thymus spleen

Question 1

types of specific resistance ?

Answer 1

cell-mediated immunity

antibody-mediated immunity

Question 2

organs of the lymphatic system?

4 organs and 3 diffuse lymphatic tissue

Answer 2

red bone marrow
thymus
spleen
lymph nodes
diffuse lymphatic tissue: tonsils, adenoids, Peyers patches

Question 3

features of lymphoid tissue

Answer 3

found free in regular ct or surrounded by capsules
stain dark because there is little cytoplasm
rich in reticular fibers that are made by fibroblast

Question 4

2 types of lymphoid tissue

Answer 4

diffuse and follicular

Question 5

encapsulared vs unecapsulated lymphatic organs

Answer 5

encap,.: spleen , lymph node and thymus

unencap: tonsils, peyer’s patch and lymphoid nodules

Question 6

function of the lymphatic system

Answer 6

Draining excess interstitial fluid & plasma proteins from tissue spaces
Transporting dietary lipids & vitamins from GI tract to the blood
Facilitating immune responses

Question 7

Secondary lymphatic organs & tissues?

Answer 7

Secondary lymphatic organs & tissues
site where most immune responses occur
lymph nodes, spleen & lymphatic nodules

Question 8

Each T lymphocyte produces ?

Answer 8

Each T lymphocyte produces numerous identical membrane-bound receptors that bind one specific antigen

Question 9

Each B lymphocyte produces ?

Answer 9

Each B lymphocyte produces numerous identical antibodies that bind one specific antigen.

Question 10

cortex vs medulla of the thymus

Answer 10

cortex: dark with many lymphocytes
medulla: lighter. few lymphocytes and many epithelial reticular cells

Question 11

5 cells of the thymus

Answer 11

Pre-T cells (bone marrow origin) 
		T lymphocytes (T cells)
		Epithelial reticular cells
		Thymic nurse cells
		Dendritic cells

Question 12

. The Autoimmune Regulator (AIRE) in thymus ??

Answer 12

. The Autoimmune Regulator (AIRE) transcription factor is activated in these cells and permits them to synthesize 3000 proteins that are normally only found in other organs.. which make the tissue speciffic “self” proteins

Question 13

stroma of thymus ?

Answer 13

epithelial cells form support structure for developing T cells
play important role in isolating T cells from foreign antigens during their development.

Question 14

one way T cells die (apoposis)

Answer 14

when the Tcell bndes to the tissue specific “self” proteins

Question 15

thymic nirse cells

Answer 15

Specialized subtype of reticular epithelial cells
Engulf as many as 20 lymphocytes and carry them within their cytoplasm
Stimulate apoptosis in a fraction of these lymphocytes and release the others

Question 16

thymic dendritic cells

Answer 16

Originate in bone marrow

Stimulate development of regulatory T cells that suppress reactions to self-proteins

Question 17

Fate of Thymic Lymphocytes

Answer 17

95% of T cells formed in the thymus are destroyed to prevent reactions against “self” proteins

Surviving lymphocytes travel to medulla and are released as various types of programmed but non-activated T cells

Question 18

Hassall’s corpuscles ?

Answer 18

Epithelial reticular cells of Hassall’s corpuscles secrete Thymic Stromal Lymphopoietin (TSL)

Question 19

Thymic Stromal Lymphopoietin (TSL) ?

Answer 19

TSL stimulates dendritic cells to hasten the maturation of regulatory T cells that suppress auto-immune reactions against “self” proteins

Question 20

How Do Cytotoxic T-Cells Kill Cells?

Answer 20

Secrete protein subunits called perforins, which can form holes in cell membranes
Secrete destructive enzymes called granzymes
Produce pro-apoptotic protein, FAS ligand

Question 21

white pulp vs red pulp oof the spleen ?

Answer 21

white : has central artery and is urrounded by red

red: has cords of billroth thatconsist od WBC macrophages, RBC, and B and T lymphocytes . has splenic sinus (filter blood )

Question 22

periarteriolar lymphoid sheath (PALS)

Answer 22

enclose central arterioles of the white pulp