Question

Ross has recently undergone severe changes in their food intake, mood and sleep patterns. An MRI scan was ordered and has revealed that they have a tumour in their deep brain structures.

Using your knowledge of the diffuse modulatory systems of the brain (M1L2), please answer the following questions below. Be sure to clearly label the different parts.

Part A. Briefly describe the functions of the diffuse modulatory systems located in the pons (1.5 marks)

Part B. If the tumour is also affecting their brain stem, what system and functions might this affect? If they are only sleeping 3 hours a night now, what do you predict their sleep cycle would look like? Explain your reasoning.

Answer 1

The set of interconnected nuclei which are located throughout the brainstem(pons) forms reticular formation which extends up in midbrain and lower in medulla oblongata.

A)The neurons of reticular formation found in rostral section regulate the modulatory functions which are -

• maintainance of behavioural arousal
• consciousness
• Sleep
• habituation
• Pain modulation

B)If tumour would affect the brainstem then -

• severe Altered consciousness e.g. coma
• modulation in sleep pattern - tumour causing wakefulness and altered sleep cycle due to excessive stimulation to wakefulness
• Repetitive behaviour as habituation is also controlled .
• Loss of dopamine can cause Parkinson's disease.