Lesson 13 of 13 · 13 min
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Must-know facts
20 facts
- 01Health: complete physical, mental and social well-being, not just the absence of disease.
- 02Typhoid: Salmonella typhi, fever 39° to 40°C, confirmed by the Widal test; Mary Mallon was a carrier.
- 03Pneumonia: Streptococcus pneumoniae and Haemophilus influenzae, alveoli fill with fluid; lips and nails turn grey to bluish in severe cases.
- 04Common cold: rhino viruses, nose and respiratory passage but not lungs, 3-7 days.
- 05Malaria: sporozoites enter by the bite of a female Anopheles; haemozoin from bursting RBCs causes chill and fever every 3-4 days; P. falciparum causes malignant malaria.
- 06Amoebiasis: Entamoeba histolytica in the large intestine; houseflies are mechanical carriers.
- 07Filariasis (elephantiasis): Wuchereria bancrofti and W. malayi in lymphatic vessels of the lower limbs, spread by female mosquitoes.
- 08Ringworm fungi: Microsporum, Trichophyton, Epidermophyton.
- 09Gambusia fish eat mosquito larvae; Aedes spreads dengue and chikungunya.
- 10Innate barriers: physical, physiological, cellular, cytokine (interferons).
- 11Antibody: H2L2, two light and two heavy chains; IgA, IgM, IgE, IgG.
- 12B cells make antibodies (humoral); T cells mediate CMI and graft rejection.
- 13Colostrum carries IgA: passive immunity. Tetanus antitoxin and snake antivenom are passive immunisation.
- 14Hepatitis B vaccine is made in yeast by recombinant DNA technology.
- 15Allergy: IgE, histamine and serotonin from mast cells; treated with anti-histamine, adrenalin, steroids.
- 16Primary lymphoid organs: bone marrow and thymus. Secondary: spleen, lymph nodes, tonsils, Peyer's patches, appendix. MALT is about 50% of lymphoid tissue.
- 17HIV: retrovirus; macrophage is the HIV factory; helper T cells fall; ELISA detects; time-lag usually 5-10 years.
- 18Cancer cells lose contact inhibition; metastasis defines malignant tumors; α-interferon is a biological response modifier.
- 19Heroin: diacetylmorphine from morphine of Papaver somniferum, a depressant. Cocaine: Erythroxylum coca, blocks dopamine transport.
- 20Nicotine releases adrenaline and nor-adrenaline; smoking raises CO and lowers haem-bound oxygen.
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Key terms
20 terms
- Pathogen
- An organism that causes disease, such as a bacterium, virus, fungus, protozoan or helminth.
- Widal test
- The test that confirms typhoid fever.
- Sporozoite
- The infectious form of Plasmodium injected by an infected female Anopheles.
- Haemozoin
- Toxic substance released when infected RBCs burst, causing the recurring chill and fever of malaria.
- Vector
- An organism that carries a pathogen to a new host, such as the female Anopheles for malaria.
- Interferon
- Protein secreted by virus-infected cells that protects non-infected cells from the virus.
- Anamnestic response
- The strong secondary immune response to a pathogen met before.
- Humoral immune response
- The antibody-mediated response, so named because antibodies are in the blood.
- Cell-mediated immunity
- The T-lymphocyte-mediated response, responsible for graft rejection.
- Colostrum
- The yellowish first milk, rich in IgA antibodies for the newborn.
- Antitoxin
- A preparation of antibodies against a toxin, injected for quick protection as in tetanus.
- Allergen
- An environmental substance that triggers an allergic, IgE-type response.
- Auto-immune disease
- Damage caused when the body's immune system attacks its own cells, such as rheumatoid arthritis.
- MALT
- Mucosa-associated lymphoid tissue in the linings of the major tracts, about half of all lymphoid tissue.
- Retrovirus
- An enveloped RNA virus that copies its genome into DNA using reverse transcriptase.
- Contact inhibition
- The stop signal normal cells receive from touching neighbours; cancer cells lose it.
- Metastasis
- Spread of malignant tumor cells through blood to start tumors at distant sites.
- Proto-oncogene
- A normal cellular gene (c-onc) that can cause cancer when activated under certain conditions.
- Addiction
- Psychological attachment to the effects of a drug or alcohol.
- Dependence
- The body's withdrawal syndrome when regular drug or alcohol use is stopped abruptly.