MSK- nerves

Question 1

which myotome is responsible for big toe extension?

Answer 1

L5 - deep peroneal nerve

Question 2

Which nerve passes behind the medial malleus?

Answer 2

Tibial nerve

Innervates Tibialis Posterior - responsible for plantarflexion of the foot

Question 3

Which structures pass behind the medial malleus?

Answer 3

Tibialis posterior
Flexor digitorum longus
Flexor hallicus longus
Posterior tibial artery
Posterior tibial vein
Tibial nerve

Question 3

Which nerve is affected if there was compartment syndrome of the anterior leg?

Answer 3

Deep peroneal (fibular) nerve - supplies the anterior compartment of the LOWER leg

Question 4

which nerve supplies the anterior compartment of the lower leg?

Answer 4

Deep peroneal (fibular) nerve

Question 5

which nerve innervates the lateral compartment of the lower leg?

Answer 5

Superficial peroneal (fibular nerve)

Question 6

which nerve innervates the posterior compartment of the lower leg

Answer 6

Tibial nerve

Question 7

which nerve innervates the skin of the lower leg

Answer 7

lateral cutaneous nerve

medial cutaneous nerve

Question 8

which artery supplies the muscles of the anterior compartment of the lower leg?

Answer 8

anterior tibial artery

Question 9

which nerve innervates the anterior compartment of the lower leg?

Answer 9

deep peroneal (fibular) nerve

• extensor digitorum longus
• extensor hallucis longus
• tibialis anterior
• fibularis tertius

Question 10

which nerve supplies the anterior compartment of the thigh

Answer 10

femoral nerve
- iliacus
- tensor fasciae latae
- sartorius
- quadriceps femoris

(femoral artery)

Question 11

which nerve innervates the medial compartment of the thigh?

Answer 11

obturator

• adductor longus, magnus, brevis
• gracilis
• obturator externus

(profunda femoris artery and obturator artery)

Question 12

which nerve innervates the posterior compartment of the thigh?

Answer 12

sciatic nerve

• semimembranosus
• semitendinosus
• biceps femoris

(branches of the profunda femoris artery)

Question 13

Which artery supplies the anterior compartment of the lower leg

Answer 13

anterior tibial

Question 14

which artery supplies the lateral compartment of the lower leg

Answer 14

peroneal (Fibular) artery

Question 15

which nerve supplies the biceps brachii

Answer 15

musculocutaneous

injury -> weakness in elbow flexion

Question 16

weakness in elbow flexion suggests damage to what nerve

Answer 16

musculocutaneous

innervates biceps brachii, coracobrachialis and brachialis

Question 17

Action of teres minor

Answer 17

External rotation of shoulder

Axillary nerve

Question 18

Actions of deltoid on the shoulder?

Answer 18

Flexion, abduction and external rotation

(anterior, lateral, posterior fibres)

axillary nerve

Question 19

innervationof adductors

ff

Answer 19

obturator nerve

Question 20

erb’s palsy- what nerves are affected?

Answer 20

upper trunk C5-C6 nerves

injury may be caused by a trauma to the head and neck. This can cause a stretching of the nerves in the plexus. This will typically cause more damage to the upper trunk.

Question 21

medially rotated arm with an extended and pronated forearm with a flexion of the wrist. What injury has she developed?

Answer 21

erbs palsy

damage to upper trunk of brachial plexus

C5-C6

Question 22

Shoulder internal rotation and wrist flexion

what nerve?

Answer 22

erbs palsy. C5/6 affected. Also known as waiters tip!

may be secondary to shoulder dystocia during birth
the arm hangs by the side and is internally rotated, elbow extended

Question 23

Klumpke’s palsy is injury were

Answer 23

(lower brachial plexus injury, C8-T1)

may be secondary to shoulder dystocia during birth. Also may be caused by a sudden upward jerk of the hand
associated with Horner’s syndrome

Question 24

On examination, the patient has weakness in dorsiflexion of the right foot and sensory loss on the dorsum of the right foot. Deep tendon reflexes are normal.

Answer 24

L5 lesion features = loss of foot dorsiflexion + sensory loss dorsum of the foot

Question 25

nerves is responsible for innervation of the triceps muscle?

Answer 25

radial nerve C7-C8

Question 26

Major contributor of blood supply to the femoral head is the

Answer 26

medial femoral circumflex artery

Question 27

most common cause of osteomyelitis

Answer 27

Staphylococcus aureus is correct. (usually by entering through skin breaks) or Salmonella in patients with sickle-cell anaemia. As this patient is not mentioned to have sickle-cell anaemia, S. aureus is the most likely causative organism. S. aureus very commonly causes skin and deeper infections by entering through wounds. Its strong bone adhesion factors allow it to bind to bone and form biofilms. This makes it the most likely cause of osteomyelitis.

Question 28

Damage may result in a 'claw hand'

Answer 28

Ulnar nerve C8-T1 (branch of brachial plexus)

Question 29

innervIate ntrinsic hand muscles except LOAF* Wrist flexion

Answer 29

Ulnar nerve C8-T1 (branch of brachial plexus)

Question 30

nto which structure does the psoas major muscle insert?

Answer 30

lessor trochanter of femur

Question 31

The unhappy triad is a collection of three injuries to the knee which occur due to a lateral impact resulting in Valgus stress. which 3 ligaments affected?

Answer 31

This tears the medial collateral ligament and the medial meniscus (which are closely related. Finally, there is also stress and thus trauma to the anterior cruciate ligament. I think of an MMA fighter kicking someone on the outside of the leg: Medial collateral Medial meniscus Anterior cruciate ligament

Question 32

TENDONS that make up the lateral border of the anatomical snuffbox?

Answer 32

The extensor pollicis brevis of the abductor pollicis longus

Question 33

Low serum calcium, low serum phosphate, raised ALP and raised PTH which metabolic bone disroder?

Answer 33

osteomalacia which is caused by vitamin D deficiency, and results in soft and weak bones. Low vitamin D results in inadequate gastrointestinal absorption of calcium. PTH is raised in this condition in an attempt to compensate for this, which subsequently lowers serum phosphate and raises ALP in the context of increased osteoclast activity.

Question 34

humeral shaft fracture, particularly in the distal third, commonly results in damage to the

Answer 34

radial nerve which innervates the extensor muscles of the forearm. Damage to these muscles can result in an inability to extend the wrist and fingers, leading to a characteristic 'wrist drop'.

Question 35

marfans syndrome - is caused by a mutation in a protein called?

Answer 35

***fibrillin - 1*** (protein vital for extracellular matrix formation) causes abnormal connective tissue (tall stature, high arched palate , aortic aneurysms) inherited in autosomal dominant fashion

Question 36

Type V (5) mutations cause?

Answer 36

ehlers danlos syndrome hypermobility, loss of skin integritiy,

Question 37

where does the biceps femoris attach

Answer 37

long and short head attach to fibular head (sudden contraction - often lead to avulsion fracture of the fibular head) **biceps femoris (hamstring muscle - knee flexion/hip extension)

Question 38

serratus anterior is supplied by

Answer 38

long thoracic nerve - muscle pulls the scapula around the thorax - damage to nerve - medial winging of scapula

Question 38

what is osteopetrosis

Answer 38

rare disorder of defective osteoclast function resulting in failure of normal bone resorption results in dense, thick bones that are prone to fracture bone pains and neuropathies calcium , phosphate and ALP are normal****

Question 38

pain and numbness in the thumb, index and middle finger is most likely caused by damage to what nerve roots

Answer 38

median nerve - carpal tunnel C5-T1

Question 39

dorsalis pedis artery is a continuation of

Answer 39

anterior tibial artery and passes beneath the inferior extensor retinaculum

Question 40

most common organisim in septic arthritis

Answer 40

staph aureus

Question 41

methotrexate is hepatotoxic a. true b. false

Answer 41

a.true monitor LFTs

Question 42

which nerve innervates the gluteus medius and maximus

Answer 42

superior gluteal nerve

Question 43

L4 nerve root compression symptoms

Answer 43

sensory deficits - anterior knee - medial malleolus - weakness in knee extension and hip abduction - diminished patellar reflex

Question 44

L2 root compression symptoms

Answer 44

sensroy loss over the anterior mid-thigh weakened hip flexion

Question 45

L3 root compression symptoms

Answer 45

sensory loss below the anterior thigh reduced strenght in hip and knee extension decreased or absent knee reflex

Question 46

claw hand and hyperextended wrist suggests damage to what nerves

Answer 46

lower brachial plexus C8-T1 ulnar

Question 47

Extension (forearm, wrist, fingers, thumb) which nerve?

Answer 47

radial nerve C5-C8 damage - wrist drop (cannot extend wrist)

Question 48

Humeral midshaft fracture might damage what nerve

Answer 48

radial nerve - wrist drop flexees the forearm, wrist, fingers and thumb