HEMATOPOIESIS III—IMMUNE SYSTEM & LYMPHOID ORGANS Flashcards Preview

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Flashcards in HEMATOPOIESIS III—IMMUNE SYSTEM & LYMPHOID ORGANS Deck (64)
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1

Name two general functions of the lymphoid system

1. helps maintain fluid balance in the tissues of the body.
2. it has a major role in the defense against infection

2

function of lymphatic vessels

1) one way system to the heart
2) return of collected excess tissue fluid
3) return of leaked protein

3

How do lymph capillaries differ from blood capillaries?

-originate as pockets rather than continuous tubes -larger diameter with thinner walls
-flattened/IR outline in sectional view
-incomplete or absent basal lamina vessel walls= act as one-way mini valves allowing excess fluid, proteins, electrolytes, bacteria and viruses not to leave
-prominent ones located in most organs but absent in areas that lack blood supply (ie: cornea, bone marrow and CNS)

4

Two types of lymphatic collecting vessels

1)Superficial in subcutaneous layer deep to skin traveling with superficial veins (ie: areolar tissues of mucous membranes lining the digestive, respiratory, reproductive and urinary tracts)

2)Deep lymphatic vessels (larger) accompany deep arteries and veins to skeletal muscle, organs of the neck, limbs, trunk and walls of visceral organs.

5

Central Lymphoid Organs

thymus
bone marrow are involved in the production and early secretion of lymphocytes

6

What is autoimmunity?

is an immune reaction against self molecules

7

Peripheral Lymphoid Organs

lymph nodes and isolated cells found in the mucosa of the digestive system (tonsils, Peyer’s patches, appendix), the respiratory system, the reproductive system, and the urinary systems are collectively known as MALT (mucosa-associated lymphoid tissue) and considered a lymphoid organ.

8

What kind of immune response does the peripheral lymphoid organs elicit?

adaptive immune response

9

What is the significant of Waldeyer's ring?

form a circle at the entrance of the gut and airway to initiate a immune response.

10

What are characteristics of Innate Response?

1) Pathogen specificity is broad and programmed in germline DNA
2) Macrophrages, neutrophils, eosinophils, and NK cells are directly involved with killing pathogens
3) Can lead to autoinflammation diseases

11

What are the two types of immune responses?

Innate (natural) repsonse and Adaptive Response

12

Antigen

molecule that is recognized by the cells of the immune system and may elicit a response.

Examples: May be soluble molecules (proteins, polysaccharides, and nucleoproteins) or molecules belonging to whole cells (bacteria, protozoa, tumor cells, or virus-infected cells).

13

Which response is the most primitive, responds to general classes of molecules?

Innate (natural)

14

Characteristics of adaptive repsonse:

Antigens
Memory Cells
Cell T
Humoral- Antibodies
Can recognize proteins, bacteria, tumor cells, virus-infected cells

15

Memory Cells

increase the speed and vigor of subsequent response

Ex: vaccinations work by inducing memory cell production

16

What is the adaptive immune response dependent on?

lymphocytic recognition of antigens

17

Which is the faster immune response?

innate

18

What is autoimmune disease a result of:

adaptive immune responses to self-antigens.

19

Two mechanisms of auto immune response

1) Cell T 2) Humoral

20

antibodies belong to which family?

antibodies = immuninoglobulin (Ig) family & combine with a specific antigen

21

Two types of antibodies

Free- circulate in plasma, leave vessels to tissues or present in the secretion of some epithelia

Not free- integral membrane proteinson the surface of lymphocytes

22

What is the role of T cells?

primarily in charge of eliminating the antigen. Directly kill infected cells or activate macrophages

23

What runs the humoral response?

antibodies

24

What do B lymphocytes differentiate into?

plasma cells

25

What do plasma cells secrete?

antibodies

26

Immunocompetent cell

cell involved in the immune response that is fully mature and functional. Performs its role by recognizing and responding to antigens

27

What are functions of the APC?

1) Determines the fate of T cells
2) Promotes cellular or humoral immunity
3) Enhance or suppress response to antigen

28

Name the development and maturation sites for B lymphocytes

1)develop from CFU-L stem cells (lymphoid colony forming unit - common lymphoid progenitor) in the bone marrow
2) DNA rearrangement and somatic mutation to generate alleles for antibody diversity
3)non responding cell or unfunctioning antigens are eliminated
4) leave the bone marrow &circulate via lymph and blood
5)develop peripheral tolerance – additional receptor editing or cell elimination to reduce autoreactivity
6)maturation and travel to secondary lymphoid tissues, e.g., lymph node

29

Name the development and maturation sites for T lymphocytes

1)develop from CFU-L progenitor cells in the thymus
2) DNA rearrangements & somatic mutations (antigen diversity)
3) circulate among secondary lymphatic tissues
4) proliferate and differentiate into one of several effector or memory cell types in response to its specific antigen in a complex with an antigen-presenting cell.

30

What are functions of plasma cells?

Secrete antibodies:
1) Block the activity of an antigen
2) Mark the antigen for phagocytosis
3) Activate the complement system which directly kills some bacteria and activates cells of the innate immune system