The Immune System MCAT Exam Study
Guide.
Innate immunity - answer✔✔-composed of defenses that are always active but unable to target
specific invaders
-nonspecific immunity
adaptive immunity - answer✔✔-specific immunity
-targets a specific pathogen
-slower to attack but retains memory of pathogens
bone marrow - answer✔✔-produces all leukocytes(white blood cells) that participate in the
immune system
spleen - answer✔✔-location of blood storage and activation of B-cells, which turn into plasma
cells to produce antibodies for adaptive immunity
humoral immunity - answer✔✔the division of adaptive immunity in the blood rather than cells
T-cells - answer✔✔-mature in thymus, small gland in front of the pericardium (sac that protects
the heart)
-T-cells coordinate the immune system and directly kill viral infected cells
Lymph nodes - answer✔✔-provide a place for immune cells to communicate and mount an
attack
Gut-associated lymphoid tissue - answer✔✔-immune tissue associated with the digestive system
-includes tonsils and adenoids, Peyer's Patches and lymphoid aggregates in the appendix
Leukocytes - answer✔✔-produced in bone marrow through hematopoiesis
-divided into granulocytes and agranulocytes
granulocytes - answer✔✔-contain granules that contain toxic enzymes and chemicals
-released by exocytosis
, ©THEBRIGHT EXAM STUDY SOLUTIONS 8/22/2024 12:54 PM
hematopoietic stem cells - answer✔✔gives rise to leukocytes, red blood cells and platelets
Agranulocytes - answer✔✔-includes lymphocytes and monocytes
lymphocytes - answer✔✔-responsible for antibody production and targeted killing of infected
cells
monocytes - answer✔✔-phagocytic cells in the membrane
-become macrophages in tissues
defensins - answer✔✔antibacterial enzymes found on the skin
lysozyme - answer✔✔antibacterial enzyme found in tears and saliva
Gastrointestinal defense - answer✔✔-stomach secretes acid to kill pathogens
-large bacteria population in gut, when new bacteria enters, they need to compete
complement system - answer✔✔-a form of non-specific defense that consists of a number of
proteins in the blood
-activated through classical pathway (antibody binds to pathogen) or alternative pathway, no
antibodies
-the proteins punch holes in bacteria
interferons - answer✔✔-proteins that prevent viral replication and dispersion
-cells that have been infected by viruses produce these
macrophages - answer✔✔-agranulocytes that reside in tissue
-become a resident population in the tissue
-once activated it phagocytizes the invader through endocytosis
-then it digests the invader with enzymes
-lastly it gives little pieces of the invader to other cells using the protein major histocompatibility
complex
MHC - answer✔✔-binds to pathogenic peptide and carries it to the cell surface to be recognized
by cells of the adaptive immune system
cytokines - answer✔✔-chemical substances that stimulate inflammation and recruit additional
immune cells to the area
MHC-I - answer✔✔-all nucleated cells in the body display these
-any protein produced in a cell can be loaded onto these and can be presented at the surface