9 - Brainstem & Cranial Nerves I

Question 1

What is the oldest part of the brain?

Answer 1

The Brainstem

Question 2

What is another name for the mesencephalon?

Answer 2

Midbrain

Question 3

What is the diencephalon made up of?

Answer 3

Hypothalamus and Thalamus

Question 4

What are the functions of the brainstem?

Answer 4

• Conduit: Long tracts to or from the spinal cord pass through the brainstem
• Cranial nerve functions: sensory input, motor and parasympathetic motor output, brainstem coordinates reflexes involving them
• Integrative centers in the brainstem: sensorimotor integration, autonomic control, somatic/autonomic modulation

Question 5

What does the dorsal (tectum) part of the brain contain?

Answer 5

cranial nerve nuclei and sensory reflex centres

Question 6

What does the middle part (tegmentum) part of the brain contain?

Answer 6

ascending pathways & reticular formation (with integrating nuclei; descending sympathetic axons

Question 7

What does the ventral part of the brain contain?

Answer 7

descending motor pathways e.g., corticospinal & corticobulbar tracts; rubrospinal, reticulospinal and vestibulospinal tracts arising in brainstem

Question 8

Draw the brainstem and label the parts of it

Answer 8

http://img.medscapestatic.com/pi/meds/ckb/17/12017tn.jpg

Question 9

Which part of the brainstem are each of these sections from?
- look at google docs

Answer 9

Midbrain - Pons - Open medulla - Closed medulla

Question 10

Name the 12 cranial nerves in order.

Answer 10

Olfactory, Optic, Oculomotor, Trochlear, Trigeminal, Abducens, Facial, Vestibulocochlear (Auditory), Glossopharyngeal, Vagus, Accessory, Hypoglossal

Question 11

What are the main functions of cranial nerves II-IV and where are they found

Answer 11

Auditory, visual and pupillary reflexes and with eye movements - Midbrain

Question 12

What are the main functions of cranial nerves V-VIII and where are they found

Answer 12

Mastication, eye movement, facial expression, taste, blinking, salivation, lacrimation, equilibrium, audition - Pons

Question 13

What are the main functions of cranial nerves VIII-XII and where are they found

Answer 13

Audition, salivation, taste, respiration, GI function, neck and shoulder function, tongue movements - Medulla

Question 14

Which is more sensory and which is more motor? - lateral to medial

Answer 14

Sensory is lateral

Motor is medial

Question 15

Which nerves are pure sensory, pure motor and mixed?

Answer 15

Pure sensory - I, II, VIII
Pure motor - III, IV, VI, XI, XII
Mixed sensory and motor - V, VII, IX, V

Question 16

What are the 3 types of motor nuclei?

Answer 16

Somatic - project to skeletal muscle
Branchial - project to muscles from branchial arches, jaw movement, facial expression, motor to larynx and pharynx, neck and shoulder
Visceral - preganglionic parasympathetic fibres

Question 17

Fill out the table on the google docs

* Important

Answer 17

Look at the google docs

Question 18

What is the function of the Medial longitudinal fasciculus?

Answer 18

Connect the cranial nerve nuclei controlling eye movement and the vestibular nuclei
Extends the length of the brainstem

Question 19

What is internuclear ophthalmoplegia?

Answer 19

Damage to the MLF, both eyes won’t look the same way, often occurs due to stoke (unilateral) or ms lesion (bilateral)

Question 20

When does the MLF become the medial vestibulospinal tract?

Answer 20

In the spinal cord

Question 21

What is the reticular formation?

Answer 21

Forms a core of interconnecting neurons - a meshwork

It acts to integrate and filter inputs - modulates motor systems

Question 22

What are the different cell groups and their function in the reticular formation?

Answer 22

Lateral (sensory) - Afferent input from all senses
Medial (motor) - Efferent output to midbrain, cerebellum, hypothalamus, thalamus and spinal cord
Midline (modulatory) - Facilitatory or inhibitory, e.g pain filtering inputs

Question 23

What are the modulatory systems in the reticular formation?

Answer 23

Nuclei with specific neurotransmitters that modulate activities

• Locus coeruleus (Noradrenaline)
• Raphe nuclei (Serotonin)
• Substantia Nigra and Ventral Tegmental Area (Dopamine)
• Pedunculopontine Nucleus (Ach)

Question 24

Where is the diffuse modulatory system found?

Answer 24

Pedunculopontine & lateral dorsal tegmental nuclei of the brainstem - AcetylCholine is released
Modulates Cortical arousal (through thalamic projection) and movement

Question 25

What is the role of monoamine dopamine and where is it released ?

Answer 25

Substantia Nigra - Control of movement

Ventral Tegmental Area - Organisation behaviour, focusing and attention

Question 26

What occurs if there is a disturbance in the Substantia nigra?

Answer 26

Parkinsons

Question 27

What deficit occurs if there is a disturbance in the Ventral tegmental area?

Answer 27

Schizophrenia, addiciton

Question 28

Where is noradrenaline released?

Answer 28

Locus Coeruleus

Question 29

What is the function of the locus coeruleus?

Answer 29

Sympathetic nervous system control centre activated by the hypothalamus
Descending fibres, ascending fibres, activates motor systems and inhibits pain

Question 30

Where is Serotonin (5-HT) released from?

Answer 30

Raphe nuclei

Question 31

What is the function of the Raphe nuclei? Where is it?

Answer 31

Rostrally - inhibits basal forebrain to produce arousal, cognition, mood
Caudally - modulates pain perception
Deficits - OCD, depression, anxiety, aggression
Midline nuclei