Neurochemical basis of emotions
Normally, a person's emotional background is supported by endogenous opioid neuropeptides (enkephalins, endoethanols, endomorphins). They are responsible for short-term analgesia, activate the reward system, and shape motivation. The balance between the "pleasure" and "punishment" systems directly depends on these substances: high secretion produces an elevated mood, while low secretion causes depression.
The pathogenesis of chemical dependency starts when a person tries to relieve negative emotions with a dose of a psychoactive substance (PAS). A crude intervention in biochemistry occurs: the exogenous antagonist enters in gigantic concentrations. The body remembers the sharp euphoric shift, and a vicious circle is formed. The physiological cycle of producing one's own opioids is displaced, leading to the destruction of the psyche and inevitable death.
Alcohol as a narcotic poison
Ethyl alcohol acts as a typical narcotic that primarily hits the central nervous system. Initially, it causes severe excitation and blocks inhibitory processes. The popular feeling of "relaxation" after a hard day is merely a consequence of euphoria, not a physiological restoration of strength.
Systematic consumption damages all organs:
- Gastrointestinal tract and liver: digestion is impaired, steatosis (fatty liver degeneration) develops.
- Cardiovascular system: even small doses are toxic; the risk of developing atherosclerosis and hypertension increases sharply.
- Respiratory tract: ethanol vapors cause direct irritation of the mucous membranes, coarsening of the voice, and a chronic cough.
It is important to note that even daily consumption of small doses before meals "to stimulate appetite" is a form of chronic alcoholic intoxication.
Pathophysiology of tobacco smoking
Nicotine is an alkaloid with narcotic action whose toxic effect manifests after several years. At the time of smoking, it creates a false sense of vigor followed by central nervous system depression: mental performance drops, attention and memory worsen. Pronounced vasoconstriction of cerebral vessels leads to tissue hypoxia, heaviness in the head, and dizziness.
In addition to nicotine, tobacco smoke carries a cocktail of poisons:
- Carbon monoxide — binds to hemoglobin, forming carboxyhemoglobin, which blocks oxygen transport.
- Carcinogens (e.g., 3,4-benzopyrene) — provoke cancer of the lung, esophagus, and urinary bladder.
- Ammonia, hydrogen sulfide, hydrocyanic acid.
In smokers, the risk of myocardial infarction and peptic ulcer disease doubles. Prevention in children works only through personal example: knowledge about the harms of smoking is powerless if adults smoke in the family.
Drug addiction and substance abuse
Drug addiction is characterized by irreversible personality destruction and physical exhaustion. The main danger lies in three stages of dependency development:
- Tolerance: previous doses cease to cause euphoria, requiring a constant increase in the amount of the substance.
- Psychological dependence: a maniacal, uncontrollable craving for psychoactive substances.
- Abstinencia (withdrawal syndrome): a painful state of physical weakness, anguish, and insomnia in the absence of the drug.
An epidemic of substance abuse — the inhalation of volatile solvents (toluene, acetone) — is recorded among adolescents. It causes persistent addiction in just 3–4 months. Clinically, substance abuse manifests as daytime sleepiness (hypersomnia), unmotivated mood swings, and a rapid decline in intellect. An additional global threat of drug addiction is the rapid spread of HIV infection through non-sterile syringes.
Briefly: answers to topical questions
Which neuropeptides belong to the family of endogenous opioids?
The family of endogenous opioid neuropeptides includes several classes of substances produced by the brain.
- Enkephalins — have a wide localization in the central nervous system.
- Endorphins — include α-, β-, and γ-endorphin fractions.
- Dynorphins — exert an influence on the hypothalamus.
- Endoethanols — discovered in 1975.
- Endomorphins — discovered in 1975.
What are the main stages of drug addiction development?
The main stages of drug addiction development include three consecutive phases:
- Initial stage — characterized by the development of psychological dependence and the appearance of the "awakening phenomenon".
- Advanced stage — distinguished by the formation of physical dependence and the onset of withdrawal syndrome (lacrimation, muscle pain, profuse diarrhea, insomnia, dysphoria).
- Final stage — accompanied by muscle atrophy, weight loss, trophic disorders, persistent hepatitis, and personality impoverishment.
Which chemicals are most commonly used in inhalation substance abuse?
Volatile chemicals and ethereal solvents are most commonly used in inhalation substance abuse. These include:
- Acetone — used via inhalation of vapors.
- Toluene — causes a "stupefying" and intoxicating effect.
- Benzene — a volatile chemical substance.
- Tetrachloromethane — belongs to the group of ethereal solvents.
Regular inhalation use of these substances leads to the rapid development of dependence (in 3–4 months) and chronic poisoning of the body.
What is the neurochemical mechanism underlying the formation of chemical dependency?
The neurochemical mechanism of chemical dependency formation is based on the activation of the reward system and includes two main phases.
- Mechanism of euphoria — psychoactive substances stimulate an intensive release of neurotransmitters (dopamine, norepinephrine, serotonin, endogenous opioids) from storage depots, causing euphoria and positive emotions.
- Mechanism of depletion — with repeated and prolonged intake, neurotransmitter stores are depleted, and a reward deficit arises. This leads to psychological dependence (fatigue, psychoemotional discomfort).
Subsequently, a compensatory enhancement of neurotransmitter synthesis and breakdown occurs, which drives the development of physical dependence.
What medications are used as specific antidotes in opioid overdose?
Naloxone — a competitive opioid receptor antagonist and the drug of choice for treating acute poisoning — is used as a specific antidote in opioid overdose. It is administered intravenously and eliminates respiratory depression caused by the stimulation of μ-opioid receptors in the respiratory center.
The triad of addiction is easily remembered by the acronym TPA: Tolerance (dose increases), Psychological craving (thoughts only of the dose), Abstinence (withdrawal without the dose).
Class and exam questions
What is the biological role of endogenous opioids?
They regulate the endocrine functions of the brain and visceral reflexes, provide short-term pain relief, and shape motivation by maintaining a balance between negative and positive emotions.
Why is the feeling of 'relief' from alcohol false?
The subjective relief of fatigue is caused by narcotic euphoria and central nervous system excitation, rather than a genuine physiological restoration of the body's expended resources.
What causes hypoxia during smoking?
Carbon monoxide from tobacco smoke binds to red blood cells, increasing carboxyhemoglobin levels. This blocks oxygen delivery, while vasoconstriction induced by nicotine further impairs tissue nutrition.
What else to study on this topic
- WHO classification of psychoactive substances
- Mechanism of vasoconstriction in nicotine intoxication
- Parenteral transmission of HIV and epidemiology of substance use disorders
- Impact of passive smoking on perinatal mortality
- Development of hygienic culture as a method of primary prevention
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