Unit 3 BIO211 McGraw

Which is not an action of interferon?

It signals the immune system that the secreting cell is part of the body and so should not be attacked.

Interferons are one of the classes of

cytokines.

A membrane attack complex is a protein grouping that

forms a channel in the target cell membrane that causes cytolysis.

In terms of their chemical structure, cytokines are _________blank; their function is to serve as _________blank.

proteins; chemical messengers

T/F: Complement facilitates inflammation by activating basophils and mast cells and by attracting macrophages and neutrophils.

True

"Complement" refers to a group of

plasma proteins.

T/F: Cytokines are agents that affect neighboring cells without triggering systemic effects.

False

T/F: High fevers can lead to protein denaturation and raise the likelihood of seizures.

True

Which type of cell attacks a variety of unwanted cells and causes those cells to undergo apoptosis?

Natural killer cells

Exudate is

fluid that leaves capillaries to "wash" the interstitial space of an injured tissue.

T/F: Bacteria are eukaryotic microbes, some of which are pathogenic.

False

Which is not one of the cardinal signs of inflammation?

Numbness

Inflammation is a(n)

nonspecific process that occurs in vascularized tissue.

If someone had a cut in their skin through which a bacterium entered, but that bacterium was then destroyed by a neutrophil, this would be an example of

failed external innate immunity, but successful internal innate immunity.

A membrane attack complex is a protein grouping that

forms a channel in the target cell membrane that causes cytolysis.

Interleukin 1 and interferons act as

pyrogens and trigger an elevation of body temperature.

Inflamed tissue feels warm due to

increased blood flow and increased metabolic activity.

Which type of cell is the most effective to attack parasitic worms such as tapeworms?

Eosinophils

T/F: Eosinophils and lymphocytes are both types of leukocytes.

True

Which of the following lists the body's first, second, and third lines of defense in order?

External innate immunity, internal innate immunity, adaptive immunity

T/F: One of the goals of an inflammatory response is to prevent the spread of an infection.

True

Active immunity requires

direct encounter with the antigen.

T/F: Both active and passive immunity can be acquired though natural or artificial means.

True

T/F: Over their life span, plasma cells produce hundreds of millions of antibodies against one specific antigen.

True

Helper T-lymphocytes are also known as

CD4⁺ cells.

Which type of cell responds to multiple antigens?

Natural killer cell

The immunity that occurs as a result of a vaccination is _________blank immunity.

active

T/F: Helper T-lymphocytes primarily contain the CD8 coreceptor.

False

Activation of a CD4+ cell requires an APC to present antigen with

MHC class II protein.

Once a helper T-lymphocyte recognizes an antigen, it begins the immune response by secreting chemical signals called

cytokines.

T/F: Some antibodies cross the placenta.

True

T/F: After maturation, T lymphocytes tend to remain in the same lymphoid structure for life.

False

An individual gets a snake bite and goes to the hospital to receive antibodies against the venom. This individual is acquiring

passive immunity.

MHC class I molecules present peptide fragments that are either "self" or "nonself"; in either case, the fragment becomes bound to the molecule while

in the rough endoplasmic reticulum.

MHC class I molecules on a cell allow it to interact with

cytotoxic T-lymphocytes.

Passive immunity lasts

from days to weeks, and does not involve development of memory cells.

Helper T-lymphocyte activation involves the

CD4 of the helper T-cell binding with MHC class II of the antigen-presenting cell.

Which type of antibody is formed in response to parasitic infections and allergies, and has the effect of activating mast cells and basophils?

IgE

The most prevalent antibody in blood and lymph is

IgG.

Cytotoxic T-lymphocytes destroy infected cells by releasing

perforin and granzymes.

As T-lymphocytes leave the thymus, they are

naive and immunocompetent.

Which cell type is targeted by the human immunodeficiency virus (HIV)?

Helper T-lymphocyte

B-lymphocyte activation involves stimulation from

IL-4 released by helper T-lymphocytes.

Antigen-presenting cells are _________blank, and they display antigens to both _________blank and _________blank.

immune cells; B-lymphocytes; T-lymphocytes

The function of helper T-lymphocytes is to

initiate and oversee the immune response.

The exchange of oxygen and carbon dioxide between the air in the alveoli and blood in the lungs is called

pulmonary gas exchange.

T/F: Consistent with Boyle’s law, air flows from a region of lower pressure (the atmosphere) into a region of higher pressure within the lungs.

False

Airflow is _________blank related to the pressure gradient and _________blank related to resistance.

directly; inversely

During quiet expiration,

thoracic cavity volume decreases.

Which is not a function of the respiratory system?

Sound reception

The expiratory reserve volume plus the residual volume equals the

functional residual capacity.

Which of the following has the highest partial pressure of carbon dioxide?

The systemic cells

The carotid bodies contain _________blank chemoreceptors that respond to changes in _________blank.

peripheral; blood concentrations of H+  and  O2

Compared to its partial pressure in the atmosphere, oxygen's partial pressure in the alveoli is

lower.

When central chemoreceptors detect a drop in the pH of the cerebrospinal fluid,

medullary respiratory centers trigger an increase in rate and depth of breathing.

Contraction of these muscles depresses the ribs, but only during forced exhalation.

Internal intercostals

During quiet expiration,

thoracic cavity volume decreases.

Which statement accurately describes pulmonary gas exchange of oxygen?

Oxygen diffuses from the alveolus to the blood because the alveolus has a higher partial pressure of oxygen.

T/F: When a partial pressure gradient exists for a gas, it will move from the area of its lower partial pressure to the area of higher partial pressure.

false

Compared to carbon dioxide, oxygen has a relatively _________blank solubility coefficient and so requires a _________blank partial pressure gradient to help diffuse the gas into the blood.

low; large

The amount of air that can be forcibly inhaled after a normal inspiration is the

inspiratory reserve volume.

You may have noticed that after a large meal you have had some difficulty breathing. Which explanation is most accurate with regard to this situation?

A full stomach impedes contraction of the diaphragm, limiting inhalation.

Air flows out of the body during expiration because

intrapulmonary pressure is greater than atmospheric pressure.

At rest, a normal person breathes about _________blank times per minute.

12