Distribution of Nerves and Vessels in the Upper Limb Flashcards Preview

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Flashcards in Distribution of Nerves and Vessels in the Upper Limb Deck (55)
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1
Q

What are the 5 osteological divisions of the upper limb?

A

1 - The pectoral girdle (clavicle and scapula).

2 - The arm (brachium).

3 - The forearm (antebrachium).

4 - The wrist.

5 - The hand.

2
Q

What are the 5 divisions of joints of the upper limb?

A

1 - Acromio-clavicular.

2 - Gleno-humeral.

3 - Radio-humero-ulnar.

4 - Joints of the wrist.

5 - Joints of the hand.

3
Q

How many bones constitute the carpus?

A

8.

4
Q

How many bones constitute the hand (including the carpals)?

A

27.

5
Q

What is the arterial supply to the upper limb derived from?

A

The subclavian artery.

6
Q

Describe the asymmetry in aortic supply between the left and right upper limbs.

A

The left subclavian artery is a branch of the aortic arch.

The left common carotid artery is also a branch of the aortic arch.

The right subclavian artery is a result of the bifurcation of the braciocephalic (innominate) artery into the right subclavian and right common carotid arteries.

7
Q

Where does the ascending aorta supply blood to?

To which of these is the arterial supply asymmetrical?

A

The heart, head, neck and upper limbs.

Asymmetry in blood supply to the head, neck and upper limbs.

8
Q

Describe the aortic supply of the upper limb.

What do these branches supply?

A
  • Derived from the arch of the aorta.
  • The 1st branch is the braciocephalic (innominate) artery.
  • This divides into the right sublcavian and right common carotid arteries.
  • The 2nd branch is the left common carotid artery.
  • The 3rd branch is the left subclavian artery.
  • The common carotid arteries supply blood to the head and neck, whilst the subclavian arteries supply blood to the upper limb.
9
Q

List each stage of the arterial tree of the upper limb in order.

A

Subclavian - Axillary - Brachial - Radial & Ulnar - Digital.

  • This is symmetrical on the left and right upper limbs.
  • The anterior humeral circumflex artery is a branch of the axillary artery.
  • The profunda brachii artery is a branch of the brachial artery.
10
Q

Where does the braciocephalic artery bifurcate into the right subclavian and right common carotid artery?

A

At the sternoclavicular articulation.

11
Q

At which level does the subclavian artery give rise to the axillary artery?

A

At the level of the lateral border of the first rib.

12
Q

Where does the axillary artery give rise to the brachial artery?

A

At the inferior border of teres minor.

13
Q

Where does the brachial artery give rise to the ulnar and radial arteries?

A

At the radial tuberosity.

14
Q

What is the clinical usefulness of staging intensity of the upper limb pulses from proximal to distal?

A

Used as an assessment of perfusion.

15
Q

What is the clinical usefulness of the axillary artery pulse?

A

It is palpated in investigations of occlusion.

  • It is difficult to palpate.
16
Q

What is the clinical usefulness of the brachial artery pulse?

A
  • Its position approximates the height of the heart.

- It is used for estimation of blood pressure. Its height is importance for the accuracy of this.

17
Q

Through which structures do superficial veins drain into deep veins?

A

Perforators.

18
Q

What helps the pumping of blood in deep veins?

A

The musculo-venous pump.

This is the contraction of large skeletal muscles that compress the deep veins and energise their drainage to the SVC.

19
Q

Which veins merge to form the subclavian vein?

A

The axillary and cephalic veins.

20
Q

Which veins merge to form the axillary vein?

A

The brachial and basilic vein.

21
Q

What does the basilic vein give branches to?

A

The median cubital vein and the median antebrachial vein.

22
Q

Which vein connects the basilic and cephalic veins?

A

The median cubital vein.

23
Q

What does the brachial vein divide into?

A

Radial and ulnar veins

24
Q

What is an axial line?

A

The boundary line between two dermatomes.

25
Q

What axial lines does the upper limb have?

What is also marked by the axial lines of the upper limb?

A

Anterior and posterior axial lines.

They also mark the boundaries between the flexor and extensor compartments of the limb.

26
Q

Which veins line the axial lines of the upper and lower limbs?

A
  • Upper limb: cephalic and basilic veins.

- Lower limb: great saphenous and small saphenous veins.

27
Q

What is the clinical importance of venous drainage of the upper limb? (6)

A
  • Lymphoedemas.
  • Venepunctures.
  • Sites for harvesting blood.
  • Sites for administration of intravenous drugs.
  • Sites for fluid replacement (e.g. for hydration).
  • Route for blood transfusion.
28
Q

How can inefficient venous drainage contribute to a lymphoedema?

A

Accumulating venous blood can increase intravenous pressure, causing more extracellular fluid to be forced out and therefore more lymph to accumulate.

29
Q

Which 3 lymph nodes span the upper limb?

A

1 - Supratrochlear lymph nodes.

2 - Axillary lymph nodes.

3 - Infraclavicular lymph nodes.

30
Q

Which two parallel systems of lymph drainage exist in the upper limb?

A

Superficial and deep lymphatic channels.

31
Q

Where in the upper limb is lymphatic drainage often disturbed?

A

In clearance of axillary lymph nodes.

32
Q

What are dermatomyotomes?

A
  • Embryonic precursors of the dermis and muscle units.
  • Dermatomyotomes eventually differentiate into dermis (dermatome) and muscle (myotome).
  • Differentiated skin and muscle units of a dermatomyotome always have common sources of nerve supply.
33
Q

Why are dermatomes and myotomes innervated by specific neural levels?

A

Because dermatomyotomes develop in association with the respective neural levels of the neural tube, and take their nerve supply with them irrespective of where they end up in the body.

34
Q

What is a spinal segmental nerve?

A

Converged dorsal roots (afferent) and ventral roots (efferent, motor or autonomic).

  • AKA mixed spinal nerve.
35
Q

What do spinal segmental nerves travel with?

A

Their equivalent segmental arteries and veins.

36
Q

How do segmental nerves branch after leaving the intervertebral foramen?

How do these branches differ in size and function?

A
  • It divides into posterior / dorsal and anterior / ventral rami.
  • The dorsal rami divide further into medial and lateral branches.
  • The dorsal rami are small and the ventral rami are big.
  • All rami contain all functional modalities for that segmental level.
37
Q

From which spinal segments is the nerve supply to the upper limb derived?

A

Spinal segments C4-T2.

Brachial plexus included in C5-T1.

38
Q

Which spinal segments form the upper trunk of the brachial plexus?

A

C5 and C6.

39
Q

Which spinal segments form the middle trunk of the brachial plexus?

A

C7.

40
Q

Which spinal segments form the lower trunk of the brachial plexus?

A

C8 and T1.

41
Q

How do the trunks of the brachial plexus divide?

A

All trunks divide into anterior and posterior divisions (there are 3 anterior and 3 posterior).

42
Q

What do the divisions of the brachial plexus give rise to?

What structure are they named relative to?

What cords are there?

A
  • Cords.
  • They are named relative to the axillary artery.
  • There are medial, lateral and posterior cords.
43
Q

What are the terminal branches of the brachial plexus?

A

MARMU:

Musculocutaneous
Axillary
Radial
Median
Ulnar
44
Q

Which branch / branches of the brachial plexus does the lateral cord contribute to?

A

The musculocutaneous and median cords.

45
Q

Which branch / branches of the brachial plexus does the posterior cord contribute to?

A

The axillary and radial cords.

46
Q

Which branch / branches of the brachial plexus does the medial cord contribute to?

A

The ulnar and median cords.

47
Q

How do the cords of the brachial plexus divide?

A

Each of the 3 cords divide into 2 branches.

*There are only 5 branches because the medial and lateral cords both contribute to the median branch.

48
Q

List all spinal nerve roots that contribute to the radial nerve.

A

C5-T1.

49
Q

List all spinal nerve roots that contribute to the musculocutaneous nerve.

A

C5-C7.

50
Q

List all spinal nerve roots that contribute to the ulnar nerve.

A

C7-T1.

51
Q

List all spinal nerve roots that contribute to the median nerve.

A

C6-T1.

52
Q

List 6 nerves of the upper limb excluding those included in the terminal nerve branches of the brachial plexus.

A

1 - Lateral Pectoral.

2 - Upper Subscapular.

3 - Lower Subscapular.

4 - Dorsal Scapular.

5 - Suprascapular Nerve.

6 - Long thoracic.

53
Q

What is a dermatome?

A

An area of skin supplied by sensory nerve fibres from a single neural level.

54
Q

Which spinal nerve roots supply the dermatomes of the upper limb?

A

C3-T2.

*Learn the distribution of the dermatomes as this is better done with an image.

55
Q

What is the difference between a sensory nerve territory and a dermatome?

A

Sensory nerve territories are the domains of the upper limb whose sensory innervation is supplied by sensory divisions of terminal nerves of the brachial plexus.

Idk how that’s different form a dermatome soz. Maybe where the dermatomes overlap with the territories, youve got sensory innervation from both.