Term
| the posterior compartment of the arm is innervated by? |
|
Definition
|
|
Term
| where does the axillary nerve end? |
|
Definition
|
|
Term
| the biceps brachii, brachialis and coracobrachialis are mainly innervated by what spinal nerve? |
|
Definition
|
|
Term
| the triceps brachii and anconeus are mainly innervated by what spinal nerve? |
|
Definition
|
|
Term
| all muscles (except part of the brachialis) of the anterior compartment are innervated by what nerve? |
|
Definition
|
|
Term
| describe the structure and function of the biceps brachii |
|
Definition
A three joint muscle, crossing the glenohumeral (accessory arm flexor), elbow, and radioulnar joints
Long & short heads help stabilize glenohumoral joint. Long head also helps arm abduction |
|
|
Term
| what muscle is the most powerful supinator? |
|
Definition
|
|
Term
| what are the main actions of the brachialis? |
|
Definition
Most powerful forearm flexor, all elbow positions.
Isometric contraction allows controlled forearm extension |
|
|
Term
| what muscle is the most powerful forearm flexor? |
|
Definition
|
|
Term
| the musculocutaneous nerve pierces what muscle as it exits the axilla? |
|
Definition
|
|
Term
| what are the main actions of the coracobrachialis? |
|
Definition
Helps flex arm
Also adducts the arm
Resists downward dislocation of the humeral head (along with deltoid and long head of triceps), for glenohumoral joint stability |
|
|
Term
| describe the course of the musculocutaneous nerve as it travels down the upper limb |
|
Definition
Branches from the lateral cord of the brachial plexus
Passes through the coracobrachialis muscle
Passes distally in the arm btwn. the biceps brachii & brachialis muscles
Emerges from the lateral edge of the biceps brachii muscle
After piercing deep fascia, it emerges as the lateral cutaneous nerve of the forearm, providing sensory innervation to skin on the lateral forearm
Innervates all the flexors in the arm |
|
|
Term
| the bicipital myotactic reflex tests what spinal nerve? |
|
Definition
|
|
Term
| how does one test for the bicipital myotactic reflex? |
|
Definition
The examinee’s limb is partially extended and relaxed
The examiner’s thumb is placed over the biceps tendon in the cubital fossa
His/her thumb is tapped with a reflex hammer
A normal response would be felt as a momentary involuntary contraction of the biceps
A positive (normal) response confirms the integrity of the C6 spinal cord segment |
|
|
Term
| what are the main actions of the triceps brachii? |
|
Definition
Forearm extensor
Can also adduct the arm
Long head resists humoral dislocation |
|
|
Term
| what are the main actions of the anconeus? |
|
Definition
Slight forearm extensor
Elbow stabilizer
Abducts ulna during pronation |
|
|
Term
| cutaneous innervation by the radial nerve is via what 2 nerves of the forearm? |
|
Definition
| Cutaneous innervation is via the inferior lateral cutaneous nerve of the arm and the posterior cutaneous nerve of the forearm |
|
|
Term
| this nerve innervates all the extensors in the arm and a small lateral part of the brachialis muscle |
|
Definition
|
|
Term
| damage to what nerve causes the clinical condition known as wrist drop? |
|
Definition
|
|
Term
| main blood supply to the upper limb is via what artery? |
|
Definition
|
|
