Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

OD2-Immunology > The Lymphoid System > Flashcards

The Lymphoid System Flashcards

1
Q

what are the primary lymphoid organs

A

bone marrow and thymus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what are the primary lymphoid organs the major site of

A

lymphopoiesis

-here, lymphocytes differentiate from lymphod stem cells, proliferate, and mature into funtional cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

where do T cells undergo most of their development

where do B cells

A

T=thymuc

B=bone marrow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

where do lymphocytes acquire their repertoire of specific antigen receptors in order to cope w/ antigenic challenges

A

primary lymphoid organs

-bone marrow and thymus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

do developing t and b cells respond to foreign antigens in the primary lympoid organs

A

no

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what is hematopoiesis

A

the process by which all red and white blood cells are produced

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

where does hematopoiesis occur in adults

A

the bone marrow of the sternum, vertebrae, iliac bones, and ribs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

hematopoiesis occurs in the yolk sac of the fetus and is then taken over by the _____, followed by the ____

A

spleen and liver

bone marrow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what is red marrow

A

marrow in which hematopoiesis occurs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what are stromal cells (reticular cells)

A

supoprting meshwork of fibroblasts and they secrete reticular fibers which red and white cells develop
aka hematopoietc cords

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

red and white cells exit the bone marrow to enter the circulation via…

A

a dense netowrk of vascular sinuses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what are all bone marrow cells dervied from

A

a common self-renewing stem cell whicih develops into a pluripotent stem cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what do pluripotent stem cells differneitate into

A

either a myeloid of lymphoid precursor cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what do the myeloid progenitors develop into

A

gives rise to all blood cells except B, T, and NK cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what do the lymphoid progenitors develop into

A

B, T, and natrual killer cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what are colony stimulated factors

A

factors that promote growth of lineage of WBCs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what act on stem cells to stimulate blood cell formation?

what are they produced by?

A

cytokines such as colony stimulated factors
and a host of cytokines referred to as interleukins
-produced by stromal cells, monocytes, and helper lymphocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what is IL3 important in

A

hematopoiesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what is neupogen

A

granulocyte CSF
used with patients with low neutrophil cell numbers
can be used for aids and cancer patients

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what are reticulocytes

A

erythrocyte stage right before full maturity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

where is the thymus located

A

in the mediastinum in the center of the chest above the great vesssels of the heart and consists of 2 lobes which are further divded into locules by fibrous septae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

where does the majority of T cell maturation occur

A

outer cortex of the thymus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what does the cortex contain, what cells

A

densely-packed T cells
macrophages
APCs called dentritic cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what speciliazed cells form the structural framework of the thymus

A

reticular ep cells aka cortical thymic ep cells (cTEC)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

the cortical thymic ep cells DO NOT secrete reticular fibers, how can they support developing T cells?

A

only with their cell membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

what are hassall’s corpuscles and wehre are they located

A

tightly packed whorls of ep cells located in the medulla

significance is unknown

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

how do the hassall’s corpuscles change after pubert

A

decrsease in number but increase in size after puberty

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

how can the hassall’s corpuscles serve as a valuable radiological marker

A

calcify later in life, show where the thymus is

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

lymphocytes destined to develop into T cells begin their maturation int he bone marrow and leave while they are….

  • they then go to the….
  • what are they called
A

still very immature, then go go to the thymus cortex and complete their differentation
known as thymocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

what do the most undifferentiated T cells do when they enter the thymus

A

proliferate, mature, and begin migrating toward the medulla, where they eventually enter the ciruclation
-they DO NOT express T cell receptors, CD4 or CD8 molec

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

what is the purpose of cTEC (cortical thymic ep cells)

A
  1. to secrete thymic homromes such as thymopoeitin, thymosin, and interleukin 7 which are though tot promote T cell matruation
  2. to bind to, and positively select for T cells with the ability to recognize and bind to self MHC molecules
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

what are the thymic hormones

A

thymopoietin
thymosin
interleukin 7

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

what happens to T cells that are unable to bind to MHC molecules

A

elminated by apoptosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

what happens to the cellular DNA, nucleus and cytoplasm during apoptosis
what happens to the cell for macrophages to phagocytose these

A

cellular DNA is fragmented
nucleus and cytoplasm condense
dying cell often framents into membrane bound apoptic bodies that are rapidly phagocytosed and digested by macrophages

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

what is positive selection

A

if a T cell matures which cannot recognize self MHC, it will be ineffective in responding to an antigenic stimulus and will be apoptosed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

where does negative selection take place

A

cortico-medullary junction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

what are dendritic cells, why are they important

A

specilaized APCs derived from the bone marrow

play a role in binding to and eliminating cells that bind to self MHC with an inappropriately high affinity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

what is negative selection

A

binding affinity to MHC alone, nothing with what antigen is

-cells with an inappropriately high affinity that bind to self MHC are eliminated through apoptosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

why is negative selection necessary

A

the T cells that bind too strong to MHC can develop into autoreactive cells which are cells tat can recognize elf antigens as foreign and attack them

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

how much % of all T cells in the thymic cortex are elminiated by positive and negative selection

A

50%

41
Q

which structure in the thymus has the structural specilializations that prevent antigen entry

A

thymic cortex, NOT medulla

42
Q

what is the blood/thymus barrier

A

the thymic cortex with ep cells slapped on that prevents antigen entry

43
Q

why must antigens need to be kept out of the thymus and bone marrow while T cells are maturing

A

bc any antigen which does not enter may interfere w/ T cell development and the T cells will NOT be able to recognzie that antigen and ignore them to be left in the thymus

44
Q

what are the speciliaztoins which constitute the blood/thymus barrier

A
  1. tight junctions btwn endothelial cells and a thick endo cell basement membrane
  2. a thin layer of ep cells which completely encloses the thymic cortex and vascular basement membranes
45
Q

the absense of afferent lymphatic vessles does what to the antigens

A

contributes to the lack of antigens in the thymic cortex

46
Q

what happens to the thymus with again

A

undergoes partial involution (gets smaller)

but it continues to produce T cells throughout the life of the indiv

47
Q

what are the 2ndary lympoid organs

A

lymph nodes
spleen
mucosal and cutaneous immune systems

48
Q

which organs do the immune cells come into contact w/ antigens

A

2ndary lymphoid organs

49
Q

what form can lymphatic tissues be found as

A

dispersed cells

aggregates of cells situated beneath epithelia

50
Q

what are some examples of mucosal and cutaneous immune systems

what do these tissues contain

A 
tonsils in the oral cavity
peyer's patches in GI tract (GALT) 
immune cells in upper resp tract and bronchi (BALT) 
conjunctiva (CALT) 
skin (SALT)

contain T and B cells, macrophages and APCs

51
Q

what ist the langerhans cell

A

an important APC in the skin

52
Q

what is an example the body’s response to antigenic stimulation (lymphatic tissue developing anywhere in bod)

A

uveitis : infl disease where lymphocytes and other immune cells wreak havoc on uvea and retina

colitis: occurs in distal ileum

53
Q

whta happens to the antigen if it escapes elimination in the subepithelia areas

A

it will be taken up by draining lymphatic vessels which are supplied with antigenic filters (lymph nodes)

54
Q

what are lymph nodes
wehre are they located
what are they surrounded by

A

small nodular aggregares of lymphoid tissue
situated along lymphatic channels
surrounded by a fibrous capsule that is pierced by numerous afferent lymphatic vessels

55
Q

what do afferent lymphatic vessels do

what do efferent lymphatics exit at

A

bring lymph fluid and cells into the node which course through the node as nodular sinuses and eventually join efferent lymphatics which exit the node at the hilus

56
Q

why are subcapsular sinuses leaky

A

to allow both cells and fluid to freely exchange btwn the sinus lumen and the parenchyma of the node
-to create back pressure

57
Q

what is the primary cell type in diffuse lymphatic tissue

what about nodular

A

diffuse=T cell

nodular=B cell

58
Q

what do radial trabeulae together with reticular fibers do

A

support the various cellular compartments w/in the lymph node

59
Q

wehre is the B cell and T cell area in lymph nodes

what does the central medulla contain

A

B cell area is the outer cortex
T cell area is the inner or para cortex
central medulla contains the differentiation products of lymphocyte activation such as plasma cells

60
Q

where are APCs especially prevalent in in the cortex

A

present throughout but especially prevalent in the outer cortex
-the cells are referred to as interdigitating or dendritic cells

61
Q

where is the bulk of lymphoid tissue found

A

outer and inner cortices

62
Q

what are medullary cords

A

some lymphoid tissue that extend into the medulla where they are found along strands of connective tissue fibers

63
Q

what are medullary cords separated by

A

large sinuses and contain most of the plasma cells in the lymph node

64
Q

macrophages are present in lymph nodes and are especialy present in…

A

the medulla

65
Q

what cells are present in primary or secondary follicles

A

B cells in the outer cortex

66
Q

what are primary follicles

A

dense, round, or ovoid aggregations of resting B cells

unstimulated

67
Q

what cells do secondary nodules contain

A

activated B cells

68
Q

what is the germinal center

what cells does it contain

A

pale staining central region which contains activated, enlarged, proliferating B cells as well as B cells that are differentiaing into plasma cells

69
Q

what surrounds the germinal center

what does it contain, how does it stain

A

the mantle zone

smaller, resting B ceslls that looks and stains like primary nodules

70
Q

where are APCs primary located

A

diffuse tissue, but also in nodular

71
Q

which tissue type of B cells in

what about T cells

A

B=nodular/flolucullar tissue

T=diffuse tissue

72
Q

where will antigens that stimulate an antibody response enter? what will they bind to? what will they induce?

A
  • enter the primary follicles
  • bind to B cell cantigen receptors
  • induce secondary follicle formation and plasma cells production
73
Q

where will antigens that stimulate a T cell response be taken up by?
how will this activate a T cell response?

A

taken up by dendritic cells in the cortex, that will bring these antigens into the T cell region of the inner cortex and activate a T cell response

74
Q

what cells will seek out and destroy antigens in the tissue

A

activated T cells (helper) and cytotoxic T cells

75
Q

what do T helper cells do

A

provide help to B cells that reponse to T dependent antigens

76
Q

what do follicular dendritic cells do

A

trap antigens complexed to antibodies or complement and display them on their surfaces for recognition by B lymphocytes
-play an important role in the selection of activated B cells whose antigen receptors bind the displayed antigens w /high affinity

77
Q

what are the palpable lymph nodes

A

cervical
inguinal
auxillary lymph nodes

78
Q

what is the englargement of a lymph node referred to as

A

lymphadenopathy

79
Q

what is erythema

A

redness due to capillary congestion

80
Q

what can cause the pre-auricular node to swell (adenopathy)

A

endoviral infection

less common in bacterial infections

81
Q

what type of infection is chlamydial conjunctivitis

-almost always exhibits a palpable pre-auricular node

A

bacterial inclusion

82
Q

if an antigen fails to be filtered out by the lymph nodes, how is it filtered

A

enter the blood stream and is filtered by the spleen

83
Q

what is the spleen the major site for

A

phagocytosis of antibody-coated microbes

84
Q

without the spleen what would one be more susceptible to

A

infectious encapsulated bacteria

85
Q

what support the variety of cells in the spleen

A

connective tissue capsule that sends trabeculae into the parenchyma of the organ and the reticular fiber framework

86
Q

what are the 2 main types of tissue in the spleen

A

red pulp: sinusoids and rest of blood cells

white pulp: WBCs, T and B cells

87
Q

what is the functinon of the red pulp

what is the function of the white pulp

A

red: mainly involved in clearing the blood of old and dying blood cells and particulate matter
white: contains lymphatic tissue capable of responding to antigenic stimulation

88
Q

where is the bulk of lymphatic tissue located around

A

located around small arterioles so it is called periarteriolar lymphatic sheath (PALS)

89
Q

where are the Tcell and B cells areas of PALS

A

T cell areas being close to central arteriole

B cell areas being found more peripherally

90
Q

how are the B cell areas of PALS organized

A

as theyare in lymph nodes: w/ areas of primary and/or secondary follicles present, depending on state of antigen

91
Q

what is the marginal zone

A

the PALS are surround by a rim of lymphocytes and macrophages called the marginal zone where it is thought that antigens first enter the white pulp

92
Q

where do the arterioles ultimately end

A

directly or indirectly in vascular sinuses w/in the region of the red pulp where macrophages clear the blood of old and dying cells

93
Q

what do blood cells that are not cleared by macrophages do

A

re-enter splenic venules and exit the spleen by way of the splenic vein

94
Q

what encapsulated bactera does the spleen remove

A

act removal of encapsulated bacteria haemophilus influenza and streptococcal pneumonia

95
Q

how to lymphocytes circulate throughout the body, tissues, and lymph compartments

A

insinuating themselves btwn the endothelial cells of post capillary venules by a process called diapedesis

96
Q

what do post-capillary venules have on their cell wall isntaed of squamous endothelial cells for the migration of lymphocytes into lymph nodes, spleen and mucosal lymphoid tissue

A

lined by high-walled cuboidal endothelial cells referred to as high endothelial venules (HEV)

97
Q

how are lymphocytes guided to the HEVS

A

by their interaction w/ vascular addressins on the surface of the endo cells (act as homing beacons for the lymphocytes)

98
Q

how to lymphocytes bind to addressins

A

integrins which also play a role in tissue migration of cells during embryogeness, tumor metastasis, and wound healing

99
Q

do lymphocytes need high endo-walled vessels to enter nonlymphatic tissue?

A

no

OD2-Immunology (4 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions