9 - Anatomy of the Hand Flashcards
1
Q
What are the three parts of the hand?
A
Carpus (Wrist)
Metacarpus
Digits (Fingers and thumb)
2
Q
A
3
Q
A
4
Q
How many carpal bones are there?
A
8
5
Q
How many metacarpal bones are there?
A
5
6
Q
How many phalanges are there?
A
14
3 in each finger
2 in thumb
7
Q
A
Proximal Row
Scaphoid - S
Lunate - L
Triquetral - Tr
Pisiform - P
Distal Row
Trapezium - Tm
Trapezoid - Td
Capitate - C
Hamate - H
8
Q
Which carpal bones make up the proximal row?
A
Scaphoid
Lunate
Triquetral
Pisiform
9
Q
Which carpal bones make up the distal row?
A
Trapezium
Trapezoid
Capitate
Hamate
10
Q
Which carpal bones articulate with the distal radius?
A
Scaphoid & Lunate
11
Q
Which is the most commonly injured carpal bone?
A
Scaphoid
12
Q
What is important about a fracture to the scaphoid bone?
A
Part of the radial artery enters the scaphoid bone - if you fracture the bone you can cut off its blood supply causing necrosis.
13
Q
What mnemonic helps you remember the order of the carpal bones?
A
Some Lovers Try Positions That They Cant Handle
14
Q
What type of bone is the pisiform? What inserts into it?
A
Sesamoid bone
Flexor Carpi Ulnaris inserts into it
15
Q
What are the four parts of a metacarpal?
A
Head
Neck
Shaft
Base
16
Q
How many metacarpals are there?
A
5
17
Q
What are the three types of a phalange?
A
Proximal
Intermediate (not in the thumb)
Distal
18
Q
A
19
Q
Name 5 joints of the hand
A
Wrist
Carpal (midcarpal)
Carpometacarpal
Metacarpophalangeal
Interphalangeal
20
Q
What is the name of the joints between the carpal bones?
A
Carpal / Midcarpal / Intercarpal
21
Q
What is the name of the joint between the carpel bones and the metacarpals?
A
Carpometacarpal joints
22
Q
What’s the name of the joint between the metacarpals and the phalanges?
A
Metacarpophalangeal joints. (MCP joints)
23
Q
What is the name of the joints between the phalanges?
A
Interphalangeal joints
24
Q
A
25
26
What type of joint is found between the carpals?
Synovial plane joints
27
Why is there limited intra-carpal movement?
Because the carpals are in a capsule which is reinforced by several ligaments.
28
What type of joint are the carpometacarpal joints?
Synovial planar joints
29
Which are the most mobile of the carpometacarpal joints?
Little finger and thumb
30
What is special about the carpometacarpal joint of the thumb?
It is a saddle joint which allows a wide range of mobility, including opposition of the thumb.
31
32
What type of joint is the metacarpophalangeal joint?
Condylar synovial joint
33
What movement is permitted by the MCP Joints?
Everything except rotation is limited.
34
What are the MCP joints reinforced by?
Palmar ligaments
Deep transverse metacarpal ligaments
Collateral ligaments
35
Which MCP joint is reinforced differently to the others?
The thumb
36
How is the thumb MCP joint reinforced?
By ulnar and radial collateral ligaments
37
What is another term for the MCP joint?
The knuckles
38
Which finger is deemed to be the axis for adduction and abduction of the fingers?
The middle finger
39
Abduction and adduction of the fingers occurs at which joint?
The MCP joints
40
Which muscle is responsible for abduction of the fingers?
Dorsal interosseous
41
Which muscle is responsible for adduction of the fingers?
Palmar interosseous
42
What is the mnemonic to remember which muscles abduct and adduct the fingers?
PAD DAB
Palmar Adduct
Dorsal Abduct
43
44
What type of joint are in the interphalangeal joints?
Hinge synovial joints
45
What reinforces the interphalangeal joints?
Collateral and volar (palmar) ligaments
46
What movement is permitted at the interphalangeal joints?
Flexion & extension only
47
48
How many interphalangeal joints are found in the thumb?
1
49
Which muscles are responsible for flexion of the fingers at the metacarpophalangeal joints?
Flexor Digitorum Profundus
Flexor Digitorum Superficialis
Interossei
50
Which muscles are responsible for flexion of the fingers at the proximal interphalangeal joints? (PIPJs)
Flexor Digitorum superficialis
51
Which muscles are responsible for flexion of the fingers at the distal interphalangeal joints? (DIPJs)
Flexor Digitorum Profundus
52
What is the function of the lumbricals?
Flexion of MCPJs and extension of PIPJ & DIPJs.
53
54
Which are the main muscles which allow extension of the fingers at the MCPJ, PIPJ and DIPJs?
Extensor Digitorum
Interossei
55
Which are the accessory muscles which allow extension of the fingers?
Extensor Indicis (Index finger)
Extensor Digiti Minimi
56
Which muscles are responsible for flexion of the thumb?
Flexor Pollicis Brevis - allows flexion at the MCPJ.
Flexor Pollicis Longus - allows flexion at the IPJ.
57
58
Which muscles are responsible for extension of the thumb?
Extensor Pollicis Brevis (proximal joint = MCPJ)
Extensor Pollicis Longus (distal joint = IPJ)
59
60
61
Which muscles are responsible for abduction of the thumb?
Abductor Pollicis Longus (APL)
Abductor Pollicis Brevis (APB)
62
63
64
Which muscle is responsible for adduction off the thumb?
Adductor Pollicis
65
66
What muscle is responsible for opposition of the thumb?
Opponens Pollicis
67
68
How many compartments are there in the hand?
5
69
Name the compartments of the hand
Central
Hypothenar
Thenar (Thumb)
Adductor
Interosseous
70
In this diagram what colour are the following?
- Central compartment
- Hypothenar compartment
- Thenar compartment
- Adductor compartment
- Interosseous compartment
Central = Pink
Hypothenar = Blue
Thenar = Orange
Adductor = Purple
Interosseous = Red
71
What are the intrinsic muscles of the hand?
What are they responsible for?
Intrinsics = muscles that start and finish in the hand (dont start in the forearm)
Responsible for = precision movement
72
What nerve supplies the intrinsic muscles of the hand? Which are the exceptions to this?
Deep branch of ulnar nerve supplies
EXCEPT
Palmaris brevis (superficial ulnar nerve)
&
Thenar Eminence
Lateral 2 Lumbricals (Median nerve)
73
What are the thenar muscles of the hand?
Abductor Pollicis Brevis
Flexor Pollicis Brevis
Opponens Pollicis
74
Which nerve supplies the thenar muscles?
The median nerve
75
How does the median nerve enter the hand?
Through the carpal tunnel
76
77
What is the thenar eminence?
The mound formed at the base of the thumb on the palm of the hand by the intrinsic group of muscles of the thumb.
78
What happens if the median nerve is squashed by carpal tunnel syndrome?
Can get wasting of the median eminence due to lack of innervation.
79
What are the muscles of the Hypothenar compartment?
Abductor Digiti Minimi
Flexor Digiti Minimi
Opponens Digiti Minimi
80
What is the nerve supply to the Hypothenar muscles?
Ulnar nerve
81
82
What is found in the central compartment of the hand?
Long flexor tendons
- Flexor digitorum superficialis
- Flexor digitorum profundus
- Flexor Policis longus
83
What happens to the flexor digitorum superficialis in regards to the flexor digitorum profundus?
The FDS is on top - and is shorter - than FDP. FDS splits to allow FDP to pass through it and insert on the distal phalange.
84
Where do the
- Flexor digitiorum superficialis
- Flexor digitorum profundus
Insert?
FDS - inserts on the middle phalanx.
FDP insertes on the distal phalanx.
85
Which tendon flexes the distal phalanx?
Which tendon flexes the proximal phalanx?
Distal = Flexor digitorum profundus
Proximal = Flexor digitorum superficialis
86
What do FDS, FDP & FPL enter the hand has?
Which compartment do they all originate in?
They enter as fibrous sheaths.
Originate from the anterior compartment of the forearm.
87
88
How many lumbricals do you have in each finger?
1
89
What is the function of the lumbricals?
To flex the metacarpophalangeal joint and to extend the interphalangeal joint.
90
What is the nerve supply of the lumbricals?
Medial 2 = Ulnar nerve
Lateral 2 = Median nerve
91
What do lumbricals join?
They are the only muscle that doesn't join a bone (is a tendon to tendon attachment).
Instead they join a flexor tendon from the back of the finger to the extensor tensor.
92
93
What is the action of the interossei muscles?
Adduction and abduction of digits.
Palmar Adduct (PAD)
Dorsal Abduct (DAB)
94
Where are the interossei muscles found?
In compartments between the metacarpals.
95
How many interosseous compartments are there?
4 Anterior
4 Posterior
96
Which joint do the interosseous muscles act on?
The metacarpophalangeal joints
97
What is the nerve supply of the interosseous muscles?
Deep branch of the ulnar nerve
98
99
What is the deepest compartment of the hand?
Adductor compartment
100
Which muscle is found in the adductor compartment?
Adductor Pollicis
101
What is the action of adductor pollicis?
Adducts the thumb &
Aids opposition of the thumb
102
What is the nerve supply of the adductor pollicis muscle?
Deep branch of the ulnar nerve
103
Where do the extensor tendons of the hand originate?
In the posterior compartment of the forearm
104
What do the extensor tendons pass under as they enter the hand?
The extensor retinaculum
105
What is the function of the extensor retinaculum?
It is an elastic band across the back of the hand that holds the extensor tendons in place - it stops them bowstringing with extension of the wrist or fingers.
106
Why is it difficult to extend different parts of the finger individually?
Due to the extensor hood = travels down the back of the finger attaching to each phalanx - means is difficult to straighten individual parts of the finger.
107
What is the extensor hood made of?
Extensor digitorum
Extensor Pollicis Longus
Form triangular aponeurosis over the back of the proximal phalanges
108
109
What are the boundaries of the anatomical snuffbox?
Lateral/anterior = Extensor pollicis brevis & Abductor pollicis longus
Medial/posterior = Extensor pollicis longus
110
What passes through the anatomical snuffbox?
The radial artery
111
112
113
Which arteries supply the blood to the hand?
Radial and ulnar arteries
114
What arches are formed in the hand
- Mainly by the radial artery?
- Mainly by the ulnar artery?
Deep palmar arch = radial main supply
Superficial palmar arch = ulnar main supply
115
116
Which digits are supplied by the ulnar artery?
The little, ring, middle & medial 1/2 of the index finger
117
Which digits are supplied by the radial artery?
Thumb and lateral 1/2 of the index finger
118
What provides superficial venous drainage to the hand?
Dorsal venous network
Cephalic and basilic veins
119
What provides deep venous drainage to the hand?
Deep veins = venae commitantes
120
121
Which nerves innervate the forearm?
Radial
Ulnar
Median
Superficial cutaneous
122
Name the following cutaneous nerves of the forearm
123
Where is the ulnar nerve found?
Lateral to the pisiform
Medial to the ulnar artery
124
What are the branches of the ulnar nerve?
Deep
Superficial
125
What does the deep branch of the ulnar nerve innervate?
Motor innervation to -
Adductor pollicis
Interossei
Medial 2 lumbricals
126
What does the superficial branch of the ulnar nerve innervate?
Palmaris brevis (motor)
Palmar surface - medial 1.5 digits (sensory)
127
How does the ulnar nerve enter the hand?
Through Guyon's canal - which is next to the ulnar artery, in front of the carpal tunnel
128
What does the superficial nerve provide in terms of innervation?
Motor supply for most of the intrinsics of the hand.
129
130
In which compartment is the median nerve found in the hand?
Anterior compartment
131
What are the branches of the median nerve?
Recurrent
Palmar digital
132
What does the recurrent branch of the median nerve innervate?
Thenar muscles (motor)
133
What does the palmar digital branch of the median nerve innervate?
Skin of the lateral 3.5 digits (sensory)
Lateral two lumbricals (motor)
134
135
Where is the carpal tunnel?
The anterior wrist
136
What travels through the carpal tunnel?
9 tendons with synovial sheaths
inc
Tendon of flexor pollicis longus
Four tendons of flexor digitorum profundus
Four tendons of flexor digitorum superficialis
Median nerve
137
What are the boundaries of the carpal tunnel?
Base (posterior) = Arch of carpal bones
Lateral = Tubercles of scaphoid & trapezium
Medial = Pisiform and hook of hamate
Roof (anterior wall) = Flexor retinaculum
138
What is anterior / superficial to the carpal tunnel?
Tendon of flexor carpal radialis (within separate sheath)
Ulnar nerve
Ulnar artery
Tendon of Palmaris Longus
139
