2.4 Sensory and Motor pathways DL

Question 1

What is the function of CN V?

Answer 1

Trigeminal Nerve:

Sensory function: transmits information about pain, temperature, proprioception, temperature, and touch from the face to the head.

Motor function: Jaw/mastification
**One of the largest nerves

Question 2

Damage to CN V could cause?

Answer 2

Sensory​: decreased sense of proprioception, pain, temperature, and touch

Motor: weaker or paralyzed jaw movement

Question 3

What is the function of CN VI?

Answer 3

Abducens nerve: pulls the ​eye away from midline via lateral rectus

Question 4

Damage to CN VI could cause?

Answer 4

Could lose the ability to move the eye laterally

Question 5

What is the function of CN VII?

Answer 5

Facial nerve:

Motor: Muscles of facial expression and the head
- swallowing
- external ear

Sensory from:
- outer ear
- taste buds on 2/3 of tongue

**Supplies major glands of head

Question 6

Damage​ to CN VII could cause?

Answer 6

• Facial paralysis (so there is an absent palpebral reflex)
• loss of taste on 2/3 of the tongue

Question 7

What is the function of CN IX?

Answer 7

Glossopharyngeal Nerve:

innovates parotid gland responsible for taste of 1/3 of the tongue

Question 8

Damage to CN IX could cause?

Answer 8

• Dysphagia and an absent gag reflex.
• loss of taste​ to 1/3 of the tongue

Question 9

What is the function of CN X?

Answer 9

Vagus Nerve: Parasympathetic to pharynx, larynx, heart, and abdomen

Question 10

Damage to CN X could cause?

Answer 10

laryngeal paralysis, regurgatation Hoarseness of voice, difficulty swallowing, GI and heartrate issues

Question 11

What is the function CN XII?

Answer 11

Hypoglossal nerve:

motor nerve that controls all muscles of the tongue except Palatglossus (CNX)

intrinsic: shape of tongue
extrinsic: protrude, retract, elevate, move

used for eating​, swallowing, and speaking

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Question 12

Damage to CN XII could cause

Answer 12

tongue paralysis

Question 13

What effects might lesions to the medulla and pons have on the following parameters: spinal reflexes?
ex: the patella reflex

Answer 13

Unusually nothing since the spinal cord is unaffected.

Question 14

What effects might lesions to the medulla and pons have on the following parameters: breathing

Answer 14

It can be affected in 3 different ways:
1. Aponea (no breathing)
2. intermittent and shallow breathing
3. regular and slow shallow breathing

Question 15

What effects might lesions to the hindbrain have on eye appearance?

Answer 15

signs associated with loss of function of CN VIII

Question 16

What effects might lesions to the midbrain have on the spinal reflexes?

Answer 16

Still present if not overwhelmed by ridgity

Question 17

What effects might lesions to the midbrain have on the menace test?

Answer 17

The animal can see but not respond to the stimulus. The nuclei of CN VII to the orbicularis oculi muscle is found here

Question 18

What effects might lesions to the cerebellum​ have on muscle tone?

Answer 18

generally reduced hypotonia

Question 19

What effects might lesions to the cerebellum have on stance and locomotion​?

Answer 19

ataxia

Question 20

What effects might lesions to the cerebellum have on planned movement? **Think about Parkinson’s​

Answer 20

1. intention tremors at the start of the movement
2. overshooting of the target (hypermertria)

Question 21

What effects might lesions to the cerebellum have on planned movement? **Think about Parkinson’s​

Answer 21

1. intention tremors at the start of the movement
2. overshooting of the target (hypermertria)

Question 22

What effects might lesions to the cerebellum have on eye movement?

Answer 22

fine oscillatory nystagmus (form of intention tremor​)

Question 23

What effects might lesions to the cerebellum have on menace response​?

Answer 23

reduced

Question 24

tumours of the pituitary gland can affect?

Answer 24

adjacent structure including cranial nerves

Question 25

The Pituitary Gland: What brain structures are most likely to be affected and what are the possible clinical manifestations?

Answer 25

• The optic chiasma, hypothalamus and occulomotor nerves.
• Deficits is vision, and the reflexes associated with CNII e.g. the menace response.
• Hypothalamic deficits in homeostasis: control of blood pressure, body temperature, fluid and electrolyte balance, endocrine signals to the pituitary etc.