What is the comprehensive definition of health beyond the absence of disease?

Health is defined as a state of complete physical, mental, and social well-being.

List the three main components that contribute to health and provide an example for each.

1. Genetic Disorders (e.g., cystic fibrosis), 2. Infections (e.g., influenza), 3. Lifestyle Factors (e.g., smoking).

Infectious diseases differ from non-infectious diseases in that they are ___ and can be caused by factors such as ___ and ___.

transmitted from one person to another; genetics, lifestyle, and environmental factors.

What is the role of pathogens in causing diseases in humans?

Pathogens disrupt normal vital activities, adapt to the host environment, and can multiply, leading to morphological and functional damage in the host.

Typhoid fever is caused by the bacterium ___ and is primarily transmitted through ___ and ___.

Salmonella typhi; contaminated food; contaminated water

What are the common symptoms of typhoid fever, and what severe complication can arise from it?

Common symptoms include sustained high fever, weakness, stomach pain, constipation, headache, and loss of appetite; a severe complication can be intestinal perforation leading to death.

Pneumonia is primarily caused by the bacteria ___ and ___.

Streptococcus pneumoniae and Haemophilus influenzae

What are the common symptoms of pneumonia that indicate severe respiratory problems?

Fever, chills, cough, headache, and potential gray or bluish discoloration of the lips and fingertips

The common cold is caused by ___ viruses that primarily infect the ___ and respiratory passages.

Rhino viruses; nose

The life cycle of Plasmodium requires two hosts, which are ___ and ___.

humans and female Anopheles mosquitoes

What are the primary symptoms associated with amoebiasis caused by Entamoeba histolytica?

Constipation, abdominal pain and cramps, and stools containing excess mucus and blood clots

Wuchereria, the causative agent of filariasis, is transmitted through the bite of ___ and can lead to ___ in the lower limbs.

infected female mosquitoes; chronic inflammation and severe deformities

What are the primary risk factors for fungal infections such as ringworm?

Direct contact with contaminated soil and personal items such as towels, clothes, or combs belonging to an infected person.

List two key practices to maintain public hygiene that help prevent the spread of infectious diseases.

Proper waste disposal and regular cleaning and disinfection of water reservoirs.

Explain the significance of vaccines in the context of infectious disease control.

Vaccines have been crucial in eradicating diseases like smallpox and in controlling others such as polio and diphtheria, thereby significantly reducing the incidence of these diseases.

What are the four types of barriers that constitute innate immunity?

Physical barriers, physiological barriers, cellular barriers, and cytokine barriers.

The initial weak response to a pathogen in acquired immunity is known as the ___ response.

primary

How does acquired immunity demonstrate memory in response to pathogens?

Upon first exposure to a pathogen, a weak primary response occurs, but subsequent exposures trigger a much stronger secondary or anamnestic response due to the body's memory of the initial encounter.

What roles do B-lymphocytes and T-lymphocytes play in the immune response?

B-lymphocytes produce antibodies that fight pathogens, while T-lymphocytes assist B-lymphocytes in this process but do not secrete antibodies themselves.

Antibodies are composed of ___ light chains and ___ heavy chains.

two light chains and two heavy chains

Why is tissue and blood group matching critical in organ transplantation?

Tissue and blood group matching is critical to ensure compatibility and prevent rejection of the transplanted organ by the recipient's immune system.

Active immunity is characterized by the body's production of its own antibodies in response to exposure to ___ or ___.

antigens, such as living or dead microbes or other proteins

What distinguishes passive immunity from active immunity?

Passive immunity involves the direct transfer of ready-made antibodies, while active immunity requires the body to produce its own antibodies in response to antigens.

During pregnancy, a fetus receives antibodies from the mother through the ___, exemplifying a form of passive immunity.

placenta

What is the role of memory B and T cells in vaccination?

Memory B and T cells recognize and respond to pathogens more quickly during future exposures, enhancing the immune response.

Recombinant DNA technology in vaccine production allows for the production of ___ in bacteria or yeast.

antigenic polypeptides

Passive immunisation involves the injection of ___ to provide a rapid immune response.

preformed antibodies or antitoxins

What is the definition of an allergy and what triggers this immune response?

An allergy is an exaggerated immune response to specific antigens in the environment, triggered by substances known as allergens, such as pollen, dust mites, and animal dander.

Explain the role of mast cells in allergic reactions.

Mast cells release chemicals like histamine and serotonin during allergic reactions, which trigger symptoms such as sneezing, watery eyes, and difficulty breathing.

How have lifestyle changes contributed to the increase in allergies among children in urban areas of India?

Lifestyle changes have led to decreased overall immunity and increased sensitivity to allergens, with more children in urban areas experiencing allergies and asthma, potentially due to overly protective environments in early childhood.

What is the significance of the ability of higher vertebrates to distinguish between foreign molecules and foreign organisms?

This ability is crucial for the immune system to effectively target and eliminate pathogens while avoiding damage to self-cells.

Autoimmune diseases occur when the body ___ its own self-cells.

mistakenly attacks

Provide an example of an autoimmune disease and describe its impact on individuals.

Rheumatoid arthritis is an example, and it can lead to chronic inflammation, pain, and joint damage, significantly affecting the quality of life for many individuals.

What are the primary lymphoid organs involved in the maturation of lymphocytes, and what specific roles do they play?

The primary lymphoid organs are the bone marrow and thymus. The bone marrow is the main site for the production of all blood cells, including lymphocytes, while the thymus is where T-lymphocytes mature and develop, being larger at birth and shrinking with age.

Explain the role of the spleen in the immune system.

The spleen filters the blood, trapping microorganisms and storing red blood cells. It plays a crucial role in activating immune responses by filtering antigens from the blood and providing a site for lymphocyte activation.

Mucosa-Associated Lymphoid Tissue (MALT) is significant for immune function; describe its location and contribution to the immune system.

MALT is located in the lining of major tracts, including the respiratory, digestive, and urogenital systems, constituting about 50% of the lymphoid tissue in the body. It contributes to the immune system by monitoring and responding to pathogens present in these areas.

AIDS is caused by the ___ virus, which is classified as a retrovirus.

Human Immunodeficiency Virus (HIV)

List the primary modes of HIV transmission.

Sexual contact, contaminated blood transfusions, sharing infected needles, and mother-to-child transmission.

Why is it crucial for HIV/AIDS-infected individuals to avoid isolation from society?

To support their physical and psychological well-being, as HIV/AIDS is not transmitted through casual contact.

What is the role of reverse transcriptase in HIV replication?

Reverse transcriptase converts the viral RNA genome into DNA, allowing it to integrate into the host cell's DNA and instructing the cell to produce new virus particles.

Explain why a decline in helper T-lymphocytes makes an individual susceptible to opportunistic infections.

The decline in helper T-lymphocytes impairs the immune response, reducing the body's ability to fight off infections that a healthy immune system could typically manage, making the individual vulnerable to opportunistic pathogens.

What are some key preventive measures against HIV infection as mentioned in the content?

Key preventive measures include education about HIV transmission, promoting safe behaviors, and initiatives by organizations like NACO and WHO to raise awareness and reduce the spread of infection.

What are the two types of tumors, and how do they differ in terms of their behavior and impact on surrounding tissues?

Benign tumors are usually harmless, remain localized, and do not invade surrounding tissues. In contrast, malignant tumors are dangerous, grow rapidly, invade nearby tissues, and can metastasize to other parts of the body, competing for nutrients and potentially starving normal cells.

Describe the role of carcinogens in the development of cancer and provide examples of different types.

Carcinogens are agents that induce the transformation of normal cells into cancerous ones. Physical carcinogens include ionizing radiation (e.g., X-rays) and non-ionizing radiation (e.g., ultraviolet light). Chemical carcinogens, such as those found in tobacco smoke, are significant causes of lung cancer. Biological agents, like oncogenic viruses, contribute to cancer by promoting cellular changes through viral oncogenes.

What are the main methods used for early detection of cancer, and how do they contribute to successful treatment?

Early detection methods for cancer include biopsy for microscopic examination of tissue samples, histopathological studies to identify abnormal cell growth, blood and bone marrow tests to detect increased cell counts in leukemia, and imaging techniques like CT and MRI for visualizing internal tumors. These methods are crucial as they enable timely diagnosis, which is essential for effective treatment and improved patient outcomes.

What are the primary effects of opioids on the central nervous system?

Opioids bind to specific opioid receptors, acting as depressants that slow down bodily functions and can lead to pain relief and sedation.

Cocaine, a coca alkaloid, primarily affects which neurotransmitter and how?

Cocaine interferes with the transport of dopamine, leading to increased levels of this neurotransmitter in the brain, which produces feelings of euphoria and heightened energy.

Tobacco consumption is linked to various health risks; what are two major cancers associated with smoking?

Smoking is linked to an increased incidence of lung cancer and throat cancer.

What are the primary categories of commonly abused drugs mentioned in the text?

Opioids, cannabinoids, and coca alkaloids

Opioids like heroin are classified as ___, while coca alkaloids such as cocaine are classified as ___.

depressants; stimulants

Tobacco use is linked to various diseases and is particularly associated with ___ and ___ cancers.

lung; oral

What are the primary factors contributing to substance use among adolescents?

Curiosity, need for adventure, stress and pressure from academics, social perception influenced by media, and family and peer influence.

Adolescence typically spans ages ___ to ___.

12 to 18

The initial experimentation with drugs or alcohol in adolescents often arises from ___ but may lead to reliance on these substances for ___ over time.

curiosity; escaping problems

What role does psychological attachment play in addiction to drugs and alcohol?

Psychological attachment drives individuals to repeatedly use drugs and alcohol due to the positive effects, such as euphoria and temporary well-being, even when such use is unnecessary or harmful.

The phenomenon of tolerance in substance use refers to ___ and results in ___ of the substances.

the body's decreased responsiveness to normal doses of drugs or alcohol; increased intake and dependency on higher doses.

Dependence on drugs or alcohol can lead to ___ when the substance is abruptly discontinued, potentially requiring ___ for severe cases.

withdrawal syndrome characterized by symptoms such as anxiety and nausea; medical supervision.

What are some immediate adverse effects of drug and alcohol abuse?

Reckless behavior, vandalism, violence, coma, death due to respiratory or heart failure, and fatalities from overdosing.

Identify key warning signs of drug and alcohol abuse among youth.

Decline in academic performance, unexplained absences, lack of interest in personal hygiene, withdrawal, depression, aggressive behavior, deteriorating relationships, and changes in sleeping and eating habits.

How can the misuse of anabolic steroids in sports affect female athletes?

Anabolic steroids can lead to side effects such as hormonal imbalances, changes in physical appearance, and psychological effects like increased aggression.

What are the psychological effects of masculinization in females due to substance use?

Increased aggressiveness, mood swings, and depression.

Identify two physical consequences of substance abuse in males.

Reduction in testicle size and risk of kidney dysfunction.

Positive parenting, which combines nurturance with consistency, is linked to ___ in adolescents.

a lower risk of substance abuse.