MSK Flashcards
Describe the unique features of the altas
- No body
- Lacks spinous process
- Widest cervical vertebrae
- Body fused with dens of axis
- Atlano-axial joint allows for rotation of head
- Atlanto-occipital joint allows for nodding of head
What are the main features of the axis?
- Dens - prevents horizontal displacement of atlas
- Large spinous process
What are the distinct features of the cervical vertebrae?
- Bifid spinous process
- Oval transverse foramen - vertebral arteries and veins
- Triangular vertebral foramen
Label this diagram of a thoracic vertebrae.
What are the features of the thoracic vertebrae?
- 2 demi-facets on each side
- 1 costal facet on each side
- Round vertebral foramen
What are the features of lumbar vertebrae?
- No foramina of transverse processes
- No costal facets or demi-facets
- Vertebral foramina is small and triangular
What is the remenant of the notocord?
Nucleus pulposus
What are the parts of the intervertebral disc?
- Annulus fibrosus
- Nucleus pulposus
Which artery is at risk of during fracture of head of humerus and mid-humeral fracture?
- Anterior/posterior circumflex humeral artery
- Profunda brachii
What are the nerve roots for:
- Musculocutaneous
- Median
- Ulnar
- Axillary
- Radial
- Musculocutaneous - C5, C6, C7
- Median - C6, C7, C8, T1
- Ulnar - C8, T1
- Axillary - C5, C6
- Radial - C5, C6, C7, C8, T1
What is the ulnar claw?
- Lesion of ulnar nerve at wrist
- Paralysis of medial 2 lumbricals - lumbricals flex MCP & extend IP joints
- Unopposed extension at MCP due to extendor digitorum
- Unopposed flexion at distal IP joint by flexor digitorum profundus
What is the ulnar paradox?
- Lesion of ulnar nerve at elbow is a injury but looks better
- Flexor digitorum profundus (medial part) is paralysed so there’s no flexion at IP joint making ulnar claw much less obvious
What are the muscles of pronation and supination?
- Supination - biceps brachii, supinator
- Pronation - pronator teres, pronator quadratus
Which muscles are innervated by musculocutaneous nerve?
- Biceps brachii
- Brachialis
- Coracobrachialis
Which muscles are innervated by radial nerve?
- Posterior compartment of arm - triceps brachii
- Posterior compartment of forearm
- x3 to wrist - ECRL, ECRB, ECU
- x3 to the fingers - ED, EDM, EI
- x3 to thumb - EPL, EPB, AbPL
- +3 - Brachioradialis, anconeus, supinator,
What are the muscles innervated by the median nerve?
Forearm
- Superficial - Palmaris longus, flexor carpi radialis, pronator teres
- Intermediate - flexor digitorum superficialis
- Deep - Lateral half of flexor digitorum profundus, flexor pollicis longus, pronator quadratus
Hand
- Muscles of thenar eminence (LOAF) - Lumbricals 1 & 2, opponens pollicis, abductor pollicis brevis, flexor pollicis brevis
What muscles are innervated by the ulnar nerve?
Forearm
- Superficial - Flexor carpi ulnaris
- Deep - Medial 1/2 of flexor digitorum profundus
Hand - everything except LOAF (median nerve)
- Muscles of hypothenar eminence:
- Opponens digiti minimi
- Abductor digiti minimi
- Flexor digiti minimi brevis
- Adductor pollicis
- Palmar/dorsal interosseui
What is the Hand of Benediction?
- Damage to median nerve
- Seen when patients asked to make a fist
- Paralysis of forearm flexors - apart from flexor carpi ulnaris and medial half of flexor digitorum profundus
- Paralysis of lateral 2 lumbricals
- Therefore unable to flex index and middle fingers as well as thumb
What are the motor functions of:
- C5
- C6
- C7
- C8
- T1
- C5 - elbow flexors
- C6 - wrist extensors
- C7 - elbow extensors
- C8 - finger flexors
- T1 - finger abductors
What are the motor functions of:
- L2
- L3
- L4
- L5
- S1
- L2 - hip flexors
- L3 - knee extensors
- L4 - ankle dorsiflexors
- L5 - long toe extensors
- S1 - ankle plantar flexors
Briefly describe embrological development of limbs
- Limb buds appear on ventro-lateral body wall (somatic mesoderm with ectodermal cover)
- Apical ecotdermal ridge secretes signalling molecules (diffusion limited) preventing differenitation of mesochyme and encourage proliferation
- Proximal parts begins to differentiate due to lack of signalling molecules from AER
- AER marks boundary between dorsal/ventral parts & secretes dorsalising/ventralising influences over mesenchymal core
- Zone of polarising activity generates asymmetry in limbs
- Digial rays occur as AER regresses over areas between digits
- Mesoderm condenses, differentiates = cartilagous model then endochondrial ossification occurs
- Myogenic precursors are taken into limbs from somites - bring innovation with them
- Merge into common muscle masses around skeleton then split into individual muscles
What are the borders of the axilla?
- Lateral wall - intertubecular groove of humerus
- Medial wall - serratus anterior and thoracic wall
- Anterior wall - pectoralis major and minor
- Posterior wall - scapularis, teres major, lastissimus dorsi
What are the contents of the axilla?
- Long head of biceps brachii
- Corocobrachialis
- Brachial plexus
- Axillary artery
- Axillary vein
‘Big boobs can bring pleasure and arousal after viagra’
What are the borders of the cubital fossa?
- Superior - imaginary line between epicondyles
- Medial - lateral border of pronator teres
- Lateral - medial border of brachioradialis
What are the contents of the cubital fossa?
- Radial nerve
- Biceps tendon
- Brachial artery
- Median nerve
‘Really need beer to be at my nicest’
What are the contents of the carpel tunnel?
- Median nerve
- Flexor pollicis longus
- Flexor digitorum superficialis
- Flexor digitorum profundus
What are the bones of the wrist?
- Scaphoid (lateral)
- Lunate
- Triquetrum
- Pisiform
- Trapezium (lateral)
- Trapezoid
- Cunate
- Hamate
‘Some lovers try positions that they cannot handle’
Common causes of carpel tunnel syndrome
- T = trauma
- R = Rheumatoid arthritis
- A = acromegaly
- M = myxoedma - swelling of skin and underlying tissues (characteristic of hypothyroidism)
- P = pregnancy
What are the borders of the anatomical snuffbox?
- Medial border = Tendon of extensor pollicis longus
- Lateral border = Tendon of abductor pollicus longus and tendon of extensor pollicis brevis
- Proximal border = styloid process of radius
What causes pain in the anatomical snuffbox?
- Fracture of scaphoid
What is the innervation of serratus anterior? What sign is caused if this nerve is damaged?
- Long thoracic nerve
- Winged scapula
What is the innervation of latissimus dorsi?
Thoracodorsal nerve
What are the borders of the femoral triangle?
- Superior = inguinal ligament
- Lateral = medial border of sartorius
- Medial = lateral border of adductor longus
- Floor = pectineus, iliopsoas, adductor longus
What are the contents of the femoral triangle?
- Femoral Nerve
- Femoral Artery
- Femoral Vein
- Femoral Canal - Lymphatics
What is the difference between midinguinal point and midpoint of inguinal ligament? What can be found at these points?
- Mid-inguinal point = midway between pubic symphysis and ASIS - femoral artery
- Mid point of inguinal ligament - midway between pubic tubercle (start of inguinal ligament) to ASIS (end of inguinal ligament) - femoral nerve
What are the borders of the popliteal fossa?
- Superiomedial = Semimembranosus
- Superiolateral = Biceps femoris
- Inferiomedial = Medial head of gastrocnemius
- Inferiolateral = Lateral head of gastrocnemius
What are the contents of the popliteal fossa?
- Popliteal artery
- Popliteal vein
- Tibial nerve
- Common fibular nerve
What are the deep lateral rotators of the hip?
- Piriformis
- Obturator internus
- Obturator externus
- Quadratus femoris
- Gemellus superior
- Gemellus inferior
‘Play golf or go on quests’
What are the muscles of anterior thigh?
- Sartorius
- Quadriceps femoris
- Rectus femoris
- Vastus medialis
- Vastus intermedius
- Vastus lateralis
- Iliopsoas
What are the nerve roots for the femoral nerve?
S2-S4
What are the muscles of the medial thigh?
- Pectineus
- Adductor brevis, longus and magnus
- Gracilis
What are the nerve roots for the obturator nerve? How does it enter the medial thigh?
- S2-S4
- Through obturator canal in obturator foramen
What are the muscles of the posterior thigh?
- Semimembranosus
- Semitendinosus
- Biceps femoris
What is the nerve roots of the sciatic nerve?
L4-S3
What are the muscles of the anterior compartment of the leg?
- Tibialis anterior
- Extensor digitorum longus
- Extensor hallucis longus
- Fibilaris tertius
What are the muscles of the lateral compartment of the leg?
- Fibularis longus
- Fibularis brevis
What are the muscles of the posterior compartment of the leg?
- Gastrosnemius
- Soleus
- Tibialis posterior
- Flexor digitorum longus
- Flexor halllucis longus
- Plantaris
- Popliteus
What is the difference between housemaid’s knee and clergyman’s knee?
- Housemaid’s - inflammation of prepatellar bursa
- Clergyman’s - inflammation of infrapatellar bursa
What is the unhappy triad?
- Force to lateral side of knee
- Damage to medial collateral ligament, medial meniscus, and anterior cruciate ligament
