7.2 - Disruptions to Body Coordination

Drugs and Body Coordination

• Drugs are chemical substances that can disrupt neurone function by delaying impulse transmission in neurones.
• Uncontrolled drug consumption disrupts body coordination and causes addiction.
• Drugs may produce beneficial or harmful effects depending on their use.
• Drugs can treat disease, but morphine and steroids must be taken under a doctor’s supervision.

Types of Drugs and Their Effects

Type	Effects and examples
Depressant	Prevents or slows impulse transmission in body coordination. The user becomes sleepy and less anxious. The effect depends on dosage. Examples: barbiturates and alcohol.
Stimulant	Speeds up impulse transmission in body coordination. The user feels very confident and alert to the surroundings. The effect depends on dosage. Examples: amphetamine and methamphetamine.
Inhalant	A chemical substance that can be inhaled through breathing. Causes hallucination and damages the brain, lungs and kidneys. Examples: solvent and gas substances.
Hallucinogen	Changes the path of impulses in the brain; causes hallucination; affects perception and muscle coordination; may cause the user to hear voices and see non-existent objects. Examples: ketamine and LSD (lysergic acid diethylamide).

Drug Abuse, Addiction and Body Coordination

• Drug abuse causes addiction. Stopping drug consumption causes withdrawal symptoms: shivering, nausea, anxiety and depression.
• Drugs may stimulate the nervous system: heartbeat, breathing rate and blood pressure increase; the user becomes more energetic, active, indecisive and aggressive.
• Drugs may slow down the nervous system: heartbeat, breathing rate and blood pressure decrease; response to stimuli becomes slow; the user becomes sleepy and muscle coordination weakens.
• Drugs can disrupt perception, causing hallucination and illusion.
• Factors causing drug abuse: curiosity, peer influence, seeking pleasure, and the desire to overcome sadness or forget a problem.

Effects of Drug and Alcohol Abuse on Body Coordination

• Most drugs affect body coordination through the nervous system. Alcohol slows the flow of nerve impulses and affects brain function.

Hormonal imbalance

• Disrupts body coordination and exposes the body to danger and injury.
• Damage to the pituitary gland may cause extreme growth or no development.
• Failure of oestrogen and testosterone to function normally stunts secondary sexual development.
• Signs include excessive height and size, weight loss, depression and poor memory.

Unclear speech

• Alcohol negatively affects the cerebrum, which controls speech; excessive consumption causes unclear speech and rambling.

Slow reflex action

• Psychoactive chemicals in drugs and ethanol in alcohol slow nervous-system responses.
• These substances occur between afferent neurones and interneurones, blocking impulse transmission and slowing transmission to the brain.
• This effect occurs in drug addicts and people who consume alcohol excessively.

Loss of balance

• Drugs and alcohol weaken muscle coordination, causing staggering and loss of balance.

Effects on Physical and Mental Health

• Drug abuse can cause liver damage, a weak immune system, brain damage and serious mental problems.
• Excessive alcohol consumption can damage most organs of the human body.

Liver cirrhosis

• Continuous consumption of large quantities of alcohol and drug abuse produce toxic effects on the liver.
• Liver cirrhosis: chronic liver damage involving scarring and hardening; the liver fails to function normally.
• Scarring spreads slowly until liver function is completely lost.

Stomach ulcer

• Alcohol can cause a stomach ulcer or peptic ulcer, in which the stomach lining is injured.
• Alcohol makes the stomach produce more acid than normal, irritating and inflaming the lining.
• Symptoms: heartburn or upper abdominal pain, bloatedness, nausea and vomiting.
• Serious symptoms: vomiting blood and passing black stools.

Violent behaviour

• Amphetamine activates brain cells and increases the rate of metabolism. The user becomes more active, unable to sleep, violent and aggressive.
• Excessive alcohol consumption can cause drunkenness, loss of senses, laughing alone, uncontrolled actions and violence.

Hallucination

• Marijuana disrupts brain function and changes perception.
• The user may experience hallucination, paranoia or suspicious feelings, and fear of others.
• Hallucination may lead to aggressive behaviour towards others.