Presentation highlights physiological changes in the body during sleep and dreams

1. PHYSIOLOGY OF
SLEEP & DREAMS
Dr. Aniket A. Shilwant
Assistant Professor
Dept. of Kriya Sharir
GJPIASR, CVM University

2. Introduction to Sleep
DEFINITION
Sleep is the natural periodic state of rest for mind and body with closed eyes
characterized by partial or complete loss of consciousness. Loss of consciousness
leads to decreased response to external stimuli and decreased body movements.
Depth of sleep is not constant throughout the sleeping period. It varies in different
stages of sleep.
SLEEP REQUIREMENT
Sleep requirement is not constant.
Average sleep requirement per day at different age groups is:
1. Newborn infants : 18 to 20 hours
2. Growing children : 12 to 14 hours
3. Adults : 7 to 9 hours
4. Old persons : 5 to 7 hours.
Dr. Aniket Shilwant, GJPIASR

3. Definition of Sleep
1)A periodic state of rest accompanied by varying degrees of
unconsciousness & relative inactivity.
2)Unconsciousness from which the person can be aroused by
sensory or other stimuli.
3)A state of altered consciousness or partial unconsciousness from
which an individual can be aroused.
4)Loss of critical reactivity to events in the environment with a
profound alteration in the functions of the Brain.
5)The mental & physical relaxation either superficially or deeply
with closed eyes.
Dr. Aniket Shilwant, GJPIASR

4. Sleep Requirement
Dr. Aniket Shilwant, GJPIASR
Sleep Rhythm
Animals & Humans – Sleep period in 24 hrs depends on habit & night period.
In Night workers – day sleeping habit
Sleep Requirement – Differs as per Age
 New born – 18 – 22 hrs
 Growing Children – 10 – 12 hrs
 Adults – 6 – 8 hrs
 Old persons – 4 – 5 hrs
 Sleep does not affect all the senses equally
 Smell & taste are mostly depressed
 Pain , touch & hearing are least affected.

5. Types of Sleep
Dr. Aniket Shilwant, GJPIASR
Stages of 2 types of sleep alternate with each other.
1) Rapid Eye Movement Sleep
REM Sleep / Paradoxical Sleep / Desynchronized Sleep)
2) Non Rapid Eye Movement Sleep
NREM Sleep

6. REM Sleep
Dr. Aniket Shilwant, GJPIASR
 Rapid conjugate movements of eyeball
 Active dreaming & active bodily muscle movement.
 Sleep is deep but not restful; Occupies about 20 – 30% of sleeping period
 Bouts of REM sleep lasting for 5 – 30 min. usually appear on average every 90-120 min.
Gradually lengthen & last about 50 min.
More difficult to arouse by sensory stimuli.
Irregular muscle movement; Muscle tone exceedingly depressed.
Usually irregular HR, RR; Brain blood flow & O2 use higher.
Highly active Brain, Metabolism increased upto 20%
EEG shows irregular waves also known as – Desynchronized waves

7. NREM Sleep
Dr. Aniket Shilwant, GJPIASR
It is of slow wave variety
Deep restful sleep
Mostly dreamless sleep
Occupies about 70 – 80% of total sleeping period.
Decrease in peripheral vascular tone
Decrease in B.P – 10 -30 %
Decrease in Respiratory rate
Decrease in BMR

8. NREM Sleep
Dr. Aniket Shilwant, GJPIASR
Stage of Drowsiness-
Diminished and abolished alpha waves
EEG shows low amplitude fluctuations
Stage of Light Sleep-
Characterized by spindle bursts superimposed by low amplitude
delta waves
Stage of Medium Sleep-
Disappearance of Spindle bursts
Stage of Deep Sleep-
Delta waves becomes more prominent.

9. Physiological Changes During Sleep
Dr. Aniket Shilwant, GJPIASR
1) Plasma volume –
Decreases by 10 %
2) Cardiovascular system –
Heart rate, cardiac output decreases
Blood pressure – systolic BP falls down and regains rise before awakening
3) Respiratory system –
Decreased respiratory rate
4) Gastrointestinal system –
Salivary secretion – decreases
Gastric secretion – does not affected except in case of duodenal & peptic ulcers

10. Dr. Aniket Shilwant, GJPIASR
5) Excretory system –
Urine formation decreases, specific gravity of urine increases
6) Sweat secretion – Increases
7) Lacrimal secretion – Decreases
8) Muscle tone – diminished. Also c/a – Sleep paralysis
9) Reflexes –
Deep – Diminished, abolished
Superficial – positive (Babinski)
10) Brain –
It is not completely inactive
In deep sleep – Delta wave In light sleep – Alpha wave
Physiological Changes During Sleep

11. Mechanism of Sleep
Dr. Aniket Shilwant, GJPIASR
Stimulation or activation of sleep-inducing centers in Brain.
Damage to sleep centers - Sleeplessness or Persistent wakefulness called
Insomnia.
SLEEP CENTERS for Onset and Maintenance of Sleep
Pathways between –
 Reticular formation of brainstem
 Diencephalon
 Cerebral cortex
Centers of Brain Stem -
 Raphe nucleus
 Locus ceruleus of pons.

12. Mechanism of Sleep
Dr. Aniket Shilwant, GJPIASR
Role of Raphe Nucleus
Raphe nucleus is situated in lower pons and medulla.
Non-REM sleep.
Cause - Release of Serotonin.
Role of Locus Ceruleus of Pons
REM sleep.
Cause – Release of Noradrenaline

13. Applied Physiology of Sleep
Dr. Aniket Shilwant, GJPIASR
INSOMNIA
It is the inability to sleep or abnormal wakefulness
Cause – Systemic or Psychiatric illness, Alcoholic and Drug addiction,
Physiologically senile age
HYPERSOMNIA
It is the excess of sleep or excess desire to sleep
Seen in –
 Brain tumors
 Encephalitis
 Endocrinal disorders-Myxedema, Diabetes Insipidus

14. Applied Physiology of Sleep
Dr. Aniket Shilwant, GJPIASR
NARCOPLEXY & CATAPLEXY
 Narcoplexy is a sudden attack of uncontrollable sleep
 Cataplexy is sudden outburst of emotion
Cause – Hypothalamus involved as center.
SLEEPAPNEA SYNDROME
 It is a temporary stoppage of breath repeatedly during sleep.
 It involves fluctuations in rate and force of respiration during
REM sleep with short apneic episode.

15. Applied Physiology of Sleep
Dr. Aniket Shilwant, GJPIASR
NIGHTMARE
Nightmare is a condition during sleep that is characterized by a sense of
extreme uneasiness or discomfort or by frightful dreams.
NIGHT TERROR
It is common in children. It is also called pavor nocturnus or
sleep terror. The child awakes screaming in a state of
fright and semi-consciousness. The child cannot recollect
the attack in the morning.

16. Applied Physiology of Sleep
Dr. Aniket Shilwant, GJPIASR
SOMNAMBULISM
Somnambulism is getting up from bed and walking in the state of sleep.
It is also called walking during sleep or sleep walking (somnus =
sleep; ambulare = to walk).
Mostly due to Psychological disturbance and Psychoneurosis
NOCTURNAL ENURESIS
It is nocturnal – Bed wetting
Poor development of Nervous control

17. Dr. Aniket A. Shilwant
Assistant Professor
Dept. of Kriya Sharir
GJPIASR, CVM University
Email – ayuraniket18@gmail.com
http://ayugjac.edu.in/Staff_CV.aspx?dl=dn3Mja19480dn3Mja19
http://scholar.google.co.in/citations?user=636K2sMAAAAJ&hl=en
https://www.researchgate.net/profile/Aniket_Shilwant
Thank You All !!!