Biology - Human Health & Diseases

Define health as complete physical, mental, and social well-being, not merely absence of disease. Explore hygiene, balanced diet, exercise, good habits, and immune system roles in preventing infections and disease.

Develop acquired immunity, also known as adaptive or specific immunity, after exposure to pathogens in vertebrates. Exhibits specificity, diversity, self and non-self discrimination, and immune memory.

Explore antigens on red blood cells and the ABO system, defining A, B, AB, and O, their surface antigens and antibodies, and universal donor and recipient concepts for blood donation.

Explore anatomical and physiological barriers of innate immunity: anatomical (skin and mucous membranes with stratum cornum, sebum) and physiological (fever, gastric acid, lysozyme, interferons) as first-line defenses.

Explore the phagocytes barrier, where neutrophils and monocytes engulf pathogens and macrophages, including Kupffer cells, protect tissues. Examine the inflammatory barrier, where histamine and prostaglandins raise vasodilation, permeability, and CRP.

The lecture outlines the acquired immune system's two main cell groups—lymphocytes and antigen presenting cells—and how B and T cells mature, circulate, and form specialized immune clones.

Explore immunity as the body's ability to recognize, neutralize, and destroy foreign pathogens, distinguishing innate non-specific immunity from acquired specific immunity with active and passive, natural and artificial forms.

Activate B lymphocytes to produce clones of helper T, cytotoxic T, suppressor T, and memory T cells that coordinate antibody production, cell killing, self-attack prevention, and faster re-exposure responses.

Explore the two forms of acquired immunity, active and passive, and their natural and artificial subtypes, with examples like vaccines and maternal antibodies.

B lymphocytes proliferate into plasma and memory cells to produce antibodies, driving humoral immunity, while antigen presenting cells process and present antigens to activate helper T cells.

Explore the structure of antibodies, including heavy and light chains, hinge region, variable and constant regions, and antigen binding sites, and explain lock-and-key binding to the epitope.

Identify ringworm as a fungal infection of skin and hair. Prevent spread and treat with antibiotics; it thrives in moist skin and forms ring-like lesions, while athlete's foot is common.

Typhoid, a common worldwide disease caused by Salmonella typhi, spreads through contaminated food and water from the feces of an infected person, stressing hygiene and safe food handling.

Explore amoebiasis, an infection from an amoeba, with cyst and trophozoite forms, transmitted via contaminated food and water, causing dysentery, diagnosed by stool examination, and treated with metronidazole.

Explore cancer as uncontrolled, undifferentiated cell growth that forms tumors; benign tumors stay restricted and surgically removable, while malignant tumors spread via metastasis and can be fatal.

Learn about the five broad cancer types—carcinoma, sarcoma, lymphoma, leukemia, and adenoma—and how metastasis and stage influence treatment options like surgery, chemotherapy, immunotherapy, gene therapy, and radiation.

Aids is an immunodeficiency syndrome caused by the HIV virus, a retrovirus with single-stranded RNA and gp41/gp120 glycoproteins, transmitted via unsafe sex, mother-to-child routes, and contaminated blood.

Clarifies AIDS transmission myths and non-spreading through hugging or sharing; outlines four stages of HIV/AIDS and preventive measures, including safe sex, blood screening, disposable needles, and avoiding sharing toothbrushes.