diseases and immunity
暂无描述。系统推荐的高质量记忆内容，适合每天坚持背诵学习。
卡片预览 (24 张)
What is a pathogen?
A disease-causing organism.
What is a transmissible disease?
A disease that can be passed from one host to another, caused by pathogens.
What is a host?
An organism in which a pathogen lives and reproduces.
Name four types of pathogens.
Bacteria, fungi, virus, protozoa.
How do pathogens damage cells?
By entering cells, producing toxins, and spreading around the host.
List two ways pathogens spread by direct contact.
Blood and semen.
List two ways pathogens spread by indirect contact.
Air droplets and contaminated surfaces.
Name three body defenses against pathogens. mechanical chemical and cells
Skin, mucus, stomach acid. phagocytosis,producing antibodies
What is phagocytosis?
White blood cells engulf and surround pathogens.
What do lymphocytes produce?
Antibodies.
What is tissue rejection?
Immune system attacks foreign cells from a transplant organ.
Why is personal hygiene important?
To reduce the risk of transmissible diseases.
How can food hygiene prevent disease?
By keeping food clean and separating raw from cooked food.
How should waste be disposed of?
In covered containers, away from human areas, or by burning/composting in a contained environment
Why must sewage be treated?
To make it safe before release into the environment.
What causes cholera?
Bacteria in contaminated food or water.
What does cholera toxin do?
Causes chloride ions to move to the intestine, drawing out water.
What is an antigen?
A foreign chemical that stimulates the production of antibodies.
What is an antibody?
A protein with a shape complementary to an antigen.
What do memory cells do?
Remain in the blood to respond quickly if the same pathogen returns.
What is active immunity?
Immunity where the body produces its own antibodies and memory cells.
What is passive immunity?
Immunity from antibodies received externally, with no memory cells produced.
Give an example of passive immunity.
Antibodies passed through placenta or breast milk.
What causes Type 1 Diabetes?
Immune system destroys pancreatic cells that produce insulin.