Project Work

The Biological Importance of Sleep and Its Connection with Stress

Introduction

Relevance of the Topic:

In modern life, due to changes in people’s lifestyles, increased speed, technological influences, and psychological pressure, serious problems with the quality and quantity of sleep have emerged. Lack of sleep leads to both physical and psychological changes in the body, particularly increasing stress levels. Sleep and stress are closely interconnected—one can be the cause or result of the other.

Purpose of the Project:

The main purpose of this project is to study the biological importance of sleep for the human body and to analyze the connection between sleep and stress. In addition, the project aims to examine the negative impact of chronic and continuous stress on health based on scientific articles and research findings.

Research Methods:

Books, scientific articles, statistical data, and practical experiments.

Table of Contents

Chapter 1: The Biological Importance of Sleep

1. What is Sleep?
2. Types of Sleep: REM and NON-REM
3. Health Benefits of Quality Sleep
4. The Effect of Sleep on Memory

Chapter 2: Stress and Its Biological Foundations

1. What is Stress?
2. Effects of Stress on the Body
3. Types of Stress
4. Recommendations for Overcoming Stress

Chapter 3: The Interconnection Between Sleep and Stress

1. How Stress Disrupts Sleep
2. Scientific Research: For example, a 2018 study involving 549 participants
3. How Sleep Deprivation Increases Stress Levels

Chapter 1: The Biological Importance of Sleep

Sleep is a vital physiological condition controlled by the central nervous system during which the body and brain rest and recover. It regularly occurs throughout a person’s life and is extremely important for maintaining good health. Sleep is an active physiological process—meaning the body doesn’t completely shut down but internal systems shift and regenerate.

During sleep, a person becomes less responsive to external stimuli and is not in a conscious state, yet not completely “switched off.” The brain processes information during sleep, strengthens memory, produces hormones, and repairs tissues.

Sleep reduces stress, enhances memory and learning, maintains heart function, boosts immunity, and restores the nervous system. One interesting fact about sleep is that a third of our lives—about 25 years—is spent sleeping. Sleep is linked to heart disease, obesity, diabetes, and insomnia. According to traffic authority statistics, fatigue and sleep deprivation are among the leading causes of road accidents. The record for the longest time without sleep is 18 days, 21 hours, and 40 minutes. The person who set the record reported hallucinations, paranoia, vision issues, speech problems, difficulty concentrating, and memory decline.

Inventors like Edison, Da Vinci, Franklin, Tesla, and Churchill reportedly slept less than the average but still felt healthy. There are several stages of sleep:

• Stage 1: Transition from wakefulness to sleep. The person may deny they were sleeping if awakened.
• Stage 2: After about 20 minutes, light sleep begins and makes up about half of total sleep time. If awakened, the person can easily fall back asleep. This may repeat several times during the day.
• Stage 3: Deep sleep. The brain starts to rest, but not completely—it still monitors other organs.
• Stage 4: REM (Rapid Eye Movement) sleep. The shortest stage, but when we dream.

How much sleep does a healthy person need?
Consistent lack of sleep negatively affects the immune system and reduces hormone production, which can disrupt the nervous system. Sleeping less than 5–5.5 hours for 3 consecutive nights can result in symptoms similar to total sleep deprivation.

Lack of sleep can cause dull eyes, brittle hair and skin. A person who passes through all 4 stages of sleep and wakes up refreshed has had truly restorative rest.

Sleep Stages:

• NON-REM Sleep (3 stages): The body rests, heart rate slows.
• REM Sleep: Dreaming occurs, the brain is highly active, while the body remains still.

Benefits of Quality Sleep:

• Improves brain function
• Supports cardiovascular health
• Maintains hormonal balance
• Reduces stress and stabilizes mental state

Chapter 2: Stress and Its Biological Foundations

Stress is a physiological and psychological response of the body to external or internal threats, pressure, fear, pain, or tension.

There are various scientific explanations for stress. One of the most popular is Hans Selye’s theory, which states that the body has mechanisms to maintain balance. Strong and prolonged external and internal stressors can disrupt this balance. In response, the body activates high-level defense and adaptation mechanisms. This adaptive reaction is known as stress.

Stress symptoms can be physiological, psychological, behavioral, or pathological, and are often accompanied by emotional tension.

Common signs of stress:

• Physiological Signs:
  Increased heart and breathing rate, facial flushing or paleness, sweating, increased adrenaline levels.
• Psychological Signs:
  Slower thinking, reduced concentration, memory loss.
• Personal Signs:
  Weakened willpower, poor self-control, anxiety, fear, restlessness.
• Pathological Signs:
  Increased neurosis, fainting, headaches, insomnia.

As N.X. Kirvin stated, “Stress is everywhere—it is the shadow of life. Some benefit from it and use it to reach success, while for others, it causes harm.”

Types of Stress:

• Eustress: Positive stress, such as the pressure before an exam that boosts performance.
• Distress: Negative stress, which harms health due to prolonged fear and anxiety.
• Chronic Stress: Long-term stress that lowers immunity and causes depression and sleep disorders.

Ways to Reduce Stress:

• Quality sleep (7–8 hours), regular exercise
• Breathing exercises, meditation
• Engaging in enjoyable activities

Sleep deprivation increases stress hormone levels in the body.

Conclusion:

The connection between sleep and stress is a complex system where both conditions directly influence each other. Developing stress management skills and reducing negative internal thoughts can help prevent sleep-related problems. This project has demonstrated that sleep is vital to human health and is closely linked to stress.   

My name is Boyqobilova Nargiz Alimardonovna. I was born on September 8, 2001, in Oqorbulok neighborhood, Oltinsoy district, Surxondaryo region. I am 25 years old. Currently, I am the beloved daughter of my parents and my parents-in-law, the cherished daughter-in-law of the family, and a loving wife to my husband. I am also the proud mother of two sweet daughters. I am a 3rd-year student at the Faculty of Natural Sciences, majoring in Biology at Termez State University.