Anatomy 29 Flashcards
1
Q
How many bones make up the carpus?
A
8
2
Q
What are the arrangement of bones in the carpus?
A
2 rows of 4 bones; 1 proximal, 1 distal
3
Q
What forms the radiocarpal joint?
A
Distal radius articulating with the scaphoid and lunate
4
Q
Which is the most commonly fractured carpal bone?
A
Scaphoid
5
Q
What is the clinical relevance of the lunate bone?
A
An anterior dislocation of the lunate bone compresses the median nerve
6
Q
Where do the metacarpals lie?
A
Distal to the carpus
7
Q
In what order are the metacarpals numbered?
A
1 – 5 from the lateral (thumb) side to the
medial (little finger) side
8
Q
What are the bones of the digits?
A
Phalanges
9
Q
How many phalanges in digits 2-5?
A
3
10
Q
How many phalanges in the thumb?
A
2
11
Q
What are the names of the 3 phalanges of the fingers?
A
Proximal
Middle
Distal
12
Q
What are the names of the 2 phalanges of the thumb?
A
Proximal
Distal
13
Q
Where does the carpometacarpal joint lie?
A
Lies between the distal row of carpal bones and the proximal parts (the bases) of the metacarpals
14
Q
Where does the metacarpophalangeal joint lie?
A
Lies between the distal parts (the heads) of the metacarpals and the proximal phalanges
15
Q
Where does the interphalangeal joint lie?
A
Lies between the phalanges
16
Q
How many interphalangeal joints are in the thumb?
A
1
17
Q
How many interphalangeal joints are in the fingers?
A
2
* the proximal interphalangeal (PIP) joints lie between the proximal and middle phalanges
* the distal interphalangeal (DIP) joints lie between the middle and distal phalanges
18
Q
What is the power grip used for?
A
To hold or squeeze objects tightly
19
Q
What is the hook grip used for?
A
Carrying objects with handles, such as bags
20
Q
What is the precision grip used for?
A
Allows us to hold objects between the pads of our thumb and index finger, such as a pen or needle.
This can be performed with or without power
21
Q
What movements can occur at the fingers?
A
- Flexion
- Extension
- Abduction (moving the fingers apart)
- Adduction (bringing the fingers together)
22
Q
What movements occur at the thumb?
A
- Flexion
- Extension
- Abduction
- Adduction
- Opposition
23
Q
Where do the extrinsic muscles of the hand lie?
A
In the anterior and posterior forearm and their tendons travel into the hand
24
Q
Where do the intrinsic muscles of the hand lie?
A
Within the hand
25
What are the muscles of the anterior forearm that are the prime flexors of the wrist?
Flexor carpi radialis
Flexor carpi ulnaris
Palmaris longus
26
What does the flexor carpi radialis insert onto?
2nd metacarpal
27
What does the flexor carpi ulnaris insert onto?
5th metacarpal
28
What does the palmaris longus insert onto?
Palmar fascia
29
Which anterior compartment muscles flex the digits?
* Flexor digitorum superficialis (FDS)
* Flexor digitorum profundus (FDP)
* Flexor pollicis longus (FPL)
30
What does the flexor digitorum superficialis (FDS) split into?
2 slips which insert on either side of the middle phalanx of digits 2-5
31
What does the flexor digitorum superficialis (FDS) flex?
The MCP joints and PIP joints of digits 2-5
32
Where does the flexor digitorum profundus (FDP) pass through?
The slit in the FDS tendon
33
What does the flexor digitorum profundus (FDP) insert onto?
The palmar aspect of the distal phalanx of digits 2-5
34
Which is the only muscle capable of flexing the DIP joint?
Flexor digitorum profundus (FDP)
35
Which joints does the Flexor digitorum profundus (FDP) flex?
DIP joint
PIP joint
MCP joint of digits 2-5
36
What does the tendon of flexor pollicis longus (FPL) insert onto?
Distal phalanx of the thumb
37
What does the flexor pollicis longus (FPL) flex?
IP joint of the thumb and is the only muscle that can do so
38
What is the function of fibrous sheaths?
Enclose the long flexor tendons.
They maintain the position of the flexor tendons in the midline of each finger
39
What are the tendons within the fibrous sheaths enclosed within?
A synovial sheath, which reduces friction and allows the tendons to slide freely within their fibrous sheath during flexion and extension
40
What is tenosynovitis?
Inflammation of the tendon and synovial sheath
41
What is the function of the thick palmar aponeurosis?
Protects the long flexor tendons, tendon sheaths and vessels in the central palm
42
What are the 4 groups of intrinsic muscles of the hand?
* thenar eminence
* hypothenar eminence
* lumbricals
* interossei
43
How many muscles does the thenar eminence contain?
3
44
How many muscles does the hypothenar eminence contain?
3
45
How many muscles do the lumbricals contain?
4
46
How many muscles do the interossei contain?
7
47
What is the adductor pollicis?
Remaining intrinsic muscle of the hand - muscle of the thumb
48
What are the intrinsic hand muscles innervated by?
Ulnar and median nerves
49
What is the thenar eminence?
This is the fleshy mass on the palm of the hand at the base of the thumb.
It contains 3 muscles that act upon the thumb
50
What 3 muscles are found in the thenar eminence?
* Flexor pollicis brevis (FPB)
* Abductor pollicis brevis (APB)
* Opponens pollicis - (OP)
51
What movement does the flexor pollicis brevis ( FPB) execute?
Flexes the thumb
52
What movement does the abductor pollicis brevis (APB) execute?
Abducts the thumb
53
What movement does the Abductor pollicis brevis (APB) execute?
Abducts the thumb
54
What movement does the Opponens pollicis - (OP) execute?
Opposes the thumb
55
Where does the opponens pollicis lie?
Lies deep to the flexor and abductor
56
What muscles are attached to the carpal bones proximally?
Thenar muscles
57
Where is the insertion point of the flexor pollicis brevis?
Proximal phalanx
58
Where is the insertion point of the abductor pollicis brevis?
Proximal phalanx, lateral aspect
59
Where is the insertion point of the opponens pollicis?
1st metacarpal
60
What is the innervation of the flexor pollicis brevis?
Recurrent branch of the median nerve
61
What is the innervation of the abductor pollicis brevis
Recurrent branch of the median nerve
62
What is the innervation of the opponens pollicis?
Recurrent branch of the median nerve
63
Where does the recurrent branch of the median nerve leave the median nerve?
After it has passed through the carpal tunnel, therefore the thenar eminence muscles are affected in carpal tunnel syndrome
64
How does the adductor pollicis differ from the thenar eminence muscles?
* it lies deep in the palm, not in the thenar eminence
* it is innervated by the ulnar nerve
65
What is the adductor pollicis attached to?
The 3rd metacarpal and to the proximal phalanx of the thumb
66
What does contraction of the adductor pollicis cause?
Pulls the thumb towards the palm – adduction
67
What are the thenar muscles important for?
Precision grip
68
What is the hypothenar eminence?
The fleshy mass on the medial side of the palm of the hand, proximal to the little finger
69
What 3 small muscles are found in the hypothenar eminence?
Flexor digiti minimi
Abductor digiti minimi
Opponens digiti minimi
70
What movement does the flexor digiti minimi execute?
Flexes the little finger
71
What movement does the adductor digiti minimi execute?
Abducts the little finger
72
What movement does the opponens digiti minimi execute?
Opposes the little finger
73
How are the hypothenar muscles attached to the carpal bones?
Proximally
74
Where is the insertion point of the flexor digiti minimi?
Proximal phalanx
75
Where is the insertion point of the abductor digiti minimi?
Proximal phalanx
76
Where is the insertion point of the opponens digiti minimi?
5th metacarpal
77
What is the innervation of the flexor digiti minimi?
Deep branch of the ulnar nerve
78
What is the innervation of the abductor digiti minimi?
Deep branch of the ulnar nerve
79
What is the innervation of the opponens digiti minimi?
Deep branch of the ulnar nerve
80
What do the 4 lumbrical muscles arise from?
The tendons of flexor digitorum profundus
81
What do the 4 lumbrical muscles travel along?
The lateral aspects of digitis 2-5
82
What do the 4 lumbrical muscles insert onto?
The dorsal aspects of digits 2-5
83
What movements do the lumbrical muscles execute?
Flex the MCP joints and simultaneously extend the IP joints
84
What are the lateral two (digits 2 and 3) innervated by?
Median nerve
85
What are the medial two (digits 4 and 5) innervated by?
Ulnar nerve
86
Where do the interossei muscles attach and lie between?
Metacarpals
87
Where do the interossei muscles insert onto?
Dorsal aspects of digits 2-5
88
What are the 2 groups of interossei muscles?
Palmar group
Dorsal group
89
How many palmar interosseous muscles are there?
3
90
How many dorsal interosseous muscles are there?
4
91
What movements do the palmar interossei muscles execute when they contract?
Adduct the fingers
92
What movements do the dorsal interossei muscles execute when they contract?
Abduct the fingers
93
What acronym can be used for the movement of the palmar and dorsal interossei muscles?
‘PAD-DAB’ (Palmar ADduct, Dorsal ABduct)
94
Where do the first palmar interosseous arise from?
Medial side of the 2nd metacarpal
95
Where do the first palmar interosseous insert onto?
The medial aspect of the 2nd proximal phalanx
96
Where do the second palmar interosseous arise from?
Lateral side of the 4th metacarpal
97
Where do the second palmar interosseous insert onto?
Lateral aspect of the 4th proximal phalanx
98
Where do the third palmar interosseous arise from?
Lateral side of the 5th metacarpal
99
Where do the third palmar interosseous insert onto?
Lateral aspect of the 5th proximal phalanx
100
Where do the first dorsal interosseous arise from?
Medial side of the 1st metacarpal and the lateral side of the 2nd metacarpal
101
Where do the first dorsal interosseous insert onto?
Lateral aspect of the 2nd proximal phalanx
102
What do the first dorsal interosseous move?
Index finger
103
Where do the second dorsal interosseous arise from?
Medial side of the 2nd metacarpal and the lateral side of the 3rd metacarpal
104
Where do the second dorsal interosseous insert onto?
The lateral aspect of the 3rd proximal phalanx
105
Where do the third dorsal interosseous arise from?
Medial side of the 3rd metacarpal and lateral side of the 4th metacarpal
106
Where do the third dorsal interosseous insert onto?
Medial aspect of the 3rd proximal phalanx
107
Where do the fourth dorsal interosseous arise from?
Medial side of the 4th metacarpal and lateral side of the 5th metacarpal
108
Where do the fourth dorsal interosseous insert onto?
Medial aspect of the 4th proximal phalanx
109
What prevents the flexor tendons from bowing when the wrist is flexed?
Flexor retinaculum
110
What important structures travel through the carpal tunnel?
* long flexor tendons of FDS, FDP and FPL
* median nerve
111
What structures cross the wrist, but travel over (superficial to) the flexor retinaculum?
* tendons of FCR, FCU and PL
* radial artery - travels on the lateral aspect of the wrist
* ulnar artery and ulnar nerve - travel over the medial aspect of the wrist, close to the tendon of FCU
112
How can sensation in the hand be assessed?
By examining:
- The territories of the peripheral nerves
- The dermatomes
113
What does the median nerve innervate?
- The palmar surface of the lateral side of the hand
- The palmar surface of the lateral 3 ½ digits
- The skin over the dorsum of the distal phalanges of the lateral 3 ½ digits
114
What does the ulnar nerve innervate?
- The palmar and dorsal surfaces of the medial side of the hand
- The medial 1 ½ digits
115
What does the radial nerve innervate?
- The dorsal surface of the lateral side of the hand
- The skin over the dorsum of the lateral 3 ½ digits as far as the DIP joint
116
What territory is used to assess the median nerve?
Palmar surface of the middle finger
117
What territory is used to assess the ulnar nerve?
Median border of the hand
118
What territory is used to assess the radial nerve?
Dorsum of the hand, lateral aspect
119
Where do the cutaneous branches of the medial and ulnar nerves arise in?
Forearm
120
What does injury to the median nerve at the wrist (or in the carpal tunnel) or the ulnar nerve at the wrist result in?
Sensory impairment over the palmar aspect of the corresponding fingers, as the cutaneous branches to the fingers arise from the nerves distal to the wrist
121
What is a dermatome?
Region of skin innervated by a single spinal nerve
122
What is the upper limb innervated by?
Brachial plexus and spinal nerves C5 – T1
123
What spinal nerve innervates the upper shoulder?
C4
124
What spinal nerve innervates the lateral side of the anterior and posterior aspects of the arm?
C5
125
What spinal nerve innervates the anterior and posterior surfaces of the forearm, the lateral sides of the anterior and posterior surfaces of the palm, and the anterior and posterior surfaces of the thumb and index fingers?
C6
126
What spinal nerves innervate the anterior and posterior surfaces of the middle finger and middle of the palm (over the 3rd metacarpal)?
C7
127
What spinal nerves innervate the the medial side of the anterior and posterior surfaces of the forearm, the medial side of the anterior and posterior surfaces of the palm, and the anterior and posterior surfaces of the fourth and fifth fingers?
C8
128
What spinal nerves innervate the medial side of the anterior and posterior surfaces of the arm?
T1
129
How is sensation of the C5 dermatome tested?
Upper lateral arm
130
How is sensation of the C6 dermatome tested?
Thumb
131
How is sensation of the C7 dermatome tested?
Middle finger
132
How is sensation of the C8 dermatome tested?
Medial border of the hand
133
How is sensation of the T1 dermatome tested?
Medial border of the arm
134
What 2 arteries supply the hand?
Radial and ulnar arteries
135
What artery are the radial and ulnar arteries terminal branches of?
Brachial artery
136
Where does the radial artery travel along?
Courses down the lateral aspect of the forearm
137
How can the radial artery be palpated?
Over the lateral aspect of the wrist
138
Where does the ulnar artery travel along?
Courses down the medial aspect of the forearm
139
How can the ulnar artery be palpated?
Over the medial aspect of the wrist, but the artery may be partially covered by the tendon of flexor carpi ulnaris, making it harder to palpate than the radial pulse
140
Where do the radial and ulnar arteries anastomose?
Deep in the palm
141
What do the radial and ulnar arteries anastomose to form?
2 palmar arches
- Superficial palmar arch
- Deep palmar arch
142
What is the superficial palmar arch formed by?
Largely by the ulnar artery with a smaller contribution from the radial artery
143
What is the deep palmar arch formed by?
Largely by the radial artery with a smaller contribution from the ulnar artery
144
What do the palmar arches give rise to?
Metacarpal and digital arteries that supply the palm and digits.
These are accompanied by digital nerves.
145
What do the anastomoses of the radial and ulnar arteries ensure?
Ensures perfusion of the hand is maintained in the event that one of the vessels is occluded or injured
146
What should be assessed before undertaking arterial puncture?
The patency of each vessel (e.g., for an arterial blood gas or placing an arterial line), as such procedures can potentially cause thrombus formation and occlusion of the vessel.
147
How is FDP tested?
The PIP joint is held immobile by the examiner and the patient is asked to flex the finger.
If the FDP tendon is intact, flexion is seen at the DIP joint
148
How is FDS tested?
The patient turns the hand supine.
The examiner uses a hand to keep all the fingers not
being tested straight - this immobilises FDP.
The patient is then asked to flex the finger that remains free.
If the FDS tendon is intact, flexion occurs at the PIP joint and this is due to the action of FDS alone
149
How is FPL tested?
Movement at the IP joint of the thumb is assessed
150
How does carpal tunnel syndrome typically present?
With impaired sensation, pins and needles or pain in the hand over the palmar aspect of the lateral 3 ½ digits
151
What is dupuytrens contracture?
The fingers are pulled into flexion by progressive fibrosis of the palmar fascia and palmar aponeurosis.
The palmar fascia is attached to the flexor
tendon sheaths of the fingers.
The fascia shortens and pulls the fingers into flexion.
The fascia can be released.
152
What is tenosynovitis?
Inflammation of a flexor tendon and its synovial sheath may result if the sheath is breached by a penetrating injury.
The finger swells and movement is painful.
Infection may potentially spread to the forearm
153
What does the scaphoid form from?
2 bones, each with its own blood supply, that fuse together.
With fusion, the artery to the proximal end degenerates, and the bone is supplied from its distal end
154
What happens when the scaphoid fractures?
The proximal part of the bone may be disconnected from the blood supply and death of the proximal segment results – this is called avascular necrosis.
155
What is a fracture of the 5th metacarpal?
Otherwise known as a ‘boxer’s fracture’, as it is typically sustained by punching something.
There is usually pain, swelling and tenderness over the 5th metacarpal.
