exam 2: nervous system brachial plexus

Question 1

T/F Spinal roots are unidirectional

Answer 1

true

Question 2

are dorsal roots or ventral roots comprised of afferent fibers
– sensory and proprioceptive fibers?

Answer 2

dorsal root

Question 3

are dorsal roots or ventral roots comprised of efferent fibers
– motor neurons (to muscles and glands)

Answer 3

ventral root

Question 4

T/F Spinal nerves are bidirectional

Answer 4

true

Question 5

Carries nerve fibers that innervate structures dorsal to the transverse processes
* Afferent and efferent fibers

dorsal or ventral branch

Answer 5

dorsal branch (smaller)

Question 6

Carries nerve fibers that innervate structures ventral to the transverse processes
* Afferent and efferent fibers

dorsal or ventral branch

Answer 6

ventral branch (larger)

Question 7

Label the layers of a spinal nerve

Answer 7

1. epineurim

2.perineurium

3. endoneurium

Question 8

Brachial Plexus

what is it
what is it formed by

Answer 8

network of nerves to thoracic limb

formed by ventral branches of spinal nerves (+/- C5) C6, C7, C8, T1, T2

Question 9

_____________branches communicate and give rise to nerves that form the
brachial plexus

Answer 9

ventral branches

Question 10

3 main functions of brachial plexus

Answer 10

Motor to skeletal muscles
Cutaneous sensory from skin
Proprioception from thoracic limb

Question 11

Brachial Plexuses are located in the ____________ regions, close related with ________ vessels

Answer 11

axillary

Question 12

Brachial Plexuses is classified as what kind of joint

Answer 12

synsarcosis (“joint of muscles)

Question 13

what is this showing

Answer 13

avulsion (seperation) of brachial plexus

Question 14

this nerve is NOT a nerve described as part of the brachial plexus, doesn’t innervate any structure in the thoracic limb but, the origin is very close to the brachial plexus.

Answer 14

Phrenic nerve

Question 15

origin of phrenic nerve

Answer 15

C5-C6-C7

Question 16

Is the phrenic nerve motor or sensory

Answer 16

Motor nerve of diaphragm

Question 17

what nerve is being pointed to

Answer 17

phrenic nerve

Question 18

Autonomous Zone (AZ) is where there is only __ nerve

Answer 18

one

Question 19

what does green represent? orange?

Answer 19

green= cutaneous area of axillary nerve

orange= cutaneous area of radial nerve

Question 20

what is being pointed to by the black arrow

Answer 20

overlap zone

Question 21

what is being pointed to by the black arrows

Answer 21

autonomous zones

Question 22

T/F: Nerves must have a cutaneous zone in order to have an overlap zone or autonomous zone

Answer 22

true

Question 23

Extrinsic muscles of thoracic limb:

cleidobrachialis m is innervated by what nerve

Answer 23

Brachiocephalic n. (motor and sensory)

Question 24

Extrinsic muscles of thoracic limb:

Superficial pectoral m. is innervated by what nerve

Answer 24

Cranial pectoral nn (motor)

Question 25

Extrinsic muscles of thoracic limb: Deep pectoral m. is innervated by what nerve

Answer 25

Caudal pectoral nn( motor)

Question 26

Extrinsic muscles of thoracic limb: Latissimus dorsi m. is innervated by what nerve

Answer 26

* Thoracodorsal n (motor)

Question 27

Extrinsic muscles of thoracic limb: Serratus ventralis m is innervated by what nerve

Answer 27

Long thoracic n (motor)

Question 28

Cutaneous trunci m. (not an extrinsic muscle) is innervated by what nerve

Answer 28

Lateral thoracic n (motor)

Question 29

what nerve is the yellow arrow pointing to

Answer 29

Brachiocephalic n. (very cranial)

Question 30

what nerve is being pointed to by the yellow arrow

Answer 30

Long thoracic n

Question 31

Nerves of the brachial plexus innervating intrinsic thoracic limb muscles: Suprascapular nerve is it motor or sensory?

Answer 31

(C6, C7) * Motor to: – Supraspinatus m. – Infraspinatus m. * No sensory innervation!!!!

Question 32

what nerve is this

Answer 32

Suprascapular n.

Question 33

Nerves of the brachial plexus innervating intrinsic thoracic limb muscles: Subscapular nerve is it motor or sensory?

Answer 33

(C6, C7) Motor to: – Subscapularis m. * No sensory innervation!!!

Question 34

what nerve is being pointed to

Answer 34

Subscapular nerve

Question 35

Nerves of the brachial plexus innervating intrinsic thoracic limb muscles: Musculocutaneous nerve (C6,C7,C8) is it motor or sensory?

Answer 35

* Motor to: – Biceps brachii m. – Brachialis m. – Coracobrachialis m. * Sensory to: – Medial aspect of antebrachium

Question 36

If there is damage to the suprascapular nerve what would the result be

Answer 36

Can't laterally stabilize humeral joint extend humeral joint

Question 37

If there is damage to the subscapular nerve what would be the result

Answer 37

Cannot medially stabilize humeral joint

Question 38

if there is damage to the Musculocutaneous nerve what would the result be

Answer 38

no flexion of cubital joint may have paralysis

Question 39

Nerves of the brachial plexus innervating intrinsic thoracic limb muscles: Axillary nerve (C7,C8) is it motor or sensory?

Answer 39

* Motor to: – Teres major m. – Teres minor m. – Deltoideus m. – Caudal part of Subscapularis m. * Sensory to: – Craniolateral shoulder area – Cranial aspect of antebrachium

Question 40

if there is damage to the axillary nerve what would be the result

Answer 40

probably cant flex humeral joint

Question 41

Nerves of the brachial plexus innervating intrinsic thoracic limb muscles: Radial nerve (C7,C8, T1, T2) what all muscles is it motor to?

Answer 41

* Motor to: – Triceps brachii m. – Tensor fasciae antebrachii m. – Anconeus m. – Extensor carpi radialis m. – Common digital extensor m. – Lateral digital extensor m. – Extensor carpi ulnaris m. – Supinator m. – Abductor pollicis longus m (not important) – Brachioradialis m. (not important)

Question 42

Nerves of the brachial plexus innervating intrinsic thoracic limb muscles: Radial nerve (C7,C8, T1, T2) sensory to?

Answer 42

Cranial and lateral aspect of antebrachium Medial and dorsal aspect of manus

Question 43

if there is damage to the radial nerve what happens

Answer 43

NO RADIAL NERVE, NO THORACIC LIMB no extension of cubital joint or carpal joint no flexion humeral joint (long head of tricep) cannot support body

Question 44

what is being pointed to in blue? red?

Answer 44

blue- superficial branch of radial nerve red- deep branch of radial nerve

Question 45

what is the blue arrow pointing to? grey arrow?

Answer 45

blue= superficial branch of radial nerve grey= cephalic vein

Question 46

label 1 and 2

Answer 46

1. Antebrachial cutaneous nn. of radial nerve 2. Dorsal common digital nn. of radial nerve

Question 47

Radial nerve innervates triceps brachii m., tensor fasciae antebrachii m. and anconeus m. then divides into

Answer 47

Deep branch (motor) Superficial branch

Question 48

Deep branch (motor) of radial nerve Innervates

Answer 48

extensors mm. and supinator m. of the antebrachium

Question 49

Superficial branch of radial nerve is sensory to:

Answer 49

Cranial and lateral aspect of antebrachium Medial and dorsal aspect of manus

Question 50

Nerves of the brachial plexus innervating intrinsic thoracic limb muscles: Median nerve (C8,T1,T2) motor or sensory

Answer 50

* Motor to: – Pronator teres m. – Flexor carpi radialis m. – Superficial digital flexor m. – Deep digital flexor m. – Pronator quadratus m. * Sensory to: – Palmar aspect of manus

Question 51

Nerves of the brachial plexus innervating intrinsic thoracic limb muscles: Ulnar nerve (C8,T1,T2) motor or sensory

Answer 51

Motor to: – Flexor carpi ulnaris m. – Deep digital flexor m. – Interossei mm. Sensory to: -Caudal aspect of antebrachium (Caudal antebrachial cutaneous n.) -Palmar aspect of manus -Lateral side of digit 5th

Question 52

what nerve is 1? 2?

Answer 52

1. Median n. 2. Ulnar n.

Question 53

what nerve is this

Answer 53

Ulnar n.

Question 54

what is being pointed to

Answer 54

Ulnar n. Cutaneous branch to digit v

Question 55

if there is damage to Median nerve what would probably happen

Answer 55

may not be able to: -flex carpal jt, metacarpophalangeal jt, proximal interphalangeal jt, digital joint - pronate manus

Question 56

if there is damage to the ulnar nerve what may the animal not be able to do

Answer 56

-flex antebrachial joint -flex carpal or digital joint -support and flex metacarpophalangeal joint