Lecture 6: Thoracic & Pelvic Distal Limb Blood Vessels & Nerves; Perineural Blocks (Exam 1) Flashcards
(79 cards)
1
Q
What forms the brachial plexus
A
Formed by the ventral branches of spinal nerves C6 to T2
2
Q
Describe the suprascapular nerve
A
- Passes over the scapula
- Supplies the supraspinatus & infraspinatus m.
- Damage to this nerve can cause atrophy of these muscles (“Sweeny shoulder”) b/c of the loss of the muscles’ ability to fix the shoulder resulting in shoulder instability
3
Q
Why is a suprascapular nerve injury common in horses
A
- B/c they lack an acromion which would protect the nerve
- The nerve is left exposed & vulnerable to injury when the horse hits its shoulder
4
Q
What muscle is supplied by the subscapular n
A
Subscapularis m
5
Q
Describe the axillary n
A
- Located btw/ the subscapularis & teres major muscles
- Supplies the muscles of the shoulder
6
Q
Describe the musculocutaneous n
A
- Innervates the muscles the flex of the shoulder
- Provides autonomic innervation to the distal limb
7
Q
Describe the median n
A
- Runs w/ the brachial artery in the humeral region
- Continues w/ the medial artery in the forearm
- Responsible for the movement of the flexors including the digital & carpal flexors
- Main autonomic innervation for the palmar surface of the distal limb
8
Q
What is the axillais
A
A structure around the axillary blood vessels that joins the median nerve w/ the musculocutaneous nerve
9
Q
Describe the radial n
A
- Large nerve trunk that originates from the brachial plexus
- Located medially
- Hiding btw/ the heads of the triceps
- later branch innervates the extensor muscles of the carpus & digit
- Autonomic innervation to the distal limb
10
Q
What nerve is this
A
Suprascapular
11
Q
What is sweeny shoulder
A
- Damage to the suprascapular nerve
- Not uncommon in horses
- Results in atrophy of supra & infraspinatus, shoulder instability, & shoulder “slip”
12
Q
What nerve is this
A
Subscapular n.
13
Q
What nerve is this
A
Axillary n
14
Q
What nerve is this
A
Musculocutaneous n
15
Q
Label the following:
A
16
Q
Label the nerves
A
17
Q
What nerve is this
A
Ulnar n
18
Q
What is the action & innervation of the radial n
A
- Action: Primary nerve responsible for extension in the forelimb
- Innervation: Triceps muscle (extends the elbow joint) & Extensor muscles of the carpus & digits (Extend the wrist & fingers)
19
Q
What is the action & innervation of the median nerve
A
- Action: Flex the wrist & fingers
- Innervation: Flexor muscles of the carpus & digits
20
Q
How does the musculocutaneous n connect to the median nerve
A
Via the ansa axillaris
21
Q
What are some symptoms of the ulnar nerve injury
A
- Weakness or paralysis of the flexor muscles in the carpus
- Difficulty w/ fine motor skills
- Sensory loss
22
Q
Describe a radial nerve injury
A
- Inability to extend the carpus
- Drooping of the limb
- Difficulty w/ extension of the digits
23
Q
Label the nerves w/ the corresponding autonomic zones
A
24
Q
Label the following extensions of the nerves that give cutaneous innervation of the fore digit
A
25
Label the different colored lines indicating the nerves of the fore digit
26
Label the following nerves
27
What are the main arteries of the humeral region
Axillary & brachial artery
28
What is the main artery supply the carpus/digits
Median artery
29
What artery is a branch of the median artery supplying the medial aspect of the palm
Medial palmar artery
30
Which artery is a branch of the medial palmar artery supplying the lateral digit
Lateral digital palmar artery
31
Which artery is a branch of the medial palmar artery supplying the medial digit
Medial digital palmar artery
32
Which artery is a very small artery originating from the radial artery
Lateral palmar artery
33
Which artery is a branch of the median artery contributing to the dorsal blood supply of the carpus
Radial artery
34
Define the rete carpi dorsales
A network of small arteries providing the dorsal blood supply of the carpus
35
Be able to describe the main arteries & branches off of them
36
Label the following arteries
37
Label the following arteries
38
What nerves from the lumbosacral plexus
Nerves from the L4 to S2
39
What does the lumbosacral plexus supplies
The proximal muscles of the pelvic limb
40
What do the cranial & caudal gluteal nerves supply
The proximal muscles of the pelvic limb
41
What does the femoral nerve supply
The quadriceps muscle & gives rise to the saphenous nerve
42
Describe the saphenous nerve
* Runs medially
* Provides autonomic innervation to the medial part of the thigh & leg
43
Describe the sciatic nerve
Divides into the tibial & common fibular nerves
44
What does the tibial nerve supply
The caudal part of the leg & the plantar aspect of the foot
45
What does the common fibular nerve supply
The cranial part of the leg & the dorsal aspect of the foot
46
What does the obturator nerve supply
The adductor muscles of the thigh
47
What can result if there is an injury to the obturator nerve
In abduction of the limb due to loss of adductor muscle function
48
Describe the chiaticosiatic nerve
A large nerve that runs laterally deep to the biceps femoris muscle
49
The (tibial/fibular) nerve runs caudal while the (tibial/fibular) nerve runs cranially
Tibial;fibular
50
What does the tibial nerve innervate
The distal limb of the pelvic limb
51
What nerve gives rise to the lateral & medial plantar nerves & what do they supply
* Tibial nerve
* Supplies the plantar aspect of the foot
52
Describe the metatarsal nerves
Small deep nerves located btw/ the metatarsal bones & the interosseous ligament
53
What does the fibular nerve divide into
The deep & superficial fibular nerves
54
Describe the deep fibular nerve
Gives rise to the lateral & medial dorsal metatarsal nerves which supply the dorsal aspect of the foot
55
Describe the superficial fibular nerve
This nerve supplies the cranial part of the leg & the dorsal aspect of the foot
56
What nerve is this (dark blue & light blue arrow)
* Dark blue: Femoral
* Light blue: Saphenous
57
What nerve is this
Obturator n
58
Label the following
59
What nerve is this (Dark blue arrow, proximal light blue arrow, distal light blue arrow)
* Dark blue: Sciatic
* P light blue: Tibial
* D light blue: Common fibularis (Peroneal)
60
Label the autonomic & cutaneous zones nerves
61
Label the branches each nerve involved in the cutaneous innervation of the hind digit
62
Label the following different colored lines with the correct nerve/branch
63
Label the different branches of the arteries starting with the femoral artery
64
Use this diagram to label the arteries
65
What arteries does the femoral give rise to
The popliteal artery & caudal tibial artery
66
What does the saphenous artery supply
The medial part of the foot
67
Describe the popliteal artery
* Gives rise to the cranial tibial artery
* Supplies the dorsal aspect of the foot
68
Describe the caudal tibial artery
* Supplies the plantar aspect of the foot
* Branches into the plantar lateral artery & the plantar medial artery
69
Describe the digital arteries
When the plantar lateral & medial arteries reach the digits they become the lateral digital artery & the medial digital artery
70
Where is the deep plantar arch
Btw/ the plantar lateral & medial arteries
71
What branches off from the deep plantar arch
Lateral & medial plantar metatarsal arteries
72
What branches off from the medial plantar artery
Medial digital plantar artery
73
Describe the lateral digital plantar artery
Branches off from the medial plantar artery but the lateral plantar artery also contributes to its supply
74
Describe a palmar digital nerve block
* Insert the needle over the neurovascular bundle @ the proximal border of the collateral cartilage
* 1.5 ml per site
* Palmar digital nerves
* numbs the most distal part of the digit (sole, navicular apparatus, coffin joint, distal flexor tendon sheath, distal sesamoidean ligaments, & loss of skin sensation @ the heel)
75
Describe an abaxial sesamoid nerve block
* Insert the needle @ the abaxial surface of the sesamoid w/ the needle pointed distally
* 2 ml per site
* Palmar digital nerves
* Numbs the foot, middle phalanx, pastern joint, distal P1, Distal SDF & DDF, distal sesamoidian ligaments, Distal annular ligament, & +/- fetlock joint
76
Describe a low 4 point block
* Insert the needle distal to the button of the splint medially & laterally; insert the needle SQ btw/ the suspensory ligament & the DDF tendon
* 1 - 2 ml per site
* Palmar metacarpal/metatarsal nerves (adjacent to the splint) & palmar nerves (btw/ suspensory & DDF tendon)
* Numbs all structures prev mentioned, fetlock joint, suspensory branches, & more proximal SDF/DDF tendons
77
What is the difference in a low 4 point block in the hind limb
* performed the same as the forelimb
* Will not reliably anesthetize the skin dorsally (impt for suturing a laceration; less impt for a lameness work up)
* Can do a dorsal ring block to anesthetize the skin
78
Describe a high 4 point block in the front limb
* Inject SQ on dorsal surface of the DDFT through the fascia (carpal retinaculum flexorum) just distal to the CMC joint; flex the limb & insert the needle along the splint bones pointed @ palmar MC3
* 2 to 5 ml per site
* Medial & lateral palmar nerves along w/ the medial & lateral palmar metacarpal n
* Numbs the flexor tendons, splint bones, interosseous ligaments (btw/ MC2/4 & MC3), proximal suspensory ligament, & the inferior check ligament
79
Describe a high 4 (6) point block in the hind limb
* 1.5 in needle inserted 1 cm distal to TMT on either side & hit the back of the MC3 non wgt, a 25g 5/8 in needle deposits 3 to 5 ml through the fascia over the DDFT on medial & lateral side, finally a 2cm distal to the TMT @ 10 & 2 o'clock positions on the dorsal cannon bone
* 3 to 5 ml per site
* Medial & lateral plantar nerves, Medial/lateral plantar metatarsal nerve, & dorsal metatarsal n
* Numbs everything distal to the TMT except the dorsum over the cannon bone & dorsal cannon
* Necessary for lacerations not commonly clinically relevant
