ATI TEAS Immune System Updated Study Guide
Questions and Answers | Focused Revision Pack
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• immune system -✓✓-protects our bodies from foreign pathogens, or infectious
agents
-comprised of the lymph nodes, thymus, bone marrow, and spleen
-all immune cells are born in the bone marrow but can mature in different locations
across the body
• first line of defense -✓✓-physical barriers, such as the skin, which prevent most
pathogens from accessing our bodies
-when these barriers are breached, immune cells from the innate and adaptive arms
target pathogens for destruction
-skin has a acidic pH b/t 3 and 5, which discourages replication of most pathogens
-skin is inhabited by flora
• pathogens -✓✓foreign infectious agent
• innate arm -✓✓-quick to respond, but not specific to individual pathogens nor
does it form memory cells
• adaptive arm -✓✓-slower to activate, but it specifically targets a pathogen and
forms memory cells
• adaptive immunity (slow response) -✓✓-B cell releases antibodies
-T cell forms a CD4+ T cell and a CD8+ T cell
-quick to respond but unable to form memory
-this system consists of granulocytes, monocytes, and natural killer cells
-slower to respond b/c it must first be activated by antigen presentation by cells of
the innate immunity system
-once activated, it will specifically target pathogens and host cells displaying the
presented antigen
-includes both T and B cells
-normally self tolerant
, • innate immunity (fast response) -✓✓-involves macrophages and natural killer
cell, lysozyme, interferons, and antimicrobial peptides
-basophil --> eosinophil --> neutrophil
-quick to respond but unable to form memory
-this system consists of granulocytes, monocytes, and natural killer cells
-DOES NOT include antibodies!
• barriers to infection -✓✓-include both physical barriers that block entry of
pathogens and proteins that impede pathogen replication
-largest physical barrier is the skin
-skin has a acidic pH b/t 3 and 5, which discourages replication of most pathogens
and is inhabited by flora
• flora -✓✓nonpathogenic microbes that compete for resources and thus prevent
pathogen occupancy
• respiratory tract -✓✓-lined w/ mucus to trap incoming pathogens
-mucus can either be expelled through coughing, eliminating harmful microbes
from the body, or swallowed
-swallowed microbes will enter the stomach, where most are killed by the low pH
of 2, and survivors must compete for resources w/ gut flora in the intestines
• chemical barriers to infection -✓✓-saliva, tears, and mucus which all contain the
enzyme lysozyme, which degrades bacterial cell walls and causes them to lyse, or
burst
-cells continuously secrete antimicrobial peptides into the bloodstream
• lysozyme -✓✓-degrades bacterial cell walls and causes them to lyse, or burst
-found in saliva, tears, and mucus
• antimicrobial peptides -✓✓-these small molecules are broad-spectrum
antimicrobials that target and kill many bacterial, viral, and fungal pathogens to
prevent infection
• interferon -✓✓-if cells become infected, they secrete interferons
-a small chemical messenger, to signal nearby cells the presence of a foreign
pathogen ad activate innate defenses in those cells
Questions and Answers | Focused Revision Pack
| A+ Verified
• immune system -✓✓-protects our bodies from foreign pathogens, or infectious
agents
-comprised of the lymph nodes, thymus, bone marrow, and spleen
-all immune cells are born in the bone marrow but can mature in different locations
across the body
• first line of defense -✓✓-physical barriers, such as the skin, which prevent most
pathogens from accessing our bodies
-when these barriers are breached, immune cells from the innate and adaptive arms
target pathogens for destruction
-skin has a acidic pH b/t 3 and 5, which discourages replication of most pathogens
-skin is inhabited by flora
• pathogens -✓✓foreign infectious agent
• innate arm -✓✓-quick to respond, but not specific to individual pathogens nor
does it form memory cells
• adaptive arm -✓✓-slower to activate, but it specifically targets a pathogen and
forms memory cells
• adaptive immunity (slow response) -✓✓-B cell releases antibodies
-T cell forms a CD4+ T cell and a CD8+ T cell
-quick to respond but unable to form memory
-this system consists of granulocytes, monocytes, and natural killer cells
-slower to respond b/c it must first be activated by antigen presentation by cells of
the innate immunity system
-once activated, it will specifically target pathogens and host cells displaying the
presented antigen
-includes both T and B cells
-normally self tolerant
, • innate immunity (fast response) -✓✓-involves macrophages and natural killer
cell, lysozyme, interferons, and antimicrobial peptides
-basophil --> eosinophil --> neutrophil
-quick to respond but unable to form memory
-this system consists of granulocytes, monocytes, and natural killer cells
-DOES NOT include antibodies!
• barriers to infection -✓✓-include both physical barriers that block entry of
pathogens and proteins that impede pathogen replication
-largest physical barrier is the skin
-skin has a acidic pH b/t 3 and 5, which discourages replication of most pathogens
and is inhabited by flora
• flora -✓✓nonpathogenic microbes that compete for resources and thus prevent
pathogen occupancy
• respiratory tract -✓✓-lined w/ mucus to trap incoming pathogens
-mucus can either be expelled through coughing, eliminating harmful microbes
from the body, or swallowed
-swallowed microbes will enter the stomach, where most are killed by the low pH
of 2, and survivors must compete for resources w/ gut flora in the intestines
• chemical barriers to infection -✓✓-saliva, tears, and mucus which all contain the
enzyme lysozyme, which degrades bacterial cell walls and causes them to lyse, or
burst
-cells continuously secrete antimicrobial peptides into the bloodstream
• lysozyme -✓✓-degrades bacterial cell walls and causes them to lyse, or burst
-found in saliva, tears, and mucus
• antimicrobial peptides -✓✓-these small molecules are broad-spectrum
antimicrobials that target and kill many bacterial, viral, and fungal pathogens to
prevent infection
• interferon -✓✓-if cells become infected, they secrete interferons
-a small chemical messenger, to signal nearby cells the presence of a foreign
pathogen ad activate innate defenses in those cells
