Lesson 14

Lesson 14: Revision - getting ready for the mid semester study break

Friday, 30 March 2012

Practice exam question

Complete the following table


• Explain the role of the reticular activating system in selective attention and wakefulness; role of the thalamus in directing attention and switching sensory input on and off

Today’s Lesson

• Understand what you need to do over the mid semester break


The Reticular Activating System

Video is on the wiki Friday, 30 March 2012

The reticular activating system

Is a network of neurons extending in many directions from the reticular formation in the brainstem to different parts of the brain and spinal cord

Functions include:

• Arousal, e.g. regulates by increasing or decreasing• Alertness, e.g. regulates wakefulness and attention• Selective attention, e.g. regulates what we choose to attend

to, directs specific cortical areas to focus on relevant information

Evidence for these functions includes:• Destroying the RAS causes a coma resembling sleep• Electrical stimulation of RAS instantly awakens sleeping animals


• Plays a role in attention by actively filtering incoming sensory information, giving more weight to and emphasising certain information.

• Regulates arousal through connection with the RAs.• Closes pathways of incoming information during sleep, preventing information

from reaching the brain as it rests

Thalamus

Is a small structure on the top of the brain stem that filters and relays incoming sensory information (except smell) to relevant cortical areas. Information moves from cortical areas to lower brain structures, the spinal cord and out to the peripheral nervous system.

Function:


1. Explain the role of the reticular activating system in humans?

2. Verie Sleapi is lying on the couch watching television. She is feeling quite relaxed and nodding off. If you were to examine her reticular activating system, what would you find.

3. Outline the relationship between the reticular activating system and the thalamus


3. The RAS controls attention and sleep and the thalamus controls attention to stimuli. Both relate to attention.

Answers

1. The RAS regulates levels of attention, sleep and consciousness.

2. There would be a decreased blood flow in the RAS because there is a lower level of activity by the neurons of the RAS. There would be less activation of neurons.


The next SAC.... the timeline

First Lesson Back: The practice SAC - Prepare like it is the real SAC.

Second Lesson Back: Learning from your mistakes

First Week Back

Second Week

SAC - Poster

Start new topic - Memory


What to do in the holidays

Create digital resource for the class - see wiki for info

Revise for the SAC

Get ahead with the summaries - Everyone should be at least 1 week ahead when you get back from holidays

Revise for the exam - Start your exam preparation now. You should revise everything we have done this term


Health & Medicine

Lesson 14