nerves and blood vessels of the front leg

Question 1

spinal nerves are nerves that come out from

Answer 1

between the vertebrae form the spinal cord, one pair per vertebra; dorsal or ventral root

Question 2

dorsal and ventral branch of spinal nerves

Answer 2

dorsal branch comes up to muscles and skin above vertebra

ventral branch everywhere else including limbs

Question 3

afferent nerves; direction of info? which root? where are cell bodie?

Answer 3

bring info IN to CNS; come in via dorsal root, cell bodies in ganglion

Question 4

efferent nerves; direction of info? which root? where are cell bodies?

Answer 4

taking signals OUT of CNS, via ventral root, cell bodies in spinal cord

Question 5

where do spinal nerves exit the vertebral column

Answer 5

between adjacent vertebra immediately above (dorsal) to the intervertebral disk

Question 6

how do you name the spinal nerves

Answer 6

C1 to C7: Exit cranially to their corresponding vertebra.
C8: Exits caudally to the seventh cervical vertebra (C7) and cranially to the first thoracic vertebra (T1).

Thoracic, lumbar, sacral, and coccygeal nerves: Exit caudally to their corresponding vertebra.

Question 7

spinal nerves to each limb forms a

Answer 7

plexus

contribution from several spinal nerves

Question 8

what do plexuses allow for

Answer 8

regrouping and reassociation of nerve fibers (motor and sensory)

Question 9

each main nerve contains fibers from

Answer 9

2-3 spinal nerves

Question 10

name 3 reasons its important to know nerves

Answer 10

• for diagnosis
• to avoid damage during surgery
• for prognosis

Question 11

the suprasacular nerve innervates which 2 muscles

Answer 11

supraspinatus and infraspinatus

Question 12

musculocutaneous nerve innervates which 2 muscles

Answer 12

flexors of the elbow

biceps brachii and brachialis

Question 13

radial nerve innervates

Answer 13

extensors of elbow, carpus and digits

triceps, extensor carpi radialis, ulnaris lateralis, CDE, LDE, supinator, abdominal pollicis longus (dorsal mm muscles)

Question 14

Median nerve innervates

Answer 14

Flexor muscles of digits and carpus

flexor carpi radialis, pronator teres, SDF and part of the DDF

Question 15

Ulnar nerve innervates

Answer 15

flexor carpi ulnaris and part of DDF (the ulna head)

Question 16

musculocutaneous, ulnar and median nerve innervates _____ muscle masses while

radial nerve innervates _____ muscle masses

Answer 16

ventral

dorsal

Question 17

General principles limb nerves

Answer 17

• They arise from a plexus with contributions from several spinal nerves
• Most have mix of motor and sensory fibers
• Sensory part of the nerve often extend distal to motor part
• Generally on medial side or deep to muscles where they are protected
• Follow the dorsal and ventral muscle masses

Question 18

reptile twist again

Answer 18

For upper limb:

From reptile to dog, dorsal becomes caudal, ventral becomes cranial **

For your lower forelimb (antebrachii) : just remember theres a double twist for the lower forelimb

From reptile to dog the dorsal becomes cranial and ventral becomes caudal

Question 19

arteries bring blood

veins bring blood

Answer 19

away from heart

to the heart

Question 20

main stem of artery in the front limb

Answer 20

axillary

Question 21

describe axillary artery as it goes down the limb

Answer 21

Main stem is axillary artery (comes out of thoracic wall) changes at the shoulder to brachial artery and then at elbow changes into median artery continues all the way down to the foot (so one artery but have 3 names as it goes down the limb)

Question 22

axillary artery arises from

Answer 22

subclavian artery in thorax

Question 23

main branches of axillary artery

Answer 23

subscapular artery and thoracodorsal artery

Question 24

brachial artery passes medially down the humerus between

Answer 24

the biceps and medial head of triceps
(palpable here)

Question 25

brachial artery is _____ at the elbow where it becomes median artery

Answer 25

cranio-medial

Question 26

median artery continues medially and supplies the

Answer 26

paw
(both palmar and digital arteries)

Question 27

major branch of median artery is

Answer 27

radial artery

Question 28

main veins in front leg

Answer 28

• also have axillary, brachial and median parts of vein
• cephalic vein

Question 29

cephalic vein has ___ routes for drainage back to heart

Answer 29

3

Question 30

the cephalic vein joins the median vein via the

Answer 30

median cubital vein

Question 31

General principles of blood vessels to limbs

Answer 31

• Major vessels on medial side of limb for protection
• One major artery to feed limb, but usually extra venous drainage
• Know the general pattern and where they are superficial