Brainscape's Knowledge GenomeTM

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


See full index

Immunity > Lymphoid System Histology I > Flashcards

Lymphoid System Histology I Flashcards

1
Q

Consists of tissues-organs with cells involved in host defense and lymph transport

A

Lymphoid System

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

What are the two primary lymphoid organs?

A

Bone marrow and Thymus

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

B-lymphocytes become immunocompetent in

A

Bone marrow

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

Migrate to the thymus for maturation

A

T-lymphocytes

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

Immunocompetent lymphocytes migrate from primary to secondary lymphoid organs to participate in host

A

Host defense

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

Diffuse or nodular lymphoid tissue for host defense in mucosa

A

MALT

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

Key parenchymal cells include lymphocytes and

A

APCs

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

Other leukocytes, such as granulocytes are also important in host defense. What are two examples?

A
  1. ) Neutrophils (anti-bacterial)

2. ) Eosinophils (anti-parasitic)

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

Supports immune cells of lymphoid tissues-organs

A

Connective tissue stroma

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

May be supported within mucosal loose connective (lamina propria underlying epithelium) and may be diffuse or organized in nodules/ follicles

A

Lymphoid cells

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

Covered by an eosinophilic dense connective tissue capsule with extensions of trabeculae that subdivide parenchyma

A

Encapsulated lymphoid organs (including thymus, lymph node, spleen)

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

Within some encapsulated organs, lymphoid cells are supported by

A

Reticular connective tissue

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

Made up of an intricate framework of fine, branching, silver-staining reticular fibers (type III collagen) secreted by fibroblast-type reticular cells

A

Reticular connective tissue

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

The predominant fiber in regions with loose and dense connective tissues and may be continuous with reticular fibers made of type III collagen in regions with reticular CT

A

Type I collagen

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

Lymphatic and cardiovascular systems are interconnected with lymphocytes entering-exiting tissues after traveling in

A

Lymph and blood

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

In mucous and cutaneous membranes, antigens that penetrate epithelium and enter the underlying loose CT, encounter lymphoid cells that can initiate

A

Immune responses

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

Carry lymph into lymph nodes for filtration

A

Afferent lymph vessels

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

Carry filtered lymph (fortified with additional immune cells to antigen) out to various regions

A

Efferent lymph vessels

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

Not present in cornea, cartilage, nervous tissue, thymus, bone marrow

A

Lymphatics

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

At the 7th month of fetal life, the primary site of hematopoiesis throughout life is the

A

Bone marrow

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

Bone marrow histological sections demonstrate architecture with hematopoietic cords of developing

A

Blood cells

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

Hematopoietic stem cells (HPSCs) generate

A

Blood cells

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

Form and mature (gene rearrangement and selection) within bone marrow

A

B-lymphocytes

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

A general term for lymphoid system cells found in the loose connective tissues of mucosa lining the gastrointestinal, respiratory, urogenital systems

A

Mucosa-Associated Lymphoid Tissue (MALT)

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

The epithelium covering lymphoid nodules in GALT contains

-appears to serve as APCs that present intraluminal antigen to GALT cells

A

M cells

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

May be organized diffusely or in nodules/follicles to guard the body as initial sites of host defense with immune response to antigens penetrating the mucosa

A

MALT cells

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

Mainly consist of B-lymphocytes with T-lymphocytes in nearby, surrounding areas

A

Lymphoid Nodules

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

After initial contact in MALT, immune cells and antigen travel to regional lymph nodes for a more elaborate immune response leading to proliferation and differentiation with progeny that return to infiltrate the mucosa as

A

Effector B- and T-lymphocytes

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

While MALT may have isolated, transient/temporary follicles that disappear after threat has been neutralized, permanent aggregations of follicles/nodules can be seen in the

A

Tonsils, ileum, and appendix

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

Appear as dark, uniform masses of mostly small B-lymphocytes (naive and memory) that are entering and leaving the follicle

A

Primary lymphoid nodules

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

Arise from primary nodules with B-lymphocytes activated by appropriate antigen or by APC-activated Th cells to form an outer mantle zone/corona (containing inactive B-lymphocytes) and a large, pale germinal center

A

Secondary Lymphoid Nodules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Contain activated B-lymphocytes that proliferate (mitotic figures visible) and form lymphoblasts with large, pale staining cytoplasm

A

Germinal Centers

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

Select lymphoblasts that have high affinity to the antigen and the remaining aberrant lymphoblasts undergo apoptosis and phagocytosis by macrophages

A

Follicular Dendritic Cells (FDCs)

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

Surviving lymphoblasts differentiate into memory cells and antibody-secreting

A

Plasma cells

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

A collection of lymphoid tissue in the pharynx that encounters antigens entering through the oral and nasal cavities

A

Waldeyer’s tonsillar ring

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

There are tonsils in the

A

Naropharynx (adenoids) and oropharynx

37
Q

Exhibit a stratified squamous epithelium that lines the surface and deep mucosal folds known as crypts

A

Palatine tonsils

38
Q

The epithelium that lines the deep crypts is thin and often obscured by penetrating lymphocytes emptying into the

A

Oral cavity

39
Q

Lymph nodes filter lymph taken up from tissues in order to activate lymphocytes in response to

A

Antigen

40
Q

The stroma of the lymph node includes the dense connective tissue capsule and its extensions of

A

Trabeculae

41
Q

Parenchymal cells of the lymph node are supported along an intricate and extensive framework of fine, branching

A

Reticular fibers

42
Q

The parenchyma of the lymph node includes an outer connective tissue capsule surrounding cells forming an outer darker cortex with nodules/follicles containing many

A

B-cells

43
Q

The parenchyma also has a paracortex containing many

A

T-cells

44
Q

The parenchyma also contains an inner, lighter medulla with

A

Plasma cells, lymphocytes, and macrophages

45
Q

Reticular CT in sinuses allows lymph to percolate slowly as macrophages within sinuses survey lymph for

A

Antigens

46
Q

Immune responses rely on close interaction of B-lymphocytes in nodules and T-lymphocytes in

A

Internodular and paracortical regions

47
Q

Activated in immune responses and are transient (in constant flux), as they enter-exit through porous endothelium along sinuses and move within and outside the lymph node

A

Lymphocytes

48
Q

Like MALT, antigen/APCs activate lymphocytes (Th and B) to form secondary follicles with

A

Germinal centers

49
Q

Activated lymphocytes and plasma cells migrate from the cortex to form cords of cells in the

A

Medulla

50
Q

From their positions in cords, plasma cells secrete antibodies into lymph passing through medullary sinuses and some activated lymphocytes pass into sinuses and leave the lymph node to remote sites to respond to

A

Antigen

51
Q

Vasculature enters and exits at the hilum, located at the concave surface of the

A

Lymph node

52
Q

Just distal to capillary beds, postcapillary high endothelial venules (HEVs) in the paracortex (and medulla) are lined by a specialized simple cuboidal epithelium that allows

A

Lymphocyte extraversion

53
Q

From the paracortex, cytokines recruit lymphocytes for distribution to regions in the

A

Cortex and paracortex

54
Q

Thus, lymphocytes can reach the lymph node via blood through

A

HEVs

55
Q

Thus, lymphocytes can reach the lymph node via lymph through

A

Afferent Lymph vessels

56
Q

Lymph node sinuses allow for lymph to slowly percolate and interact with

A

Immune cells

57
Q

Filtration through lymph nodes occurs as the lymph flows through

A

Sinuses

58
Q

Contain reticular fibers for support and to slow flow so that APCs can interact with lymph

A

Sinuses

59
Q

Pierce the capsule at the lymph node’s convex surface to bring lymph and immune cells into sinuses

A

Afferent lymph vessels

60
Q

Often difficult to identify and can be seen as containing valves, leukocytes (lymphocytes, macrophages, no RBCs), and sometimes metastatic cancer cells

A

Afferent Lymph Vessels

61
Q

Lymph flows from afferent lymph vessels to

A

Subcapsular/marginal sinuses

62
Q

Then from the subcapsular/marginal sinuses to the

A

(Para)trabecular sinuses

63
Q

Then from the (para)trabecular sinuses (along trabeculae) to the irregular medullary sinuses (weaving among medullary cords) to the

A

Efferent lymph vessels at concave hilum

64
Q

The lymph leaving the lymph node in efferent lymph vessels contains

A

Lymphocytes and antibodies

65
Q

Inflammation of lymph nodes-lymph vessels from severe bacterial infections, sometimes seen as red streaks under skin in areas with lymph drainage from infected area

A

Lymphadenitis-lymphangitis

66
Q

In contrast to lymph filtration by lymph nodes, the spleen filters blood in adult humans to remove

A

Senescent RBCs

67
Q

The spleen also mounts immune reactions to

A

Blood-born antigens

68
Q

In the adult, the spleen may contribute to extramedullary hematopoiesis when marrow function is

A

Insufficient

69
Q

Consists of a capsule, trabeculae, and reticular fibers

A

Stroma of the spleen

70
Q

Deep to the visceral peritoneum (mesothelium), the dense collagenous connective tissue capsule of spleen also contains

A

Elastic and smooth muscle fibers

71
Q

Extend from the capsule and carry branches/tributaries of splenic vessels entering/exiting at the hilum

A

Trabeculae

72
Q

Made up of two types of pulp that are based on the red and white coloring of fresh, gross tissue

A

Spleen parenchyma

73
Q

Macrophages in red pulp remove aged/damaged

A

RBCs

74
Q

Mounts immune responses to blood-borne antigens and is similar to lymph nodes, which mount immune responses to lymph-borne antigens

A

White Pulp

75
Q

Borders between the white and red pulps and contains many macrophages and lymphocytes

A

Marginal Zone

76
Q

Branches of trabecular arteries enter the white pulp as central arteries/arterioles whose tunica adventitia are infiltrated by

-Forms pariarterial lymphoid sheath (PALS)

A

T-lymphocytes

77
Q

Branches of the central artery/arteriole in white pulp shed PALS and travel through the marginal zone as penicillar arteries and capillaries surrounded by

A

Macrophages

78
Q

In the spleen’s closed circulation, capillaries empty directly into

A

Red pulp sinuses

79
Q

Allows for blood to percolate among macrophages and lymphocytes in the cords and marginal zone, resulting in more effective exposure of RBCs and antigens leading to removal of old RBCs and immune responses

A

Humans open circulation in spleen

80
Q

Formed by a central artery/arteriole invested in a periarterial lymphoid sheath (PALS), an arterial cuff of mostly T-lymphocytes, and occasional, adjacent primary or secondary lymphoid nodules/ follicles mainly made up of B-lymphocytes that push the central arteriole to appear eccentric

A

White pulp

81
Q

The marginal zone borders the white pulp and red pulp and contains many macrophages and lymphocytes for

A

Antigen presentation

82
Q

Made up of splenic cords (of Billroth) and splenic sinuses/sinusoids

A

Red pulp

83
Q

Contain macrophages, erythrocytes, and other cells that are supported by reticular CT

A

Splenic cords

84
Q

From the splenic cords, macrophage processes and antibodies secreted by plasma cells encounter blood-borne pathogens by passing through the

A

Interendothelial slits

85
Q

Epithelial reticular cells (ERCs) in the thymus are unlike the reticular fiber-secreting reticular cells in the

A

Lymph node and spleen

86
Q

Rather than an extensive mesh of reticular fibers, thymocytes are intimately supported by a network of large, pale, stellar-shaped, euchromatic

A

ERCs

87
Q

The processes of these ERCs are linked by

A

Desmosomes

88
Q

Involved in thymocyte selection-deletion, contribution to blood-thymus barrier, secretion of hormones and cytokines, and degeneration into thymic corpuscles

A

Epithelial reticular cells (ERCs)

Immunity (33 decks)

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