ATI TEAS Immune System, well done 2023/2024

Immune system - answers-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 - answers-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 - answersforeign infectious agent innate arm - answers-quick to respond, but not specific to individual pathogens nor does it form memory cells adaptive arm - answers-slower to activate, but it specifically targets a pathogen and forms memory cells adaptive immunity (slow response) - answers-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) - answers-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 - answers-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 - answersnonpathogenic microbes that compete for resources and thus prevent pathogen occupancy respiratory tract - answers-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 - answers-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 - answers-degrades bacterial cell walls and causes them to lyse, or burst -found in saliva, tears, and mucus antimicrobial peptides - answers-these small molecules are broad-spectrum antimicrobials that target and kill many bacterial, viral, and fungal pathogens to prevent infection interferon - answers-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 memory - answersthe ability to remember a pathogen that has been previously encountered granulocytes - answers-cells of the innate immune system named for the dense granules, containing reactive oxygen compounds and cytokines in their cytoplasm -include basophils, eosinophils, and neutrophils basophils - answersgranulocytes responsible for releasing histamine and mediating allergic reactions eosinophils - answersgranulocytes responsible for killing parasites neutrophils - answersmost common of the granulocytes and are responsible for phagocytosing, or eating, bacteria and medicating inflammatory responses phagocytosing - answerseating bacteria inflammation - answersleads to swelling of the tissue and fever, as well as recruitment of immune cells monocytes - answersinclude macrophages and dendritic cells dendritic cells - answers-phagocytic cells that kill extracellular pathogens -they recognize pathogen associated molecular patterns (PAMPs) -following phagocytosis, present microbial antigens to cells of the adaptive immune system leading to their activation