Human Health & Diseases. Class XII. BIOLOGY. CBSE. NEET

1. AIDS
CANCER
DRUG & ALCOHOL ABUSE
SHUBHADEEP BHATTACHARJEE

2. AIDS (Acquired Immuno
Deficiency Syndrome)
 First reported in USA in 1981
 Pathogen: Human Immunodeficiency Virus
(HIV)
 HIV:
-Retrovirus (RNA as the genetic
material)
-Protein envelope enclosing a RNA
genome

3.  Transmission:
Sexual contact with
an infected person
contaminated blood
and blood products
Sharing infected
needles
From infected
mother to child across
placental barrier

4.  HIGH RISK
INDIVIDUALS:
i. Individuals having
multiple sexual
partners
ii. Drug addicts
indulging in
intravenous drugs
iii. Individuals requiring
repeated blood
transfusion
iv. Children born to HIV
infected mother

5. Life Cycle of HIV
 Virus infects the macrophages
 RNA replicates and form viral DNA (Enzyme: Reverse Transcriptase)
 Viral DNA gets incorporated into the host cell’s DNA
 Produces more viruses by replication

6.  Virus produced by the Macrophages infect helper T-lymphocytes
 No. of helper T-cells progressively decreases
 Infected person suffers from various pathogens like Mycobacterium, viruses
and parasites such as Toxoplasma
 Diagnosis: ELISA (Enzyme Linked Immuno Sorbent Assay)

8. Prevention of AIDS:
 NACO (national AIDS Control Organization) established in 1991 and other NGOs
are trying to educate people about AIDS
 WHO has taken a no. of initiatives to prevent spread of HIV infections:
i. Making blood from blood banks HIV free
ii. Use of only disposable needles and syringes
iii. Free distribution of condoms
iv. Controlling drug abuse
v. Advocating safe sex and promoting regular check ups.
Treatment:
i. Cichoric acid from coffee
ii. Vaccine for preventing HIV transmission- under preparation
iii. Retrovirals

9. Cancer
 Uncontrolled division or
proliferation of cells without
any differentiation
 Breakdown in the regulatory
mechanism of cell division
 Cells undergo repeated cell
division (clone of cells)
 No cell-cell adhesion
 Mass of undifferentiated cells
– neoplasm
 Tumors
 Tumors result is pressing of
the surrounding tissue causing
discomfort and disruptions in
function

10. Types of tumors
 Benign (non-cancerous)&
 Malignant (cancerous)
Benign tumors Malignant tumors
1. Non- cancerous Cancerous
2. Non- invasive Invasive (metastatic)
3. Stops growth after reaching a
particular size
Indefinite growth capability
4. Limited cell-cell adherence No cell-cell adherence
5. Less fatal Mostly fatal

11. Characteristics
of cancer cells
 Uncontrolled cell division
 Do not require extracellular
growth factors (EGFs)
 Cells differentiate into a large
mass of tissue called TUMOR
 The cells pass from the primary
tumor to new sites forming other
secondary tumors- METASTASIS
 No. of lysosomes increase
No. of melanin increases
No. of mucous and fat droplets
increases
 LOSS OF CONTACT INHIBITION

13. Causes of cancer
Chemical
carcinogens
Physical/
mechanical irritants
Radiation Biological Agents
Nitrosodiumethylene
(cigarette smoke-
lung cancer), 4-
benzopyrene
(Cigarette smoke/
coal tar- skin & lung
cancer)
Chewing tobacco
(mouth cancer)
UV radiation, X-rays,
radioactive isotopes
and other ionizing
agent cause cancer
e.g., leukemias, skin
cancers
Certain excessive
hormonal secretions,
certain viruses
(Oncogenic viruses),
Parasitic invasions

14. Types of cancer
 Carcinomas:
i. cancer of the epithelial tissue
(skin/ glands/ mucous membranes/
lungs/ breast/ pancreas/ stomach/
mouth/ throat/ uterus/ cervix/
prostrate etc.)
 Melanomas:
i. tumors arising from the
melanocytes of skin and other organs
(mucosal melanoma/ nodular
melanomas)
 Sarcomas:
i. cancer of the mesodermal
tissue (bone/ cartilage/ fat etc.)
 Leukemia and lymphomas
i. Cancer of haemopoietic cells
(types of blood cancer)

15. Cancer & Genes
 Oncogenes: changed/ mutated
genes
 Proto-oncogenes: unchanged
regulatory genes
 Cancer associated genes are
divided into three types:
a. Proto oncogenes: control
cell division/ cell growth/
differentiation
b. tumor suppressor genes
inhibits cell proliferation and
suppresses tumor formation
c. Genes that control
programmed cell death

16. Cancer detection
 Biopsy and histopathological studies
 Radiography (X-rays), CT (Computed tomography) & MRI (Magnetic Resonance
Imaging)- cancer of the internal organs

17.  Antibodies against cancer specific antigens are also used for detection of
certain cancers

18. Treatment of cancer
 Surgery, radiation therapy and immune therapy
 Chemotherapy
 a-interferons and monoclonal antibodies


19. DRUGS & ALCOHOL ABUSE
 Commonly abused
drugs:
i. opioids
ii. Cannabinoids
iii. Coca alkaloids
(Some od them are
obtained from Fungi,
but, most of them are
obtained from
flowering plants.)

20. Opioids
 Bind to specific opioid receptors in the CNS and GI tract
Example: Morphine and Heroin.
 Heroin is commonly called smack, chemically it is
diacetylmorphine which is a white, odorless, bitter
crystalline compound generally obtained by acetylation of
morphine
 Morphine is extracted from the latex of poppy plant
Papaver somniferum.
 They are taken by smoking and injection.
 Heroin is a depressant and slows down body functions

21. Cannabinoids
 They interact with the cannabinoid
receptors present in the brain
 They are obtained from the
inflorescence of the plant Cannabis
sativa.
 Marijuana, hashish, charas and
ganja are produced by various
combinations of flowers, tops,
leaves and resin of the cannabis
plant.
 It is generally taken by inhalation
and oral ingestion.
 They are known for their effect on
the cardiovascular system of the
body.

22. Coca alkaloids or Cocaine
 It is derived from the
leaves and young branches
of South American plant
called Erythroxylum coca.
 It interferes with the
transport of the neuro-
transmitter dopamine.
 Its generally sniffed or
smoked.
 It is a strong stimulant,
when taken in overdoses
causes headache,
convulsions, hallucinations
and death due to
cardiovascular or
respiratory failure.

23. Hallucinogens
 It is obtained from the
plant like Atropa
belladonna and Datura sp.
 These drugs change
thoughts, feelings and
perceptions of an
individual.
 These drugs are called
psychedelics because of
their effect on the
cerebrum and sense organs.

24. LSD (Lysergic Acid Diethyl Amides)
 It is most dangerous
drug causing
chromosomal and
foetal abnormalities.
 LSD is derived from
dried fruiting body
called sclerotium of
ergot fungus (Claviceps
purperea)

25. Tobacco
 It is smoked, chewed and used as a
snuff
 It’s a high source of nicotine which
is an alkaloid
 Nicotine stimulates the adrenal
glands which releases adrenaline
and nor-adrenaline which increases
blood pressure and heart rate
 It increases chances of lung cancer,
bronchitis, emphysema, coronary
heart diseases, cancer of throat,
gastric ulcers, cancers of the
urinary bladder etc.
 Smoking leads to an increase in
carbon mono oxide content of blood
and reduces concentration of haem
bound oxygen, as a result, oxygen
deficiency in the body is created.
 Chewing tobacco causes oral cancer
which is fatal in most cases.

26. Alcohol
 Alcohol has an anaesthetic effect on the nervous system
 It effects cerebrum and cerebellum
 It causes peptic ulcers, gastric carcinoma, hepatitis, liver failure, liver cell
carcinoma etc.
Addiction & Dependence:
 Social pressure
 Curosity
 To escape from stress, depression and frustration etc.
 To overcome hardships of daily life
 Unstable or unsupportive family structure