Human Physiology: Defence Against Infectious Diseases Flashcards
What is blood clotting
Clotting functions to?
Prevent blood loss from the body and limit pathogenic acess to the bloodstream when the skin is broken.
Describe coagulation cascade process
• First of all, theclotting factorsstimulate the release of the enzymethrombin
• Thrombin catalyses the conversion of the soluble proteinfibrinogenintofibrin, which is insoluble
• Fibrin forms ameshthat traps more platelets and blood cells to prevent entry through the wound
• A small initial stimulus isamplifiedto produce a large amount of fibrin so that the wound is quickly sealed
• Exposure to air results in the hardening of the mesh to create ascab
How does the skin help in body defense
The skin provides a tough physical barrier that prevents entry of pathogens
Production of sebum form the sebum glands, a chemical responsible for maintaining low skin pH inhibiting the growth of microorganisms.
How do the mucus membranes help in body defense
Microorganisms become trapped by the mucus and are then either swallowed or expelled, preventing infection.
Mucus also contains lysozyme enypzymes which have antibacterial properties.
Explain non specific immune response?
Phacocytes move to the site of infection and attach to pathogens
the cell surface membrane of the phacocyte extends out and around the pathogen, engulfing it by Endocytosis.
They then digest the pathogens using enzymes which are stored within lysosomes.
Explain specific immune response?
It is known as specific immune response because one lymphocyte will respond to just o e type of antigen.
Functional regions of antibodies?
Explain antibody production?
How does hiv affect the immune system?
Hiv attacks t helper cells(a key component in the production of antibodies) so Hiv inhibits the bodies capacity to produce antibodies ,rendering the immune system unable to fight off other pathogens
What is an antigen
What is antibody
What are antibiotics
How do antibiotics work
antibiotics block specific processes in prokaryotic cells but do not have the same effect on eukaryotic cells.
Viruses do not possess a metabolism (they are not alive) and instead take over the cellular machinery of infected host cells. So cannot be treated with antibiotics and must instead be teated with specific antiviral agents.
How do bacteria develop antibiotic resistance
Antibiotics are often misused.
When the bacterial population is treated with this antibiotics, the ressitant bacteria do not die.
The resistant bacteria continue to Reproduce with less Competition from the non resistant bacteria.
The gene for antibiotics resistance are passed on to the next generation
Overtime, the whole population of bacteria becomes antibiotic resistant
