Arm & Cubital Fossa Flashcards
1
Q
Compartments of Limb
A
- Separated by deep fascia and bone
- Functionally related
- Same blood supply
- Same innervation
2
Q
Arm
A
- Posterior Compartment
- Generally Extensors
- Anterior Compartment
- Generally Flexors
3
Q
Cubital Fossa
A
Triangular depression on anterior portion of elbow
- Boundaries:
- Medial: Pronator Teres
- Laterally: Brachioradialis
- Superior: Line drawn between Medial & Lateral Epicondyles
- Contents:
- Biceps Brachii Tendon
- Brachial a.
- Median n.
- Radial n.
- Median Cubital v. (Superficial to fossa)
4
Q
Forarm
A
Compartments:
-
Posterior:
- Extensors
-
Anterior:
- Flexors
5
Q
The Carpal Tunnel
A
Boundaries:
- Carpal Bones (Floor/Walls)
-
Flexor Retinaculum: dense CT
- Roof
Contents:
- Tendons
- Median n.
6
Q
Hand
A
Comparments:
-
Hypothenar (light blue)
- Control Pinky
-
Thenar (orange)
- Control Tumb
- Central (pink)
- Adductor (purple)
- Interosseous (brown)
7
Q
Arterial Supply of Upper Limb
A
-
Suclavian Artery: main blood supply to limb
- At lateral border of 1st rib: Axillary Artery
- At inferior border of teres major: Brachial Artery
- First branch: Deep Brachial Artery (goes to posterior compartment)
- Bifurcates (around cubital fossa) into ulnar a. and radial a. (supply forearm)
- These anastomose and form superficial and deep palmar arches
8
Q
Venous Drainage
A
- Deep veins have same names as arteries
- Cephalic Vein: on thumb border
- Basilic Vein: on pinky border
- Connected via Median Cubital vein
- Location of venipuncture
9
Q
Dermatome
A
Area of skin innervated by a single spinal nerve
- Preaxial Border: innervated by C5-C7
- Postaxial Border: innervated by C8-T2
Assessment:
- C5: lateral shoulder
- C6: first digit
- C7: third digit
- C8: fifth digit
- T1: medial elbow
10
Q
Fascia and Compartments of Arm
A
- Superficial Fascia (fatty layer) contains: superficial veins, cutaneous nerves, lymphatics
-
Deep Fascia = Brachial Fascia
- Gives off medial and lateral intermuscular septa to divide into anterior/posterior compartments
- Does not stretch: compartment syndrome (compression of a, v, n from inflammation)
11
Q
A
12
Q
Anterior Compartment Muscles
A
- Primarily flexors (of shoulder and elbow)
- All innervated by musculocutaneous nerve
- Biceps Brachii
- Coracobrachialis
- Brachialis
13
Q
Biceps Brachii
A
Innervation:
- Musculocutaneous n.
Origin:
- Supraglenoid tubercle (long head)
- Coracoid Process (short head)
Insertion:
- Radial tuberosity
Action:
-
Flexes and supinates elbow
- Powerful supinator
Bloody Supply:
- Brachial a.
14
Q
Coracobrachialis
A
Innervation:
- Musculocutaneous n.
Origin:
- Coracoid process
Insertion:
- Humerus
Action:
- Flexes shoulder
Blood Supply:
- Brachial a.
15
Q
Brachialis
A
Innervation:
- Musculocutaneous n.
Origin:
- Humerus
Insertion:
- Coronoid process and ulnar tuberosity
Action:
- Flexes elbow
Blood Supply:
- Brachial a.
16
Q
Supination
A
- Rotation of the forearm so palm faces anteriorly
17
Q
Pronation
A
- rotation of forearm so palm pointing posteriorly
18
Q
Posterior Compartment Arm Muscles
A
- Primarily extensors of elbow
- Innervated by radial nerve
- Blood Supply: deep brachial a.
19
Q
Triceps Brachii
A
Innervation:
- Radial n.
Insertion:
- Olecranon process of ulna
Action:
- Extend shoulder
Blood Supply:
- Deep brachial a.
20
Q
Anconeus
A
Innervation:
- Radial n.
Origin:
- Lateral epicondyle of humerus
Insertion:
- Olecranon and ulna
Action:
- Extends elbow
Blood Supply:
- Deep brachial a.
21
Q
Cutaneous Innervation of Arm
A
- Branches of axillary n.: upper lateral arm
-
Intercostalbrachial n.: upper medial arm
- Involved in heart attacks
- Medial cutaneous nerve of arm: medial and anterior arm
- Radial n.: posterior and lateral arm
22
Q
Does Ulnar n. go through cubital fossa?
A
- No
- Goes posterior to elbow“funny bone”
23
Q
Elbow Joint
A
- Hinge synovial joint between humerus, radius, ulna
-
Stable in adults (not in kids)
- Two triangular ligaments:
-
Ulnar collateral ligament (medial)
- Medial epicondyle to ulna
-
Radial collateral ligament (lateral)
- Lateral epicondyle to radius
-
Ulnar collateral ligament (medial)
- Two triangular ligaments:
-
Flexion and Extension (supination/pronation in forearm)
- Close Pack: extension
- Loose Pack: flexion
24
Q
Annular Ligament
A
- Surrounds head of radius (holds in place)
- Fits tightly in adults (not in kids)
25
Q
Elbow Dislocations
A
- Majority are posterior: humerus moves anteriorly, while forearm bones dislocate posteriorly
- Usually the result of a fall on an outstretched hand
- More common in children (joint not as firm)
- Elderly are, however, more prone to fall
26
Q
What nerve is compromised in posterior dislocation of elbow?
A
Ulnar n. (runs posterior)
- Median n and brachial a maybe
27
Q
Subluxation of Head of Radius
A
- “Partial Dislocation”
- Occurs when there is sudden pull on pronated forearm
- Tears annular ligament (thinner in children)
- Radial head pulled out
- Common in children
Treatment:
- Supinate and extend the forearm
- Apply posteriorly placed pressure on head of radius
