Blank Cells Activate Cd4 Cells.

Tears and mucus membranes would be a part of which defense system?

innate external defenses

Phagocytotic cells such as macrophages identify a variety of enemies by recognizing markers unique to pathogens. They would be classified as which type of defense system?

innate internal defenses

00:0501:23

What cells make antibodies?

plasma B cells

What is the name of the unique area (specific region) that a lymphocyte recognizes and binds to?

an antigenic determinant

What type of immunity can be transferred by bodily fluids from one person to another, thus conferring immunity to the recipient?

humoral immunity

If a virus attacks a cell, which type of immunity would be activated?

cell-mediated immunity (cellular immunity)

Cancer cells would be attacked by which of the following cells?

Cytotoxic T cells

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.
Submit

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.
Submit

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 cells
to that specific virus are stored in the lymph nodes for many years. When the student comes into contact with this specific Rhinovirus, these memory cells quickly divide and differentiate into antibody-producing plasma cells. The antibodies will prevent the virus from reaching an infectious titer (number that causes infection).

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

2,4,1,3

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

00:0301:23

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

2,1,4,3,5

Which pair of molecules do NOT directly interact with one another?

BCR and TCR
Both of these molecules interact with epitopes. BCRs interact with epitopes on the whole pathogen. TRCs interact with processed epitopes when presented on MHC-II.

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?
1. Innate defenses are enough to keep a person healthly.
2. Adaptive defenses include humoral immunity only.
3. Memory B cells are typically established when the B cell binds to an antigen.
4. Adaptive defenses include both humoral and cellular immunity.

4. Adaptive defenses include both humoral and cellular immunity.

Which of the following is not an antigen-presenting cells (APC)?

T cells do not act as APCs. Quite the opposite, APCs present antigens to T cells.

Which of the following cells engulf antigens by phagocytosis and present fragments of them on their own surfaces for recognition?

Dendritic cells are antigen-presenting cells that engulf antigens and then present fragments of them to their own surfaces, where T cells can recognize them.

Which cells secrete histamines that trigger inflammatory pathways?

Mast cells have granules that contain histamines.

Which of the following is an effect of complement activation?

opsonization

Class II MHC proteins are found on which of the following cell types?

antigen-presenting cells

Which class of MHC proteins presents exogenous antigens?

class II MHC proteins present antigens that originated from outside the cell (phagocytized extracellular pathogens).

Class I MHC proteins are recognized by which of the following cell types (that are destined to become T cells)?

CD8

Which of the following types of cells display protein fragments produced by the cancer within them?

all nucleated cells

Which major class of lymphocytes become cytotoxic T cells?

CD8 cells become cytotoxic T cells.

Which of the following activate CD8 cells?

antigen fragments on class I MHC proteins
Submit

What type of T cell can directly attack and kill other cells, such as virus-infected cells?

Cytotoxic T (TC) cells can distinguish between self cells and foreign cells. If a cytotoxic T cell recognizes its own antigen on a virus-infected cell, the T cell will destroy it.

Which of these mechanisms do cytotoxic T (TC) cells use to destroy a target--that is, to deliver a lethal hit?

Perforin molecules released by the cytotoxic T cause the formation of pores in the target membrane, leading to the cell's death. T cells can also cause apoptosis (cell lysis).

T cells achieve self-tolerance in the __________.

thymus

Which of the following are NOT appropriately matched?

helper T cells: destroy infected body cells

Activated CD8 T cells become __________.

cytotoxic T cells

The root word phago- means eating or feeding.
The root word immuno- means immunology or physical immunity.
The root word -toxic means poison.
The root word neutr- means neutral or neutrophil.
The root word hist- means tissue.

...

When a cell eats, and the "food" joins with a lysosome prior to digestion, a phagolysosome is formed.
Chemicals like bacterial toxins that poison cells are described as being cytotoxic.
When antibodies block all binding sites on a virus, neutralization has occurred.
The proteins secreted by B cells are called antibodies or immunoglobulins.
MHC, or major histocompatibility complex, proteins are responsible for displaying antigens to immune cells.

...

A recent measles outbreak in your community has sparked interest in antibody testing to determine which patients are immune, which are at risk for infection, and which patients actually have measles. Which patient status and lab values are incorrectly matched?

Never immunized and ill with measles for 3 days: IgG +/ IgM -

Your patient is living with HIV infection and has not developed AIDS. She knows that her CD4 count is carefully monitored, and she asks why this test is important. How would you explain the role of CD4 cells?

"CD4 cells are special lymphocytes (white blood cells) that activate other immune cells and direct your body's response to invaders."
Submit

Your clinical instructor wants a brief description of the four cardinal signs of inflammation. What would you tell him?

The heat and redness are caused by increased blood flow to the infected areas, and the pain and swelling are caused by excessive leakage of fluid from the capillaries into the infected area.

Cilia and mucous are examples of which line of defense?

First line of defense

Natural killer (NK) cells and the inflammatory response are examples of which line of defense?

Second line of defense

What is the role of interferon?

Prevent further viral replication
Submit

Antibodies are produced from which cells?

Plasma cells

Dendritic cells activate CD4 cells.
Helper T cells and dendritic cells activate CD8 cells.
Activated CD8 cells form a clone of Cytotoxic T (TC) cells.
Activated CD4 cells form a clone of Helper T (TH) cells.

...