Lymphoid Organs Flashcards
1
Q
Scattered throughout red pulp of spleen are discreet nodules of ______, which contain large #’s of wbc’s•
A
white pulp
2
Q
Central Aa continue into red pulp, branch into perpendicular _______—branch into arterioles, terminate in 2-3 _______
A
penicillar Aa; sheathed capillaries
3
Q
If spleen is removed (splenectomy), function taken over by ______ and _______
A
liver & bone marrow
4
Q
Hemopoiesis in fetus is a function of
A
spleen
5
Q
Sinusoids lined by endothelial cells called
A
stave cells
6
Q
Lymphatic sinuses are filled with ______
A
reticular fibers & Mφ processes
7
Q
As T cells mature they express what 3 things?
A
Ag specific t-cell receptors; CD (cluster of differentiation) surface markers; Class I & II HLA (human leukocyte Ag) surface markers
8
Q
Secretion of hormones regulating t-cell development & maturation is a function of
A
Function of thymus
9
Q
Characteristic large, thick bands of dense connective tissue ______ extend into body of spleen, contain trabecular Aa & Vv
A
trabeculae
10
Q
Thymic blood vessels also surrounded by connective tissue sheath called _________—forms continuous antigenic barrier; isolates thymus from immune system
A
blood-thymus barrier
11
Q
The outer fibrous capsule of lymph nodes are made of ______ tissue
A
dense, irregular CT
12
Q
Recycles Fe from Hb is a function of
A
spleen
13
Q
MALT produces ______
A
primary IgA (secretory IgA)
14
Q
Thymus has a highly cellular ____ packed with lymphocytes, mostly t cells and macrophages
A
cortex
15
Q
Aggregation & proliferation of t-cells & induction of cytotoxic immunity
A
Function of lymph node
16
Q
epithelial cells within thymus, provide nurse function & structural support; Secrete various hormones (thymotaxin, thymosin, & thymopoietin)—attract, regulate & promote t-cell proliferation & differentiation into Tc, Ts & Th cells
A
Nurse cells
17
Q
GALT is mucosa associated lymphoid tissue in
A
gut
18
Q
fatty infiltration & lymphatic depletion that happens in the thymus
A
thymic involution
19
Q
Highly vascular; largest lymphoid organ in body
A
spleen
20
Q
Palatal & pharyngeal tonsils collectively referred to as
A
NALT(nasal associated lymphoid tissue)
21
Q
post-capillary venules (= high endothelial venules) are lined by ________ endothelium
A
cuboidal to columnar endothelium
22
Q
BALT is Mucosa associated lymphoid tissue in
A
respiratory tract
23
Q
Central Aa surrounded by t-cells rather than b-cells form ___________ ; Lack germinal centers, because minimal t-cell proliferation•Less well developed in humans than other species & require immunohistochemical staining to make positive ID•Term often used interchangeably with 1’ follicles in white pulp
A
periarteriolar lymphatic sheaths (PALS)
24
Q
Lymphoid organ characterized by hemicapsule & skin-like epithelium with crypts; no cortex & medulla
A
Palatine tonsil
25
Special type of MALT scattered throughout small intestine; most common in ileum, least common in duodenum•Project into lumen of gut in
Peyer's patches
26
Interspersed throughout cortex & medulla of lymph node are very thin, collagenous _______
trabeculae
27
Within cortex or lymph nodes are densely packed, highly cellular
lymphoid follicles
28
outer cellular Layer of lymph node that contains b cells, t cells, and plasma cells
cortex
29
lack endothelial lining; surrounded by Mφ; Forms a non-continuous perivascular sheath, or cuff—Acts as part of filtering mechanism, active in phagocytosis
Blind ending capillaries
30
Network of blind-ended vessels in connective tissue; Provide a route which allows cells & large molecules in ECS to re-enter bloodstream; Assist circulation of lymphocytes, concentrate Ag for elimination within lymph nodes
Lymph vessels
31
If a follicle in the cortex contains a pale region called a germinal center, it is referred to as a _______; indicates the follicle is responding to an antigen
secondary follicle
32
lymphocytes of all types, derived from bone marrow; enter node via bloodstream
lymphoid cell
33
Endothelium of sinus is continuous on side adjacent to ________
capsule
34
Aggregation, activation, & proliferation of b-cells with subsequent Ab production
Function of lymph node
35
The thymus is embryologically derived from epithelial outgrowth of __________
3rd pharyngeal pouch
36
Luminal surface of palatine & lingual tonsils covered by characteristic ___________ epithelium —invades tonsil, forming blind-ended tonsilar crypts
stratified squamous nonkeratinized epithelium
37
•Clonal proliferation of Tc cells is a function of
Function of thymus
38
fibroblast-like cells with phagocytic capability
reticular cells
39
Clonal deletion of self-Ab’s is a function of______ ; Development of immunologic self-toleranceFailure of clonal deletion may => autoimmune diseases
Function of thymus
40
After leaving the lymph node through a single efferent vessel, lymph returns to bloodstream via ______ or ________
thoracic ductor R lymphatic duct
41
Blind-ended sac, vestigial cecum; Atrophies in adults; contains mostly b-cells; Important digestive organ in herbivores; used for bacterial fermentation
Appendix
42
T/F: Palatine tonsils have a distinct cortex and medulla
False; does not
43
Lymphoid organ characterized by mostly t-cells, not b-cells; Hassal’s corpuscles; cortex & medulla present
Thymus
44
What types of cells does the cortex of the thymus have?
lymphocytes, mostly t cells and macrophages
45
T/F: In white pulp of spleen, the follicular areas may or may not have germinal centers containing primary b cell
True
46
Both diffuse and dense lymphoid tissue contain large number of what type of cells?
Lymphocytes
47
If appendix is inflamed, it is called _______; treatment with _______
appendicitis; surgical removable
48
Peyer's patches are most common in _____ and least common in ______
ileum; duodenum
49
________ divide thymus into lobules
Interlobular septa or trabeculae
50
Functions as site of Ag presentation, phagocytosis; contains large #’s of Mφ, plasma cells, & t-helper cells
White pulp of spleen
51
T/F: Endothelial slits between stave cells allow free passage of blood cells
True
52
MALT is located within subepithelial connective tissue of _______
lamina propria
53
Thymus looks similar to lymph nodes but lack what?
Lymphoid follicles, medullary cords and sinuses
54
in Medullary sinuses, Lymph drains from hilus of node via
single, efferent lymph vessel
55
Base of tonsil supported by cup-shaped, collagenous
hemicapsule
56
Within red pulp are what 2 things?
pulp cords and sinusoids
57
Non-specific filtering of particulate matter & microorganisms from lymph
Function of lymph node
58
Is spleen an open or closed circulation model?
Open
59
The thymus has a thin capsule made of ________ tissue
dense irregular CT
60
Is palatine tonsil encapsulated or unencapsulated?
Unencapsulated
61
Interaction of circulating lymphocytes with Ag in lymph
Function of lymph node
62
Palatal, lingual, & pharyngeal tonsils collectively referred to as _______—forms a ring of immunologic protection ~ GI & respiratory tracts
Waldeyer’s ring
63
Which type of lymphoid tissue is common in respiratory and digestive tracts as MALT?
Diffuse
64
NALT is Mucosa associated lymphoid tissue in
pharynx
65
________ tonsils (= adenoids) in nasopharynx, associated with Eustacian tubes
pharyngeal
66
(immune accessory cell) Mφ at periphery of germinal centers; Ag-presenting cells
follicular dendritic cells
67
Production of mature, immunocompetent Th & Tc cells is a function of
Function of thymus
68
b and t cells Migrate across walls of specialized _________ lined by cuboidal to columnar endothelium; located in deep, inner cortex of node at corticomedullary junction, or paracortical zone
post-capillary venules (= high endothelial venules)
69
Lymph vessels assist circulation of _______ and concentrate ______ for elimination within lymph nodes
Lymphocytes; antigens
70
What types of cells does the medulla of the thymus have?
mostly b-cells, plasma cells & Mφ
71
encapsulated aggregates of lymphocytes & lymphoid tissue, distributed throughout body; Arranged in chains or clusters along vessels of lymphatic origin
Lymph nodes
72
b- & t-cell replication, manufacture of Ab, Ag removal is a function of
spleen
73
Tissue trabeculae contain _______ and ______
trabecular Aa & Vv
74
endothelium & basement membrane of blood vessels;
blood-thymus barrier
75
(splenic circulation) Branches of splenic A enter white pulp within trabeculae via ______, branch & form ______ to white pulp
trabecular Aa; central Aa
76
Lymphoid aggregates contain large #’s of _______ and _____ cells
b and t
77
Proliferation of lymphocytes leads to what changes in lymph nodes?
swollen glands and lymph node enlargement
78
Component of red pulp of that contains mostly blood
Sinusoids
79
Lymphocytes respond to Ag by ↑ Ab production via _______
clonal expansion
80
T/F: Spleen lacks cortex and medulla
True
81
What sinuses are in the outer cortex of lymph node?
cortical, trabecular, and peritrabecular sinuses
82
diapedesis is facilitated by complementary ____ that are present on both endothelial cells & lymphocytes
adhesion molecules (= addressins)
83
Diffuse, unencapsulated lymphoid aggregates associated with mucosal surfaces; Located in subepithelial connective tissue of lamina propria•Contains mainly b-cells
MALT (Mucosa associated lymphoid tissue)
84
______ Responsible for Ag sampling & transfer from gut lumen into lymphoid follicles
M cells
85
Blood cells leave sheathed capillaries via _____, enter sinuses in __________ pulp
diapedesis; red pulp
86
______ lymphoid tissue is organized into discreet structures or organs
Dense
87
Degenerates at puberty, vestigial in adults; Undergoes fatty infiltration & lymphatic depletion
Thymus
88
Lymphoid follicles scattered throughout parenchyma—may include germinal centers in what lymphoid organ?
Palatine tonsils
89
T/F: Inner surface of capsule has continuous epithelium to isolate thymus
True
90
malignant tumors of immune system that involve blood
leukemia
91
Paired structures located at junction of oral & pharyngeal cavities, within tonsillar crypts, between anterior & posterior tonsilar pillars
Palatine tonsil
92
Sites of b-cell proliferation, (2’ hemopoiesis), contain what types of cells?
lymphoblasts, Mφ, & immature b- & t-cells
93
_______ tonsils present at base of tongue
Lingual
94
Blood thymus barrier consists of what cells and fibers
epithelioreticular cells, reticular fibers, fibroblasts, Mφ, plasma cells
95
are eosinophilic, lamellated structures within both medulla & cortex, represent degenerate reticular & epithelial nurse cells
Thymic or Hassal’s corpuscles
96
Blood drains out of spleen via ______ which empties into _______
trabecular Vv; splenic V
97
MALT in gut contains specialized ________ cells; squamoid enterocytes— located in surface epithelium with microfoldson surface (not microvilli)
M cells
98
Project into lumen of gut in dome areas with cuboidal mucosa; also contain M-cells; Histologically similar to MALT; Germinal centers frequent; associated with foci of b-cells
Peyer's patches
99
less cellular inner layer of lymph node
medulla
100
T/F: Lymphatic drainage to regional lnn important in metastasis of tumor cells
True
101
Lymphoid organ characterized by cortex with 1’ & 2’ follicles & medulla with medullary cords & sinusoids
Lymph node
102
Bulk of spleen composed of spongy matrix of ______
red pulp
103
Lobular, lymphatic organ located in mediastinum; Embryologically derived from epithelial outgrowth of 3rd pharyngeal pouch; important hematopoietic organ during fetal development
Thymus
104
Blood vessels enter & leave lnn at _______
hilus
105
Appendix contains mostly _____ cells
B cells
106
Removes particulate matter & aged or defective rbc’s from circulation via phagocytosis is a function of
spleen
107
Cells of lymph nodes that are made of fibroblasts and reticular cells
stromal cells
108
MALT formed during ____________
fetal development
109
T/F: MALT may contain germinal centers similar to lymph. nodes
True
110
Areas of white pulp of spleen with central A in middle and surrounded by thin, basophilic mantle zone surrounded by paler marginal zone
follicular areas
111
MALT contains mostly _____ cells
B cells
112
Component of red pulp that are more cellular, contain large #’s of Mφ, lymphocytes
Pulp cords
113
Because t-cells not fully differentiated, no _____ lymph vessels to thymus, only _____, for lymph drainage
afferent; efferent
114
Post capillary venules are located in deep inner cortex of the lymph node at ___________
paracortical zone or corticomedullary junction
115
lymphoid tissue where b- & t-cells acquire surface receptors(bone marrow with b-cells & thymus with t-cells)
Primary lymphoid tissue
116
Darker staining rim surrounding germinal center called _______; it is the region of Ag presentation in a follicle
mantle zone
117
_______ cells and ______ and ______ fibers form connective tissue skeleton of lymph nodes
stromal cells; collagen and reticular fibers
118
What type of lymphoid tissue makes up lymph nodes, spleen, thymus, and tonsil?
Dense
119
The ____ of the spleen is important in splenic contraction in some species, acts as a reservoir for rbc’s
fibro-elastic outer capsule
120
Endothelium of sinus is discontinuous on side adjacent to _______
parenchyma
121
b- & t-cells leave bloodstream & enter node via
diapedesis
122
space beneath capsule where numerous afferent lymph vessels drain into
subcapsular sinus
123
Lymphoid organ characterized by robust capsule & trabeculae; no cortex & medulla, red & white pulp instead
Spleen
124
Extensions of cortical tissue that extend into medulla are called
medullary cords
125
Mature b- & t-cells migrate to all other lymphoid tissue, referred to as
Secondary lymphoid tissue
126
Medullary sinuses contain what cells?
lymphocytes, plasma cells, Mφ
127
immune accessory cell primarily found in germinal centers; possess numerous phagocytic vesicles that stain prominently
Tingible body Mφ
128
broad, lymphatic channels in inner, less cellular medulla; contain lymphocytes, plasma cells, Mφ; converge on hilus
Medullary sinuses
129
T/F: Peyer’s patches produce appreciable quantities of IgA
False: do not
130
Spleen contains a dense fibro-elastic outer capsule contains _____ cells
smooth muscle
131
enlarged germinal centers visible to naked eye
Splenic nodules
132
Medullary cords are separated by vorad lymphatic channels called
medullary sinuses
133
______ lymphoid tissue is located throughout body, associated with mucous membranes
Diffuse
134
______ distribution is at its maximum in childhood, progressively atrophies with age
MALT
135
In what lymphoid organ are secondary follicles absent; limited local clonal expansion of t-cells
Thymus
136
_______ Samples antigenic material, produces lymphoblasts, secretes Ab
MALT
137
malignant tumors of immune system that involve solid organs
lymphomas
138
Pulp cords of red pulp of spleen supported by connective tissue skeleton of what cells and fibers?
reticular cells & reticular fibers
139
Ag presenting cells including Mφ, b- & t-cells; originate in bone marrow
immune accessory cell
140
Component of red pulp of spleen supported by connective tissue skeleton of reticular cells & reticular fibers
Pulp cords
141
T/F: Lymphatic sinuses are open spaces like blood sinuses
False
142
What are the three hormones nurse cells secrete?
thymotaxin, thymosin, & thymopoietin
