Visceral afferent systems

Question 1

What is the general function of the visceral afferent system?

Answer 1

Transmits sensory information from viscera to the central nervous system. This system is stimulated by stretch, distension, pressure, and chemical changes.

Question 2

Which nerves are involved in the visceral afferent system?

Answer 2

• Facial nerve (VII)
• Glossopharyngeal nerve (IX)
• Vagus nerve (X)
• Spinal ganglia

These nerves have specific areas of innervation and sensory function.

Question 3

Where are the cell bodies of general visceral afferent (GVA) neurons located?

Answer 3

• Geniculate ganglion of facial nerve
• Distal ganglia of glossopharyngeal and vagus nerves
• Spinal ganglia

These ganglia serve as relay points for sensory information.

Question 4

What role does the solitary tract play in the visceral afferent system?

Answer 4

Projects to GVE cell bodies or interneurons in the reticular formation

This projection is crucial for integrating visceral sensory information.

Question 5

True or False: The enteric nervous system can function independently of the CNS.

Answer 5

True

This autonomy allows it to regulate gastrointestinal functions.

Question 6

What is referred pain?

Answer 6

Visceral pain perceived at surface GSA neurons

For example, diaphragm pain may be referred to the shoulder and neck.

Question 7

Which cranial nerves carry taste sensations from the tongue?

Answer 7

• Facial nerve (VII) - rostral 2/3 of tongue
• Glossopharyngeal nerve (IX) - caudal 1/3 of tongue
• Vagus nerve (X) - caudal pharynx and larynx

These nerves transmit taste information to the brain.

Question 8

What is the primary function of the olfactory system?

Answer 8

Detects and processes smells

This system involves bipolar neurons located in the olfactory epithelium.

Question 9

How do olfactory neurons communicate with the brain?

Answer 9

Axons form CN I nerves that pass through the cribriform plate to olfactory bulbs

Olfactory projections primarily terminate in the ipsilateral olfactory cortex.

Question 10

What happens when there are unilateral lesions of the olfactory bulb?

Answer 10

Causes unilateral anosmia

Anosmia is the loss of the sense of smell.

Question 11

What can cause complete anosmia?

Answer 11

Bilateral lesions of olfactory mucosa, bulbs, peduncles, or piriform lobes

Complete loss of the sense of smell can result from various injuries or conditions.

Question 12

What is the role of the limbic system in olfaction?

Answer 12

Projections to limbic structures, including the septal area and amygdala. This connection links olfaction with emotions and memory.