MSK Flashcards
(226 cards)
What is the most common site of fracture of the humerus?
-Surgical neck
Name the anatomical landmarks of the humerus
- Head, anatomical neck, surgical neck
- Greater tubercle, lesser tubercle, intertubecular groove
- Deltoid tuberosity, radial groove
- Lateral epicondyle, medial epicondyle, olecranon fossa, capitulum (radius), trochlea (ulna)
Name the anatomical landmarks of the radius
- Head, neck
- Radial tuberosity
- Styloid process
Name the anatomical landmarks of the ulna
- Olecranon
- Trochlear notch
- Coracoid process
- Ulnar styloid process
Name the carpals of the hand
- Scaphoid
- Lunate
- triquetral
- Pisiform
- Trapezium
- Trapezoid
- Capitate
- Hamate
What are the 3 defining features of a synovial joint? What disease affects these?
- Articular capsule (synovium)
- Synovial fluid
- Articular cartilage
- Rheumatoid Arthritis
Give 3 causes of hypotonia
- Cerebella lesion
- LMN lesion
- Primary degeneration of muscles (myopathies)
- Loss of sensory afferents from muscle spindle
Explain the processes which occur at a NMJ
- AP arrives at end plate causing influx of Ca
- Causing binding of vesicles containing neurotransmitter to fuse with pre-synaptic membrane via synaptotagmin
- Ach released
- 2 molecules of Ach bind to 1 nicotinic receptor
- Opening of Na channels
- AP continues
What is unfused and fused tetanus? State a disease which is linked to this
- Unfused tetanus is a series of action potentials causing muscle twitching in which muscles have time to relax before next ap delivered
- Fused tetanus is when the ap are delivered at a frequency which does not allow the muscle fibre to relax and sustained contraction occurs.
- Clostridium tetani produces a toxin causing tetanis carachterised by painful muscle spasms
What are the nerve roots of the brachial plexus and where do they emerge?
- C5-T1
- C5-c8 above c5-t1 vertebrae and t1 below t1
name the 5 branches of the brachial plexus and the nerve roots of each
- Musculocutaneous (C5,6,7)
- Axillary (C5,6)
- Median (C6,7,8,T1)
- Radial (C5,6,7,8,T1)
- Ulna (C8,T1)
Briefly describe development of the limbs
- limb buds elongate and develop thickened ridge distally known as apical ectodermal ridge
- AER drives elongation and prevents differentiation by releasing signalling molecules
- The proximal portion of the limb buds are too far away to be influenced so begin differentiating whilst the distal keeps elongating
- AER begins to regress except for primordia of digits.
- Interdigital spaces undergo apoptosis and elongation of fingers occurs
- Mesenchyme turns to cartilaginous model and endochondral ossification occurs
What is the zone of proliferating activity in the developing limb buds
-Area which controls dorsal-ventral patterning
What is a dermatome? Demonstrate them on the upper and lower limb
-Strip of skin supplied by a single spinal nerve
What nerve innervates trapezius?
-CNXI
Describe the different muscles whcih abduct the arm and their associated degrees
- Supraspinatus -> 0-15
- Deltoid -> 15-90
- Trapezius -> 90+
What nerve supplies the deltoid and why is examination of the deltoid particularly relevant?
- Axillary
- Loss of sensation over regimental badge shows damage to axillary nerve
- Biggest muscle group in arm so wasting is easily visible
Name the muscles of the rotator cuff and state its main function
- Supraspinatus
- Infraspinatus
- Teres minor
- Subscapularis
- Stabilise the soulder joint
What factors make the shoulder joint unstable? In which direction is it most likely to dislocate? What local structures are most at risk of damage
- Shallow glenoid cavity
- Disproportionate articular surfaces
- Multiplanar movements
- Anterior inferior from an abducted position
- Rotator cuff, axillary nerve
What is the coracoacromial arch and its clinical significance
- Made be coracoid process, acromion and coaracoacromial ligament
- prevents upper dislocation of humerous
- Painful arc syndrome -> supraspinatus tendon inpingement under CAA -> irritation and inflammation producing pain on abduction between 50-130 degrees
Give risk factors for painful arc syndrome
- Repetitive use -> racquet sports or occupation involving arms over head
- Age
What are bursae? List the diseases you know involving bursae
- Synovial membrane-lined sacs filled with synovium to facillitate movements of tendons and muscles over bone by reducing friction
- Bakers cyst -> popliteal bursitis
- Housemades knee -> infrapatella bursitis
- Clergymens knee -> pre-patella bursitis
- Painful arc -> subacromial bursitis
Which movements flex, extend, abduct and adduct the shoulder?
- Flexion -> pec major, coracobrachialis, biceps brachii, anterior deltoid
- Extension -> posterior deltoid, lat dorsi, teres major
- ABduction -> supraspinatus, deltoid, trapazius, serratus anterior
- ADduction -> lat dorsi, pec majr and teres major
Which arteries supply the glenohumeral joint?
-Anterior and posterior circumflex