Immune System

Question 1

Exchange of substances between blood and tissue fluid occurs in:

Answer 1

capillary beds

Question 2

Substances that cannot enter or return through the capillary walls, including excess fluid and protein molecules, are returned to the blood as:

Answer 2

lymph

Question 3

A fluid formed in the tissue spaces that is transported by way of lymphatic vessels to eventually reenter the bloodstream carried by the cardiovascular system.

Answer 3

lymph

Question 4

The lymphatic system includes:

Answer 4

• Lymph
• lymphatic vessels
• lymph nodes
• specialized lymphatic organs such as the thymus and spleen

Question 5

Lymph forms in this way:

Answer 5

blood plasma filters out of the capillaries into the microscopic spaces between tissue cells because of the pressure generated by the pumping action of the heart.
(there the liquid is called interstitial fluid)

Question 6

Much of it goes back into the blood by the same route it came out (that is, through the capillary membrane).

Answer 6

interstitial fluid

Question 7

Permit excess tissue fluid and some other substances such as dissolved protein molecules to leave the tissue spaces.

Answer 7

lymphatic capillaries

Question 8

Lymphatic and blood capillaries:

Answer 8

_vessels are microscopic

-both are formed from sheets that consist of a cell layer of simple squamous epithelium called endothelium .

Question 9

The movement of lymph in the lymphatic vessels:

Answer 9

goes one way only.

Question 10

The lymphatic vessels often have a ______ appearance because:

Answer 10

• “beaded” appearance

- resulting from the presence of valves that assist in maintaining a one-way flow of lymph.

Question 11

Lymphatic vessels eventually empty into one of two terminal vessels called:

Answer 11

Right lymphatic duct and the thoracic duct.

which empty their lymph into the blood in large veins in the neck region.

Question 12

Thoracic duct:

Answer 12

• Largest lymphatic vessel.

- Lympth from 3/4 of the body drains in it.

Question 13

The thoracic duct in the abdomen has an enlarged pouch like structure which serves as a temporary holding area for lymph moving toward its point of entry into the veins. called:

Answer 13

cisterna chyli

Question 14

Lacteals

Answer 14

Lymphatic capillaries in the wall of the small intestine that transport fats obtained from food to the bloodstream.

Question 15

Located in clusters along the pathway of lymphatic vessels.

Answer 15

Lymph nodes

Question 16

The structure of the lymph nodes makes it possible for them to perform two important immune functions:

Answer 16

-defense and white blood cell formation.

Question 17

Lymph nodes are considered lymphoid organs because:

Answer 17

-they contain lymphoid tissue, which is a mass of developing lymphocytes and related cells.

Question 18

Lymph nodes, tonsils, thymus, and spleen are important:

Answer 18

-structural components of the immune system because they provide immune defence and development of immune cells.

Question 19

A process in which cells (phagocytic cells in this case) alter the contents of the filtered fluid.

Answer 19

biological filtration

Question 20

These vessels deliver lymph to the node.

Answer 20

afferent lymphatic vessels

Question 21

Lymph percolates” slowly through spaces called:

Answer 21

sinuses

Question 22

Lymph exits from the node through:

Answer 22

A single efferent lymphatic vessel.

Question 23

Small lymphoid tissue organ located in the mediastinum, extending upward in the midline of the neck.

Answer 23

Thymus

Question 24

Plays a central and critical role in the body’s vital immunity mechanism.

Answer 24

Thymus

virtually gone by age 80+

Question 25

Thymosins

Answer 25

-A group of hormones secreted by the thymus that influences the development of T cells.

Question 26

Located on each side of the throat:

Answer 26

palatine tonsils

Question 27

Known as adenoids when they become swollen, are near the posterior opening of the nasal cavity.

Answer 27

pharyngeal tonsils

Question 28

Near the base of the tongue. The tonsils serve as the first line of defense from the exterior and as such are subject to chronic infection.

Answer 28

lingual tonsils

Question 29

-The largest lymphoid organ in the body.

Answer 29

Spleen

Question 30

Functions of the spleen:

Answer 30

- removes by filtration and phagocytosis many bacteria and other foreign substances, - destroys worn out red blood cells. - salvages the iron found in hemoglobin for future use. - serves as a reservoir for blood that can be returned to the cardiovascular system when needed.

Question 31

Red pulp which contains many red blood cells and White pulp which resembles lymphoid nodules are found inside the fibrous capsule of what organ?

Answer 31

Spleen

Question 32

Two types of immunity defenses are:

Answer 32

- Nonspecific defenses (immunity) | - Specific defenses (immunity)

Question 33

These defenses Operate together to provide resistance to infection and disease.

Answer 33

Nonspecific and specific defenses

Question 34

What type of immunity is maintained by mechanisms that attack any irritant or abnormal substance that threatens the internal environment. (confers general protection.)

Answer 34

Nonspecific immunity

Question 35

Often called innate immunity

Answer 35

Nonspecific immunity

Question 36

Membranes that are Nonspecific mechanical barriers that prevent entry into the body by bacteria and many other substances such as toxins and harmful chemicals.

Answer 36

skin and mucous membranes

Question 37

Tears and mucus contribute to what kind of immunity ?

Answer 37

nonspecific immunity

Question 38

Oils on the skin, as well as stomach acid act as what kind of barriers?

Answer 38

chemical barriers

Question 39

Phagocytosis of bacteria by white blood cells is a:

Answer 39

nonspecific form of immunity.

Question 40

Seven major categories of nonspecific defences:

Answer 40

``` – Physical barriers – Phagocytes – Immunological surveillance – Interferons – Complement – Inflammatory response – Fever ```

Question 41

Attack and remove dangerous microorganisms

Answer 41

Phagocytes

Question 42

Immunological Surveillance

Answer 42

Constantly monitors normal tissues with natural killer cells (NK cells)

Question 43

Type of lymphocyte able to bind to certain tumor cells and virus-infected cells without the stimulation of antigens, and kill them by the insertion of granules containing perforin.

Answer 43

NK cells

Question 44

Chemical messengers that trigger production of antiviral proteins in normal cells.

Answer 44

Interferons

Question 45

-Can be activated by antibodies (‘Complement’ action of antibodies) as well as cells of the nonspecific immune system.

Answer 45

Complement (C) Proteins

Question 46

Nonspecific Defenses

Answer 46

- Inflammation | - Fever

Question 47

A set of nonspecific responses that often occurs in the body.

Answer 47

inflammatory response

Question 48

Includes protective mechanisms that confer very specific protection against certain types of threatening microorganisms or other toxic materials.

Answer 48

Specific immunity

Question 49

Iinvolves memory and the ability to recognize and respond to certain harmful substances or bacteria.

Answer 49

Specific immunity

Question 50

Because it is able to adapt to newly encountered “enemies," it is often called adaptive immunity.

Answer 50

Specific immunity

Question 51

_____ are slow compared to _______immune responses.

Answer 51

specific immune responses, nonspecific

Question 52

______ immune responses have memory — the ability to produce a stronger, faster response to repeated exposure to the same antigen.

Answer 52

Specific

Question 53

Classified as either “natural” or “artificial” depending on how the body is exposed to the harmful agent.

Answer 53

Specific immunity

Question 54

May be “active” or “passive.”

Answer 54

Natural and artificial immunity

Question 55

Occurs when an individual's own immune system responds to a harmful agent, regardless of whether that agent was naturally or artificially encountered

Answer 55

Active immunity

Question 56

Results when immunity to a disease that has developed in another individual or animal is transferred to an individual who was not previously immune.

Answer 56

Passive immunity

Question 57

Protein molecules critical to immune system functioning

Answer 57

Antibodies and complement proteins.

Question 58

- Protein compounds that are normally present in the body. - Uniquely shaped concave regions, called combining sites, on its surface. - Combines with a specific compound called an antigen.

Answer 58

Antibodies

Question 59

Compounds whose molecules have small regions on their surfaces that are uniquely shaped to fit into the combining sites of a specific antibody molecule as precisely as a key fits into a specific lock.

Answer 59

Antigens

Question 60

Protein molecules embedded in the surface membranes of threatening or diseased cells, such as microorganisms or cancer cells.

Answer 60

Antigens

Question 61

Produce Humoral, or antibodymediated, immunity by changing the antigens in a way that prevents them from harming the body.

Answer 61

Antibodies

Question 62

If an antigen is a toxin (that is, a substance poisonous to body cells), the toxin is _____ or made _______ by becoming part of an _____________.

Answer 62

- neutralized or made non-poisonous, | - antigenantibody complex.

Question 63

if antigens are molecules in the surface membranes of threatening cells, when antibodies combine with them, the resulting antigen-antibody complexes may _______ the enemy cells (make them stick together in clumps). Then macrophages or the other phagocytes can rapidly destroy them by ingesting and digesting large numbers of them at one time.

Answer 63

agglutinate

Question 64

Promotion and enhancement of Phagocytosis.

Answer 64

important function of antibodies

Question 65

The most important way in which antibodies act is a process called:

Answer 65

complement cascade

Question 66

When antigens that are molecules on an antigenic or foreign cell's surface combine with antibody molecules, they change the shape of the antibody molecule slightly but just enough to expose two previously hidden regions called:

Answer 66

complement-binding sites

Question 67

Name used to describe a group of protein enzymes normally present in an inactive state in blood.

Answer 67

Complement

Question 68

Complement proteins serve roles in the immune system, such as:

Answer 68

* attracting immune cells to a site of infection * activating immune cells * marking foreign cells for destruction, and * increasing permeability of blood vessels. * play a vital role in producing the inflammatory response.

Question 69

Two important phagocytes:

Answer 69

neutrophils and monocytes

Question 70

Act as antigenpresenting cells (APCs)

Answer 70

Macrophages

Question 71

Most numerous cells of the immune system.

Answer 71

Lymphocytes

Question 72

Two major types of Lymphocytes:

Answer 72

B and T lymphocytes but usually called B cells and T cells.

Question 73

All lymphocytes that circulate in the tissues arise from primitive cells in the bone marrow called _____and go through two stages of ______.

Answer 73

Stem cells, B cell development

Question 74

Changes a mature, inactive B cell into an activated ‘Supercharged’ B cell.

Answer 74

second stage of B cell development

Question 75

Clone:

Answer 75

-a family of many identical cells, all descended from one cell.

Question 76

Made up of two kinds of cells, plasma cells (also called effector cells) and memory cells.

Answer 76

Clones of B cells

Question 77

- Secrete huge amounts of antibody into the blood. | - Activated B cells develop into this.

Answer 77

Plasma cells.

Question 78

B cells function indirectly to produce.

Answer 78

humoral immunity

Question 79

Humoral immunity:

Answer 79

Resistance to disease organisms produced by the actions of antibodies binding to specific antigens while circulating in body fluids.

Question 80

Lymphocytes that have undergone their first stage of development in the thymus gland:

Answer 80

T cells

Question 81

The second stage of T-cell development takes place:

Answer 81

When and if a T cell comes into contact with its specific antigen.

Question 82

Form a group of effector cells along with memory cells.

Answer 82

B cells and T cells.

Question 83

The _____ T cells actively engage in immune responses, whereas the _____ T cells do not.

Answer 83

Effector, memory

Question 84

Produce cell-mediated immunity:

Answer 84

Activated T cells

Question 85

"Helper T cells" produce their deadly effects indirectly by means of compounds that they release into the area around enemy cells.

Answer 85

Activated T cells

Question 86

When bound to antigens they release a substance that acts as a specific and lethal poison against the abnormal cell.

Answer 86

cytotoxic T cells

Question 87

Resistance to disease organisms that results from the actions of cells- chiefly, sensitized T cells.

Answer 87

cell-mediated immunity

Question 88

Release the chemicals needed to help trigger the activation of B cells.

Answer 88

Helper T cells.