Lecture 15 - Musculoskeletal 4

Question 1

what are the three joints of the elbow?

Answer 1

Humero-ulnar
Humero-radial
Superior radio-ulnar joint

Question 2

which two joints allow flexion and extension of the ebow

Answer 2

Humero-ulnar and humero-radial

Question 3

which two joints allow pronation and supination of the forerm/elbow?

Answer 3

humero-radial and superior radio-ulnar

Question 4

what are the two condyles of the humerus

Answer 4

trochlea and the capitulum

Question 5

which humero joint does the trochlea contribute to?

Answer 5

• similar to trochlea in knee
  humero ulna

Question 6

what are the specific articulating surfaces of the trochlea?

Answer 6

articulates at the trochlear notch of the ulna, at the olecranon and the coronoid process.

Question 7

where is the olecranon?

Answer 7

at the superior posterior ulna

Question 8

trochlea notch = ?

Answer 8

coranoid process + olecranon

Question 9

what are the only articulating structures we can see on the humerus in exploded posterior view of the elbow?

Answer 9

the trochlea (or the olecranon if not exploded view)
the superior surface of the radius

Question 10

which humero joint does the capitulum contribute to?

Answer 10

humero-radial

Question 11

true or false, the capitulum is visible from posterior view of the humerus

Answer 11

false

Question 12

describe the shape of the superior surface of the radius and its benefits?

Answer 12

concave, so can rotate at the surface, which is important for supination

Question 13

what are the specific articulating surfaces of the superior radio-ulnar joint?

Answer 13

the head of the radius and the radial notch

Question 14

true or false, the radial notch is visible from posterior view of the ulna

Answer 14

false

Question 15

what are the fossa of the humerus?

Answer 15

anterior: radial fossa (accomodates radius) and coronoid fossa (accomodates coronoid process)
Posterior: olecranon fossa (you guessed it)

Question 16

why do we have fossa of the humerus?

Answer 16

increases the range of motion in both flexion and extension

Question 17

what secondarily supports the articular capsule of the elbow?

Answer 17

the muscles of the arm (e.g brachialis)

Question 18

are there more protective structures anteriorly and posteriorly or medially and laterally at the articular capsule of the elbow?

Answer 18

medially and laterally

Question 19

what prevents abduction and adduction of the elbow?

Answer 19

the ulnar collateral ligament and radial collateral ligament

Question 20

where does the ulnar collateral ligament attach?

Answer 20

to the medial epicondyle of the humerus and the coronoid process of the ulna

Question 21

why doesn’t the radial collateral ligament attach directly to the radius?

Answer 21

it would limit rotation which would negatively impact supination and pronation

Question 22

where does the radial collateral ligament attach?

Answer 22

the anular ligament of the radius and the lateral epicondyle of the humerus

Question 23

where does the anular ligament attach

Answer 23

from the edge of the radial notch, round the radius and attaches to the posterior edge of the radial notch (allows rotation without causing abduction)

Question 24

where is the sacciform recess of the elbow, and why is it there?

Answer 24

at the radius, it contains synovial fluid and allows radius to rotate

Question 25

Ulnar nerve?

Answer 25

Funny bone! runs from posterior humerus to anterior ulnar, and it is very close to the medial epicondyle. nerves dont like to be compressed so we get electric shock feeling

Question 26

what is the purpose of fat pads at the joints?

Answer 26

reduces volume of joints, fill the fossa of the radius when there is no bone articulating in them

Question 27

true or false, the fat pads are continuous with the articular capsule

Answer 27

true

Question 28

what is the sail sign?

Answer 28

when the fat pads are lifted due to bleeding into the joint space.

Question 29

what fractures commonly happen when the elbow is dislocated?

Answer 29

- coranoid process fracture - olecranon fracture - head of the radius fracture (worst case scenario)

Question 30

how come the skin on our elbow moves over the olecranon really easily?

Answer 30

due to a bursa of the olecranon

Question 31

what is bursitis of subcutaneous olecranon bursa

Answer 31

infected bursa - bacteria love growing in bursa

Question 32

which bone is medial of the forearm?

Answer 32

ulna

Question 33

how does the shape of the radius and ulna change as we move from proximal to distal?

Answer 33

ulna is broad and stable at proximal end when radius is small and round, and this swaps at distal end. this is ideal for supination and pronation

Question 34

describe the inferior radio-ulnar joint

Answer 34

the lateral head of the ulnar (articular cartilage) articulates with the medial radius at the ulnar notch

Question 35

what is the radial styloid processes

Answer 35

can feel them in surface anatomy, ligaments attach (such as collateral of the wrist) and aligns with the position of the wrist joint proper

Question 36

what is the fibrous articular disc of the wrist?

Answer 36

deformable fibrocartilage that runs from the distal unlar notch to the ulnar styloid process.

Question 37

what is the function of the fibrous articular disc?

Answer 37

allows the two bones to change position, and separates the inferior radio-ulnar joint from the wrist joint proper joint space

Question 38

does the distal ulna articulate at the wrist joint proper?

Answer 38

no, the fibrous articular disc prevents that. the radius moves over the ulna during supination and pronation

Question 39

what is the carrying angle

Answer 39

larger in women than men, due to women with narrow shoulders and broad hips

Question 40

what position are our forearms in most commonly?

Answer 40

mid-pronation, so the hand is in line with the axis of the humerus. this wastes less energy when carrying things. almost never in anatomical position and never in full pronation when dead

Question 41

what is the interosseous membrane

Answer 41

a very strong collagenous sheet like material - acts as a hinge while holding bones relative to each other - muscle attachment - force transmission (when leaning on hands, fibres oriented to resist all weight on the radius and distribute it to ulna also)

Question 42

describe the comparment of the forearm most proximal

Answer 42

anterior flexor compartment: Brachialis and biceps brachii tendons posterior: olecranon medial: Flexor and pronator (becomes anterior) lateral: extensor and supinator (becomes posterior)

Question 43

describe the comparment of the mid forearm

Answer 43

anterior: flexor pronator (8 muscles, more bulk, stronger) posterior: extensor supinator (12 muscles, less bulk) with a lateral and medial intermuscular septa

Question 44

describe the comparment of the forearm most distal

Answer 44

anterior and posterior. mostly tendons, less muscle bellies because we need more wrist movement

Question 45

do you need to know all the carpals of the hand?

Answer 45

yes, all by name.

Question 46

how many carpal bones are there in the hand?

Answer 46

2 rows of 4, 8 bones in total

Question 47

meta carpals make up the?

Answer 47

palm

Question 48

what are the phalanges?

Answer 48

3 bones each finger, 2 in thumb. - proximal phalanges - middle phalanges (not in thumb) - distal phalanges

Question 49

thumb is what number?

Answer 49

1, then through to pinky as 5

Question 50

what bones make up the proximal row of carpals from lateral to medial in anatomical position?

Answer 50

scaphoid, lunate, triquetrum, pisiform

Question 51

what bones make up the distal row of carpals from lateral to medial in anatomical position?

Answer 51

trapezium, trapezoid, capitate, hamate

Question 52

what is the pneumonic?

Answer 52

some lovers try positions that they cannot handle

Question 53

what are the three main joints of the carpals?

Answer 53

- radio carpal (true wrist, scaphoid, lunate, triquetral) - midcarpal (all but pisiform) - carpometacarpal joint (not the trapezium. hardly any movement due to held together by tough ligaments)

Question 54

which carpometacarpal joint is there a lot of movement in and why?

Answer 54

the first one, with the trapezium. due to opposable thumb

Question 55

what is the flexor retinaculum?

Answer 55

deep fascia from forearm gets thick as is transitions to hand, and holds together carpals. this creates the carpal tunnel, where all the tendons run

Question 56

which nerve runs in the carpal tunnel?

Answer 56

median nerve. can be compressed due to movement of fingers, and cause carpal tunnel. surgeons cut through flexor retinaculum to release pressure when resolving issue