Forearm & posterior hand-->sievert Flashcards
1
Q
T/F There are no muscles in your posterior hand.
A
TRUE
2
Q
So, if there are no muscles in your posterior hand, what are there?
A
tendons from muscles of the forearm
3
Q
What are phalanges & where are they found?
A
basically, parts of a finger.
3 phalanges per finger
2 phalanges per thumb
4
Q
What are the names associated with each phalange of the fingers?
A
proximal phalange
middle phalange
distal phalange
5
Q
What are metacarpals & how many of them are there?
A
there are 5
they are the bones that go in your hand up until the point of phalanges.
6
Q
What are the joints of the fingers?
A
MP: metacarpal phalangeal joint
PIP: proximal interphalangeal joint
DIP: distal interphalangeal joint
7
Q
Can the MP, PIP, & DIP joints be acted on separately? Explain.
A
- *they can be flexed individually
* *they are all extended at once b/c of the extensor hood arrangment
8
Q
Which muscle extends the MP, PIP, & DIP joints all at once?
A
the extensor digitorum
9
Q
What is the thing that can pull on the extensor hood & cause extension of the fingers?
A
long extensor tendon
10
Q
What are the 2 continuations of the extensor hood onto the fingers?
A
Central band: connects to middle phalanx
Lateral bands: connects to distal phalanx
11
Q
What are the 2 muscle types that act on the extensor hood? What is their action when they act together?
A
lumbricals
interossei
Together: extend interphalangeal joints
flex metacarpophalangeal joints
12
Q
What does the flexor digitorum profundus flex?
A
DIP joint
13
Q
What does the flexor digitorum superficialis flex?
A
PIP joint
14
Q
T/F Without extensor tendons at your wrist, you couldn’t make a tight fist.
A
True.
15
Q
What is the retinaculum? Where is it located?
A
Retinaculum is a tendon that keeps the tendons from moving around underneath.
It is is right before the wrist. It runs transversely.
On the posterior side of the hand: called extensor retinaculum.
16
Q
What protects the tendons underneath the retinaculum from being torn up by the retinaculum moving against it?
A
it is protected by synovial tendon sheaths that surround it. there are a lot of these & they can become infected.
17
Q
Most posterior forearm muscles come from where?
A
common extensor tendon
18
Q
Where does the common extensor tendon attach?
A
the lateral epicondyle or the supracondylar ridge of the humerus
19
Q
What are the exceptions to the rule, which muscles of the posterior forearm don’t come from the common extensor tendon? What are some places where these come from?
A
3 thumb muscles
extensor indices
supinator
**radius, ulna, interosseus membrane
20
Q
What position is your hand in when it is supinated?
A
it is in a position to hold a soup bowl!
21
Q
All posterior forearm muscles are innervated by what nerve?
A
Radial nerve, mainly the deep branch.
22
Q
What is the posterior forearm’s rule of 3s?
A
there are 3 muscles that go to the thumb
there are 3 muscles that go to the fingers
there are 3 muscles that go to the wrist
there are 3 muscles that don’t cross the wrist joint
23
Q
What are the 3 posterior compartment forearm muscles that go to the thumb?
A
extensor pollicis longus
extensor pollicis brevis
abductor pollicis longus
24
Q
What are the 3 posterior compartment forearm muscles that go to the fingers?
A
extensor digitorum
extensor indicis
extensor minimi
25
What are the 3 posterior compartment forearm muscles that go to the wrist?
extensor carpi radialis longus
extensor carpi radialis brevis
extensor carpi ulnaris
26
What are the 3 posterior compartment forearm muscles that don't cross the wrist joint?
anconeus
supinator
brachioradialis
27
T/F In the anatomical position, the thumb is in the same plane as the fingers.
FALSE. It is in a different plane. off by 90 degrees, why we are humans & not chimps or something.
28
What does abduction & adduction look like for fingers?
So...the midline in this case is the middle finger. Abduction is spreading the fingers out & adduction is smooshing the fingers closer together.
29
What does flexion & extension of the fingers look like?
Flexion: bending fingers @ creases, almost making a fist
Extension: straightening out your fingers.
30
When your fingers flex, what plane & what axis do they do it in?
Fingers Flex
Plane: sagittal plane
Axis: transverse axis
31
When your thumb flexes, what plane & what axis does it do it in?
Thumb Flexes
Plane: Coronal Plane
Axis: AP axis
32
What does extension of the thumb look like?
like a hitch hiker's thumb
33
On which axis do you abduct & adduct your fingers?
transverse axis
34
What is the anatomical snuff box?
sort of the triangular portion of the dorsum of your hand, by your thumb.
35
Of the posterior forearm muscles to the thumb, which is the most ventral-leaning? Which is the most strictly dorsal? How many joints does each cross? Where does each one insert?
Abductor pollicis longus: more ventralish, crosses 1 joint, inserts @ base of the metacarpals.
Extensor pollicis brevis: middle, crosses 2 joints, inserts @ proximal phalanx
Extensor pollicis longus: most dorsal, crosses 3 joints, inserts @ distal phalanx.
36
T/F The abductor pollicis longs comes from the lateral epicondyle.
False. Remember, all the thumb muscles are an exception to the rule & don't come from the lateral epicondyle or the supracondylar ridge.
37
What are the muscles/tendons that make up the boundaries of the anatomic snuff box?
abductor pollicis longus
extensor pollicis brevis
extensor pollicis longus
38
What is the most important thing that is found in the snuff box?
**radial artery
this is where the radial artery changes from being on the anterior surface of the hand to being on the posterior surface.
39
Aside from the radial artery, what else is found in the snuff box?
radial artery
base of the first metacarpal
styloid process of the radius
crossed by dorsal digital branches of the radial nerve
40
What's the deal with the extensor digitorum?
this is one of the posterior forearm muscles that supplies the fingers. It divides into 4 tendons, 1 for index, 1 for middle, 1 for ring. Additionally, there is a branch off of the ring finger tendon for the pinky finger.
41
What's the deal with the extensor digiti minimi?
this is a muscle that supplies the pinky finger.
42
What's the deal with the extensor indicis?
this is a deep muscle that comes off the ulna & continues onto the index finger
43
Aside from helping extend the fingers, what can the extensor digitorum, extensor digiti minimi, & extensor indicis do?
They can assist in the extension of the wrist.
44
Of the posterior forearm muscles that go to the wrist, which arises most superiorly?
the extensor carpi radialis longus comes from the supracondylar ridge, high up.
45
Which of the posterior forearm muscles that act on the wrist are near the radial side & which are near the ulnar side?
```
Radial side/thumb side:
extensor carpi radialis longus
extensor carpi radialis brevis
Ulnar side/pinky side:
extensor carpi ulnaris
```
46
Where do the posterior forearm muscles supplying the wrist attach?
**to the bases of metacarpals
| extensor carpi radialis longus & brevis attach to the base of the 1 & 2 metacarpals.
47
T/F there is not a whole lot of movement b/w carpals & metacarpals.
True.
48
What actions of the wrist do the posterior forearm wrist muscles assist in?
extension of the wrist
abduction of the wrist
adduction of the wrist
49
What is abduction of the wrist like?
aka radial deviation
| shifting the wrist more away from the body
50
What is adduction of the wrist like?
aka ulnar deviation
| shifting the wrist more towards the body.
51
What's the deal with the anconeus?
it's not really important
comes from the supracondylar/lateral epicondyle area & inserts @ the ulna
helps pull away the capsule of the joint & assists in extension
52
What is the highest muscle attaching to the supracondylar ridge/lateral epicondyle area?
brachioradialis muscle
53
What is super special about the brachioradialis muscle?
it is a posterior compartment muscle & is innervated by a posterior compartment nerve (radial nerve) but it serves an anterior compartment function
54
Where does the brachioradialis muscle attach?
styloid process of the radius
55
What are the actions of the brachioradialis muscle?
flexion at the elbow joint
| putting the hand in the handshake position (accomplishes a little pronation in this process)
56
Where is the supinator? What is its action? Which muscle sometimes helps it out?
this comes from the ulna & wraps around the radius
* *it supinates the radius
* *biceps also partially supinates.
57
What does the radial nerve innervate?
all the muscles of the posterior compartment
58
Describe the branching of the radial nerve.
first: radial nerve proper gives off a branch to the brachioradialis muscle & the extensor carpi radialis longus muscle.
then: radial nerve proper splits into a superficial & deep branch.
59
What happens to the superficial branch of the radial nerve?
it travels underneath the brachioradialis muscle & becomes cutaneous on the dorsum of the hand.
this is a sensory nerve.
it supplies the thumb, index, middle, & half of the ring finger.
60
What happens to the deep branch of the radial nerve? What does it become known as?
this innervates the rest of the muscles of the posterior compartment
as some point it becomes known as the posterior interosseus muscle
61
If you damaged the radial nerve where it comes out on the dorsum of the hand...what would result?
cutaneous sensory loss only to the hand & fingers
62
If you damaged the radial nerve only where the deep radial nerve branch is...what would result?
motor loss to the muscles of the posterior compartment
63
If you damaged the radial nerve @ the level of the mid-humeral shaft...what would result?
in addition to losses to the muscles of the posterior compartment, you would get losses to the triceps
64
Where does the medial ante brachial cutaneous nerve come from? What dermatome does it innervate?
comes from the brachial plexus
innervates middle & medial side of the arm & forearm anteriorly
innervates medial side of the forearm posteriorly
65
Where does the lateral ante brachial cutaneous nerve come from? What does it innervate in terms of dermatomes?
comes from the musculocutaneous nerve
| innervates the lateral side of the forearm posteriorly & anteriorly.
66
What does the musculocutaneous nerve innervate?
the anterior compartment muscles of the arm
67
What innervates the tips of the fingers in terms of dermatomes?
on both the anterior & posterior side:
thumb, index, middle & half ring fingers: median nerve
half of the ring finger & little finger: ulnar nerve
68
What innervates the dorsum of the thumb?
radial nerve
69
What innervates the palms & bulk of the fingers (anterior side)?
Anteriorly:
pinky, half of ring finger & that portion of the palm innervated by ulnar nerve
half of ring finger, middle, index, & thumb & that portion of the palm innervated by median nerve
70
What innervates the dorsum of the hand & bulk of the fingers on the posterior side?
Posteriorly:
pinky & half of ring finger & that portion of the dorsal hand: ulnar nerve
half of ring finger & middle & index & thumb & that portion of the dorsum hand: radial nerve.
BUT: dorsal tips of fingers of the middle, index, thumb are median nerve.
71
If you damage the radial nerve high in the arm, what will the result be?
wrist drop
weak wrist & digit extension
no elbow extension
reduced grip strength (b/c w/o extension, not enough ROM to make a fist)
72
If you damage the radial nerve in the forearm, what will the result be?
primarily affect the wrist & digit extensors
73
What is compartment syndrome?
this is when you get a snake bite to your arm or forearm (maybe even your leg) or you get some other cause of massive swelling/edema. The investing fascia is so restrictive that the swelling can damage the blood vessels, nerves, muscles b/c of the high pressure.
Blood flow impairment-->permanent damage.
74
What procedure may be necessary if a patient is experiencing compartment syndrome?
fasciotomy, you remove parts of the fascia to release pressure.
75
Where does the axillary artery begin? What does the axillary become as it travels down the arm? When does this transition happen?
Begins @ first rib
Axillary turns into the brachial artery
this happens after the axillary passes the teres major muscle.
76
What is an important branch of the brachial artery when it is still in the arm? What course does this artery branch mimic?
deep brachial artery branches off in the arm, called profunda brachii artery
**mimics the course of the radial nerve
77
T/F There are some important anastomoses around the elbow joint from brachial artery branches.
True.
78
Does the brachial artery pass anterior or posterior to the elbow joint? What branches occur after the brachial artery passes the elbow joint?
It passes anterior.
After it passes the elbow, it branches into the radial & ulnar arteries. Interosseous arteries branch off of the ulnar artery (both posterior & anterior branches after that).
Ulnar recurrent artery branches off the ulnar artery & swings up around again.
Radial recurrent artery branches off the radial artery & swings back up around again.
79
Which artery is sometimes taken for bypass surgery when other things aren't working out?
the radial artery. but you need to first make sure that the person will still have enough blood flow to their hand
80
Why can the radial artery sometimes be taken for bypass surgery?
b/c there are anastomoses in the hand. the superficial & deep palmar arches. this connects w/ the ulnar artery. If a person has an ulnar artery dominant hand--they would probably be okay.
81
How can you tell if someone has a radial artery or ulnar artery dominant hand?
Allen test. You block both arteries & then release one & test capillary refill time. Repeat with other artery & compare.
82
Which arch supplies more of the blood to the digits?
the superficial arch
83
What is the exception to the rule of the superficial arch supplying more blood to the digits?
the deep arch supplies more blood to the index finger & the thumb.
**radial artery esp contributes to the thumb & radial side of the index finger.
84
Where does the musculocutaneous nerve come from? What does it branch into & ultimately supply?
comes from the brachial plexus.
supplies the muscles of the anterior compartment of the arm
it branches into the lateral cutaneous nerve of the forearm. this supplies the radial side of the forearm.
85
What does the median nerve supply in the forearm?
anterior compartment forearm muscles (all)
| except: flexor carpi ulnaris & medial 2 heads (ulnar half) of the flexor digitorum profundus (deep)
86
If the median nerve doesn't supply the flexor carpi ulnaris & the medial 2 heads of the flexor digitorum profundus, then what does?
the ulnar nerve!
| & that is pretty much all the ulnar nerve supplies in the forearm--the stuff that the median nerve doesn't.
87
Review: what is the deal with the radial nerve?
it travels with the deep brachial artery
it innervates the 3 heads of the triceps
superficial branch comes out from underneath the brachioradialis muscle & goes onto the dorsum of the forearm/hand. -->this supplies cutaneous sensory innervation to the middle back of the forearm & the back of the hand & the thumb, index, middle & half the ring fingers
deep branch supplies motor to all of the muscles of the posterior compartment of the forearm.
88
What is the function of the interosseus membrane & what is it considered?
it is a nice place to attach muscles
it maintains the integrity of the 2 bones, keeping them bound together & allowing them to rotate
considered the middle radioulnar joint
fiber orientation allows it to act as a shock absorber when you fall on your hands
89
When you touch your pinky to your thumb...what tendon pops out? What does it appear not to be contained by?
palmaris longus
| not contained by the flexor retinaculum apparently
90
What is the function of the palmaris longus?
it tightens up the palmaris aponeuroses
| functions in flexion
91
You should see 3 tendons pop out when you flex for hand...what are they?
Near thumb: flexor carpi radialis
Middle: palmaris longus
Near pinky: flexor carpi ulnaris
92
5 muscles arise from the medial epicondyle & are all attached by ____ ____ ____. These are superficial/deep muscles of the anterior/posterior forearm.
common flexor tendon
| superficial muscles of the anterior forearm
93
What are the 5 muscles of the superficial anterior forearm? What is the trick for showing their position.
```
Trick: put my right hand in the anatomic position. set the dorsum of my left hand @ the right elbow, point my middle finger towards my middle finger. My left hand fingers will be in the position of the muscles.
1/Thumb: pronator teres
2/Index: Flexor Carpi Radialis
3/Middle: Palmaris Longus
4/Ring: Flexor Digitorum Superficialis
5/Pinky: Flexor Carpi Ulnaris
```
94
Some books consider there to only be 4 muscles of the anterior forearm superficial compartment. Which muscle is sometimes excluded & why?
Sometimes excluded: flexor digitorum superficialis
this is excluded b.c of its extensive origin. Half comes from medial epicondyle & half comes from radius
It is considered intermediate compartment.
95
Where do the deep muscles of the anterior forearm originate from?
interosseus membrane
| or radius & ulna
96
What are the 3 deep muscles of the anterior forearm?
flexor pollicis longus goes to the thumb
pronator quadratus is a quadrangular muscle that is located near the wrist
flexor digitorum profundus splits into 4 tendons for the fingers
97
There is a relationship TAN related to the biceps tendon. What is this relationship?
Biceps Tendon Brachial Artery Median Nerve
| from lateral to medial.
98
There are 2 pronators of the forearm & 2 supinators of the forearm. What are they?
Supinators:
Supinator
Biceps
Pronators:
Pronator Teres
Pronator Quadratus
99
T/F Some people do not have a palmaris longus.
True
100
What are the wrist flexors?
Flexor Carpi Radialis
Palmaris Longus
Flexor Carpi Ulnaris
101
What are the finger flexors?
flexor pollicis longus: thumb
flexor digitorum superficialis (fingers)
flexor digitorum profundus (distal phalanx of fingers)
102
What is the relationship b.w the flexor digitorum superficial is & the flexor digitorum profundus?
FDS attaches to the base of the middle phalanx. It splits into 2. Underneath this split FDS tendon, the FDP creeps in & attaches to the base of the distal phalanx.
Pulleys keep the tendons tight on the finger so they don't become loose & lose their function.
