Lymphoid Tissues (Exam II) Flashcards
(192 cards)
1
Q
Lymphoid tissue organized into discrete structures or organs
A
Dense lymphoid tissue
2
Q
Lymph nodes, spleen, thymus and tonsils are all examples of:
A
Dense lymphoid tissue
3
Q
Lymphoid tissue located throughout the body, associated with mucous membranes
A
Diffuse lymphoid tissue
4
Q
Both dense and diffuse tissue contain a large number of ____ cells
A
Lymphocytes
5
Q
Diffuse lymphoid tissue is commonly seen in respiratory and digestive tracts as:
A
MALT
6
Q
Lymphoid tissue where B and T-cells acquire surface receptors
A
Primary lymphoid tissue
7
Q
In primary lymphoid tissue, the B cells are located in the _____ while the T cells are located in the _____
A
B cells —-> bone marrow
T cells —-> Thymus
8
Q
Mature B and T cells that secondarily migrate to all other lymphoid tissue are referred to as
A
Secondary lymphoid tissue
9
Q
Malignant tumors of the immune system are referred to as ______ when they involve solid organs and as _____ when they involve the blood
A
Lymphomas; leukemias
10
Q
Circulating immune cells that are neoplastic
A
Leukemia
11
Q
Network of blind-ended vessels in connective tissue
A
Lymphatic vessels
12
Q
Lymphatic vessels provide a route in which allows cells and large molecules in the ECS to:
A
Re-enter the bloodstream
13
Q
Lymphatic vessels assist circulation of ______ concentrate _____ for elimination within lymph nodes
A
Lymphocytes
Antigen
14
Q
Encapsulated aggregates of lymphocytes and lymphoid tissue, distributed throughout the body
A
Lymph nodes
15
Q
Lymph nodes are arranged in ____ or ____ along the vessels of lymphatic origin
A
Chains or clusters
16
Q
Submandibular, cervical, axillary, femoral, popliteal, and hilar are all locations in which we find
A
Lymph nodes
17
Q
Four functions of lymph nodes:
A
1- nonspecific filtering of particulate matter & microorganisms from lymph
2- interaction of circulating lymphocytes with antigen in lymph
3- aggregation, activation & proliferation of B cells with subsequent antibodies production
4- aggregation & proliferation of T cells and induction of cytotoxic immunity
18
Q
Due to the presence of macrophages, lymph nodes are:
A
Self-cleaning
19
Q
Lymphocytes of all types- derived from the bone marrow
A
Lymphoid cells
20
Q
Lymphoid cells enter the lymph node via:
A
Bloodstream
21
Q
Antigen-presenting cells found within the lymph node
A
Immune accessory cells
22
Q
Immune accessory cells include
A
Macrophages
B cells
T cells
23
Q
Immune accessory cells (macrophages, B cells, T cells) originate in the:
A
Bone marrow
24
Q
Immune accessory cell- macrophages at the periphery of germinal centers; antigen-presenting cells
A
Follicular dendritic cells
25
Immune accessory cells primarily found in germinal centers that possess numerous phagocytic vesicles
Tingible body macrophages
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Fibroblasts and reticular cells (fibroblast-like cells with phagocytic capability)
Stromal cells
27
What forms the connective tissue skeleton of lymph nodes
Stromal cells and extracellular products (collagen, reticular fibers)
28
The lymph node contains and outer, fibrous ____ of dense irregular connective tissue
Capsule
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Grossly, lymph nodes have dense, outer, cellular ______ & less cellular inner _____
Cortex
Medulla
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Type of cells found in the outter cellular cortex of lymph nodes
B cells, T cells, plasma cells
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The medulla of the lymph node is less ______ than the cortex
Cellular
32
Extension of cortical tissue into the medulla of the lymph node
Medullary cords
33
The medullary cords of the lymph node are separated by broad lymphatic channels called:
Medullary sinuses
34
Interspersed throughout the cortex of the lymph node are very thin, collagenous:
Trabeculae
35
Blood vessels enter and leave the lymph node at the:
Hilus
36
Process of B & T cells leaving the blood stream and entering the lymph node
Diapedesis
37
Diapedesis is facilitated by complementary:
Adhesion molecules
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Complementary adhesion molecule that facilitate diapedesis of B & T cells are called:
Addressins
39
Addressins are present on both:
Endothelial cells & lymphocytes
40
During diapedesis, the B & T cells migrate across the walls of specialized:
Post-capillary venules
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Post-capillary venules are considered:
High endothelial venules
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Post-capillary venules are lined by:
Cuboidal to columnar endothelium
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Post-capillary venules are located in the deep inner cortex of the lymph node at the _____ junction or _____ zone
Corticomedullary
Paracortical
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Space beneath the capsule where numerous afferent lymph vessels drain into
Cortical/subcapsular sinus
45
Lymphatic vessels that drain into the cortical or subcapsular sinus are _______ vessels
Afferent lymph
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In the lymph node, endothelium on sinus on the side adjacent to the capsule is _____ to prevent leakage, but ______ on the side of the parenchyma
Continuous; discontinuous
47
Lymphatic sinuses are not open spaces like blood sinuses but rather are filled with:
Reticular fibers & macrophage processes
48
Sinuses of the lymph nodes are that are located in the cortex:
Cortical sinuses, trabecular sinuses, peritrabecular sinuses
49
Broader lymphatic channels in the inner, less cellular medulla
Medullary sinuses
50
The medullary sinuses contain what type of cells
Lymphocytes, plasma cells, monocytes
51
The medullary sinuses converge on the:
Hilus
52
Lymph drains from the hilus of the node via:
Single efferent lymph vessel
53
Eventually lymph returns to the bloodstream via:
Thoracic duct or right lymphatic duct
54
Lymphatic drainage to regional lymph node is important in:
Metastasis of tumor cells
55
With the cortex of the lymph node, are densely packed, highly cellular:
Lymphoid follicles
56
Lymphoid follicles can also be called:
Lymphatic nodules or primary follicles
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Lymphoid follicles contain a paler, less dense ____
Germinal center
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If a germinal center is presetn in a lymphoid follicle, the follicle is considered:
Secondary follicle
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A secondary follicle (germinal center presents) indicates the node is:
Responding to antigen
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Lymphocytes respond to antigen by increasing antibody production via:
Clonal expansion
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Secondary follicles are sites of:
B cell proliferation
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Secondary follicles (sites of B cell proliferation) can be referred to as:
Secondary hemopoiesis
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Cells present at sites of B cell proliferation (secondary hemopoiesis) (4):
Lymphoblasts
Macrophages
Immature B cells
Immature T cells
64
Proliferation of lymphocytes within the lymph node results in:
Lymph node enlargement
Swollen lymph node
65
Dark staining rim around the germinal center of the lymph node
Mantle zone
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The mantle zone of the germinal center of the lymph node is the region of:
Antigen presentation
67
Organization of lymphocytes in the cortex of the lymph node is:
NOT uniform
68
The secondary follicle of lymph node is light staining due to:
Lots of cytoplasm
69
Lobular lymphatic organ located in the mediastinum
Thymus
70
The thymus is embryologically derived from:
Epithelial outgrowth of 3rd pharyngeal pouch
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Important hematopoietic organ during fetal development
Thymus
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The thymus is similar in appearance to the lymph node but lacks ______ and the medulla lacks _____
Lymphoid follicles
Medullary cords & sinuses
73
The thymus has a _______ of dense, irregular connective tissue
Thin capsule
74
The thymus contains slender ______ or ______ that divide the thymus into lobules
Interlobular septa or trabeculae
75
The thymus has a darker staining _____ and a paler _____
Cortex
Medulla
76
Functions of the thymus (4):
1- production of mature, immunocompetent Th (helper) & Tc (cytotoxic) cells
2- clonal proliferation of Tc (cytotoxic) cells
3- clonal deletion of self antibodies
4- secretion of hormones regulating T cell development & maturation
77
The clonal deletion of self antibodies of the thymus aid in the development of:
Immunologic self-tolerance
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In the thymus, failure of clonal deletion of self antibodies may result in:
Autoimmune diseases
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As T cells of the thymus mature they express (3):
1- antigen-specific T cell receptors
2- CD surface markers (cluster of differentiation)
3- Class I & II HLA surface markers (human leukocyte antigen)
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The thymus contains a highly cellular cortex packed with:
Lymphocytes- mostly T cells and macrophages
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What is absent in the thymus
Secondary follicles
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The lack of secondary follicles in the thymus causes limitation resulting in only:
Local expansion of T cells
83
Place where T cells migrate to become immunocompetant
Thymus
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The less cellular central medulla of the thymus contains mostly:
B cells, plasma cells and macrophages
85
Epithelial cells within the thymus that provide structural & physiological support
Nurse cells
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Cells in the thymus that secrete hormones that collectively regulate T cell proliferation and differentiation
Nurse cells
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Three hormones nurse cells secrete
1- thyotaxin
2- thymosin
3- thymopoietin
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Attract, regulate and promote T cell proliferation and differentiation into cytotoxic T cells (Tc), suppressor T cells (Ts) and helper T cells (Th)
Thymotaxin, thymosin & thymopoietin
89
Eosinophilic, lamellated structures within both medulla & cortex of the thymus that represent degenerate & epithelial nurse cells
Hassals corpuscles
90
Type of cells Hassals corpuscles represent
Degenerate nurse cells
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Organ that degenerates at puberty & is vestigial in adults
Thymus
92
The thymus undergoes: (in adults)
Fatty infiltration & lymphatic depletion
93
The thymus undergoing fatty infiltration & lymphatic depletion is called:
Thymic involution
94
The thymus contains an inner surface of capsule lined by _____ to isolate the thymus
Continuous epithelium
95
Because the T cells are not fully differentiated, there’s no _____ lymph vessels to the thymus, only _____ vessels for lymph drainage
Afferent; efferent
96
Thymic blood vessels are also surrounded by a connective tissue sheath called:
Blood-thymus barrier
97
The blood thymus barrier forms:
Continuous antigenic barrier
98
Isolates the thymus from immune cells
Thymus barrier
99
The connective tissue sheath (blood-thymus barrier) consists of a wide variety of cells & fibers including:
Epithelial reticular cells
Reticular fibers
Fibroblasts
Macrophages plasma cells
100
The blood-thymus barrier surrounds the:
Endothelium & basement membrane of blood vessels
101
Structure important in maintaining the integrity of the thymus
Blood-thymus barrier
102
Largest lymphoid organ in the body
Spleen
103
B & T cell replication
Manufacture of antibody
Antigen removal
Removal of particulate matter, aged or defective RBCs fron circulation via phagocytosis
Recycling of Fe from Hb
Hemopoiesis in the fetus
These are all functions of the:
Spleen
104
Non-specific filtering of particular matter in microorganisms from lymph
Interaction of circulating lymphocytes with antigen and lymph
Aggregation, activation & proliferation of B cells with subsequent antibody production
Aggregation & proliferation of T cells & induction of cytotoxic immunity
These are all functions of:
Lymph nodes
105
Production of mature, immunocompetent cytotoxic and helper T cells
Clonal proliferation of cytotoxic T cells
Clonal deletion of self antibodies
Secretion of hormones regulating T cell development & maturation
These are all functions of:
Thymus
106
If the spleen is removed the functions are taken over by the:
Liver and bone marrow
107
Describe the capsule of the spleen:
Dense, fibroblastic outter capsule
108
The dense, fibro-elastic outer capsule of the spleen contains ______ cells important in:
Smooth muscle cells
Splenic contraction
109
In some species the spleen acts as a:
Reservoir for RBCs
110
Characteristic large, thick bands of dense connective tissue that extend into the body of the spleen
Trabeculae
111
Trabeculae of the spleen contain:
Trabecular arteries and veins
112
Unlike the lymph nodes and thymus, the spleen lacks:
Cortex & medulla
113
Bulk of the spleen is composed of spongy matrix of:
Red pulp
114
Within the red pulp of the spleen (2):
Pulp cords
Sinusoids
115
The sinusoids within the red pulp of the spleen contain:
Mostly blood
116
Pulp cords (cords of Bilroth) within the red pulp of the spleen are more cellular & contain large numbers of:
Macrophages & lymphocytes
117
Pulp cords within the red pulp of the spleen are supported by connective tissue skeleton of:
Reticular cells & reticular fibers
118
Scattered throughout the red pulp are discreet nodules of ___ which contain large numbers of _____
White pulp
WBCs
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Areas of white pulp are considered ____ areas that may or may not have _____
Follicular; germinal centers
120
The germinal centers in the follicular areas of white pulp contain primarily:
B cells
121
Located within the follicular areas (white pulp) of the spleen is a:
Central artery
122
The areas of white pulp of the spleen are surrounded by a thin, basophilic ______ which is further surrounded by a paler ______
Mantle zone; marginal zone
123
The white pulp of the spleen functions as a site of:
Antigen presentation & phagocytosis
124
The white pulp of the spleen contains large numbers of:
Macrophages, plasma cells, & T helper cells
125
Enlarged germinal centers of the spleen visible to the naked eye
Splenic nodules
126
Central arteries of the spleen are surrounded by ____ cells and form:
T cells
PALS
127
PALS
Periarteriolar lymphatic sheaths
128
PALS lack _____ because they have minimal ___
Germinal center; T cell proliferation
129
PALS are less well-developed in:
Humans
130
Term often used interchangeably with primary follicles in white pulp
PALS
131
PALS should ALWAYS be referring to _____ foci
T Cell
132
Branches of splenic artery enter the spleen within trabeculae via the _____ and branch and form ______ to white pulp
Trabecular arteries; central arteries
133
The central arteries of the spleen branch continue into the red pulp, where they branch into perpendicular:
Penicillar arteries
134
The penicillar arteries of the red pulp (of the spleen) branch into ____ and then terminate into 2-3 ____
Arterioles; sheathed capillaries
135
Blind-end capillaries that lack endothelial lining and are surrounded by macrophages
Sheathed capillaries
136
The sheathed capillaries form a non-continuous:
Peri-vascular sheath, or cuff
137
The perivascular sheath act as part of the _______ active in phagocytosis
Filtering mechanism
138
Blood cells leave sheathed capillaries via ______
Diapedesis
139
Blood cells leave the sheathed capillaries via diapedesis and enter the ______ of _____
Sinus of red pulp
140
The sinusoids of the spleen are lined by endothelial cells called:
Stave cells
141
______ between stave cells allow for free passage of blood cells
Endothelial slits
142
Blood drains out of the spleen via:
Trabecular venules
143
After the blood drains out of the spleen via trabecular venules, it empties into:
Splenic vein
144
Type of circulation found in the spleen
Open
145
Paired structures located at the junction of the oral & pharyngeal cavities
Palatine tonsil
146
The palatine tonsil is located within the:
Tonsillar crypts
147
The tonsillar crypts that house the palatine tonsils are located between anterior & posterior:
Tonsillar pillars
148
Anterior tonsillar pillar
Palatoglossal arch
149
Posterior tonsillar pillar
Palatopharyngeal arch
150
Tonsils located at base of tongue
Lingual tonsils
151
Pharyngeal tonsils are also referred to as:
Adenoids
152
Pharyngeal tonsils/adenoids are located in the _____ and associated with _____
Nasopharynx; eustacian tubes
153
Palatal + lingual + pharyngeal tonsils are collectively referred to as:
Waldeyer’s ring
154
Ring of immunological protection around the GI & respiratory tracts
Waldeyer’s ring
155
Palatal + pharyngeal tonsils are collectively referred to as:
NALT
156
NALT
Nasal associated lymphoid tissue
157
The palatine tonsil is similar to lymph nodes but it is:
Unencapsulated
158
Base of palatine tonsils is supported by:
Collagenous hemicapsule
159
Palatine tonsil contains no distinct:
Cortex & medulla
160
In the palatine tonsil, lymphoid follicles are scattered throughout the ____ and may include ____
Parenchyma
Germinal centers
161
Luminal surface of palatine & lingual tonsils is covered by:
Stratified squamous nonkeratinized epithelium (SSNKE)
162
The stratified squamous nonkeratinized epithelium invades the tonsils, forming blind-ended:
Tonsilar crypts
163
Organ containing cortex with primary and secondary follicles & medulla with medullary cords & sinusoids
Lymph node
164
Organ containing mostly T cells, not B cells, Hassals corpuscles; cortex & medulla present
Thymus
165
Organ containing robust capsule & trabeculae; no cortex & medulla, red & white pulp instead
Spleen
166
Organ containing hemicapsule & skin-like epithelium with crypts; no cortex & medulla
Palatine tonsil
167
Blind-ended sac, vestigial cecum
Appendix
168
In adults, the appendix:
Atrophies
169
The appendix contains mostly ____ cells
B Cells
170
An important digestive organ in herbivores- used for bacterial fermentation
Appendix
171
Most organized structure of diffuse lymphoid tissue
Appendix
172
MALT in the gut
MALT in respiratory tract
MALT in pharynx
GALT
BALT
NALT
173
Diffuse unencapsulated lymphoid aggregates associated with mucosal surfaces
MALT
174
MALT is located in the ____ tissue of the _____
Subepithelial connective tissue; lamina propria
175
Type of cells present primarily in MALT
B cells
176
Malt primarily produces:
IgA (secretory IgA)
177
Similar to the lymph nodes, MALT may contain:
Germinal centers
178
Samples antigenic material, produces lymphoblasts, secretes antibody
MALT
179
MALT in the gut contains specialized:
M-cells
180
M-cells of MALT in the gut are:
Squamous enterocytes
181
M-cells (squamoid enterocytes) are located in surface epithelium with _____ on surface
Microfolds (NOT microvilli)
182
MALT is responsible for antigen sampling & transfer from _____ into _____
Gut lumen
Lymphoid follicles
183
MALT is formed during:
Fetal development
184
MALT distribution is maximum in ______ and progressively atrophies with _____
Childhood; age
185
Special type of MALT scattered throughout the small intestine
Peyer’s patches
186
Peyers patches are most common in the _____ and least common in the _____
Ileum
Duodenum
187
Peyers patches project into the lumen of the gut in _______ with cuboidal mucosa
Dome areas
188
Peyers patches also contain _____ cells
M cells
189
Peyers patches are histologically similar to:
MALT
190
Peyers patches are lymphoid aggregates that contain large numbers of:
B & T cells
191
Peyers patches ________ produce appreciable quantities of IgA
Do not
192
Frequent in Peyer’s patches and are associated with the foci of B cells
Germinal centers
