Forearm

Question 0

what are the extensor muscles of the forearm innervated by?

Answer 0

they are all innervated by branches of the radial nerve

Question 1

where are the extensor muscles of the forearm located?

Answer 1

located in the posterior compartment of the forearm (extensor, supinator)

Question 2

what are the three groups of extensor muscles of the forearm?

Answer 2

1. muscles that extend, adduct, or abduct the hand at the wrist joint
2. muscles that extend the medial four digits
3. muscles that extend or abduct the thumb

Question 3

what muscles make up the group of muscles that extend, adduct, or abduct the hand at the wrist joint?

Answer 3

extensor carpi radialis longus and brevis, and extensor carpi ulnaris

Question 4

what muscles make up the group of muscles that extend the medial four digits?

Answer 4

extensor digitorum, extensor indicis, and extensor digiti minimi

Question 5

what muscles make up the group of muscles that extend or abduct the thumb?

Answer 5

abductor pollicis longus, extensor pollicis brevis, and extensor pollicis longus

Question 6

what does the extensor retinaculum do?

Answer 6

it holds the extensor tendons in place in the wrist region and prevents bowstringing of the tendons when the hand is extended at the wrist joint

Question 7

what are synovial tendon sheaths useful for?

Answer 7

covers tendons as they pass over the dorsum of the hand

reduces friction of extensor tendons as they traverse the osseofibrous tunnels

Question 8

what does the attachment of the extensor retinaculum to the distal radius and ulna make?

Answer 8

osseofibrous tunnels

Question 9

what are the superficial muscles of the forearm?

Answer 9

ECRL, ECRB, extensor digitorum, extensor digiti minimi, ECU, brachioradialis

Question 10

what are the “outcropping” muscles of the deep layer of the forearm?

Answer 10

abductor pollicis longus, extensor pollicis longus and brevis, and extensor indicis

Question 11

what happens to the four tendons of the extensor digitorum after they pass deep to the extensor retinaculum?

Answer 11

they spread out as they run towards the fingers

Question 12

how are tendons that run adjacent to the tendons of the extensor digitorum tendons linked to the proximal metacarpophalangeal joints?

Answer 12

adjacent tendons are linked proximally to the metacarpophalangeal joints by 3 oblique intertendonous connections.

Question 13

what is the importance of the 3 oblique intertendonous connections?

Answer 13

they restrict independent extension of the fingers and no finger can remain fully flexed while the other ones are fully extended

Question 14

where are extensor expansions located and what are they formed by?

Answer 14

formed by the four flattened tendons of the extensor digitorum and located on the distal ends of the metacarpals and along the phalanges

Question 15

what is the relationship of extensor expansions to the metacarpal and phalanx?

Answer 15

each expansion is a triangular aponeurosis which wraps around the dorsum and sides of the head of the metacarpal and base of the proximal phalanx

Question 16

what anchors the “hood” of an expansion over the head of the metacarpal?

Answer 16

the palmar ligament

Question 17

where does the palmar ligament originate from?

Answer 17

it is a thickened portion of the fibrous layer of the joint capsule of the metacarpophalangeal joint

Question 18

what does each tendon of the extensor digitorum divide into and where do they attach?

Answer 18

a median band, passes to the base of the middle phalanx

two lateral bands, passes to the base of the distal phalanx

Question 19

what joins up with the lateral bands of extensor expansions?

Answer 19

tendons of interosseous and lumborical muscles of the hand

Question 20

retinacular ligament

Answer 20

runs from the proximal phalanx and fibrous distal sheath obliquely across the middle phalanx and two interphalangeal joints

Question 21

what happens to the retinacular ligament duing flexion of the distal interphalangeal joint and what does that cause?

Answer 21

it becomes taut and the ligament pulls the proximal interphalangeal joint into flexion (same thing happens during extension of the proximal interphalageal joint)

Question 22

boundries and contents of the snuff box:

Answer 22

this box is visible as hollow on the lateral side of the wrist when the thumb is fully extended
laterally bounded by the tendons of the APL and EPB muscles
medially bounded by the EPL
the radial artery is in the floor of the box
radial styloid process can be palpated proximally and the base of the first metacarpal can be palpated distally in the snuff box
scaphoid and trapezium can be felt on the floor of the box btwn radial styloid process and the first metacarpal

Question 23

ligaments of the distal radio-ulnar joint:

Answer 23

anterior and posterior ligaments: extend from the radius to the ulna across the anterior and posterior surfaces of the joint

Question 24

what are the ligaments of the elbow joint?

Answer 24

collateral ligaments (radial and ulnar), and anular ligament

Question 25

boundaries of the cubital fossa:

Answer 25

superiorly: imaginary line between the medial and lateral epicondyles medially: pronator teres laterally: brachioradialis floor: brachialis and supinator roof: brachial and antibrachial fascia, bicipital aponeurosis, subcutanious tissue, and skin

Question 26

what are the contents of the cubital fossa?

Answer 26

terminal part of brachial artery and the commencement of the terminal branches (brachial artery lies between the biceps tendon and median nerve) the radial and ulnar arteries (and deep accompanying veins of the arteries) biceps brachii tendon median nerve radial nerve (dividing into superficial and deep branches)

Question 27

what ligament extends from the lateral epicondyle and blends distally with the anular ligament of the radius?

Answer 27

radial collateral ligament

Question 28

where is the ulnar collateral ligament found?

Answer 28

extends from medial epicondyle to coranoid process and olecranon of the ulna

Question 29

what is the function of the anular ligament?

Answer 29

encircles and holds the head of the radius in radial notch of the ulna this permits pronation and supination

Question 30

what are the three bands of the ulnar collateral ligament?

Answer 30

anterior (cord-like) band: strongest band and limits extension and is slacked during flexion posterior (fan-like) band: weakest band and can limit flexion oblique band: deepens socket for trochlea of humerus oblique cord: (connects the ulna and radius) runs from lateral side of ulnar tuberosity to radius, slightly below the radial tuberosity

Question 31

true or false: women have a smaller carrying angle than men.

Answer 31

false, males have a carry angle of 5-10 degrees while women have a carrying angle of 10-15 degrees

Question 32

what structures limit flexion of the pectoral girdle?

Answer 32

(flexion of sc, ac, gh, and scapulohumeral joints) ligaments: posterior part of the coracohumeral, trapezoid, andposterior part of the joint capsule of the gh joint muscles: rhomboids, levator scapulae, extensor and lateral rotator muscles, rotator muscles of the gh joint

Question 33

what structures limit abduction of the pectoral girdle?

Answer 33

(abduction of the sc, ac, gh, and st joints) ligaments: middle and inferior glenohumeral, trapezoid, and the inferior part of the joint capsule of the gh joint muscles: rhomboids, levator scapulae, adductor muscles of the gh joint bony apposition between the greater tubercle of the humerus and the superior part of the glenoid cavity/laborum or lateral aspect of acromion

Question 34

what structures limit extension of the pectoral girdle?

Answer 34

(extension of gh joint) ligaments: anterior part of the coracohumoral and anterior part of the joint capsule of the gh joint muscles: clavicular head of the pectoralis major

Question 35

what structures limit medial rotation of the pectoral girdle?

Answer 35

(medial rotation of gh joint) ligaments: posterior gh joint capsule muscles: infraspinatus and teres minor

Question 36

what structures limit lateral rotation of the pectoral girdle?

Answer 36

(lateral rotation of the gh joint) ligaments: gh, coracohumeral, and anterior part of gh joint capsule muscles: latissimus dorsi, teres major, pectoralis major, sbscapularis

Question 37

name each muscle of the 6 posterior compartments and which one they are found in?

Answer 37

1. abductor pollicis longus, extensor pollicis brevis 2. extensor carpi radialis longus and brevis 3. extensor pollicis longus 4. extensor digitorum, extensor indicis 5. extensor digiti minimi 6. extensor carpi ulnaris

Question 38

anatomical snuff box borders and contents:

Answer 38

``` laterally bounded by the APL and EPB medially bounded by the EPL floor has the radial artery contains the superficial branch of the radial nerve Scaphoid ```

Question 39

cubital fossa contents and where they are positioned in relation to each other:

Answer 39

medially is the median nerve then just lateral is the brachial artery and viens (can also see the artery split into radial and ulnar) then lateral to that is tendon of biceps brachii then lateral to that is the radial nerve

Question 40

where does the axillary artery end and the brachial artery begin?

Answer 40

at the inferior border of teres major

Question 41

which ligament stabilizes stress against valgus stress?

Answer 41

ulnar collateral ligament in elbow joint

Question 42

what prevents proximal displacement of the radius on the ulna?

Answer 42

interosseous membrane

Question 43

where is the joint capsule of the elbow joint weakest?

Answer 43

anterior and posteriorly

Question 44

supination has more or less degrees of rotation than pronation?

Answer 44

more - 90 degrees supination and 80-85 degrees of pronation

Question 45

supracondylar fracture:

Answer 45

when the head of the radius gets pulled out of the anular ligament

Question 46

which extensor muscles are involved in fist clenching?

Answer 46

ECRB and ECU

Question 47

when is flexion able to be the greatest for the brachioradialis muscle?

Answer 47

midpronated position

Question 48

what muscles are innervated by the posterior interosseous nerve?

Answer 48

EDM, ECU, APL, EPL, EPB, and Extensor Indicis

Question 49

which type of deviation allows for greater movement at the wrist?

Answer 49

ulnar deviation

Question 50

what muscles make up each layer of the anterior forearm?

Answer 50

superficial layer: pronator teres, FCR, palmaris longus, and FCU intermediate layer: flexor sigitorum superficialis deep layer: flexor digitorum profundus, FPL, and pronator quadratus

Question 51

which flexor digitorum muscle flexes the distal phalanges?

Answer 51

FDP (FDS flexes the middle phalanges)

Question 52

which anterior forearm muscles are innervated by the ulnar nerve?

Answer 52

FCU and medial part (4th and 5th fingers) of FDP

Question 53

what encloses the Carpal Tunnel?

Answer 53

the flexor retinaculum

Question 54

what passes through the carpal tunnel?

Answer 54

``` tendon of flexor pollicis longus 4 tendons of flexor digitorum superficialis 4 tendons of flexor digitorum profundus median nerve (most superficial structure) ```

Question 55

what will you find in Guyon's Canal?

Answer 55

Ulnar never and artery (can be pinched at wrist elbow or neck

Question 56

where do the opponens pollicis, abductor pollicis brevis and flexor pollicis brevis muscles all originate from?

Answer 56

flexor retinaculum and tubercles of scaphoid and trapezium

Question 57

what muscle allows for flexion at the MCP joint and extension at the IP joints of 2-5 fingers which makes an appearance of a sock puppet?

Answer 57

lumbricals 1 and 2