Biological Processes Relating To SAD & Role Of Brain In Sleep

Question 1

What is the definition for sleep?

Answer 1

A reduced state of conscious awareness which the body is less active and responsive

Question 2

What is a circadian rhythm

Answer 2

Circadian rhythm is an internal body clock which lasts approximately 24hrs, environmental factors reset it such as light

Question 3

Stages 1 & 2 of non rem sleep?

Answer 3

These are the light sleep stages, during these stages brainwave patterns become slower and more rhythmic, starting with alpha waves and progressing to theta waves

Question 4

Stages 3 & 4 of non REM sleep?

Answer 4

Stages 3 and 4 are ‘deep sleep’ or slow wave sleep stages, where it is difficult to wake someone up. This stage is associated with slower delta waves

Question 5

Stage 5 (REM sleep)

Answer 5

Stage 5 is REM or dream sleep, here the body is paralysed (to stop the person acting out their dream) and brain activity resembles that of an awake person

Question 6

The cycles of sleep can repeat up to how many times and how long does it last for?

Answer 6

Each cycle lasts 90 minutes and a person can experience up to 5 cycles a night

Question 7

Role of the hypothalamus?

Answer 7

Controls homeostatic processes

Question 8

Example of a homeostatic process?

Answer 8

Adenosine building up throughout the day in the cells in the basal forebrain, making us tired. When we sleep the adenosine is cleared and replaced with glycogen- our energy for the next day

Question 9

What is the role of the SCN?

Answer 9

• controls circadian rhythm through gathering information from the nerve cells in the eye which tells them whether its light or dark
• if cells indicate its dark, SCN will send info to pineal gland to secrete melatonin

Question 10

Role of the brain stem?

Answer 10

Brain stem releases GABA which enables the body to relax and fall asleep

In REM sleep GABA makes sure muscles are relaxed and limbs arent moving

Question 11

What is the role of the thalamus during sleep?

Answer 11

Thalamus acts as a messenger between the senses in the brain and the cerebral cortex, allowing the cerebral cortex to be aware of things we are seeing etc

Question 12

What is the role of the cerebral cortex during sleep?

Answer 12

Cerebral cortex processes information from STM-LTM

Question 13

What is the function of the amygdala?

Answer 13

Amygdala is responsible for processing our emotions