenohumeral joint: Stabilizing muscles and ligaments

Answer 80

**Muscles:** **Biceps brachii:** A humeral head depressor **Rotator Cuff Muscles SITS** * Supraspinatus - suprascapular nerve * Infraspinatus - suprascapular nerve * Teres minor - axillary nerve * Subscapularis - upper and lower subscapular nerves **Ligaments: Coracohumeral ligament, glenohumeral ligaments** **Glenoid labrum:** Deepens the glenoid cavity

Question 81

Outline the borders and contents of the femoral triangle

Answer 81

**Borders:** Adductor longus medially, sartorius laterally, inguinal ligament superiorly, fasica lata roof **Contents:** Femoral nerve, femoral artery, femoral vein, empty space and lymph nodes ☆ Femoral artery and femoral vein are in the femoral sheath ☆Femoral artery travels down the femoral canal, gives off its profunda femoris branch and passes through the adductor hiatus to enter the posterior compartment of the thigh Clinical link: Locating the femoral pulse. Found half way between ASIS and the pubic symphysis

Question 82

**Clinical link:** Intervertebral disc pathology Changes with age, herniation and extrusion

Answer 82

**Changes with age:** With age the nucelus pulposus becomes dessicated, becoming more fibrotic and less gel like **Herniation/prolapse:** The cartilaginous disc protrudes between the vertbrae **Extrusion:** The nucleus pulposus pushes out of the annulus fibrosus beyond the confines of the disc ☆ IV disc herniation can cause compression of spinal nerves leading to neurological issues

Question 83

Lower limb: Anterior compartment of the leg

Answer 83

**Innervation:** Deep fibular nerve (from common fibular nerve) (L4-S3) **Muscles:** Extensor digitorum longus, tibialis anterior **Actions:** Extensor of toes (dorsiflexion) and inversion compartment **Clinical relevance:** Damaged in neck of fibular fracture, leads to foot drop/high stepping gate (due to unopposed plantarflexion), sciatic nerve injury may also affect the compartment

Question 84

Outline the borders and contents of the **anatomical snuffbox**

Answer 84

**Borders:** EPL laterally, APL and APB medially **Contents:** Cephalic vein, radial artery and cutanous branch of radial artery, scaphoid, trapezium

Question 85

Muscles of the forearm: Brachioradialis - location and action

Answer 85

Located within the **posterior compartment** of the **forearm** Acts to **flex the wrist**