Immune System Flashcards
Communicable Diseases
Caused by Micro-Organisms (virus, fungus, bacteria). Trasmitted from one person to another
Pathogens
Disease causing organisms. Defence against pathogens are specific and non specific
Pathogens - Specific
Work against selected Pathogens
Pathogens - Non Specific
A generalised responce against all pathogens, infections or injuries
Bacteria
Microscopic livign organism (1 celled) found everywhere. Can be dangerous or beneficial
Pathogenic bacteria
Enter body via different ways - mouth or cut skin. Able to multiply (sufficiently = infection). By bacteria themelves or toxins they produce
Bacteria structure - capsule, cell wall, plasma membrane, cytplasm, dna, flagellum
Capsule: Protect cell, Cell wall: Protect & give shape, Plasma membrane: Controls movement in and out of cell, Cytoplasm: Organells and cytosol - live activities occur, DNA: Genetic instriction, Flagellum: Allows Movement
Bacteria reproduction
Binary Fission -> Bacteria split into two
Conditions to reproduce
Warm temperature, protien rich environment, neutral/ slight acidic ph (some excemptions occur)
Viruses
10 - 100 times smaller than bacteria.
Virus multiplication
Only within living cells of a host - target specific tissues.
Virus examples
Influenza - respiratory tract, Hepatitis - Liver, Poliovirus - motor neurons and spinal cord
Virus - Flu
Lock onto target cell in respiratory system & enter cell. Use cell as a factory as they take over it, produce millions of copies which come streaming out. Infect other cells or escape body. Taking over cell kills host cell - inflamtion
Virus structure
Spike proties: for attachement to specific cell receptors, Envelop: Protective outer layer, Protien coat: surrounds genetic material, Dna: Genetic instructions
Transmission of pathogens
Through direct/indirect means (Sti’s), transfer of bodily fluids, infection by droplets, ingestion of contaminated food/drink, airborne transmissions or by vectors.
Defencce of our body
Keep microbes out of the body. Non specific attack on microbes. Specific attack on microbes.
First line Defence
The first line of defence is that the body takes against pathogens is to prevent their entry into and reproduction insdie human body.
External defences
Ear, eyes, mouth, trachea, stomach, vagina, nasal cavity, skin, urethra, anus
Ear - defence
Cerumen inhibits bacteria growth
Mouth cavity - defence
Mucous membrane traps microorganisms and mouth cleaned by saliva
Trachea + bronchi - defence
Mucous layer traps microorganisms
Stomach - defence
Acidic juices kill many microorganisms
Vagina- defence
Acidic secretion inhibits growth of pathogens
Nasal cavity - defence
Hairs and mucus trap microorganisms
Skin - defence
an impervious barrier. Large amount of bacteria on skin - difficult for new pathogenic establishments
Urethra - defence
Urine flow prevents bacterial growth
Anus - defence
Mucous membrane traps microorganisms
Mucous membranes
FOund in digestive, urinary, respiratory and urogenital tracts - line body cavities and inhibits entry of micro organisms
Hairs - defence
Trap micro organisms
Cilia
Found in respiratory tract. Tiny microscopic hair like progections. Moves muccous towards throat.
Acids
Found in stomach, vagina and sweat. kills microorganisms ingested w/ food or in mucous.
Lysozyme
Enzyme that kills bacteria. Lysozyme -> enzyme created byy lysosomes. Found in tears, saliva, sweat, nasal secretions, tissue fluid.
Cerumen
Found in outer ear, slightly acidic and contains lysozymes.
FLushing action
Occurs in urine flowing through urethra, tears, sweat and saliva. - cleansing action
Protective reflexes
Sneezing, coughing, vomiting, diarrhea
Sneezing
Irritation of walls of nasal cavity - forceful expulsion of air from lungs
Coughing
Irritation of respiratory tract - bronchi/bronchioles. Air forced from lungs.
Vomiting
Psychological - excessive stretching of stomach - muscles of abdomen and diaphragm contract. stomach contents expelled.