Notes-Part-2-Class-12-Biology-Chapter-10-Human Health and Diseases-Maharashtra Board

Human Health and Diseases

Maharashtra Board-Class-12th-Biology-Chapter-10


Topics to be Learn : Part-1

  • Introduction
  • Immunity
  • Structure of antibody
  • Common human diseases

Topics to be Learn : Part-2

  • Adolescence
  • Addiction
  • Drugs abuse

Adolescence :

Adolescence : Adolescence is transitional stage of physical and mental development during puberty and the legal adulthood. National youth policy defines phase of adolescence during 13-19 years. This period is marked with sexual and reproductive maturity, mental development, adult identity and transition from socioeconomic and emotional dependency to relative independence.

Stages of Adolescence :

Stages of Adolescence :

i. Early period (10 to 14 years) :

  • Appearance of secondary sexual characters
  • Rapid physical growth
  • Concrete thinking;
  • Defining boundries of dependence/independence
  • Self-exploration.
  • Developing body image
  • Development of intense friendship
  • Seeking to counter instability and evaluation.

ii. Middle period (15 to 17 years) :

  • Complete development of secondary sexual characteristic.
  • Growth slows down, approximately 95 % of the adult stature is attained
  • Thinking is more abstract.
  • Concrete thinking under stressful conditions
  • Reestablishing of body image capable of long range thinking
  • Sense of leadership and all powerfulness.
  • Ability testing to attract opposite sex, peer group pressure.

iii. Late period (18 to 19 years) :

  • Total physical maturity established.
  • Abstract thinking,
  • Intellectual and functional identity.
  • Peer group recedes in favor of individual relationship.
  • Stable relationship and change from childhood to adulthood relationship.


Physical changes of adolescence :

  • Growth spurt.
  • Sexual development
  • Emotional and social changes

Mental Health and Adolescence :

Mental Health and Adolescence :

  • Confusion, irritation, moodiness, frustration, nausea, less concentration, hyper activities, anger, effects on lifestyles like obesity, addictions, accidents, leading to ill health, etc. are common problems in adolescent age. '
  • Psychoses or neuroses may appear.
  • Psychoses include delusions, hallucinations, disturbance in the thinking process, etc.
  • Amnesia (loss of memory), Bullimia (extreme over indulgence in food), Anxiety (fear or apprehension), Anorexia nervosa (emotional aversion to food) depression (sadness, inactivity reduced to enjoy life, etc.), illusions, hallucination, etc.
  • Characterized by number of cognitive, emotional, behavioural, physical and attitudinal changes.
  • Parental communication and other conditions mould the adult personality.
  • Improper peer pressure may result into addictions, like smoking, taking drugs, etc.


Treatment : Treatment of such disorders should be done only through counselling and not medicines with due respect to rights of children. Mental health Gap Action Programme (mhGAP) gives the guidelines as per WHO for treating such cases. Parental relations are most important in any treatment.


Addiction: Compulsive use of substance despite its harmful consequences is addiction. Addiction cause the impairment of physical, physiological and psychological functions of the body.

Addictive substances : Alcohol, opioids, cocaine, nicotine and some behaviours such as gambling.

  • All addictive behaviours share ' key neurobiological features, involving brain pathways of reward and reinforcement.
  • Neurotransmitter dopamine released during motivation.
  • Neurological changes are reversible after the substance abuse or behaviour is discontinued.

Causes of substances abuse during adolescence :

  • Parental neglect and insufficient parental supervision and monitoring.
  • No communication between child and parents.
  • Absence of poorly defined rules
  • Family conflicts.
  • Favourable parental attitudes towards alcohol and drug uses.
  • Risk taking behaviour.

Measures to control drug abuse :

  • Always remember ‘Prevention is better than cure’.
  • Children should not be pressurized. Over expectations from them should be avoided.
  • Suitable education and counselling whenever required.
  • Sublimation and channelization of the energy of child in sports, studies and other constructive activities.

Drugs Abuse :

Drugs Abuse : Drugs and alcohol use in youth leads to many harmful effects. Improper lifestyle with dangerous behaviour pattern should not be accepted as it is hazardous for all.

Commonly abused drugs :

Commonly abused drugs : The drugs, which are commonly abused, are opioids, cannabinoids and alkaloids of coca, Hallucinogens.

Opioids : (Smack, Heroin)

  • These drugs binds to opioid receptors present in central nervous system and gastrointestinal tract.
  • Heroin, otherwise called smack is chemically di-acetyl morphine. It is extracted from latex of poppy plant Papaver somniferum.
  • Heroin is depressent and slows down the activity of body.

Cannabinoids : (Marijuana, hashish, charas and ganja)

Interact with receptors present in brain.

Inhalation and ingestion of these substances affect the cardiovascular system. These are obtained from inflorescences and the parts of Cannabis sativa.

Marijuana, hashish, charas and ganja are other different forms of drugs obtained from this plant.

Cocain : (Crack, Coke)

  • This is an alkaloid obtained from coca plant- Erythroxylum coca.
  • It increases level of neurotransmitter-dopamine.
  • It’s excessive dosage causes extreme happiness, irritability, paranoia.

Hallucinogens (mind expanding drugs) :

  • These are alkaloids causing day-dreaming.
  • Lycergic acid and cannabis are hallucinogenic substances. Atropa bellodona and Datura spp. also have hallucinogenic properterties.
  • Hallucination are unreal perceptions of unreal object due to the disorder of nervous system.


Addiction and Dependence :

  • Inherent addictive nature of alcohol and drugs result into psychological attachment to certain effects—such as euphoria and a temporary feeling of well-being.
  • Repeated use of drugs increases the tolerance level of the receptors present in our body.
  • Person getting addicted, starts self-destructive behaviour.
  • Withdrawal symptoms : If regular addictive substance is discontinued, it results in withdrawal symptoms. All the symptoms seen in such person is called withdrawal syndrome, which is characterized by anxiety, trembling, nausea and sweating.

Effects of Drug/Alcohol Abuse :

Effects of Drug/Alcohol Abuse :

  • Reckless behaviour, vandalism and violence.
  • Excessive doses of drugs can cause coma and death due to respiratory failure, heart failure or cerebral haemorrhage.
  • Overdose and even deaths occur if there is weird combination of drugs and alcohol.

Warning signs of drug and alcohol abuse among youth :

  • Drop in academic performance. '
  • Unexplained absence from school/college.
  • Lack of interest in personal hygiene, withdrawal, isolation, depression, fatigue, aggressive and rebellious behaviour, deteriorating relationships with family / friends.
  • Loss of interest in hobbies.
  • Change in sleeping and eating habits.
  • Fluctuations in weight, appetite, etc.
  • May turn to crime for money.

Other hazards :

  • Those who take drugs intravenously are likely to acquire serious infections like HIV and hepatitis B.

Long-term effects :

  • Loss balance, liver cirrhosis, pancreatitis.
  • It could lead to heavy drinking in adulthood.
  • Chronic use of drugs and alcohol damages nervous system and liver (cirrhosis). Use of drugs and alcohol during pregnancy adversely affects the foetus.


Performance enhancers :

  • Performance enhancers are certain drugs used by sportspersons to enhance their performance during competitions.
  • Narcotic analgesics, anabolic steroids, diuretics and certain hormones are misused by such sportspersons to increase muscle strength and bulk. It also promotes aggressiveness and improve overall performance.
  • Use of anabolic steroids cause side effects.

Side effects of Anabolic steroids :

Side effects of Anabolic steroids:

  • Effects in females : Masculinization in females, increased aggressiveness, mood swings, depression, abnormal menstrual cycles, excessive hair growth on the face and body, enlargement of clitoris, deepening of voice.
  • Effects in males : Acne, increased aggressiveness, mood swings, depression and reduction of size of the testicles, decreased sperm production, kidney and liver dysfunction, breast enlargement, premature baldness, enlargement of the prostate gland.
  • Prevention and Control : Habits such as smoking, taking drug or alcohol should be avoided right from young age. Identify the situations which can form addictions and take remedial measures. Help from parents and teachers should be sought.


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