Which of the following defense systems would be involved in fighting a viral pathogen?
According to the animation, antibodies interact with which innate defenses?
Phagocytosis and the complement system
Mycobacterium tuberculosis is an intracellular pathogen of humans. After being ingested by a macrophage, it prevents formation of the ___________ by preventing fusion of the phagosome with the ___________________.
In which intracellular compartment would you expect most of the digestive enzymes involved in pathogen destruction to be found?
In macrophages and dendritic cells (so-called antigen-presenting cells) some small parts of the phagocytosed particle are presented to other cells of the immune system. If you were to draw an arrow leading to "antigen presentation" as described above, from which word would it extend?
If one is examining a blood smear from a patient with a parasitic worm infection, which of the following leukocytes would be found in increased numbers (as opposed to a blood smear from a normal patient NOT infected with worms)?
What direct effect do histamines and leukotrienes have on capillaries?
They allow capillary walls to open and become leaky.
Why is vasodilation important to tissue repair?
It allows for an increased delivery of oxygen, nutrients, and phagocytes to the site of damage.
Which of the following can release histamines?
Cells from damaged tissues and the complement pathway
In the classical pathway, which of the following directly activates cellular responses?
C3a, C5a, and C5bC6C7
Which of the complement pathways was discovered first?
They act as opsonins for phagocytosis, they attach to carbohydrates on some bacterial and viral surfaces, and they activate C2 and C4.
How does cytolysis occur via the complement pathway?
Formation of the MAC in invading cells, killing them
If a person could not form C2, which result of complement would be affected?
Cytolysis, chemotaxis, inflammation, and opsonization
Which of the following is an event that ultimately results in activation of complement C3 by splitting it into C3a and C3b?
interaction of mannose-binding lectin with mannose molecules on a bacterium
Which of the following are best described as short chains of amino acids that are very stable and can have a variety of different antimicrobial activities, such as forming pores in bacterial plasma membranes and inhibiting cell wall synthesis?
________________ is/are always present in an individual's blood. However, in the absence of infection, it is in an inactive form.
You note that the body temperature of one of your patients is starting to increase. As a result, you can infer that all of the following may be occurring in this patient EXCEPT __________.
dilation of blood vessels
Which statement regarding the lymphatic system is true?
Lymphatic capillaries possess one-way valves. These valves permit the uptake of fluid from the body but do not allow the fluid to flow back out of the capillaries into the intracellular spaces.
A response that is uniquely directed against pathogenic Bordetella pertussis would involve what component?
First line defenses have what aspect in common with each other?
They are physical barriers against invading pathogens.
Both the innate and adaptive defenses of the immune system work to prevent
the penetration and colonization by pathogens, and the diseases they cause.
If a new bacterial pathogen entered a human body through an accidental needle stick, the first cell that would try to kill the pathogen would likely be
The process by which a phagocyte moves toward a chemical signal at the site of an infection is called
What is the role of opsonins?
They create "handles" that make it easier for the pseudopods of phagocytes to attach to the microbe invader.
How is Streptococcus pneumoniae able to avoid destruction by a phagocyte?
Their capsules make them "slippery" to phagocytes.
Which microorganism requires the low pH inside a phagolysosome in order to reproduce?
Which of the following microorganisms use M protein to avoid destruction of a phagocyte?
How is phagocytosis in the immune system different from protozoan phagocytosis?
Protozoan phagocytosis is used for feeding; phagocytosis by immune cells is used to fight infection.
If a person turns their ankle, how would one determine if damage to the tissue in the ankle has occurred?
The ankle is red, swollen, and warm to the touch.
What is the function of inflammation in response to a burn from a hot iron?
To repair the damaged tissue
Based on the animation, which of the complement proteins can directly bind to the surface of a bacterial cell?
What is the role of helper T cells in the adaptive immune response?
Helper T cells activate B cells and cytotoxic T lymphocytes to kill infected host cells.
What is meant by the clonal expansion of a B cell?
An activated B cell divides into cells that give rise to memory B cells and plasma cells.
The student who caught the cold caused by this specific Rhinovirus was exposed to the exact same Rhinovirus 18 months later. What component of the immune system will protect her from getting the same cold again?
Memory B cells
Correctly order the steps involved cellular immunity:
1.The Tc recognizes the infected host cell
2 The Tc interacts with epitope presented by MHC-I on the dendritic cell
3.The Tc secretes perforin and granzyme, causing apoptosis
4.The helper T cell activates the Tc cell
Which of the following is NOT a step used by cytotoxic T cells to kill infected host cells?
Recognition of infected host cell using its CD4 glycoprotein
Place the following steps of phagocytosis in the order that they occur:
1.Endosome fuses with lysozome
2.Dendritic cell engulfs Rhinovirus
3.Epitopes are attached to MHC-II
4.Digestion of the Rhinovirus
5.MHC-II plus the attached epitope move to the outside of the dendritic cell
Which of the following is NOT a step that ultimately leads to antibody production?
Activation of cytotoxic T cells by helper T cells
A person who has AIDS contracts rare and often life-threatening infections because their helper T cell count is so low. Which of the following components of the immune response still respond to antigen despite the low helper T cell count?
Clonal selection of B cells
Which of the following statements is true?
Adaptive defenses include both humoral and cellular immunity.
Which of the following statements about innate immunity is true?
Bacteria are digested when the phagosome fuses with a lysosome.
The function of the "ciliary escalator" is to
trap inhaled dust and microorganisms in mucous and propel it away from the lower respiratory tract.
A differential cell count is used to determine each of the following EXCEPT
the number of red blood cells.
The complement protein cascade is the same for the classical pathway, alternative pathway, and lectin pathway beginning with the activation of
A child falls and suffers a deep cut on her leg. The cut went through her skin and she is bleeding. Which of the following defense mechanisms will participate in eliminating contaminating microbes?
phagocytosis in the inflammatory response
Which of the following statements is TRUE?
Gamma interferon causes bactericidal activity by macrophages.
Each of the following is an effect of complement activation EXCEPT
interference with viral replication.
Which of the following is an effect of opsonization?
increased adherence of phagocytes to microorganisms
Normal microbiota provide protection from infection in each of the following ways EXCEPT
they produce lysozyme.
Each of the following provides protection from phagocytic digestion EXCEPT
formation of phagolysosomes.
All of the following are part of the mechanism of action of alpha and beta interferons EXCEPT
they are effective for long periods.
The alternative pathway for complement activation is initiated by
lipid-carbohydrate complexes and C3.
All of the following are true regarding NK cells EXCEPT
they destroy infected body cells by phagocytosis.
All of the following pertain to fever EXCEPT that it
accelerates microbial growth by increasing iron absorption from the digestive tract.
Several inherited deficiencies in the complement system occur in humans. Which of the following would be the MOST severe?
deficiency of C3
Which of the following statements about the classical pathway of complement activation is FALSE?
C3 is not involved in the classical pathway.
Lysozyme and the antibiotic penicillin have similar mechanisms of action in that they both cause damage to the bacterial
Which non-specific defense mechanism is mismatched with its associated body structure or body fluid?
mucociliary escalator intestines