Biology For Class X - Chapter No. 9 - Pharmacology- Long Question Answers

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CHAPTER 9: PHARMACOLOGY
C. Extensive Response Questions And Notes:

Q.1: What is pharmacology? Pharmacy and pharmacist.
Ans: PHARMACOLOGY:
Definition:

"Pharmacology is the branch of biomedical science which is concerned to the uses, effects, and modes of action of drugs. This branch is studied under the discipline of pharmacy."

In other words,

"Pharmacology is the study of drug composition, properties, medical applications and sources of drugs."

Clinical pharmacology was present in the Middle Ages. Early pharmacologists focused on natural substances. It was developed in 19th century as a biomedical science when Oswald Schmiedeberg, who is known as the founder of modern pharmacology, studied the pharmacology of chloroform and chloral hydrate.

PHARMACY:

"Pharmacy is the study of preparation of medicines and drugs."

PHARMACIST:

"One who studies pharmacy responsible for dispensing prescription medications to patients and advising them are called pharmacists."

Q.2: Define Drug. What are its types?
Ans: DRUGS:

"Any substance that is absorbed into the body of a living organism, alters normal body function is known as a drug."

OR

"It is defined as any chemical substance used in the diagnosis, cure, treatment or prevention of diseases."

OR

"Drug is a chemical substance used to treat, cure, prevent a disease or to promote well-being or artificial pleasure."

TYPES OF DRUGS:
Drugs can be derived from plants and animals. Drugs are broadly classified into two types:

1. Pharmaceutical drug OR Medicinal drug:
   They are used to treat the diseases and make the patient physically normal.
   
   
2. Addictive drugs:
   Some drugs often make person dependent on them and make the person relaxed by give them a feeling of pleasure, acting on the CNS of the person, finally they make a person addicted. These drugs are called as addictive drugs.

Q.3: Write a detailed note on medicinal drugs with its sources and also describe main uses of important medicinal drugs?
Ans: DRUGS:
It is defined as any chemical substance used in the diagnosis, cure, treatment or prevention of diseases.

MEDICINAL DRUGS:
Medicinal drugs are used to treat the diseases to prevent patient, and make the patient physically normal. These drugs are very beneficial.

SOURCES OF MEDICINAL DRUGS:
These beneficial drugs are obtained from various sources. They are as follows:

1. Drugs from Plants:
Many important medicines are obtained from plants . Plants produce special substances in their roots, leaves, flowers or seeds that help to form drugs in laboratory. Some of them can be used directly as herbs to treat certain diseases. Some examples are:

• The cardiotonic digitalis is made from leaves of purple flowered plant foxglove used to stimulate heart.
• The pain reliever morphine is made from opium, which are extracted from the unripe seed pods of the opium poppy plant.
• Many addictive illegal drugs e.g., marijuana are also obtained from plants.
• Cinchona tree contains Quinine in its bark which is used in the prevention and treatment of malaria.

2. Drugs from microorganisms:
Microorganisms like bacteria and fungi not only produce primary metabolites but are also capable of making secondary metabolites which are used in the production of antibiotics and anti fungal drugs. Some examples are:

• The antibiotic penicillin comes from a fungus.
• Tetracyclin are produced by bacteria.
• Lovastatin are produced by fungi.

3.Drugs obtained from animals:
Certain animal parts and animal products are used as drugs in therapeutics. The major group of animal products used in medicine are as follows:

• Hormones, enzymes, animal extractives, organs and bile acids.
• Drugs produced by animals are usually their glandular products, such as Fish liver oil, musk, bees wax, etc.
• Certain hormones and antitoxins are also obtained from animal sources.
• Gonadotropin hormone are prepared commercially from either horse serum or from the urine of pregnant woman. They controlled the production of sex hormone in the body.
• Hyaluronidase enzyme is produced by some micro organisms found in the heads of leeches, in snake venoms and in mammalian testes.

4. Drugs from minerals:
Several common drugs are obtained (synthesized) from minerals or can be given with minerals as supplement:

• The mineral iodine is used in making tincture of iodine, a liquid that helps to prevent infection when applied to cuts and bruises.
• The powder form of silver nitrate is applied on wounds to stop bleeding and prevent infection.
• While testing soil, researcher resulted in the development of one antibiotic terramycin which is used to treat many infections.
• Iron is used to treat iron deficiency (anemia).
• Zinc is used to make zinc oxide paste which is used in wounds and in eczema.
• Gold salts are used in the treatment of rheumatoid arthritis.

5. Synthetic Drugs:
Synthetic drugs are synthesized in labs by using man-made chemicals rather than natural ingredients. A number of synthetic drugs are available in the market . There are almost 200 identified synthetic drug compounds and more than 90 different synthetic drugs.
An example is:

• Synthetic marijuana goes by many names: K2, Spice, fake pot, potpourri, legal weed, and more.

USES OR PRINCIPLE USAGE OF IMPORTANT MEDICINAL DRUGS:
Drugs are classified on the basis of their chemical properties and modes of action. Their uses are as follows:

• Analgesics (Pain killers):
  Reduce pain e.g. Aspirin, Paracetamol and Panadol etc.
  
  
• Antibiotics:
  Inhibit or kill bacteria and treat bacterial infections e.g., Tetracycline, Cephalosporin, Penicillin etc.
  
  
• Vaccines:
  Vaccine is vital for one's life, vaccines prevent the living body from the microbial diseases by developing immunity against viral and bacterial infections, e.g. vaccines against small pox, whooping cough, hepatitis vaccine, rabies vaccine, covid-19 vaccine etc.
  
  
• Sedatives:
  Sedative drugs are helpful for treating anxiety and sleep problem by reducing irritability or excitement. e:g., Diazepam (Valium), Alprazolam (Xanax) and Clonazepam( Klonopin). Antiseptics: Reduce the possibility of infections on skin.

Q.4: What things must be kept in mind while using medicines? OrWhat are the side effects or danger zone kept in mind while using medicines?
Ans: While taking medicines we should keep the following things in mind:

• An allergic reaction could happen with any drug. That can range from itching and rash all the way to a life-threatening anaphylactic reaction.
• Over dose of pain killers and sedatives can make a person addictive which on leaving causes severe risk factors.
• Some vaccines contain “inactive” virus, and it is impossible to get the disease from them. Other have active but weakened virus designed to prevent the disease.
• The children who are given antibiotics for routine upper respiratory infections are more susceptible to aggressive antibiotic-resistant strains of the bacteria.
• Aggressive antibiotics which are helpful in treating a serious infection, can wipe out many useful gut bacteria.

Q.5: Write about the contribution of Joseph Lister and Sir Alexander Fleming in the field of pharmacology.
Ans: Contribution of Joseph Lister:
Joseph Lister is called the “Father of Antiseptic surgery” due to his discovery of antiseptics which lead to safer medical procedures reducing the deaths from child birth and surgery. Antiseptics are antimicrobial substances that are applied to living tissues or skin to prevent microbial infections.
Lister used carbolic acid as disinfectant and used it for washing hands and instruments. He also designed spray machine with carbolic acid to kill air borne germs.

Contribution of Alexander Fleming:
The greatest contribution of Alexander Fleming, a Scottish researcher is the discovery of Penicillin in 1928. He was experimenting with influenza virus in the Laboratory of the Inoculation Department at St. Mary's Hospital in London.
After two week vacation when Fleming returned he found a mold developed on an accidentally contaminated staphylococcus culture plate. He discovered that this mold that has culture prevented the growth of staphylococcus. This accident led the discovery of antibiotic named as Penicillin.

Q.6: What do you know about addictive drugs?
Ans: DRUGS ADDICTION:

"one drugs often make person dependent on them or addicted. By using such drugs, the person's body become familiar to it and the user cannot function well without it. This is called drug addiction."

Addictive drugs acts on the pleasure center in the brain, causing a shortcut to reward that, when repeated, can change the way a person processes information.

Drugs' addictive qualities may be enhanced by make a person feel good when using them and they may make user feel bad when they wear off.

TYPES OF ADDICTIVE DRUGS:
The major categories of addictive drugs are as follows:
Sedatives:
These drugs interact with central nervous system to depress its activities. Sedative drugs have following effects:
Effects:

• One of the most marked effect of sedatives is their potential for abuse and addiction.
• Induces dizziness (drowsiness), sleepiness and lethargy
• Slows normal brain function and depression
• Long term use of sedative induce suicidal thoughts
• Reduces heart rate and breathing
• Reduces anxiety

Narcotics:
Narcotics are strong pain killers. These drugs are often prescribed in conjunction with other less potent pain killers (paracetamol or aspirin). These drugs bind with the pain receptors present in CNS and reduces the pain.
Uses and effects:

• These are used to relieve pain for patients with chronic diseases such as cancer.
• These are also used to relieve acute pain after operations.
• Some people may abuse narcotics for ecstatic effects.
• The short term effects of opiate use can include feelings of euphoria, pain relief, drowsiness and sedation.
  
  

Examples:
The most abused narcotics are the following:

1. Heroin:
   It is highly addictive.
   Heroine and other opioid drugs interact with dopamine levels in brain, therefore causes burst of pleasure.
   It abuse leads to drug tolerance, dependence and addiction.
   
   
2. Morphine:
   It is used to relieve moderate to severe pain.
   It remains active in blood stream upto 6 hrs.
   It acts on the CNS and causes relief from pain.
   Its side effects and abuse causes nausea, vomiting, constipation, lightheadedness, dizziness, drowsiness and sweating.

Hallucinogens:
Hallucinogens are the class of drugs that hallucinations-profound distortion (cause changes) in a person's perception of reality, thought, emotion and consciousness.
Effects:

• Increased breathe rate.
• It effects Sympathetic nervous system.
• It causes dilation of pupils.
• Constriction of some arteries.
• Rise in blood pressure.
• Increased heart rate and irregular heart beats.
• Palpitations
• Blurred visions.

Example:

1. Marijuana:
   Marijuana (Hashish) is a hallucinogen which is smoked. It is the most commonly used illict drugs in the world. It is obtained from the flowers, stems and leaves of the marijuana plant (Cannabis indica). People smoke it in hand rolled cigarettes or in pipes.
   Effects:
   
   • Small doses of marijuana result in a feeling of well-being that lasts two to three hours.
   • High doses produce immediate sensations - increased heart rate.
   • It affects the production of sperms in men.
   • It weakens the short term memory.
   • Reduces coordination and balance.
   • Affects brain development.
   • Produce a "dreamy" unreal state of mind.
   • If teenagers are using marijuana, the drug may impair thinking, memory and learning functions and the affect the brain builds connections between the areas necessary for these functions.

Q.7: What are the symptoms of addiction.
Ans: The following are the signs that can help us identify a addictive person.

• When a person is addicted to a substance, such as a drug, alcohol or nicotine, they are not able to control the use of that substance.
• When body levels of that substance go below a certain level the patient has physical and mood-related symptoms.
• There are cravings for drugs, bouts of moodiness, bad temper, poor focus, a feeling of being depressed and empty, frustration, anger, bitterness and resentment.
• Sometimes the addict may engage in risky activities, such as driving fast.

Q.8: What are antibiotics? How do they work OR Discuss their uses and misuses?
Ans: ANTIBIOTICS:
Antibiotics are chemical substances that are mostly used to fight infections caused by bacteria. It is a drug that kills or retards the growth of bacteria. They are the chemicals can be produced naturally by or derived in laboratory or can be synthesized in labs by microorganisms (bacteria and fungi). They are only used to treat bacterial infections. They can treat viral or fungal infections.

TYPES OF ANTIBIOTICS:
There are two types of antibiotics:

1. Bactericidal Antibiotics:
   Some antibiotics are "bactericidal”, meaning that they kill bacteria.
   
   
2. Bacteriostatic Antibiotics:
   are those which inhibit (work by stopping) the bacterial growth.

MISUSE OF ANTIBIOTICS:
Antibiotics have some harms and side effects as well because they are prescribed for a particular infection and can harm normal flora beneficial to our body. Some of the harmful side effects are as follows:

• Antibiotic resistance
• Diarrhea
• Upset stomach
• Thrush, which is a fungal infection that can affect the mouth or digestive tract.
• Vaginal yeast infection caused by Candidia albican (discharge, burning, pain, itchiness).
• Can cause yellowing of teeth.

Q.9: How bacteria produces antibiotics resistance?
Ans: ANTIBIOTIC RESISTANCE:
Antibiotics are most important in medicine but over use of antibiotics can cause antibiotic resistance. Unfortunately bacteria are capable of developing resistance to them. Such bacteria are not affected by commonly used antibiotics, this condition is called antibiotic resistance.
Ways Of Resistance:
Bacteria have number of ways of developing resistance.

• Sometimes bacteria become habitual for that antibiotics or alter strategy to hinder the effect of antibiotic.
• The change either protects the bacterium from the action of the medication or neutralized the medication.
• Bacteria can also transfer the genes responsible for antibiotic resistance between them.
• Such bacteria make it possible for other bacteria to acquire resistance by getting a resistance gene encoded to its chromosomes.
• Another cause of antibiotic resistance is their use in diseases in which they have no efficacy (e.g. antibiotics are not effective against infections caused by viruses).

Problems Related to Resistance to antibiotics:

• Some bacterial infections are becoming more difficult to treat.
• Some of the resistant bacteria can be treated with more powerful antibiotics.
• Some infections do not eliminate even with new antibiotics.

Q.10: What are vaccines? Illustrate mechanism of vaccination? Who introduced world's first vaccination?
Ans: VACCINE:
A vaccine is a material containing weakened or killed pathogens and is used to produce immunity to a disease by stimulating the production of antibodies.

MECHANISM OF VACCINATION:
A vaccination is a biological preparation that improve immunity to a particular disease. A vaccine typically contains an agent that resembles a disease-causing microorganism, and is often made from weakened or killed forms of the microbe, its toxins, or one of its surface proteins. A vaccine can confer active immunity against a specific harmful agent by stimulating the immune system to attack the agent.

World's First vaccination.
In 1796, a British physician, Edward Jenner, infected a young boy with cowpox, by injecting pus cells. After the boy had recovered from cowpox, Jenner injected the pus cells from a smallpox patient into him. The boy did not get smallpox, So it became clear that intentional infection with cowpox protected people from small pox. This method was named vaccination and the substance used to vaccinate is called a "vaccine".

Q.11: Define Immunization?
Ans: IMMUNIZATION:
Immunization is the process in which a person is made immune or resistant to an infectious disease by administering a vaccine.