Microorganisms and disease Flashcards
Explain why nurses need an understanding of microbiology
To understand and prevent disease
Define normal flora and transient flora
Normal flora - microorganisms which inhabit the human body and do not cause disease in normal circumstances
Transient flora - microorganisms that we pick up then deposit on other surface, they are likely to cause disease
Benefits of normal flora
Stimulate the immune system improving defence against pathogens.
Manufacture vitamin K for blood clotting and vitamin B12 for making red blood cells
State the locations where normal flora is found
Skin, Mucous membrane, upper respiratory tract, mouth, vagina, external opening of urethra
What are the different phases in the chain of infection
Infectious agent, reservoir, portal of exit, mode of transmission, portal of entry, host
What is an opportunist microorganism
A microorganism that takes advantage of a host cause disease where it normally would cause disease eg candida - antibiotics
State 3 situations which allow opportunist to become pathogens
- People who are sick, elderly, malnourished.
- Babies and children who have an underdeveloped immune system
- access to body sites - broken skin
List 6 portals of entry
Upper respiratory tract Blood Skin Mucous membrane Urogenital tract Gastroinestial tract
Name the 4 stages of infection
Incubational period
Prodromal period
Illness stage
Convalescene period
Explain age-related changes to the skin
Wrinkling - occurs as collagen fibres decrease in number and stiffen
Hair loss - hair follicles stop producing hair
Dryness and cracking - due to sebaceous gland atrophy
Describe the structure and functions of skin
Epidermis - thin, superficial layer, composed of epithelial tissue
Dermis - Deep, thicker layer, composed of connective tissue
Sub- cutaneous / hypodermis - composed of areolar and adipose tissues, attaches the skin to the underlying tissues and stores fat
Describe six conditions that influence bacterial growth
Temperature close to 37 degrees pH close to 7 Oxygen Water/moist environments Availability to nutrients Isotonic surroundings
Describe the structure of
a Biofilm
Biofilm is slime layer, made up of many prokaryotic organisms that combine to form a colony.
State four advantages of a biofilm, for bacteria and explain implications for treatment
Protects bacteria from desiccation, antibiotics, destruction by the immune system and changes in pH
List five locations where a biofilm may be found
Tooth plaque, mucous membrane, urinary catheter, almost all indwelling medical devices,
contact lenses
