Exam 1: Immune Responses

Question 1

What is immunity?

Answer 1

a defense mechanism which provides protection from infectious disease.

Question 2

What is tissue injury caused by an immune response to microbes called?

Answer 2

immunopathy

Question 3

what is the smallest unit (antigenic determinant) to which an AB can be made?

Answer 3

~ 3 to 6 AAs or ~5 to 6 sugar residues

Question 4

what do t-cell receptors recognize?

Answer 4

linear AA sequences

Question 5

what are Ags that can stimulate an immune response called?

Answer 5

immunogens

Question 6

What are haptens?

Answer 6

very small (low molecular weight) molecules that can bind to ABs or TCR, but cannot initiate immune response

Question 7

What are the components of the Innate immune system?

Answer 7

1. Cellular and chemical barriers: skin, mucosal epithelia, antimicrobial molecules. 2. Blood Proteins: Complement, acute phase proteins, cytokines, others. 3. Cells: NK, Phagocytes, dendritic, innate lymphoid cells.

Question 8

What are the components of adaptive immunity?

Answer 8

1. Cellular and chemical barriers: Lymphocytes in epithelia; antibodies secreted at epithelial surfaces 2. blood proteins: antibodies, cytokines 3. B & T Lymphocytes.

Question 9

T-cell maturation site and end product.

Answer 9

mature in thymus, stimulated by Ag. Give rise to cellular immunity

Question 10

B-cells maturation site and end product,

Answer 10

Under the influence of bone marrow, give rise to humoral immunity–> production of immunoglbbulins.

Question 11

what are Cytokines?

Answer 11

are a large group of secreted proteins with diverse structures and functions, which regulate and coordinate many activities of the cells of innate and adaptive immunity.

Question 12

What is inflammation?

Answer 12

Inflammation is the process of recruitment of leukocytes and plasma proteins from the blood, their accumulation in tissues, and their activation to destroy the microbes

Question 13

Humoral Immunity

Answer 13

B lymphocytes secrete antibodies that prevent infections and eliminate extracellular microbes.

Question 14

Cell Mediated Immunity

Answer 14

T Helper lymphocytes activate macrophages to kill phagocytized microbes or Cytotoxic T lymphocytes CTLs directly destroy infected cells.

Question 15

Active Immunity:

Answer 15

Conferred by a host response to a microbe or microbial Ags and generates immunolgic memory

Question 16

Passive Immunity

Answer 16

conferred by adoptive transfer of ABs or T lymphocytes specific for the microbe.

Question 17

What does activation of naive T lymphocytes require?

Answer 17

recognition of peptide-MHC complexes presented on dendritic cells.

Question 18

B Lymphocytes

Answer 18

recognize soluble Ags and develop into AB-secreting cells

Question 19

T helper lymphocytes

Answer 19

recognize Ags on the surfaces of APCs and secrete cytokines, which stimulate different mechanisms of immunity and inflammation. (T helper 1 &2 cells)

Question 20

Regulatory T cells

Answer 20

suppress and prevent immune response (e.g to self antigen)

Question 21

What are normal blood cell counts?

Answer 21

Question 22

what is the most abundant population of circulating spherical WBCs? what do they do?

Answer 22

Neutrophils, mediate the earliest phases of inflammatory reactions.

Question 23

where are neutorophils produced? How is their production stimulated?

Answer 23

Produced in the bone marrow (arise from precursors that also give rise to mononuclear phagocytes).

Production is stimulated by the cytokine Granulocyte Colony-stimulating factor (G-CSF)

Question 24

Primary function of phagocytes

Answer 24

to ingest and destroy microbes and get rid of damages tissues (scavenger function)

Question 25

what are the steps of functional responses of phagocytes?

Answer 25

• recruitment of cells to the sites of infection
• recognition of and activation by microbes
• ingestion of the microbes by the process of phagocytosis
• destruction of ingested mirobes

Question 26

what are neutrophils called polymorphonuclear leukocytes

Answer 26

b/c their nucleus is segmented into three to five connected lobules.

Question 27

after entering the tissues, nutrophils finction only for?

Answer 27

1-2 days then die :(

Question 28

Mast cells

Answer 28

bone marrow–derived cells present in the skin and mucosal epithelia, which contain abundant cyto- plasmic granules filled with histamine and other media- tors

-stain purble with giemsa

Question 29

Blood basophil

Answer 29

Basophils are blood granulocytes with many structural and functional similarities to mast cells.

blue granules stain with giemsa

Question 30

Eosinophil granules

Answer 30

Eosinophils are blood granulocytes that express cytoplas- mic granules containing enzymes that are harmful to the cell walls of parasites but can also damage host tissues.

stained red with acidic dye eosin.

Question 31

cells of the macrophage lineage arise from….

Answer 31

committed precursor cells in the bone marrow, driven by monocyte/macrophage colony-stimulating factor (M-CSF).

Question 32

explain a mature macrophage in the tissues

Answer 32

mature monocytes enter the blood circulation and then migrate into tissues where they mature into macriphages, especially during inflammation.

Question 33

what four types of macrophages are found in the spleen?

Answer 33

1. white-pulp
2. redu-pulp
3. marginal-zone
4. metallophilic

Question 34

Where do dendritic cells (DCs) arise from?

Answer 34

a common precursor cell of the lyeloid lineage in the bone marrow.

Question 35

Where can inflammatory DCs arise from?

Answer 35

monocytes in inflammed tissues.