Zoology is studied as a ‘pure science’ (knowledge gaining) and it has application in other branches such as euphenics, eugenics, biotechnology, bioenergetics, bioinformatics, etc. As applied science, it has tremendous scope in agriculture, aquaculture, animal husbandry, human health, diseases, ...
It is not an exaggeration to say that there is no person in this world who has not
suffered from cold at least once in his life time.
Common cold: It is caused by Rhino virus group of viruses. They infect nose
and respiratory passage but not lungs.
Mode of infection: Contamination by direct inhalation of the droplets resulting
from cough or sneezes of an infected person or indirectly through contaminated
objects such as pens, books, cups, door-knobs, computer keyboard or mouse etc.
Generally all the medicines that are used against cold cause drowsiness. Try to
find out the reason for this from your family doctor.
Symptoms: Nasal congestion, discharge from nose, sore throat, hoarseness,
cough, headache, tiredness, etc., which usually last for 3-7 days.
Do you know: ‘Cold’ treated is cured in just ONE week, and ‘cold’ untreated is
cured in SEVEN DAYS. What is the implied meaning?
6.3.3 Fungal Diseases
Ringworm: It is one of the most common infectious diseases in
man. It is caused by many fungi belonging to the genera
Microsporum, Trichophyton and Epidermophyton. Heat and
moisture help these fungi grow in the skin folds such as those
in the groin or between the toes.
Mode of infection: Contamination by using towels, clothes or
combs of the infected persons or even from soil.
Symptoms: Appearance of dry, scaly, usually round lesions
accompanied by intense itching on various parts of the body
such as skin, nails and scalp.
Fig. 6.13 Ringworm infection
6.3.4 Prophylaxis
i) In the case of bacterial & viral diseases: The advancements made in biological
science have armed us to deal with many infectious diseases effectively. The
immunization programmes by the use of vaccines have enabled us to completely
eradicate a deadly disease like smallpox. A large number of other infectious
diseases like polio, diphtheria, pneumonia and tetanus have been controlled to
a large extent by the use of vaccines.
ii) In general: Biotechnology is at the verge of making available newer and safer
vaccines. Discovery of antibiotics and various other drugs has also enabled us
to treat infectious diseases effectively.
,Biology in Human Welfare 165
6.4 TOBACCO, DRUGS AND ALCOHOL ABUSE (TDA ABUSE)
Recent surveys and statistics show that the use of tobacco, drugs and alcohol has
been on the rise especially among the youth. This is really a cause of concern as it could
result in many harmful effects. Proper education and guidance would enable the youth
to safeguard themselves against these dangerous habits and follow healthy lifestyles.
Any addict requires counselling and medical help to get rid of the habit.
6.4.1 Tobacco
Tobacco has been used by human beings for more than 400 years. It contains a
large number of chemical substances including nicotine, an alkaloid. While buying
cigarettes one cannot miss the statutory warning printed on the packet ‘Smoking is
injurious to health’.
Mode of abuse: It is smoked or chewed as ‘gutkha’ or used in the form of ‘snuff’.
Effect: Smoking increases the carbon monoxide (CO) level and reduces the
oxygen level in the blood. Nicotine stimulates the adrenal gland to release adrenaline
and nor-adrenaline into blood. These hormones raise the blood pressure and increase
the heart rate. Smoking is associated with bronchitis, emphysema, coronary heart
disease, gastric ulcers and increases the incidence of cancers of throat, lungs, urinary
bladder etc. Smoking also paves the way to addiction to hard drugs[1]. Yet, smoking is
very prevalent in society, both among the young and old. Tobacco chewing is
associated with increased risk of cancer of the oral cavity.
Do you think passive smoking is also dangerous? Why?
6.4.2 Drugs
Drugs are the chemical substances used in the treatment,
cure and prevention of diseases so as to enhance one’s physical
or mental well being. For hundreds of years, several plants,
fruits and seeds with hallucinogenic properties have been
used in folk-medicine, religious ceremonies (such as ‘bhang’
on the ‘Holi festival’ day) and rituals all over the globe. When
these are taken for a purpose other than the medicinal
use or in excess amounts that impair one’s physical or
psychological functions, it constitutes ‘drug abuse’.
The drugs commonly abused are opioids, cannabinoids
and coca alkaloids. Majority of them are obtained from flowering
plants but some are obtained from certain fungi.
1. Opioids: These are the drugs obtained from opium poppy
plant Papaver somniferum (vernacular name: ‘Nallamandu
Fig. 6.14 Opium poppy
,166 Zoology
mokka’). They bind to specific opioid receptors present in our central nervous
system and gastrointestinal tract. Some of the opioids are morphine, heroin, etc.
i) Morphine: It is extracted from the dried latex of the unripe seed
CH2
capsule (pod) of poppy plant. It occurs as colourless crystals or
O
N CH2 a white crystalline powder.
H
Mode of abuse: Generally it is taken orally or by injection.
O Effect: It is a very effective sedative and painkiller. It is very useful
in patients who have undergone surgery.
H O
ii) Heroin: It is a white, bitter, odourless and crystalline compound,
Fig. 6.15 Structure of
obtained by the acetylation of morphine. Chemically it is
morphine
diacetylmorphine. It is commonly called ‘smack’.
Mode of abuse: Generally it is taken by ‘snorting’ and injection.
Effect: Heroin is a depressant and slows down the body
functions.
2. Cannabinoids: These are a group of chemicals obtained from
Indian hemp plant Cannabis sativa (vernacular name: Ganjai
mokka). They interact with cannabinoid receptors present in
the brain. The flower tops, leaves and the resin of this plant are
Fig. 6.16 Leaves of Cannabis used in various combinations to produce marijuana, hashish,
charas and ganja. These days, cannabinoids are being abused
OH
by even some sports-persons (doping).
Mode of abuse: These are generally taken by inhalation and
oral ingestion.
O
H
Effect: Show their effects on cardiovascular system of the body.
Fig. 6.17 Structure of
cannabinoid molecule
3. Coca alkaloid or Cocaine: It is a white, crystalline alkaloid
that is obtained from the leaves of Coca plant Erythroxylum coca,
native to South America. It is commonly called ‘coke or crack’.
Mode of abuse: It is usually snorted
Effect: It has a potent stimulating action on the central nervous
system as it interferes with the transport of the neuro-transmitter
‘dopamine’. Hence it produces a sense of euphoria and increased
energy. (NCERT Text) Excessive consumption of crack causes
Fig. 6.18 A branch of Datura
hallucinations.
4. Other well-known plants with hallucinogenic properties are Atropa belladonna
and Datura. Certain drugs like ‘Barbiturates (sleeping pills), Amphetamines (cause
sleeplessness), Benzodiazepines (tranquilizers), Lysergic acid diethyl amides (LSD) and
other similar drugs, normally used as medicines to treat patients with mental illnesses
like depression, insomnia, etc.,’ are often abused.
, Biology in Human Welfare 167
6.4.3 Adolescence and TDA abuse
1. Adolescence: It is the time period between the beginning of puberty and the
beginning of adulthood. In other words, it is the bridge linking childhood and
adulthood. The age between 12-18 years is considered ‘adolescence period’. It is
both ‘a period and a process’ during which a child becomes mature. It is accompanied
by several biological and behavioural changes. Thus, adolescence is a very
‘vulnerable phase’ of mental and psychological development of an individual.
2. TDA abuse: Curiosity, desire for adventure and excitement, experimentation,
are the common causes for the motivation of youngsters towards the use of tobacco,
drugs and alcohol. The first use of drugs or alcohol may be out of curiosity or
experimentation, but later the person starts using them to escape facing problems.
Recently ‘stress from the pressure to excel in academics or examinations’ has played a
significant role in alluring the youngsters to try certain drugs. Television, movies,
newspapers and internet also help promoting this wrong perception. Other factors that
are associated with tobacco, drug and alcohol abuse among adolescents are unstable
or unsupportive family structures and peer pressure.
The consumption of drugs in any form is a non bailable offence. But the seeds of
Opium are easily available in any provision store. They are treated in such a way
that they can never germinate. They are generally used in the preparation of some
curries. What are they? Clue: Find the Telugu name of poppy seeds.
6.4.4 Addiction and Dependence
The TDA abuse leads to addiction and dependence.
1. Addiction: It is a psychological attachment to certain effects such as euphoria.
The most important thing one fails to realise is, the inherent ‘addictive nature’ of
tobacco, drugs and alcohol. With the repeated use of TDA, the tolerance level of the
receptors present in our body increases. Consequently the receptors respond only
to higher doses leading to greater intake and addiction. However it should be clearly
borne in mind that use of TDA even once, can be a fore-runner to addiction. Thus,
the addictive potential of tobacco, drugs and alcohol pull the users into a vicious
circle leading to their regular use (abuse) from which they may not be able to get out.
In the absence of any guidance or counseling, people get addicted and become
dependent on them.
2. Dependence: It is the tendency of the body to manifest a characteristic and
unpleasant condition (withdrawal syndrome) if the regular dose of drugs or alcohol
is abruptly discontinued. The withdrawal syndrome is characterised by anxiety,
shakiness (tremors), nausea and sweating which may be relieved when the regular use
is resumed again. Dependence leads the patients to ignore all social norms.
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller susanwanjiku. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $23.99. You're not tied to anything after your purchase.
