Nerve Part 1
Which nerve pierces coracobrachialis and what muscles does it innervate
Musculocutaneous Nerve
- innervates coracobrachialis, biceps brachii and brachialis
Which extensor muscles are not innervated by the posterior interosseous nerve
Extensor carpi radialis longus is innervated by the radial nerve
Extensor carpi radialis brevis is innervated by the deep branch of radial nerve before it becomes the posterior interosseous nerve
Where does the axillary artery start and from which artery is its formed?
where and how does the anterior interosseous artery move from the anterior compartment to the posterior compartment?
The anterior interosseous artery pierces the interosseous membrane in distal third of forearm. This allows for a more extensive blood supply to the posterior compartment.
Where do the basilic vein and cephalic vein originate from?
dorsal venous arch
Damage of which trunk as well as which nerve root results in erb's palsy
Which nerves innervates the posterior wall of the axilla
Upper subscapular nerve - subscapularis
Thoracodorsal nerve - Latissimus dorsi
Lower subscapular nerve - subscapularis and teres major
thoracoacromial artery arises from which part of the axillary artery? What other artery arises from this part?
Thoracoacromial artery arises from the second part of the axillary artery along with the lateral thoracic artery
at which anatomical region does the brachial artery branch into ulnar and radial arteries?
Neck of radius
Between which two heads of a muscle can the ulnar nerve be entrapped. What is this called?
The ulnar can be entrapped between the two heads of flexor carpi ulnaris
This is called cubital tunnel syndrome
Will supraspinatus be weak if the suprascapular nerve is injured in the spinoglenoid notch?
No, supraspinatus will be innervated by the suprascapular nerve before it reaches the spinoglenoid notch. However, infraspinatus will be affected.
Describe a characteristic of the brachial artery at the elbow.
The brachial artery forms an extensive anastomoses over the elbow joint to ensure constant blood supply over a highly active and mobile joint.
Eg. superior and inferior ulnar collateral artery
Injury to the axillary nerve may result in a loss of sensation of which area of the upper limb
Axillary nerve has a posterior division that continues on to form the upper lateral cutaneous nerve of the arm. This supplies the skin over lateral deltoid region (around insertion point)
What separates the two heads of pronator teres?
Median nerve
Which artery passes through the triangular interval and which artery is it branched from
The profunda brachii artery passes through the triangular interval. It is a branch of the brachial artery
Which reflex may be diminished due to a radial nerve lesion and what is also another common sign of radial nerve palsy (why does this affect grip)
The triceps tendon jerk may be affected by a radial nerve lesion (C5,6,7)
Another clinical sign of radial nerve palsy is wrist drop. Lack of innervation to wrist extensors leads to active insufficiency of the long finger flexors, affecting grip
Does the median nerve supply (anterior interosseous nerve) supply flexor digitorum profundus?
Yes, the median nerve supplies the lateral half of flexor digitorum profundus.
At what point does the brachial artery start
lower border of teres major
What actions are affected by an ulnar nerve compression at guyon's canal?
loss of motor function of abduction and adduction
- adductor pollicis longus
- 3rd and 4th lumbricals
- palmar and dorsal interossei