Defense against diseases Flashcards
Microorganism/agent that causes a disease
Pathogen
State types of pathogens
Bacterium, virus, fungi, protist and prion
Mention chemical and physical barriers
Skin, mucous membrane and sebaceous glands
State the mechanism of skin and sebaceous glands
Skin- composed of keratin in the surface, prevents the entrance of pathogen
Sebaceous glands- secretes oils that reduces pH
Describe the mechanism of mucous membrane
Grabs pathogen and kills it by lysozyme, and the remaining stays there and gets out while coughing
Explain the pathway of blood clotting
Platelets place in injury, production of Ca+2 along with thromboplastin activates prothrombin, turns into thrombin. Then thrombin activates fibrinogen turns into fibrin that produces a mesh result in a blood clot.
Contrast innate and adaptative immune response
Innate- chemical and physical barriers and phagocytes. Non-specific responses and quicker
Adaptative- Lymphocytes B and T-helper. Specific and longer
Explain phagocytes mechanisms for infections
Receptor molecules recognize and creates pseudopodia, egulfs pathogen, creation of phagosome, phagosome maturation, fusion with lysosome creating phagolysosome and digestion of pathogen
Where does Lympocytes B and T mature?
bone marrow and thymus
What is an antigen?
A substance that triggers immune response
What is the type of immune response produced by B cells and T-helper cells?
B - hummoral immunity (antibodies)
T helper and cytotoxic- cell-mediated response (no antibodies)
Describe the clonal selection theory
Phagocyte- cell antigen- presenting- T-helper- activation of B cells- multiplication and differentiation- Memory cells and plasma cells
Name the cells affected by HIV
T-helper cells
State the type of virus and enzyme use by HIV for transcription
Retrovirus, uses ARN as genetic material. Uses reverse transcriptase to transcipe DNA from RNA
State transmission of HIV
Unprotected sexual activity, sharing needles, transffusion blood and breastfeeding
Describe HIV stages
- Replication and destruction of T-helper cells
- Chronic HIV (no sympthoms)
- AIDS opportunistic infections
State the mechanisms of antibiotics
Cell wall synthesis, DNA replication, metabolic pathways and interfere protein’s synthesis machinery
What is zoonotic disease?
Transmit from non-human vertebrate animals to humans (rabie)
What are the categories of vaccines?
Live attenuated (weakened fomr of whole pathogen)
DNA vaccines (use plasmids to encode for antigens)
RNA vaccines (puts mRNA for immune response)
What is herd immunity?
Phenomenon of indirect immunity of people due to a high percentage of population immune for a specific disease (needs 95% of people vaccinated)
