PNS

Question 1

What nerve innervates the shoulder flexors?

Answer 1

Axillary

Question 2

What nerve innervates the elbow flexors?

Answer 2

Musculocutaneous

Question 3

What nerve innervates the forelimb extensors?

Answer 3

Radial

Question 4

What nerve innervates the flexors of carpi and digits?

Answer 4

ulnar and median

Question 5

What does the obturator nerve supply?

Answer 5

Abductors of the hindlimb

Question 6

What nerve innervates the tarsal extensors and digital flexors?

Answer 6

Tibial

Question 7

What nerve innervates the sartorial?

Answer 7

Sapheneous

Question 8

What nerve innervates the quadriceps femoris?

Answer 8

Femoral

Question 9

What muscle group does the common fibular nerve innervate?

Answer 9

Tarsal flexors and digital extensors

Question 10

What nerve innervates the hip extensors in horses?

Answer 10

sciatic

Question 11

Which nerve innervates the superficial gluteal muscle?

Answer 11

Caudal gluteal

Question 12

Which spinal nerves make up the brachial plexus?

Answer 12

Ventral branches of C6-T2

Question 13

Which spinal nerves make up the lumbosacral plexus?

Answer 13

L4-S3

Question 14

Name the nerves that leave the brachial plexus (9)

Answer 14

• median
• ulnar
• radial
• suprascapular
• subscapular
• musculocutaneous
• axillary
• pectoral
• brachiocephalic

Question 15

Name the nerves that leave the lumbosacral plexus (8)

Answer 15

• femoral
• sapheneous
• siatic
• obturator
• tibial
• common fibular
• caudal gluteal
• cranial gluteal

Question 16

In the case of a neuronal forelimb issue, how would you test if you had injury to a nerve that has left the plexus or a spinal nerve?

Answer 16

test the cutaneous truni reflexes, if they are not present then it is a problem with the spinal nerve

Question 17

What are the two branches of the sciatic?

Answer 17

common fibular and tibial

Question 18

Where are the cell bodies of sensory neurones found?

Answer 18

Dorsal root ganglion

Question 19

What is a motor unit?

Answer 19

A single alpha motor neurone and all the corresponding muscle fibres it innervates

Question 20

What technique can be used to measure action potential in muscles?

Answer 20

electromyography

Question 21

What is a muscle spindle?

Answer 21

A stretch receptor that detects dynamic and static changes in muscle length.

Question 22

What is the role of muscle spindles in reflexes?

Answer 22

when a muscle is stretched there is a reflex contraction of the muscle

Question 23

What is a Golgi tendon organ?

Answer 23

A tension receptor that monsters the tension in a muscle to prevent damage during excessive force

Question 24

How do Golgi tendon organs prevent muscle damage?

Answer 24

They create a reflex relaxation of the muscle

Question 25

What is a monosynaptic reflex?

Answer 25

A reflex whereby only two neurones and one synapse is involved

Question 26

What is a myotatic reflex?

Answer 26

A reflex involving muscle spindles that cause muscle contractions when the muscle is stretched

Question 27

Why would pulling the leg of a dog when lying down cause the other leg to extend?

Answer 27

Because you are causing the withdrawal myotatic reflex, since interneurones cross sides, the opposite effect happens in the contralateral limb

Question 28

What are the proprioceptive receptors in muscles called?

Answer 28

Muscle spindles

Question 29

Do muscles spindles lie perpendicular or parallel to extrafusual fibres (normal muscle fibres)?

Answer 29

Parallel

Question 30

What type of sensory neurones are attached to a muscle spindle? (2)

Answer 30

Ia and II

Question 31

Which proprioceptive muscle receptor responds to static information?

Answer 31

Golgi tendon organ

Question 32

What motor neurones leave muscle spindles?

Answer 32

Gamma

Question 33

How do Golgi tendon organs work?

Answer 33

If too much tension is applied to the muscle they will inhibit action potentials to stop the muscle contracting

Question 34

What is pain?

Answer 34

An unpleasant sensory and emotional experience associated with actual or potential tissue damage

Question 35

What are the two types of cutaneous pain?

Answer 35

- Short and sharp | - long and dull

Question 36

What nerve fibres are responsible for short sharp pain?

Answer 36

Fast A fibres

Question 37

What nerve fibres are responsible for long dull pain?

Answer 37

Slow C fibres

Question 38

What tract is responsible for superficial pain?

Answer 38

Spinocervicothalamic

Question 39

What tract is responsible for deep visceral pain?

Answer 39

Spinoreticular

Question 40

Why can't the brain localise visceral pain as well as superficial?

Answer 40

It is multi synaptic, there is a large overlapping receptor field and so is poorly localised

Question 41

What is referred pain?

Answer 41

Pain that is felt in a part of the body that is not the source