MICR 270 Module 1 Exam Questions With
Complete Answers
Colony-forming unit (CFU) - ANSWER Unit used to estimate the number of viable
bacterial or fungal cells in a sample
Pathogen - ANSWER Infectious biological agent that causes disease
Opportunistic pathogen - ANSWER Microorganism that takes advantage of an
opportunity not normally available which causes disease (i.e. a weakened immune
system)
Functions of the immune system - ANSWER 1. Discrimination: recognize self from
non-self
2. Elimination: destroy non-self and altered cells
Dysfunctions of the immune system - ANSWER 1. Autoimmunity and hypersensitivity:
misdirected or overly active
2. Immunodeficiency: underachieve
Antigen - ANSWER Foreign macromolecule, usually a protein, that induces an immune
response, typically the production of antibodies
,Antibody - ANSWER Protein circulating in the blood produced in response to
encountering a specific antigen
Lymphatic System - ANSWER Network of vessels that drains lymph that has escaped the
blood from the capillaries and entered surrounding tissues (interstitial space)
Lymph - ANSWER Colourless fluid containing white blood cells that bathes the tissues
and drains through the lymphatic system into the bloodstream
Circulatory System - ANSWER Where lymph comes from and goes after being filtered,
lymphatic vessels carry lymph toward the thoracic vena cava where it re-enters the
circulatory system
Immune System - ANSWER Cells travel in the circulatory and lymphatic systems
Bone Marrow - ANSWER Structure -> flexible tissue, divided into 2 types (red marrow -
WBCs, yellow marrow), contains hematopoietic cells
Location -> central cavity of bones
Function -> site of hematopoiesis and B-cell development
Not many vertebrates generate lymphocytes here
Hematopoietic cells - ANSWER Cells within bone marrow that are responsible for
producing the cells that circulate in the blood - RBCs, WBCs, platelets
, Hematopoiesis - ANSWER Formation and differentiation of blood cells
Lymph Nodes - ANSWER Structure -> small (1-25 mm), bean-shaped, numerous (~600),
divided into 3 concentric regions (cortex, paracortex, medulla), filled with lymphocytes,
B-cells and T-cells
Location -> along the lymphatic vessels
Function -> filters the lymph, first organized structure that foreign molecules encounter
Recent evolutionary trait
Lymphocytes - ANSWER WBCs that arise from the lymphoid progenitor lineage
Mucosal Associated Lymphiod Tissues (MALT) - ANSWER Structure -> combined surface
areas of BALT, GALT, lamina propria of intestinal villa, Peyer's patches, tonsils, appendix
Location -> mucous membranes of digestive, respiratory, and urogenital systems
Function -> initiates immune response to antigens encountered along all mucosal
surfaces
Bronchus Associated Lymphoid Tissue (BALT) - ANSWER Lungs and bronchus
Gut Associated Lymphoid Tissue (GALT) - ANSWER Lumen of small intestine
Almost all vertebrates
Lamina Propria of Intestinal Villa - ANSWER Thin layer of connective tissue rich in
Complete Answers
Colony-forming unit (CFU) - ANSWER Unit used to estimate the number of viable
bacterial or fungal cells in a sample
Pathogen - ANSWER Infectious biological agent that causes disease
Opportunistic pathogen - ANSWER Microorganism that takes advantage of an
opportunity not normally available which causes disease (i.e. a weakened immune
system)
Functions of the immune system - ANSWER 1. Discrimination: recognize self from
non-self
2. Elimination: destroy non-self and altered cells
Dysfunctions of the immune system - ANSWER 1. Autoimmunity and hypersensitivity:
misdirected or overly active
2. Immunodeficiency: underachieve
Antigen - ANSWER Foreign macromolecule, usually a protein, that induces an immune
response, typically the production of antibodies
,Antibody - ANSWER Protein circulating in the blood produced in response to
encountering a specific antigen
Lymphatic System - ANSWER Network of vessels that drains lymph that has escaped the
blood from the capillaries and entered surrounding tissues (interstitial space)
Lymph - ANSWER Colourless fluid containing white blood cells that bathes the tissues
and drains through the lymphatic system into the bloodstream
Circulatory System - ANSWER Where lymph comes from and goes after being filtered,
lymphatic vessels carry lymph toward the thoracic vena cava where it re-enters the
circulatory system
Immune System - ANSWER Cells travel in the circulatory and lymphatic systems
Bone Marrow - ANSWER Structure -> flexible tissue, divided into 2 types (red marrow -
WBCs, yellow marrow), contains hematopoietic cells
Location -> central cavity of bones
Function -> site of hematopoiesis and B-cell development
Not many vertebrates generate lymphocytes here
Hematopoietic cells - ANSWER Cells within bone marrow that are responsible for
producing the cells that circulate in the blood - RBCs, WBCs, platelets
, Hematopoiesis - ANSWER Formation and differentiation of blood cells
Lymph Nodes - ANSWER Structure -> small (1-25 mm), bean-shaped, numerous (~600),
divided into 3 concentric regions (cortex, paracortex, medulla), filled with lymphocytes,
B-cells and T-cells
Location -> along the lymphatic vessels
Function -> filters the lymph, first organized structure that foreign molecules encounter
Recent evolutionary trait
Lymphocytes - ANSWER WBCs that arise from the lymphoid progenitor lineage
Mucosal Associated Lymphiod Tissues (MALT) - ANSWER Structure -> combined surface
areas of BALT, GALT, lamina propria of intestinal villa, Peyer's patches, tonsils, appendix
Location -> mucous membranes of digestive, respiratory, and urogenital systems
Function -> initiates immune response to antigens encountered along all mucosal
surfaces
Bronchus Associated Lymphoid Tissue (BALT) - ANSWER Lungs and bronchus
Gut Associated Lymphoid Tissue (GALT) - ANSWER Lumen of small intestine
Almost all vertebrates
Lamina Propria of Intestinal Villa - ANSWER Thin layer of connective tissue rich in
