MicroBiology

SmartBook Assignment 8

Innate Immunity Includes

  • First-line defenses, sensor systems, and innate effector action

When microbes attempt to attach to the outermost surface of the skin, there is a simple mechanism that prevents an infection from occurring. This simple mechanism occurs as the cells continuously flake off, taking with them any attached microbes.

Which of the following predisposes a person to diseases caused by Clostridioides difficile growing in the intestine and Candida albicans growing in the vagina? Antibiotic use

Neutrophils can release their cell contents to form NETs, an acronym that stands for neutrophil extracellular traps.


Which of the following is best described as "scouts" and "sentinels" of the immune system? Dendritic cells

The three general components of the innate immune system are first-line defenses, sensor systems, and effector actions.

Due to its dense layering of tightly joined cells, the skin provides a highly efficient barrier that prevents microbes from entering our deeper tissues.

What are the two outcomes of a ligand binding to its receptor on a cell's surface?

  • A response is triggered in the cell, initiating some change.

  • The internal portion of the receptor becomes modified.

Examples of microbe-associated molecular patterns (MAMPs) include .

  • Peptidoglycan

  • Teichoic acids

  • Lipopolysaccharide

  • Lipoproteins

  • Flagellin subunits

  • Microbial nucleic acid

What is the main role of neutrophils? Phagocytosis

If a macrophage's pattern recognition receptors (PRRs) detect bacterial products, then that macrophage will produce pro-inflammatory cytokines.

Dendritic cells provide a link between the innate and adaptive immune systems by engulfing material, then presenting it to the adaptive immune system cells.


Which of the following are most susceptible to complement lysis? Gram-negative bacteria

If a macrophage detects microbial components in its cytoplasm, it triggers an inflammatory response.

A molecule that can bind to a given surface receptor is called a ligand for that receptor.

Which descriptions are true for neutrophils but not macrophages?

  • They have more killing power.

  • They release granule contents and DNA strands to entrap and destroy microbes.

Some PRRs recognize DAMPs, which are molecules that indicate a host cell is damaged.

If a virally infected cell's PPRs detect viral nucleic acid, that cell will produce an interferon.

The inflammatory process involves a cascade of events that results in dilation of blood vessels, leakage of fluid from those vessels, and migration of leukocytes out of the bloodstream and into the tissues. True

A pore-like structure formed on a target cell surface by complement proteins C5b, C6, C7, C8, and C9 is known as a MAC. What does this stand for? Membrane attack complex (MACs)
Macrophages can function as sentinel cells because they produce pattern recognition receptors.

What are features of the inflammatory response?

  • It can damage host tissues

  • It can help eliminate an invading microbe

A macrophage usually kills microbes by ingesting microbes and destroying them internally, while a neutrophil can additionally kill by releasing toxic granule components.

Programmed cell death that does not trigger an inflammatory response is known as apoptosis.

The increase in temperature from a moderate fever helps the body fight an infection in three ways, including

  • slowing or preventing the growth of microbes that have lower optimum temperatures

  • enhancing the inflammatory response

  • enhancing phagocytic activity and the multiplication of lymphocytes

The inflammatory response can be both helpful and harmful.

A human is infected with a bacterial pathogen whose optimum growth temperature is 33οC. If the infection leads to a moderate fever, this will reduce the growth rate of the pathogen.