Chapter 9 - immunity and infection Flashcards
What is the presence of countless microscopic organisms around, on, and in us referred to?
Microbiota or Microbiome.
Are most microbes beneficial or harmful?
Most microbes are beneficial, but some can cause disease.
How is an infection defined?
An infection is the invasion of the body by microorganisms.
What is a pathogen?
A pathogen is a microorganism that causes disease.
What is a reservoir?
A reservoir is a natural environment in which a pathogen typically lives.
What does the portal of exit refer to?
The portal of exit refers to how the pathogen exits the reservoir.
What are the two means of transmission?
Means of transmission can be direct or indirect.
What are vectors in the context of pathogens?
Vectors are insects, rodents, or other organisms that carry and transmit a pathogen from one host to another.
How can a pathogen enter the body through the portal of entry?
The portal of entry can either be through direct contact or penetration of the skin, inhalation, or ingestion.
What is a systemic infection?
A systemic infection is an invasion by a microorganism that spreads through the blood or lymphatic system to large portions of the body.
what are factors that determine whether the pathogen will be able to establish itself and cause infection?
the host’s immune response, the type of pathogen, the portal of entry, and the overall health and susceptibility of the host.
How does the process of pathogen entry into the body begin?
It starts when a pathogen, like bacteria, enters the body through means such as touching contaminated surfaces or inhaling airborne particles.
What happens during the incubation period of an infection?
The pathogen needs time to replicate and establish itself in the body, a phase known as the incubation period, during which the infection takes hold.
Are symptoms typically present during the incubation period?
No, often, the person doesn’t experience symptoms during the incubation period, even though the pathogen is present and replicating.
When do symptoms of an infection usually begin to appear?
Symptoms start to appear as the pathogen multiplies and begins affecting tissues or organs.
What is the goal of the body’s immune system during an infection?
The goal is to recognize and eliminate harmful bacteria, initiating a response to clear the infection.
What preventive measure is emphasized today to interrupt the chain of infection?
Continuous handwashing is emphasized as a highly effective preventive measure, helping remove pathogens from the hands and reducing the risk of transmission
What is the immune system?
It’s the body’s collective physical and chemical defenses against foreign organisms and pathogens.
What role does the immune system play in the body?
It serves as our first line of defense, protecting against foreign invaders and pathogens.
What is the primary function of the skin in relation to microorganisms?
The skin prevents microorganisms from entering the body.
How do membranes contribute to protecting the body against unwanted organisms?
Membranes protect us when the skin does not cover an area, as the cells within the membrane are designed to prevent the passage of unwanted organisms and particles.
What are cilia, and how do they function in the body’s defense?
Cilia are cells with hair-like protrusions that sweep foreign matter up.
Example: in the lungs; trapping particles like smoke.
What is the function of neutrophils in the immune system?
Neutrophils act as first responders, traveling in the bloodstream to areas of invasion, attacking, and ingesting pathogens.
Neutrophils are a type of white blood cell, also known as leukocytes.
Describe the role of neutrophils in infections.
Neutrophils are pivotal in the initial immune response, swiftly reacting to infections or foreign pathogens upon the body’s encounter with them.
What is the primary function of macrophages in the immune system?
Macrophages are large immune cells that engulf and devour pathogens and worn-out cells, serving as frontline defenders stationed in various tissues throughout the body.
Where are macrophages notably present, and how do they contribute to tissue defense?
Present in the lungs and contribute to tissue defense by engulfing and digesting foreign particles or pathogens.
They play a critical role in the body’s defence system.
What is the unique ability of natural killer (NK) cells in the immune system?
NK cells directly destroy virus-infected and cancerous cells.
Where do dendritic cells reside, and what is their role in the immune system?
- Dendritic cells reside in tissues.
- They eat pathogens, and activate lymphocytes.
What is the role of B cells in immune responses, and what is their natural ability?
Relationship to antibodies.
B cells play a key role in immune responses by producing antibodies, and they have a natural ability to create antibodies that recognize and neutralize harmful particles in the body.
Antibodies play a crucial role in the immune system’s defense against in
What is the function of T cells in the immune system, and where do they arise?
T cells coordinate immune responses, arise in bone marrow, and are crucial for the body’s defense against infections.
Where do T cells mature, and where do B cells mature?
T cells mature in the thymus after arising in the bone marrow, while B cells mature in the bone marrow.
What is the role of Helper T cells in the immune system?
Helper T cells activate other T cells and may help B cells.
What is the function of Killer T cells in the immune system?
Killer T cells kill body cells invaded by foreign organisms and cells that have turned cancerous.
How long do Memory T and B cells last, and why are they crucial?
Memory T and B cells last for years and are crucial for recognizing specific pathogens to prevent illness.