Module 9: 1.Patho: Define the factors influencing infection. COPY Flashcards
What are some factors that can cause damage to the human body?
Factors include sunlight, pollutants, physical trauma, infectious agents like viruses and bacteria, and internal factors like cancer.
How can damage impact the body?
Damage can range from affecting a single cell to multiple cells, tissues, or organs, potentially leading to disease and, in severe cases, death.
Why does the body need defense mechanisms?
The body requires defense mechanisms to protect against the various factors that can cause damage, ensuring its survival and well-being.
What is innate immunity?
Innate immunity, also called natural immunity, comprises physical and biochemical barriers and inflammation, which protect the body from injury and infection.
What is the role of physical and biochemical barriers in innate immunity?
These barriers are the first line of defense, present from birth, to prevent damage and thwart infections by harmful microorganisms. They can also host helpful microorganisms known as the “normal flora.”
What happens if an injurious agent breaches the surface barriers?
If an injurious agent penetrates the surface barriers, the second line of defense, the inflammatory response, is activated to protect the body from further injury, prevent infection, and promote healing.
Describe the nature of the inflammatory response.
The inflammatory response is a rapid and relatively nonspecific reaction to different types of tissue damage, initiated regardless of the specific cause. It aims to protect the body.
What is the third line of defense in the body’s immune system?
The third line of defense is adaptive (acquired) immunity, also known as specific immunity.
How does adaptive immunity differ from innate immunity in terms of speed and specificity?
Adaptive immunity is slower and more specific, targeting particular invading microorganisms.
What is the role of “memory” in adaptive immunity?
Memory in adaptive immunity results in a faster response upon re-exposure to the same microorganism.
What are the three levels of human defenses?
The three levels of human defenses are Barriers, Innate Immunity, and Adaptive (Acquired) Immunity.
What is the primary role of Barriers in the defense system?
Barriers serve as the first line of defense, providing physical and biochemical protections, including skin, mucous membranes, and secretory molecules.
What characterizes the second line of defense, Innate Immunity?
Innate Immunity represents the second line of defense and involves immediate responses like inflammation, along with cells such as mast cells, neutrophils, and macrophages.
How is Adaptive (Acquired) Immunity different from the other defense levels in terms of specificity?
While Barriers and Innate Immunity have broad specificity, Adaptive (Acquired) Immunity is highly specific, targeting specific antigens.
What is the role of memory in the immune system?
While Barriers and Innate Immunity have broad specificity, Adaptive (Acquired) Immunity is highly specific, targeting specific antigens.
What is the role of memory in the immune system?
Adaptive immunity involves specific immunological memory, allowing for a faster and more efficient response upon re-exposure to the same antigen.
Which cells are involved in the third line of defense, Adaptive Immunity?
T cells, B cells, macrophages, and dendritic cells are among the cells involved in Adaptive (Acquired) Immunity.
What are some active molecules used in human defenses?
Active molecules include defensins, complement, antibodies, and various cytokines.
How does each level of defense provide protection?
Barriers offer protection through physical and biochemical mechanisms, Innate Immunity uses inflammation and immune cells, while Adaptive (Acquired) Immunity employs activated T and B cells, antibodies, and cytokines for protection.
What are the external physical barriers in the body?
The external physical barriers consist of tightly associated epithelial cells in the skin and linings of the gastrointestinal, genitourinary, and respiratory tracts.
How does the body remove pathogens attempting to breach these barriers?
Mechanical processes like coughing, sneezing, vomiting, flushing by urine, and the continual replacement of dead epithelial cells remove pathogens.
What is the role of mucus and cilia in the upper respiratory tract?
Epithelial cells in the upper respiratory tract produce mucus and have hair-like cilia that trap and move pathogens upward, leading to their expulsion through coughing and sneezing.
How do low temperatures and low pH levels contribute to defense against microorganisms?
Low temperatures and low pH levels on the skin and in the stomach generally inhibit the growth of microorganisms, as most microorganisms require higher temperatures and near-neutral pH for efficient growth.
What protective substances are secreted by epithelial cells to guard against infection?
Epithelial cells secrete mucus, perspiration, saliva, tears, and earwax.