Lecture 11: MSK 2 Flashcards
1
Q
What type of bone is the humerus?
A
Long bone
2
Q
What are the distal articulations of the humerus?
A
Trochlea with the trochlear notch of the ulna (elbow joint)
Capitulum with the head of the radius
3
Q
Indentations of humerus (anterior and posterior)
A
Anterior = Coronoid fossa (Ulna – Coronoid process)
Posterior = Olecranon fossa (Ulna - Olecranon process)
4
Q
Where is the ulna on the forearm?
A
Medial
Little finger side
5
Q
What bone is part of the “proper” elbow joint
A
Ulna
6
Q
Distinguishing features of proximal head of ulna
A
Olecranon process
Trochlear notch
Coronoid process
Radial notch
See figure
7
Q
Olecranon process
A
proximal end of ulna, shaped like wrench
8
Q
Trochlear notch
A
Proximal end of ulna
Inner portion of wrench structure
9
Q
Coronoid process
A
Proximal end of ulna
lower lip of wrench
10
Q
Radial notch
A
Proximal end of ulna
faces laterally to accommodate radius
11
Q
Distinguishing feature of distal end of ulna
A
Distal head = Styloid process
12
Q
Which side of forearm is radius on?
A
Lateral
Thumb side
13
Q
What does radius articulate with directly?
A
Carpal bones (wrist joint)
14
Q
Proximal and distal ends of radius - features
A
Proximal: small rounded head
Distal: larger, ends as radial styloid process laterally
See figure
15
Q
What do carpal bones allow?
A
Allow for mobility of the hand and opposition which is unique to the human species
16
Q
Proximal row of carpals from lateral to medial
A
Scaphoid
Lunate
Triquetrum
Pisiform
See figure
17
Q
Distal row of carpals from lateral to medial
A
Trapezium
Trapezoid
Capitate
Hamate
See figure
18
Q
What do 5 metacarpals make up?
A
Palm of hand
19
Q
Numbering of 5 metacarpals
A
Numbered 1 to 5 beginning with the thumb…the 5th metacarpal is on the ulnar side of the hand.
20
Q
What type of bones are the metacarpals?
A
Long bones
Consist of a proximal base, shaft and distal head
21
Q
What are the phalanges?
A
Fingers of the hand
22
Q
How many phalanges per hand?
A
14
23
Q
How many phalanges in thumb?
A
2
Proximal and distal
24
Q
How many phalanges in each digit?
A
3
Proximal, middle and distal
25
How can you identify whether you are looking at anterior or posterior writs?
Anterior: can see hamate and pisoform
Posterior: do not see pisiform
26
What bones make up the elbow joint?
Humerus
Radius
Ulna
(mostly ulna and humerus)
27
What type of joint is the elbow joint?
Synovial joint
Hinge type
28
Movement of elbow joint
Flexion/Extension
29
What happens during elbow flexion
Trochlear notch of ulna articulates with the
trochlear surface of the humerus
Radial head glides on the capitulum of the
humerus.
30
What happens during elbow extension
Olecranon process of the ulna fits into the
| olecranon fossa of the humerus (boney end-feel)
31
Carrying angle of forearm
Ulna naturally migrates laterally because trochlea is thicker medially
15 degree carrying angle (cubitus valgus) of forearm
Greater in females than males to accommodate for wider pelvic girdle
32
Where is the proximal radioulnar joint located?
Below elbow
Between proximal radius and ulna
33
Radioulnar joint type
Synovial joint
Pivot type
34
Movement of radioulnar joint
Pronation/Supination
Proximally radius and ulna are always side by side
Distally they cross each other when pronated
35
What is the wrist joint comprised of?
distal end of the radius and the proximal row of the carpal bones of the hand
Concave shape of the distal radius directly articulates with the convex shape of the scaphoid and lunate
36
How is the ulna separated from the carpals in the wrist joint?
fibro-cartilagenous disc
Ulna does not contribute to wrist joint
37
Wrist joint type
Synovial joint
Condyloid type
38
Movement of wrist
Flexion/Extension
Adduction/Abduction
(Ulnar/Radial Deviation)
See figure
39
What bones make up the Carp-metacarpal (CMC) joints
Distal row of the carpals & proximal base of the metacarpals
40
CMC joint type
Synovial joints
Condyloid type
41
Movements of CMC joints
Flexion/extension
| Abduction/adduction
Ulnar/Radial deviation
42
Where is the 1st CMC joint
Thumb
Between the trapezium and the base of the first metacarpal.
43
1st CMC joint type
Saddle type
44
What movement does 1st CMC joint allow?
Opposition (limited type of rotation)
Flexion/Extension
Abduction/adduction
See figure
45
What is the corresponding anatomical structure of the metacarpal phalangeal (MCP) joints? What bones?
Knuckles of hand
Heads of metacarpels contact the
base of the 1st phalanges
46
MCP joint type
Synovial joints
Condyloid type
47
Movements of MCP joints
Flexion/extension
Abduction/adduction (Middle finger used as the point of reference to describe abduction and adduction)
48
Where are the interphalangeal joints?
joints between the phalanges of the fingers
49
Where are there proximal interphalangeal joints (PIP)?
Digits 1-5
50
Where are there distal interphalangeal joints (DIP)?
Digits 2-5
51
What type of joint are interphalangeal joints?
Synovial joints
Hinge type
52
Movement of interphalangeal joints
Flexion / extension
| in the sagittal plane
53
Where is the biceps brachii located?
Superficial
Anterior arm
2 headed muscle
54
Where do the heads of the biceps brachii attach?
Long head – attaches to glenoid fossa (thru bicipital groove)
Short head – attaches to the coracoid process of the scapula
55
What joints does the biceps brachii cross?
Shoulder joint
Elbow joint
56
Actions of biceps brachii
Elbow Flexion
Shoulder Flexion
Forearm Supination
57
Innervation of biceps brachii
Musculocutaneous nerve
58
Shape of brachialis
Flat, thin muscle
59
Joints crossed by brachialis
Only crosses Elbow joint
Humerus to radius
60
Actions of brachialis
Elbow Flexion
61
Innervation of brachialis
Musculocutaneous nerve
62
Where is coracobrachialis located?
Deep to pectorals major, pectorals minor and deltoid
63
What joints does coracobrachialis cross?
Only shoulder
Humerus to coracoid process
64
Actions of corachobrachialis
Shoulder Flexion
65
Innervation of corachobrachialis
Musculocutaneous nerve
66
Triceps brachii - How many heads? Location?
3 heads
Posterior arm (Brachium)
67
Where do the heads of the triceps brachii insert?
All insert on the Olceranon process of the ulna
Long head – glenoid fossa of the scapula
Lateral head – posterior humerus
Medial head – posterior humerus
68
Actions of triceps brachii
Elbow Extension
Shoulder Extension
69
Innervation of triceps brachii
Radial nerve
70
Compartments of the forearm
Anterior forearm
Posterior forearm
Each compartment contains a superficial and deep region
71
Movement of forearm muscles
All forearm muscles are “extrinsic muscles” of the hand.
Involved in power movements of the wrist, thumb and fingers.
72
Anterior forearm - muscle types?
Flexion (wrist and fingers)
Pronation
Ulnar deviation (adduction)
Radial deviation (abduction)
Thumb flexion
73
Posterior forearm - muscle types, where do they arise?
Extension (wrist and fingers)
Supination
Ulnar deviation (adduction)
Radial deviation (abduction)
Thumb extension
74
Where do muscles of anterior forearm arise?
Arise from the Medial Epicondyle
75
Where do muscles of posterior forearm arise?
Arise from the Lateral Epicondyle
76
5 muscles of anterior compartment, superficial layer, forearm
1. Pronator Teres
2. Flexor Carpi Radialis
3. Plamaris Longus
4. Flexor Carpi Ulnaris
5. Flexor Digitorum Superficialis
See figure
77
Innervation of muscles of anterior compartment of forearm, superficial layer
All innervated by median nerve
EXCEPT flexor carpi ulnaris, which is innervated by the ulnar nerve
78
3 muscles of the anterior compartment, deep layer, forearm
1. Flexor Digitorum Profundus
2. Flexor Pollicus Longus
3. Pronator Quadratus
See figure
79
Innervation of 3 muscles of anterior compartment, deep layer, forearm
All innervated by median nerve
EXCEPT medial half of flexor digitorum profundus, innervated by ulnar nerve
80
What is the flexor retinaculum? Role?
Creates Carpal Tunnel
Prevents the tendons from
bowstringing
Marginal Carpals; Cupping of Palm
81
Where is the brachioradialis? What is it's function?
At top of forearm (beer drinking muscle)
Flexes elbow in semi-pronation
Does not cross the wrist joint SO TECHNICALLY - not considered a member of either the flexor or extensor group of forearm muscles.
See figure
82
Innervation of brachioradialis
Radial nerve
83
5 muscles of posterior compartment of forearm, superficial layer
1. Extensor Carpi Radialis Longus
2. Extensor Carpi Radialis Brevis
3. Extensor Digitorum
4. Extensor Digiti Minimi
5. Extensior Carpi Ulnaris
See figure
84
Innervation of 5 muscles of posterior compartment of forearm, superficial layer
Radial nerve
85
5 muscles of posterior compartment of forearm, deep layer
1. Supinator
2. Abductor Pollicis Longus
3. Extensor Pollicus Longus
4. Extensor Pollicis Brevis
5. Extensor Indicis
See figure
86
Innervation of 5 muscles of posterior compartment of forearm, deep layer
Radial nerve
87
What does the palmar aponeurosis do?
Connects skin to underlying structures of the hand
See figure
88
What are the three compartments of the intrinsic muscles of the hand?
1. Thenar (3)
2. Hypothenar (3)
3. Central (3)
89
Function of intrinsic muscles of hand
Precision movement
fine motor skills
90
Anatomical position of thenar muscle group
Fleshy prominence on the radial side of the palm (thumb)
91
Thenar group muscles
1. Flexor pollicis brevis
2. Abductor pollicis brevis
3. Opponens pollicis
Act on thumb
92
Innervation of thenar muscle group
Median nerve
93
Anatomical position of hypothenar muscle group
Fleshy prominence on the ball of the little finger
94
Hypothenar group muscles
1. Flexor digiti minimi brevis
2. Abductor digiti minimi
3. Opponens digiti minimi
See figure
95
Innervation of hypothenar muscle group
Ulnar nerve
96
What are the central compartment muscles?
Muscles between hypo and thenar regions
More prominent on palmar surface
97
3 muscle groups in central compartment
1. Lumbricals (4) – flex MCP
2. Interossei:
PAD: 3 palmer / adduct MCP - toward midline
DAB: 4 dorsal / Abduct MCP - away from midline
3. Adductor pollicis
See figure
98
Innervation of central compartment
Ulnar nerve
99
What are the 5 roots of the brachial plexus?
C5
C6
C7
C8
T1
100
What are the branches of the brachial plexus?
Musculocutaneous nerve
Axillary nerve
Radial nerve
Median nerve
Ulnar nerve
101
Why is there a C8 nerve but no C8 vertebrae?
In the cervical spine, the nerve roots are named after the vertebrae that lies below them.
Thoracic and lumbar nerve roots are named after the vertebrae above them
So, there is no C7, but since C8 lies above T1, it is called C8
102
Nerves of upper arm
Axillary nerve - Deltoid & Teres minor
Musculocutaneous nerve - Anterior compartment muscles (Biceps brachii, Brachialis & Coracobrachialis)
Radial nerve - Posterior compartment muscle (Triceps brachii)
103
Nerves of forearm and hand
Radial nerve - Posterior compartment
(Superficial & Deep), Brachioradialis
Ulnar nerve - Flexor carpi ulnaris, Medial 1⁄2 of Flexor digitorum profundus, Hypothenar muscle group, Central compartment muscles
Median nerve - Anterior compartment muscles
except those above, Thenar muscle group
104
Sensory nerves of hand
Median nerve
Ulnar nerve
Radial nerve
See figure
105
Main sections of blood supply of upper extremity
1. Subclavian artery becomes the Axillary artery at the lateral border of the 1st rib.
2. Axillary becomes Brachial artery at lower border of teres major muscle.
3. Brachial divides into Radial & Ulnar artery in cubital fossa.
4. Below wrist radial and ulnar arteries each divide and contribute to formation of Superficial and Deep Palmer Arches
See figure
106
Blood supply in hand
Ulnar artery becomes superficial arch
Radial artery becomes deep arch
See figure
