Neurophysiology - Sleep Flashcards

1
Q

Biological Rhythms - Circadian Rhythm

A

Sleep-wake cycle, 24h and 11m. Supported by pacemaker cells and clock genes (tells you when to sleep).
External cues can influence the pacemaker, to assist in balancing the rhythm:
- Light conditions
- Entertainment
- Synchronization (accustom to waking up and falling asleep at a certain time)
- Internal mental processes (can’t stop thinking about things)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Light Input

A

Photoreceptors in the retina, sends info through the retinohypothalamic tract. Sensitive to wavelengths 484 to 500nm.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Suprachiasmatic Nucleus

A

The pacemaker, sets the circadian rhythm. Perceives light, sends signals for melatonin when light goes down.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is happening in our brain during sleep?

A

We burn more energy asleep than awake.
We re-experience everything (thoughts, emotions, expectations…) we did during the day and compare it to all other memories we have.
Brain takes away our consciousness to be able to do this. So that we can create memories.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the pathway responsible for us re-experiencing everything during sleep and comparing it to all other memories? (REM cycle)

A

AM → HPC → Striatum → AM
AM → LC (NE)
Striatum → Raphe nuclei (SE)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Sleep - Definition

A

Active, natural periodic state of rest where consciousness is completely or partially lost, so that a decrease in responsiveness can be observed.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Sleep cycle

A

Contains multiple cycles (4-6) lasting 55-85 minutes. Each sub-cycle contains 2 phases, REM (rapid eye movement)(5-15min,25%) and NREM(50-70min,75%).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

NREM Stages (4)

A

Stage 1: sleep onset, light sleep. 5%.
Stage 2: deep sleep, 45%.
Stage 3&4: slow wave sleep, deeper state of sleep, more stimulation is needed to recover wakefulness. 25%. Sleep spindles appear, REM in 2-3min.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

REM Phases (4)

A

Rapid eye movements
Low PNS activity leading to stimulated paralysis
Highest encephalic activity
Formation of dreams.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Sleep Spindles - Definition and Characteristics

A

Burst of oscillatory short synchronized activity, occurs during N2.
- 12-15 Hz
- 0,5-2 secs
- Origin: thalamic reticular nucleus
- Synchronized by thalamocortical interactions.
Associated with dynamic alterations in synaptic plasticity during sleep.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Sleep Function Theories (3)

A

Circadian theory
Recuperation theory
Memory consolidation/sleep promoting learning theory

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the 5 things that happen during completely or partially interrupted sleep that affects rehabilitation?

A

↑ cortisol → ↓BDNF,GNF, reduce glucose tolerance, increase sympathetic nervous system activity.
Aggravate pain.
↑ heart rate, blood pressure and sympathetic activity magnifying individual’s response to stress.
Fatigue.
↑ risk of psychological dysfunction and mental illness.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly