Motivation

Question 1

How does the biological clock work?

Answer 1

Controls the pineal gland 
An endocrine gland posterior the thalamus 
Releases melatonin (hormone that makes us sleepy)

Question 2

Stimulus that changes the biological clock

Answer 2

Zeitgebar

Question 3

Why is light so important?

Answer 3

Small branch of optic nerve goes directly from retina to SCN, and not visual cortex

Question 4

Stages of sleep

Answer 4

1 and 2 - Irregular activity, high but declining, bursts of activity, cortex still receiving sensory input
3 and 4 - slow wave sleep, neuronal activity highly synchronised, sensory input reduced

Question 5

REM in sleep

Answer 5

Rapid eye movement (90 min cycle)
Also called paridoxical sleep
Deep because muscles are relaxed, light because lots of brain activity

Question 6

Emotion..

Answer 6

Lateral geniculate nucleus in the thalamus (limbic system)

Question 7

Movement (inhibits)

Answer 7

Pons (brain stem) (bridge)

Axons from cortex cross here to the spinal cord

Question 8

Where is the biological clock?

Answer 8

Suprachiasmatic nucleus or SCN (part of hypothalamus)

Question 9

PGO waves

Answer 9

Pons-geniculate-occipital

If animals are deprived of sleep these waves pop up during wakefulness

Question 10

What happens when you lesion the pons?

Answer 10

Experiments with cats, still has REM sleep, but muscles aren’t relaxed, chases pray and pounces .. Acting out dreams?

Question 11

Insomnia

Answer 11

Stress anxiety depression
Abiding, circadian rhythms
Dependence of sleeping pills

Question 12

Sleep apnea

Answer 12

Inability to breath whilst sleeping

Obesity/old age

Question 13

Narcolepsy

Answer 13

Attacks of sleepiness during the day

REM during day

Question 14

Periodic limb movement disorder

Answer 14

Involuntary movement in legs/arms

Something to do with pons?

Question 15

Sleep as a form of hibernation?

Answer 15

Conserving energy when you can’t get much done - lack of food, light too high or low

Question 16

REM importance

Answer 16

1/5 sleep time in REM
Emotional activity during this time
If deprived brain attempts during waking hours
Babies have more REM sleep than adults
Mammals and birds have REM, not other animals
Biological function?

Question 17

Function of REM sleep

Answer 17

Strengthening memories

moistening eyeballs

Question 18

Dreaming - activation-synthesis hypothesis

Answer 18

Effort to make sense of distorted info
PGO waves from pons activate parts of the cortex, which synthesises a story
Not always in REM..

Question 19

Dreaming - the clinico-anatomical hypothesis

Answer 19

Dreaming is thinking
Senses are suppressed, brain left to its own devices
Motor cortex suppressed so no action
Prefrontal cortex suppressed al no working memory to linked in a believable story

Question 20

Thirst - if water is scarce..

Answer 20

Pituitary gland secretes vasopressin
Blood vessels constrict
Raises blood pressure and compensates for low fluid volume

Question 21

Why do hangover make us thirsty

Answer 21

Drinking alcohol blocks production of vasopressin by pituitary gland
Prevents kidneys from absorbing water
Makes urine more diluted

Question 22

When to eat

Answer 22

Centres around hypothalamus, this has neurons sensitive to hunger and feeling full
Many areas are involved

Question 23

Anorexia

Answer 23

0.3% young women

No genetic basis

Question 24

Bulimia

Answer 24

Imbalance of hormones associated with feeding
May result in erratic eating
Similar to drug addiction

Question 25

2 main ways men and women differ

Answer 25

1. Sexual strategies

2. Cognition

Question 26

Role of hormones in sexual strategies

Answer 26

Men: androgens (testosterone) produced in testes and adrenal gland (brain) removal decreased sex drive but still some (in brain)
Women: oestrogen’s produced by ovaries and androgens
Post menopausal women can still have high sex drife due to androgens