Lecture 40 - Comparative Limb Innervation

Question 1

List the nerves of the thoracic limb

Answer 1

1. subscapular
2. suprascapular
3. musculocutaneous
4. median
5. ulnar
6. radial
7. lateral thoracic
8. axillary
9. thoracodorsal

Question 2

List the nerves of the pelvic limb

Answer 2

1. femoral
2. saphenous
3. obturator
4. sciatic
5. common fibular (superficial and deep)
6. tibial
7. cranial gluteal
   8 caudal gluteal
8. caudal cutaneous femoral

Question 3

what is the applied nerve anatomy of “dropped elbow”

Answer 3

radial n. dysfunction that leads to an inability to extend the thoracic limb for weight-bearing

*potential hyperextension of the limb backward

Question 3

what is the applied nerve anatomy of “sweeny”

Answer 3

suprascapular n. injury which leads to denervation atrophy of the supra and infraspinatus

lateral shoulder instability

Question 4

what are the clinical signs of femoral n. paralysis? why?

Answer 4

inability to extend stifle, collapse in pelvic limb

innervates quadriceps femoris - responsible for stifle extension

Question 5

what nerve innervates the extensors of the elbow? name the muscles

Answer 5

triceps brachii and TFA

radial n.

Question 6

what are the clinical signs of obturator n. paralysis? why?

Answer 6

common in recently calved cows, slippery footing causes splay

innervates the adductors of the pelvic limb

Question 6

what nerve innervates flexors of the shoulder? name the muscles

Answer 6

deltoideus, teres major, teres minor

axillary n.

Question 7

what nerve innervates extensors of the shoulder? name the muscles

Answer 7

supraspinatus, infraspinatus, subscapularis

subscapular n.
suprascapular n.

Question 8

what nerve innervates the flexors of the elbow? name the muscles

Answer 8

biceps brachii, brachialis

musculocutaneous

Question 9

what nerve innervates the extensors of the carpus and digits? name the muscles

Answer 9

ECLU

radial n.

Question 10

what nerve innervates the flexor group?

Answer 10

median and ulnar n.

Question 11

where are nerve blocks performed in the thoracic limb

Answer 11

palmar digital n.
abaxial sesamoid
low palmar/4 point/metacarpal

Question 12

Describe a low palmar (4-point) block (nerves and effect)

Answer 12

medial and lateral palmar nn.

desensitizes distal metacarpus, fetlock, and digit

Question 13

Describe an abaxial sesamoid block (nerves and effect)

Answer 13

medial and lateral palmar digital nn.

desensitizes pastern and all of foot

Question 14

Describe a palmar digital n. block (nerves and effect)

Answer 14

medial and lateral palmar digital nn.

desensitizes palmar structures, sole, and distal interphalangeal joint

Question 15

where are needles inserted for a palmar digital n. block

Answer 15

distally (above collateral cartilage)

Question 16

where are needles inserted for an abaxial sesamoid block

Answer 16

border of each proximal sesamoid bone

Question 17

what block is best for laminitis assessments/tx

Answer 17

abaxial sesamoid block

Question 18

what is the purpose of a palmar digital neurectomy

Answer 18

partial removal of the nerve to relieve foot pain from navicular syndrome

Question 19

what two structures must be avoided when placing a 4-point block

Answer 19

1. communication branch
2. digital flexor tendon sheath

Question 20

where are pelvic limb nerve blocks performed

Answer 20

1. plantar digital n
2. abaxial sesamoid
3. low plantar/6-point
4. high suspensory

Question 21

what does the 6-point block include

Answer 21

1/2 - medial and lateral plantar
3/4 - medial and lateral metatarsal plantar
5/6 - medial and lateral dorsal metatarsal

blocks metatarsus and below

Question 22

what does the high suspensory block include

Answer 22

deep branch of lateral plantar n.

blocks origin of suspensory l.