infection and response

• Health is a state of both physical and mental well-being
• People exist on a spectrum of health, with some being more or less healthy than others
• Factors for good health include a well-balanced diet, exercise, sleep, and access to medical care
• Preventive measures like vaccines contribute to good health
• Lack of these factors or high stress levels can lead to decreased health or illness
• Disease encompasses a large group of conditions that can cause ill health
• Diseases can be caused by various factors, such as an unhealthy diet leading to diabetes
• Diseases can be communicable (infectious) or non-communicable
• Communicable diseases can spread between people and are caused by viruses, bacteria, parasites, and fungi
• Examples of communicable diseases include the common cold, malaria, and meningitis
• Non-communicable diseases cannot be spread between people and include asthma, coronary heart disease, diabetes, and cancer
• Different types of diseases can interact with each other and with physical and mental health issues
• Problems with the immune system can lead to increased susceptibility to infectious diseases like the common cold or influenza
• Some viruses, like HPV, can cause certain types of cancer, such as cervical cancer
• Skin rashes and asthma can be caused by the body's immune system overreacting to pathogens
• Physical health can impact mental health, affecting psychological and emotional well-being
• Severe physical health problems can lead to mental health issues like depression or chronic anxiety
• Pathogens are microorganisms that can cause disease
• Pathogens can spread from person to person
• Diseases caused by pathogens are known as communicable or infectious diseases
• Pathogens affect both animals and plants
• Pathogens can be classified into four types: bacteria, viruses, protists, and fungi
• Some pathogens can spread through the air
• Airborne pathogens like the influenza virus or measles virus can be carried in tiny droplets expelled when coughing or sneezing
• Some pathogens can spread through contaminated food and water
• Cholera is a bacterial disease spread by drinking contaminated water
• Salmonella bacteria is spread by eating contaminated food, particularly from chickens
• Some pathogens require direct contact for transmission
• Athlete's foot, a fungal infection, can be spread by walking barefoot on contaminated surfaces
• Measures to reduce the spread of pathogens include:
• Being generally hygienic, such as washing hands after using the bathroom and before preparing food
• Cleaning cooking items like knives and chopping boards
• Killing vectors of pathogens, such as mosquitoes carrying malaria, with insecticides
• Vaccinating people to prevent them from catching diseases and spreading them
• Isolating or quarantining individuals who have caught a serious disease to prevent further spread
• Fungi are eukaryotic organisms, like plants and animals, and can be either unicellular or multicellular
• Examples include yeast (unicellular) used to make bread and rice, and mushrooms (multicellular) with hyphae structures
• Hyphae can spread through soil, over plants, or penetrate human skin causing disease
• Hyphae can produce spores that spread easily and grow into new fungi
• Rose black spot is a fungal disease causing purple or black spots on plant leaves, especially roses