Anatomy Posterior Forearm and Hand Flashcards
How can the anterior hand be divided?
into the thenar (thumb) and hypothenar (little finger) compartments and lumbricals and interossei
Are there intrinsic hand muscles in the dorsum of the hand?
no
What are the lumbricals and interossei?
true intrinsic muscles of the hand
What are found lateral and medial to the palmar aponeuroses?
Lateral to the aponeurosis are the thenar mucles
medial to the aponeurosis are the hypothenar muscles
What are the kinds of muscles of the thenar muscles and the hypothenar muscles.
Each has an O A F
opponens, abductor, flexor
What does the palmaris longus tendon turn into?
the palmaris aponeurosis
What is this:
a disease of the palmar fascia resulting in thickening and shortening of fibrous bands on the palmar surface of the hand and fingers
Dupuytren’s contracture
What are the three thenar muscles of the anterior hand?
opponens pollicis
abductor pollicis brevis
flexor pollicis brevis
What nerve innervates the thenar muscles?
the median nerve
Why is the adductor pollicis not considered part of the thenar muscles?
cuz it is not innervated by the median nerve
What are the three muscles of the hypothenar muscles?
opponens digiti minimi
abductor digiti minimi
flexor digiti minimi (brevis)
What nerve innervates the hypothenar muscles?
ulnar nerve
Where do opponen muscles attach to?
to the metacarples
What is known as the million dollar nerve?
the recurrrent branch of the median nerve that goes to thenar muscles; million dollar cuz if you have damage here you will lose your ability to use your thumb (i.e. no grasping)
What canal does the ulnar nerve an artery travel in?
Guyon’s canal
A main entrance to the hand is found in the (blank)
carpal tunnel
What artery and nerve does not pass through the carpal tunnel?
ulnar artery and nerve (cuz they have their own tunnel, the guyon canal ;)
How many tendons and what nerve does the carpal tunnel have?
9 tendons and median nerve
If you compressed the anterior portion of your wrist? What would be the symptoms associated with it?
median nerve
cutaneous issues, numbness, parasthesia in 1, 2, 3, and 1/2 fingers
What are the 9 tendons and the nerve of the carpal tunnel?
4 from the FDS
4 from the FDP
1 from the FPL
median nerve
If your hand is in the anterior position, and you are looking at the carpal tunnel where would you find the FPL?
laterally
What muscles of the hand are associated with long tendons?
lumbricals
What are the muscles on the posterior part of your hand closest to the skin?
the dorsal interosseus muscles
What are the muscles on the anterior part of your hand closest to your skin?
lumbricals
What happens if you rupture the tendon sheath of the 2nd phalanx?
It will rupture into the thenar space
What happens if you rupture the tendon sheaths of the 3rd and 4th phalanges?
it will rupture into the midpalmar space
What happens if tendon sheaths 1 and 5 become infected and rupture?
they rupture into the forearm
The (blank) hold the long flexor tendons tightly against the metacarpals and the phalanges.
fibrous digital sheaths
Bands (blank) and (blank) are on the proximal and middle phalanx respectively, and bands (blank), (blank), and (blank), are near the MP, PIP and DIP respectively.
A2 and A4
A1, A3, and A5
In the finger synovial tendon sheeths, how many tendons are there?
2
Where do the lumbricals originate from?
the flexor digitorum profundus tendons
Where do the lumbricals insert into?
extensor hoods
What are the lumbricals innervated by?
median and ulnar nerves
What side of the tendons of the flexor digitorum profundus do the lumbricals attach to?
the radial side
What fingers are innervated by the median nerve?
1,2,3
What fingers are innervated by the ulnar nerve?
ring and pinky finger
The (blank) nerve takes care of all the intrinisic muscles of the hand, except for the thenar compartment and the lumbricals to the functional midline of the radial side (i.e. index and middle).
ulnar
What does the ulnar nerve innervate?
all the intrinisc muscles of the anterior hand except for the thenar compartment muscles and lumbricals to the funtional midline of the radial side (index and middle)
What are the interosseus muscles?
dorsal and palmar muscles
Where do interosseous muscles originate and where do they insert?
metacarples and insert on the extensor hood
What do the interosseous muscles do?
adduct (palmar muscles adduct PAD
abduct (dorsal muscles abduct) DAB
the MP joints relative to digit 3
Where do we find the dorsal and palmar muscles of the hand?
How is this so?
they are both anterior compartment muscles
Because they are both innervated by the ulnar nerve
How do the interosseous muscles pass the MP joint?
Why is this important?
anteriorly
Cuz they allow for flexion at this joint
The lumbrical and the interosseous muscles insert into the (blank).
extensor hood
So all in all, what do the lumbricals and the interosseous muscles do?
they flex the MP (interosseous) and extend the PIP and DIP (lumbricals)
The FDP flexes the (blank)
distal interphalangeal joint
The FDS flexes the (blank)
proximal interphalangeal joint
If you dont have extensor tendons at your wrist can you make a tight fist?
nope
If you tear off your central band what would happen?
it would extend the DIP and flex the PIP
If you tear off your lateral band what would happen?
cannot extend the DIP
The (blank) artery goes across the snuff box and forms part of the deep palmar arch.
radial artery
What does the deep palmar arch communicate with?
the radial artyer and superficial palmar arch
What do the palmar arches give off?
common digital branches which split and give off small dorsal branches
What is their an important anastomosis between that is utilized in the alan test?
between radial and ulnar arteries
What is the most common wrist fracture in children
fracture of scaphoid
(blank) is permanent failure of healing following a broken bone.
Nonunion
What is worrisome about a scaphoid fracture?
sometimes hard to notice and you get non-union due to poor blood supply and the proximal portion can can undergo necrosis
On the posterior part of your hand, what all does your median nerve innervated?
What about on the anterior part?
just the last part of your thumb, index, middle, and half the ring?
palm and thumb, index, middle and half of ring
On the posterior part of your hand, what all does your ulnar nerve innervate?
On the anterior part of your hand?
the pinky and half your ring finger
pinky and half your ring finger
On the posterior part of your hand, what does the radial nerve innervated?
On the anterior part of the your hand?
most of the back of the hand up to halfway to 1,2,3, and half of a half of 4
just lower part of thumb like the snuff box area
what is the innervation to the shoulder?
to the elbow?
to the wrist?
to the hand?
C5,6
C6,7
C7,8
C8,T1
What innervates the anterior ARM?
musculocutaneous
How is the anterior FOREARM innervated?
all is median except for flexor carpis ulnaris and 4,5 of flexor digitorum profundus
What innervates the anterior hand?
all ulnar except thenar compartment muscles and the three lumbricals to the functional midline on radial side (median)
What nerve innervates the shoulder?
axillary (deltoid and teres minor)
What innervates the posterior ARM and FOREARM?
radial
What is this:
damage to upper trunk of brachial plexus, and shoulder movements are most dramatically affected
Erb-Duchenne paralysis
(C5 and C6) damage
Why will patients with erb-duchenne palsy sometimes have flexes wrists?
because the ulnar nerve is still intacted creating more flexion than usual
What do you call erb-duchenne palsy in adults?
Porter’s tip hand
What is klumpke’s paralysis?
What nerve roots contribute to this damaged part of the plexus?
damage to lower trunk of brachial plexus
C8,T1 contribute and thus will e damaged.
What is most affected in klumpke’s paralysis?
had movements are affected most (remember damage to the lower trunk will affect your medial pectoral, medial brachial, medial antebrachial and ulnar the most, so sad day)
In klumpke’s paralysis, you lose C8 and T1, so what will losing T1 do?
make you lose sympathetics to the head so you will get squinty eyes
If you damage your axillary nerve what will be weakened?
wont be able to abduct
wont have lateral rotation
If you damage your musculocutaneous what will be weakened?
Almost no forearm flexion (cuz brachioradialis does some flexion from the radial nerve), weakened arm flexion
Where is the axillary nerve prone to injury?
at the surgical neck
What does the supraspinatus and the deltoid initiate?
abduction
Why will you have weakened lateral rotation if you damage your axillary nerve?
because you will lose teres minor BUT you will still have supraspinatus nerve to the infraspinatus which will allow for some lateral rotation
What will happen if you damage your radial nerve?
you will get NO forearm extension, are may be slightly flexed (cuz you wont have counteracting forces)
What branches off the radial nerve and gives sensation to the posterior forearm?
the posterior antebrachial cutaneous nerve of forearm
What innervates the teres major?
lower subscapular nerve
What what does the teres minor do?
it laterally rotates the arm
What does the teres major?
medially rotates the arm
What does pec minor do?
makes you small like arnold
protraction, medially rotates scapular, depression
What does pec major do?
adductor and medially rotate
SO the (blank) nerve splits into a superficial and deep branch. The deep innervates the muscles in the posterior forearm and the superficial is basically sensory and ends in the hand as cutaneous branches to the fingers.
Radial
What does the deep branch of the radial nerve innervate?
it innervates the posterior compartment muscles of the forearm
What does the superficial branch of the radial nerve innervate?
it is a sensory nerve to the hand
Does the superficial branch of the radial nerve do anything before it reaches the hand?
NO, it only gives cutaneous innervation to the hand
If you damage the radial nerve high in the arm what will it cause?
wrist drop, weak or absent wrist and digit extension and no extension at the elbow, and lack of grip strength (due to lack of ability to extend your wrist)
If you damage to the radial nerve in the forearm what will happen?
have problems with wrist, digit extension and grip strength
What is the easiest way to get radial nerve damage?
mid humeral shaft fracture
What is the motor branches to the anterior arm?
musculocutaneous nerve
How does the musculocutaneous nerve give cutaneous innervation to the forearm?
the musculocutaneous nerve gives off the lateral antebrachial cutaneous branch that gives innervation to the lateral forearm
What does the median nerve do in the arm?
What does the median nerve do in the forearm?
Nothing
innervates all muscles except flexor carpi ulnaris and half of flexor digitorum profundus
What does the median nerve do in the hand?
MOTOR innervation to the 2LOAF
2 lumbricals
thenar compartment (abductor policis brevis, oppnenens policis, flexor policis brevis)
How does the median nerve give cutaneous innervation?
it gives it in the 3 1/2 digits
(3 and 1/2 digits and most of palm on anterior side)
top half of 3 1/2 digits on the posterior side
What supplies muscular branches to all anterior forearm compartment muscles except flexor carpi ulnaris and the medial two heads of FDP?
Median nerve
The motor innervation to the flexor carpi ulnaris and the medial two heads of FDP is innervated by the (blank) nerve.
ulnar nerve
What does the median nerve supply with motor innervation in the hand?
thenar compartment muscles and lumbricals to digits 2 and 3
What gives cutaneous innervation to the palm and three and 1/2 digits (radial side) on the palmar surface and the top halves of the 3 1/2 digits (radial side) on the posterior part of the hand?
Median nerve
Damage at the elbow results in the (blank)
hand of benediction
If you get damage to your median nerve what will your hand look like?
You will lose all flexion to pip and dip of 2+3 but not complete for 4+5 and get derotated thumb
(i.e hand of benediction)
How do you get carpal tunnel?
you compress the median nerve in your wrist
So tell me what you look like if you have carpal tunnel?
you will have a jacked up thumb (derotated) and muscle wasting of your thumb. and decreased flexion of your lumbricals (3 1/2)
What does the ulnar nerve do in the hand?
it innervates all muscles except for the thenar compartment and half the lumrbicals
What cutaneous innervation does the ulnar nerve supply?
gives cutaneous innervation to 1 1/2 digits (vertically split)
What does the ulnar nerve do in the arm?
nothing
What is the most likely way you will get ulnar nerve damage?
at the elbow by damaging medial epicondyle OR in guyon’s canal
If you get ulnar nerve damage what will your hand look like?
claw hand
Lose ALL interossei resulting in hyperextension at MP joints which causes flexion of fingers.
(but 14,5 are really affected)
At what joint do the interossei mostly work at?
the MP joint (typically flex MP joint)
Following tendon and ligament injuries, the hand takes on distinctive positions due to:
(blank, blank, and blank)
loss of movement
unopposed pulls
shifted axes
What kind of injury will you get if you tear the FDP off the distal phalanx?
jersey finger
How do you know if you have a FDP problem?
they cannot flex their DIP will holding their MP or PIP
How do you know if you have a FDS problem?
pull back all their fingers except affected on and see if they can flex the affected one, if they have a problem they wont be able to do this
How do you get a mallet finger?
Injury to the joint extensor tendon at the distal interphalangeal joint
(break lateral band)
What are the 2 ways you can injure the joint extensor tendon?
avulsion fracture or ruptured tendon via break of lateral band
What is a boutonniere deformity?
when you get a volar migration of the lateral band due to a central band injury resulting in lose of extension at PIP (so get flexion) and get more extension at the DIP
Repair of fractures of the 4th and 5th metacarpal rely on the (blank) for holding the metacarpal in place.
transverse metacarpal ligaments
(blank) stabilize the hand in single metacarpal fractures.
transverse metacarpal ligament
Why cant you abduct your fingers when your wrist is flexed?
because your transverse metacarpal ligament becomes tight in this position.
To flex and extend at the humeroulnar joint, what axis will you be on?
transverse
TO flex and extend at the humeroradial joint, what axis will you be one?
transverse
To pronate and supinate (rotation) of the humeroradial joint what axis will you be on?
vertical
To rotate (pronate and supinate) the radioulnar joint, what axis will you be on?
vertical
To flex and extend the radiocarpal joint, what axis will you be on?
transverse
To abduct and adduct the radiocarpal joint, what axis will you be on?
AP
The (blank) joints are five joints in the wrist that articulate the distal row of carpal bones and the proximal bases of the five metacarpal bones.
carpometacarpal (CMC)
SO what are the significant carpometacarpals?
1st and 5th
Why is the 1st carpometacarpal significant?
because it is multiaxial
Ab/AD
Flex/Extend
Rotation
Are the MP joints 2-5 uniaxial, biaxial or multiaxial?
they are biaxial
flex/extend
ab/ad
IS the MP joint of 1, uniaxial, biaxial, or multiaxial?
uniaxial
flex and extend
What axis do the interphalangeal joints (DIP and PIP) work on?
uniaxial
flex extend on transverse axis
A (blank) is defined as a union between two or more rigid elements of the skeleton-bone or cartilage.
joint
What are the two general classifications of joints?
synovial
nonsynovial
What is a synovial joint?
skeletal elements that are separated by a joint cavity or space that contains synovial fluid “freely movable”
What is a nonsynovial joint?
the skeletal elements are directly connected or continuous with each other “non movable”
What kind of joints are these:
sutures
tooth ‘socket’
interosseous membrane b/w shafts of radius and ulna
non-synovial fibrous joints
What kind of joint is this:
skeletal elements are connected to each other by connective tissue
non-synovial fibrous joints
Is there are lot of movement in fibrous joints?
What is an exception?
no (but there are exceptions)
interosseous membrane b/w radius and ulna is a fibrous joint with movement
Are cartilaginous joints synovial or non synovial?
non synovial
What are skeletal elements connected by?
cartilage
Is there a lot of movement at cartilaginous joints?
slight movement (but there are lots of exceptions)
What is a movable cartilaginous joint (i.e. one of the exceptions)?
pubic symphysis and intervertebral discs
Most of the upper limb joints are (blank)
synovial
There is a (blank) separating the skeletal elements that contain synovial fluid in synovial joints.
space (cavity)
The articular surfaces of the skeletal elements are covered by (blank) in synovial joints
articular/hyaline cartilage
(blank) joints are usually characterized by free movement
synovial
What are the six components of the synovial joints?
skeletal elements articular cartilage (usually hyaline cartilage) joint capsule (fibrous capsule) synovial fluid in synovial cavity synovial membrane ligaments
(blank) function to stabilize a joint and help to prevent or limit unwanted movement at a joint
ligaments
What is the most common ligament?
the capsular ligament
Describe an extracapsular ligament
ligament then little space and then joint capsule
What is an intrascapular ligament?
ligament within the capsule that is not subject to synovial fluid of capsule
The (blank) ligaments are the reason why the clavicle breaks where it does. Without these ligaments AC separations would be more frequent.
coracoclavicular ligaments
(blank) forms roof of glenohumeral joint and helps stabilize shoulder joint
coracoacromial ligament
(blank) ligament forms capsule of shoulder joint anteriorly and is strengthened by the tendons of the rotator cuff.
glenohumeral joint
The (blank) is an inherently unstable joint.
glenohumeral joint
The (blank) joint allows gliding movement when you elevate or depress the clavicle.
AC
(blank) is a continuous ring of cartilage around the glenoid fossa that helps deepen the socket but is unfortunately easy to rip off.
glenoid labrum
Why is the glenoid labrum easily ripped off?
cuz the long head of the bicep attaches to the supraglenoid tubercle which can pull at the glenoid labrum, so a tear in the bicep can tear this.
What surrounds the tendon of the bicipital long head as it emerges from the glenohumeral joint capsule between the lesser and greater tubercle?
What is special about this?
a bursa
common site of bursitis AKA bicipital tenosynovitis
Are there any tendons inferiorly of the glenohumeral cavity?
no, that is why you most often have a tear that is inferior and anterior
What are the rotator cuff muscles and what are they used for?
stability of GH joint
Supraspinatus (innervated by supraspinatus nerve)
infraspinatus (innervated by supraspinatus nerve)
teres minor (axillary nerve)
subscapularis (upper and lower subscapular nerve)
How do you get shoulder dislocation?
trauma to GH
rotator cuff tear/trauma
happens when you have abduction or extension
How do you get shoulder separation?
injury to the AC joint and coracoclavicular ligaments
What are the three articulations in the region that we call the “elbow joint”?
humeroulnar
humeroradial
proximal radioulnar
What happens at the humeroulnar articulation?
flexion and extension at the elbow joint
What happens at the proximal radioulnar articulation?
pronation and supination of forearm
Describe the elbow joint
its baggy on anterior and posterior aspects to facilitate flexion and extension
What side of the humerus is the capitulum on?
it is on the anterior part near the radial side
What does the radial notch do?
allows radius to glide along it
What ligament of the elbow prevents adduction of forearm?
radial collateral ligament
What ligament of the elbow prevents abduction of forearm?
ulnar collateral ligament
What ligament of the elbow surrounds the radius head?
annular ligament
What does the radial collateral ligament attach to?
to the annular ligament
Where does the annular ligament attach to?
to the ulna anteriorly, superiorly and posteriorly
wraps around radius and goes to ulna which holds the head of the radius against the capitulum
What is this:
force causes radial head to subluxate (slightly removed, not as severe as a dislocation which is completely removed) from anular ligament. Arm will be slightly flexed and supinated
nurse made elbow
caused by pulling up on the arm of a child
What are the three joints between the radius and ulna?
proximal radioulnar (anular ligament) middle radioulnar (interosseous membrae) distal radioulnar (couple of ligaments)
What are the three joints between the radius and ulna used for?
pronation and supinationn
The (blank) is designed to transfer forces from the radial carpal joint to the radius, to the membrane, over to the ulna, and up to the humeroulnar joint.
interosseus
The distal radio-ulnar joint has a (blank)
disc
The (blank) attaches to scaphoid and trapezium laterally and pisiform and hamate medially
transverse carpal ligament (flexor retinaculum)
What does the transverse carpal ligament (flexor retinaculum attach to)?
laterally-attaches to scaphoid and trapezium
medially-pisiform and hamate
What are the bones of the wrist?
Some Lovers Try Positions That They Cant Handle
Scaphoid, Lunate, Triquetral, pisiform, trapezium, trapezoid, capitate, hamate
