1C. Proprioception

Question 1

Participates in local, segmental, and regional communication

Answer 1

Reflex Activity

Question 2

Information sent to higher levels of the Nervous System

Answer 2

Relay Activity

Question 3

What type of reflex does the following describe?
- Limbs and trunk via spinal nerves
- may need to coordinate over several cord segments to reach appropriate lower motor neurons that contract body/limb muscles

Answer 3

Spinal Reflexes

Question 4

What type of reflex does the following describe?
- head and face via Cranial nerves
- may need to travel through different adult brain divisions to reach appropriate lower motor neurons that contract face muscles

Answer 4

Brainstem Reflexes

Question 5

Reflex where there’s going to be one synapse in our reflex arc, are also relatively rare in the body

Answer 5

Monosynaptic Reflex

Question 6

List the components of the Monosynaptic Reflex:

Answer 6

• Stimulus receptor synapse
• Motor Cell
• Neuromuscular Junction (NMJ)
• Muscle (effector)

Question 7

List the components of the Polysynaptic reflex:

Answer 7

• multiple synapses (for proper effect); usually incorporates Interneurons

Question 8

Name an example of a Monosynaptic Reflex:

Answer 8

Knee jerk = patellar tendon reflex (causes stifle to extend)

Question 9

Help spread the effect of the stimulus a long a few localized segments so that the proper muscle unit can be recruited in order to cause a full contraction of the muscle

Answer 9

Interneurons

Question 10

Formed by interconnections of interneurons to recruit appropriate segments of the spinal cord for totality of response

Answer 10

Fasciculus Proprius Pathway

Question 11

What is a good example of a clinical application of the Fasciculus Proprius?

Answer 11

Skin twitch reflex

Question 12

It is a strip of skin that is innervated by one spinal nerve

Answer 12

Dermatomes

Question 13

Location of motor neurons (__________) for lateral thoracic nerve that innervates cutaneous trunci muscle

Answer 13

C8, T1

Question 14

It is the awareness of body position, knowing where both the trunk and the limbs are located in space

Answer 14

Proprioception

Question 15

The proprioceptive system is active when the animal is standing still (limbs at rest)

Answer 15

Conscious Proprioceptive System

Question 16

The proprioceptive system is active when the animal is actually walking

Answer 16

Subconscious Proprioceptive system

Question 17

The modified nerve ending, a receptor in general, but it is designed to detect changes as the body relates to the external environment

Answer 17

Exteroceptor

Question 18

The pathway for conscious proprioception (pelvic limb):

Answer 18

Fasciculus Gracilis

Question 19

The Fasciculus gracilis conscious proprioception pathway is:

Answer 19

contralateral

Question 20

Fasciculus Gracilis - Pelvic Limb
- spinal ganglion or dorsal root ganglion (DRG)
- Axons ascend ipsilaterally forming fasciculus gracilis

Answer 20

1st neuron

Question 21

Fasciculus Gracilis - Pelvic Limb
- nucleus gracilis
- axons cross midline as deep arcuate fibers, form contralateral medial lemniscus and ascend through the brainstem

Answer 21

2nd neuron

Question 22

Fasciculus Gracilis - Pelvic Limb
- ventral caudal lateral nucleus (VCL) of the thalamus
- axons contribute to the formation of the internal capsule, and terminate in the appropriate part of the sensory cortex (somesthetic cortex) in the parietal lobe

Answer 22

3rd neuron

Question 23

Dorsal Spinocerebellar Tract - Pelvic Limb (1 of 2 Subconscious Proprioception)
- Spinal ganglion or dorsal root ganglion

Answer 23

1st neuron

Question 24

Dorsal Spinocerebellar Tract - Pelvic Limb (1 of 2 Subconscious Proprioception)
- dorsal gray column in Clarke’s Nucleus (also known as thoracic nucleus)
- axons ascend ipsilaterally in lateral funiculus forming DSCT, pass through superficial arcuate fibers, enter caudal cerebellar peduncle, terminate in the appropriate area of the cerebellum

Answer 24

2nd neuron

Question 25

Ventral Spinocerebellar Tract - Pelvic Limb (2 of 2 Subconscious Proprioception)
- spinal ganglion or dorsal root ganglion

Answer 25

1st neuron

Question 26

Ventral Spinocerebellar Tract - Pelvic Limb (2 of 2 Subconscious Proprioception)
- dorsal gray column
- axons cross in ventral white commissure, ascend contralateral in lateral funiculus forming VSCT, enter rostral cerebellar peduncle, recross to terminate in appropriate area of cerebellum

Answer 26

2nd neuron

Question 27

Clinical Signs
1. Conscious Deficit:__________________
2. Unconscious Deficit: ________________
- Wide stance, wobbly
- Limbs swing out wide while moving
3. detected by testing postural reactions such as placing, hopping, and hemiwalking

Answer 27

1. detect signs of knuckling
2. Sensory Ataxia (lesion in one of these subconscious sensory pathways)

Question 28

Conscious Proprioception
Fasciculus Cuneatus - Thoracic Limb
- DRG
- Axons ascend ipsilaterally forming fasciculus cuneatus

Answer 28

1st neuron

Question 29

Conscious Proprioception
Fasciculus Cuneatus - Thoracic Limb
- medial cuneate nucleus
- axons cross midline as deep arcuate fibers, form contralateral medial lemniscus and ascend through the brainstem

Answer 29

2nd neuron

Question 30

Conscious Proprioception
Fasciculus Cuneatus - Thoracic Limb
- ventral caudal lateral nucleus (VCL) of the thalamus
- axons contribute to the formation of the internal capsule and terminate in the appropriate part of the sensory cortex (somesthetic cortex) in the parietal lobe

Answer 30

3rd neuron

Question 31

Subconscious Proprioception (1 of 2)
Cuneocerebellar Tract - Thoracic Limb
- spinal ganglion or dorsal root ganglion (DRG)
- axons ascend ipsilaterally in most lateral part of fasciculus cuneatus

Answer 31

1st neuron

Question 32

Subconscious Proprioception (1 of 2)
Cuneocerebellar Tract - Thoracic Limb
- lateral cuneate nucleus
- axons ascend ipsilaterally through the brainstem, enter the caudal cerebellar peduncle, terminate in the appropriate area of the cerebellum

Answer 32

2nd neuron

Question 33

Subconscious Proprioception (2 of 2)
Rostral Spinocerebellar tract - Thoracic Limb
- DRG

Answer 33

1st neuron

Question 34

Subconscious Proprioception (2 of 2)
Rostral Spinocerebellar Tract - Thoracic Limb
- dorsal gray column
- axons ascend ipsilaterally in lateral funiculus as RSCT, enter caudal and rostral cerebellar peduncle, terminate in the appropriate area of the cerebellum

Answer 34

2nd neuron