Anatomy Forearm and Posterior Hand Flashcards
HOw can you get the MP, PIP, and DIP joint to extend at the same time in a single digit?
THe extensor hood forces them to contract together when the extensor digitorum contracts
What is the MP, PIP, DIP?
MP-> metacarpaphalangal
PIP-> proximal interphalangal
DIP-> distal phalangal
WHen you pull on the extensor hood, you will cause tension/contraction on what two bands?
lateral band and central band
What two muscles work together and extend the interphalangeal joints and flex the metacarpophalangeal joints?
lumbricals and interossei
What does the central band do?
attaches the extensor hood to middle phalanx
What does the lateral bands do?
attach the extensor hood to the distal phalanx
Where do the muscles of the fingers attach?
onto the lateral bad of the extensor hood
if you pull on the long extensor tendon what happens?
You extend you DIP and PIP
What does the FDP (flexor digitorum profundus) do?
flexes the distal interphalangeal joint
What does the FDS (flexor digitorum superficialis) do?
flexes the proximal interphalaneal joint
Without (blank) tendons at wrist you cant make a tight fist.
extensor
What do the tendons of the hand need in order to pass under the retinaculum?
a synovial tendon sheet
What is the retinaculum?
a CT sheeth that holds the tendons of the hands taught to prevent bow stringing and protect proper function
On the posterior side of the hand, what is the retinaculum called?
On anterior side?
the extensor retinaculum
the flexor retinaculum
Are the tendons of the hands exposed to the synovial fluid of the synovial tendon sheeth?
NOOOO, the synovial fluid sheeth forms a double walled synovial fluid filled capsule in which the tendon runs through the center without actually touching the fluid.
Most posterior forearm muscles arise from the common (blank) off the lateral epicondyle or the supracondylar ridge.
extensor tendon
Most posterior forearm muscles arise from the common extensor tendon off the (blank) or (blank).
(remember there are a few exceptions)
lateral epicondyle or the supracondylar ridge
off the sides of humerus
What are the exceptions to the “posterior forearm muscles come from lateral epicondyle or the supracondylar ridge)?
the three thumb muscles, the extensor indices, and the supinator
All posterior muscles are innervated by the (blank)
radial nerve (mostly the dep nerve)
What is the forearm muscle rules of three?
3 muscles to the thumb
3 muscles to the fingers
3 muscles to the wrist
3 muscles that do not cross the wrist joint
What are the three muscles to the thumb?
abductor pollicis longus
extensor pollicis brevis
extensor pollicis longus
What are the three muscles to the posterior wrist?
extensor carpi radialis longus
extensor carpi radialis brevis
extensor carpi ulnaris
What are the three muscles to the fingers?
extensor digitorum
extensor digit minimi
extensor indicis
What are the three muscles that do not cross the wrist joint?
brachioradialis
supinator
anconeus
How do you flex your hand?
What is your midline of your hand?
What is anatomical position of your thumb?
you make a fist
from wrist to tip of middle finger
perpendicular to the plane (i.e straight up 90 degrees from your palm)
When you flex your fingers what plane are you moving in?
the sagital across a transverse axis
putting your thumb out laterally from 90 degrees is considered what kind of movement? moving medially from 90?
extension
flexion
Flexion and extension of the thumb happens on what axis and in what plane?
AP axis
coronal
Ab/adduction of the thumb happens on what axis?
transverse axis and sagital plane
The muscles to the thumb are in what kind of order?
alphabetical from the thumb to the pinky
abductor pollicis longus, extensor pollicis brevis, extensor pollicis longus
Where does the abductor pollicis longus go and how many joints does it cross?
WHere does the extensor pollicis brevis go and how many joints does it cross?
where does the extensor pollicisi longus go and how many joints does it cross?
metacarple, 1 joint
proximal phalanx 2 joints
distal phalanx 3 joints
What two tendons create the snuff box?
Abductor pollicis longus (APL)
Extensor pollicis longus (EPL)
What is found within the snuff box?
radial artery
base of 1st metacarpal
styloid process of radius
crossed by dorsal digital branches of radial nerve
The extensor digitorum breaks into (blank) tendons.
4, one for each finger or 3 where the ring finger branches into 2 to make sort of 4
The extensor digiti minimi has a tendon for the (blank) finger
pinky
The extensor indicis has a tendon for the (blank) finger.
index
The extensor digitorum, extensor digiti minimi, and extensor indicis extends the fingers as well as the (blank)
wrist
Extensor carpis radialis longus and extensor carpis radialis brevis attach to which metacarples?
the longus attaches to the second metacarple and the brevis attaches to the third metacarple
What does carpi mean in latin?
wrist :)
What do the extensor carpi ulnaris and the extensor carpi radialis (brevis and longus) do besides extension on the wrist?
adduction and abuduction
What is the highest muscle attaching to the lateral superchondrial ridge?
the brachioradialis
Where does the radial nerve gain access to the posterior forearm and divide into a superficial and a deep?
The brachioradialis
What is the brachioradialis innervated by?
the radial nerve
What is super peculiar about the brachioradialis?
it is a posterior compartment muscle, innervated by a posterior compartment nerve that acts as an anterior compartment muscle i.e it undergoes flexion
Why is the brachioradialis considered the friendly muscle?
because it allows you to drink beer and handshake
From anatomical position, how will your brachioradialis make you move?
pronate to halfway (handshake) position
What muscle am I talking about:
it is a deep muscle and comes from the ulna and wraps around the radius and functions in supination?
the supinator
(when you have your palms facing your butt (i.e pronated) it will work to make your palms face outwards (i.e supinated).
What besides the supinator, allows for supination?
biceps
Where do you find pronators?
on the anterior compartment of the forearm but same sort of distribution of the supinator
What innervates all the muscles of the posterior compartment?
radial nerve
Which part of the radial nerve innervates most of the muscles in the forearm?
the deep
Before the radial nerve divides, what does it innervate?
the brachioradialis and the extensor carpi muscles
What part of the radial nerve goes underneath the brachioradialis and gives off cutaneous branches (sensory) to the thumb, index and half of the middle finger?
the superifical branch of the radial nerve
The deep radial nerve turns into what once it hits the wrist area?
turns into the posterior interossesous nerve
What will damage to the radial nerve at the wrist cause?
sensory loss at your fingers and thumb
What will damage to the deep radial nerve cause?
motor loss o posterior compartment muscles resulting in loss of extension and loss of flexion of brachioradialis
IS the deep radial a motor or sensory nerve?
ALLL motor baby
If you had a midhumeral shaft break that damaged your radial nerve what would happen to your tricep?
it would lose motor function
What gives cutaneous sensation to the shoulder?
axillary
What gives cutaneous sensation to the lateral part of the arm?
radial and lateral antebrachial cutaneous (off of musculocutaneous branch)
What gives cutaneous sensation to the to the medial side of the arm?
medial antebrachial cutaneous
What gives cutaneous sensation to the middle posterior forearm and thumb, index and middle finger and half of the ring finger ?
radial nerve
What gives cutaneous sensation to the pinky finger and half of the ring finger?
ulnar
What gives cutaneous sensation to the majority of your palm and your thumb, index, pointer ,and half of your ring finger?
median
Damage to the radial nerve in the forearm will have primary effects in the (blank) and (Blank)
wrist (wrist extension) extensor digitorum (finger extension)
Why will you lose grip strength if you mess up your radial nerve?
cuz to achieve max grip you wrist needs to be extended, loss of extension-> loss of grip
How do you get compartment syndrome?
trauma restricts blood flow in a fascial compartment resulting in high pressure and edema and damage to nerves and muscles
What does the radial artery come off of?
the brachial artery
If you tie off the brachial artery below the profunda can you still get flow to your forearm?
yes via the profunda brachii which comes of the brachial artery and turns into the radial collateral artery and anastomoses with the radial artery
AND
Via the ulnar artery
If you tie off the brachial artery above the profunda can you still get flow between the shoulder and the arm?
yes because you the posterior humeral circumflex anastomoses with the profunda which will meet the brachial artery
What are the two arches of the hand that allow for collateral flow between the ulnar and radial artery?
superificial and deep palmar arches
most blood to the digits comes from the (blank) arch except the index finger and thumb.
superificial
What is this:
motor branch to anterior arm muscles
cutaneous (sensory) branch as lateral cutaneous nerve of forearm (lateral antebrachial cutaneous nerve to forearm)
musculocutaneous nerve
What is this:
Gives off muscular branches to all forearm EXCEPT flexor carpi ulnaris and the medial two heads (little finger and ring finger) of the flexor digitalis profundus which get their innervation for the ulnar
median nerve
What muscles does the median nerve NOT Innervate in the forearm?
median 2 heads of the flexor digitorum profundus and the flexor carpi ulnaris
What does the ulnar nerve innervate?
the anterior compartment muscles that the median nerve does not innervate (flexor carpis ulnaris, flexor digitorum profundus medial 2 heads pinky and ring finger) AND cutaneous innervation to the hand
What comes out around the spiral groove wand innervates the three heads of the triceps?
the radial nerve
What part of the radial nerve will give cutaneous info to the hand (3 1/2 digits on the posterior surface)?
superficial radial
What part of the radial nerve will give motor innervation to all the muscles of the posterior forearm?
the deep radial
What is a nice place to attach muscles and maintain the integrity of the ulna and radius?
the interosseus membrane
What allows for the radius to rotate over the ulnar?
the interosseus membrane and the proximal and distal radialulnar joint
Why does the interosseus membrane have a particular orientation to its fibers?
to allow for tightening when a persons falls on their hand to absorb the shock (i.e. it is a shock absorber)
The brachial comes down and divides into way 2 arteries?
the radial and ulnar
Which of the wrist tendons are held in place by the flexor retinaculum?
the deep tendons (flexor carpi ulnaris and flexor carpi radialis)
What are the five superficial muscles of the anterior forearm?
1) pronator teres
2) flexor carpi radialis
3) palmaris longus
4) flexor digitorum superficialis
5) flexor carpi ulnaris
(in order from lateral to medial)
What does pollicis mean?
inch (for the thumb, cuz thumbs were used to measure inches)
What are the three deep muscles of the anterior forearm?
flexor pollicis longus
flexor digitorum profundus
pronator quadratus
Many books place the (blank) in an intermediate position of the anterior forearm because of its extensive origin.
Flexor digitoris superficialis
Where do the deep muscles of the anterior forearm arise from?
the interosseus membrane or radius and ulnar
What is the relationship between the bicep tendon and the brachial artery and median nerve?
it goes tendon, brachial artery, medial nerve (from lateral to medial)
What deep anterior forearm muscle goes to the thumb?
What deep anterior forearm muscle goes to four of your digits?
What deep anterior forearm muscles is a quadrangular muscle sitting near your wrist?
flexor pollicis longus
flexor digitorum profundus
pronator quadratus
What are your three wrist flexor muscles?
flexor carpi ulnaris
flexor carpi radialis
palmaris longus
What are the two finger flexor muscles?
flexor digitorum superficialis
flexor digitorum profundus
What muscle does this:
it will attachs at the radius and medial condyle and extends into the hand where its tendons will split and attach to the base of the middle phalanx?
What muscle has its tendon go through this slit and attaches to the base of the distal phalanx.
flexor digitorum superficialis
flexor digitorum profundus
What joints do the FDS and FDP work at?
FDS works at MC, PIP, wrist
FDP works at MC, DIP, wrist
How do you keep the tendons of the FDS and FDP from bow stringing?
the central/lateral bands and extensor hood
What are the three muscles to the anterior wrist?
Flexor carpi radialis
Flexor carpi ulnaris
Palmaris longus
