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