6 - Anatomy of Arm & Brachial Plexus Flashcards
1
Q
Where is the arm found?
A
Between the shoulder and elbow joint
2
Q
What is the part of the upper limb that is found between the elbow and the hand?
A
The forearm
3
Q
What is the part of the humerus bone called where the head joins the shaft?
A
Anatomical neck
4
Q
What is the part of the humerus bone called which is the most common place for a fracture?
A
Surgical neck
5
Q
What are the names of the tubercles which are found close to the head of the humerus on its proximal end?
A
Greater and lesser tubercles
6
Q
Which muscle attaches to the greater tubercle of the humerus?
A
Supraspinatus
7
Q
Which muscle attaches to the lesser tubercle of the humerus?
A
Subscapularis
8
Q
What is found between the greater and lesser tubercles of the humerus?
A
The intertubercular sulcus (groove)
9
Q
Which muscle runs through the intertubercular sulcus?
A
The long head of the biceps brachiallis tendon
10
Q
Which muscles meet at the lower part of the intertubercular sulcus?
A
Pectoralis major
Latissimus dorsi
Teres major
(A lady between two majors)
11
Q
What part of the scapula does the head of the humerus articulate with?
A
Glenoid cavity
12
Q
A
13
Q
A
14
Q
Where does the deltoid muscle attach on the humerus?
A
To the deltoid tuberosity on the lateral border
15
Q
What is found on the posterior side of the humerus?
A
The radial groove (aka spiral groove)
16
Q
What can be found running within the radial groove?
A
- Radial nerve
- Profunda brachii artery
17
Q
What separates the humerus into top and bottom halves?
A
The spiral groove
18
Q
Which muscles attach to the anterior part of the humeral shaft?
A
Brachialis
Coracobrachialis
19
Q
Which muscle attach to the posterior part of the humeral shaft?
A
Lateral head of triceps (above spiral groove), medial head of triceps and long head of triceps.
20
Q
What are the names of the two articular surfaces of the distal humerus?
Together what are these called?
A
Capitulum
Trocholear
Humeral condyle
21
Q
What does the capitulum articulate with?
A
The head of the radius
22
Q
What does the trochlea articulate with?
A
The trochlear notch of the ulnar.
23
Q
Which bumps are found either side of the condyle?
A
Lateral & medial epicondyle
24
Q
What is the function of the epicondyles of the humerus?
A
They are a site where the muscles of the forearm can attach.
25
What is found above the condyle of the humerus on the anterior side?
The radial and coronoid fossae.
26
What is the function of the radial fossa?
It allows the radius to fit into the bone of the humerus when the forearm flexes at the elbow joint.
27
What is the function of coronoid fossa?
It allows the coronoid process of the ulnar to fit against the humerus when the forearm is flexed at the elbow joint.
28
29
Which articular surface of the condyle extends to the posterior side of the humerus?
The trochlea - the capitulum does not extend to the back of the humerus.
30
Which fossa is found above the trochlea on the posterior side of the humerus?
The olecranon fossa
31
What is the purpose of the olecranon fossa?
It allows the olecranon process of the ulna to fit against the humerus when the arm is extended.
32
How many compartments of the arm are there?
What are they called?
Two compartments - anterior and posterior
33
What divides the arm into compartments?
Fascia which comes off the humerus laterally and travels around the arm as a deep fascia.
34
35
Which compartment is responsible for (a) flexion and (b) extension of the arm?
(a). Anterior
(b). Posterior
36
What is the name of the fascia which separates the anterior and posterior compartments of the arm?
Intermuscular septum - the arm has a lateral intermuscular septum and a medial intermuscular septum.
37
Which muscles are found in the anterior compartment of the arm?
Biceps brachii
Coracobrachialis
Brachialis
38
What is the motor nerve supply of the anterior compartment?
Musculocutaneous nerve
39
Which spinal nerve roots innervate the musculocutaneous nerve?
C5, C6 & C7
40
Which artery supplies the arm?
The brachial artery
41
How many heads does the biceps brachii have?
Two - the long head (attaching to supraglenoid fossa) and short head (attaches to coracoid process).
42
What is the action of the biceps brachii muscle?
Flexion and supination of the forearm; fibers from the short head provide flexion of the upper arm, while fibers from the long head provide abduction of the upper arm.
43
What is the action of the coracobrachialis muscle?
Flexion of the forearm, adduction and internal rotation of the upper arm.
44
What is the action of the brachialis muscle?
Flexion of the forearm
45
Which muscle is found in the posterior compartment of the arm?
Triceps brachii
46
What are the three heads of the triceps muscle?
Lateral, medial and long heads.
47
What does the triceps muscle attach to?
Origins:
Long head = infraglenoid tubercle
Medial head = posterior humeral shaft
Lateral head = posterior humeral shaft
Insertion:
Olecranon
48
What is the function of the triceps brachii?
Extension of the forearm at the elbow joint
Long head crosses the glenohumeral joint - means this can extend and adduct the arm at the glenohumeral joint.
49
50
What does the axillary artery arise from?
The subclavian artery
51
Where does the subclavian artery become the axillary artery?
At the outer edge of the 1st rib
52
The axillary artery is divided into 3 parts by the ?.
What are these three parts called?
Divided into 3 parts by the pectoralis minor muscle.
First, second and third parts
53
What does the axillary artery become? Where is this transition?
Becomes the brachial artery
At the lower border of teres major.
54
Which compartment of the arm is the brachial artery found in?
The anterior compartment
55
What does the brachial artery bifurcate into? And where?
The radial and ulnar arteries
Antecubital fossa
56
Which branch of the brachial artery travels in the radial groove?
What travels alongside it?
Profunda brachii
Radial nerve
57
What is the main branch of the brachial artery?
The profunda brachii
58
59
60
Why are joints often surrounded by anastomoses of the arteries?
So the arterial supply is not compromised during movement of the joint.
61
What structures pass through the triangular interval?
The profunda brachii and the radial nerve
62
Which veins produce superficial drainage to the arms.
Cephalic vein
Basilic vein
63
Which vein provides anterior drainage to the arm?
Cephalic vein
64
What does the cephalic vein join?
The axillary vein
65
Which vein in the arm penetrates the deep fascia to become the axillary vein?
The basilic vein
66
What does the axillary vein become?
The subclavian vein
67
Which veins provide deep venous drainage to the arm?
The paired brachial veins
68
69
The cephalic vein remains superficial until where?
Until it reaches the axilla
70
When does the basilica vein become deeper?
Halfway up the arm - joins the venae comitantes of the brachial artery at the lower border of teres major
71
What is another name for the paired brachial veins?
The venae comitantes
72
Which nerves supply the arm with motor innervation?
Musculocutaneous nerve
Radial nerve
73
Which nerves supply the cutaneous sensation to the arm?
Medial cutaneous
Superior lateral cutaneous
(Also - inferior lateral and posterior cutaneous nerves)
74
Which nerve supplies motor innervation to the anterior compartment of the arm?
Musculocutaneous
75
Which nerve supplies motor inertia to the posterior compartment of the arm?
Radial
76
Which nerve do the medial and lateral cutaneous nerves arise from?
The axillary nerve
77
Which nerves pass through the arm but dont innervate it?
The median and ulnar nerves
78
79
80
81
What are the four walls of the axilla called?
What is the top and base of the axilla called?
Walls = anterior, posterior, lateral and medial
Top = Inlet
Base = Outlet
82
What are the boundaries of the inlet of the axilla?
Rib 1
Posterior clavicle
Superior border of scapula
83
What are the boundaries of the outlet of the axilla?
Chest wall (medial)
Anterior axillary fold (lower border of pec major) - anterior
Posterior axillary fold (lat dorsi & teres major) - posterior
84
What are the boundaries of the anterior wall of the axilla
85
What are the boundaries of the anterior wall of the axilla?
Pectoralis major
Pectoralis minor
Subclavius
Clavipectoral fascia
86
What are the boundaries of the posterior wall of the axilla?
Costal surface of scapula
Subscapularis
Latissimus dorsi & Teres major
87
What are the boundaries of the medial wall of the axilla?
Ribs
Intercostal muscles
Serratus anterior
88
What are the boundaries of the lateral wall of the axilla?
Intertubercular sulcus of humerus
89
What is the function of the posterior wall gateways?
Allow structures to pass from the front to the back of the arm
90
What are the names of the posterior wall gateways?
Quadrangular space
Triangular space
Triangular interval
91
Which posterior wall spaces are above teres major and which are below it?
Quadrangular space and triangular space are above
Triangular interval is below
92
What structures pass through the quadrangular space?
The axillary nerve, posterior circumflex humeral artery and vein
93
What structures pass through the triangular space?
The circumflex scapular artery and vein
94
What structures pass through the triangular interval?
The radial nerve and the profunda brachii artery
95
96
Which artery passes through the axilla?
The axillary artery and its branches
97
Which vein passes through the axilla?
The axillary vein and its tributaries
98
What other structures are found in the axilla in addition to the axillary artery and the axillary vein?
The nerves (cords and branches) of the brachial plexus
Lymphatic vessels & nodes
Axillary process (tail) of the breast)
99
Which muscles are located in the axilla?
The coracobrachialis (proximal part)
Short head of biceps brachii
100
Which rami of which spinal nerves form the brachial plexus?
The anterior rami of C5 - T1
101
How many cervical nerves are there?
8
102
Over which rib does the brachial plexus pass?
Rib 1
103
Where are the cords and terminal branches of the brachial plexus found?
In the axilla
104
What is the brachial plexus?
A somatic nerve plexus
105
What are somatic nerves?
Part of the peripheral nervous system - they control voluntary movement of skeletal muscle
106
Which is the most commonly fractured bone in the body?
The clavicle
107
What do you need to consider if there is an fracture of the first rib?
Whether the brachial plexus has been affected.
108
Name the stages starting with the anterior rami through the brachial plexus.
Anterior Rami (C5-T1)
Roots
Trunks
Divisions (Anterior and Posterior)
Cords (Lateral, Posterior and Medial)
Terminal branches
109
Which parts of the brachial plexus are found in the posterior triangle of the neck?
Roots
Trunks
Divisions
110
Which parts of the brachial plexus are found in the axilla?
Cords
Terminal branches
111
112
Which roots make up the following:
Superior Trunk
Middle Trunk
Inferior Trunk
of the brachial plexus?
Superior = C5 & C6
Middle = C7
Inferior = C8 & T1
113
Which trunk of the brachial plexus lies on Rib 1? Which artery is it posterior to?
Inferior trunk lies on Rib 1
Is posterior to the subclavian artery
114
What does each trunk of the brachial plexus divide into?
Anterior and Posterior divisions
115
What does the anterior divisions of the brachial plexus innervate??
The anterior compartment of the upper limb
116
What does the posterior divisions of the brachial plexus innervate?
The posterior compartment of the upper limb
117
The posterior divisions of the brachial plexus all combine - what do they form?
The posterior cord
118
How do the anterior divisions of the brachial plexus join and what to they form?
The superior and middle anterior divisions join to form the lateral cord.
The inferior anterior division forms the medial cord.
119
Which nerve roots innervate the following:
-Lateral cord
- Medial cord
- Posterior cord
Lateral cord = C5 - C7
Medial cord = C8 - T1
Poster cord = C5 - T1
120
What nerves does the lateral cord give rise to?
Musculotaneous (C5-C7)
Median nerve (C5 - T1) - also innervated by the medial cord
121
What nerves does the medial cord give rise to?
The median nerve (C5 - T1)
The ulnar nerve (C8 & T1)
122
What nerves does the posterior cord give rise to?
The axillary nerve (C5 & C6)]
Radial nerve (C5-T1)
123
