Lymphoid Tissue (Exam II) Flashcards
(194 cards)
1
Q
Lymphoid tissue organized into discrete structures or organs
A
Dense lymphoid tissue
2
Q
Lymph nodes, spleen, thymus, & tonsils are all examples of:
A
Dense lymphoid tissue
3
Q
Lymphoid tissue located throughout the body, associated with mucus membranes
A
Diffuse lymphoid tissue
4
Q
Dense and diffuse tissue both contain a large number of ______ cells
A
Lymphocytes
5
Q
Diffuse 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 migraine to all other lymphoid tissue are refferred to as:
A
Secondary lymphoid tissue
9
Q
Malignant tumors of the immune system are refferred to as ____ when they involve solid organs and as _____ when they involve the blood
A
Lymphomas; leukemia
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 which allows cells and large molecules in the ECS to:
A
Re-enter bloodstream
13
Q
Lymphatic vessels assist circulation of _____, and concentrate _____ for elimination within lymph nodes
A
Lymphocytes; concentrate antigen
14
Q
Encapsulated aggregates of lymphocytes & lymphoid tissue, distributed throughout the body
A
Lymph nodes
15
Q
Lymph nodes are arranged in _____ or ____ along vessels of lymphatic origin
A
Chains or clusters
16
Q
Areas where we find lymphnodes:
A
Submandibular, cervical , axillary, femoral, popliteal, and hilar
17
Q
What are the 4 functions of lymph nodes:
A
- Non specific filtering of particulate matter and microorganisms form lymph
- Interaction of circulating lymphocytes with antigen in lymph
- Aggregation, activation, and proliferation of B cells with subsequent antibody production
- Aggregation & proliferation of T cells and induction of cytotoxic immunity
18
Q
Due to the presence of macrophages, lymphnodes 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 cell found within the lymph node:
A
Immune accessory cell
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
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Immune accessory cell- primarily found in germinal center that possess numerous phagocytic vesicles
Tingible body macrophage
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Fibroblasts and reticular cells (fibroblasts like cells with phagocytic capability)
Stromal cells
27
What forms the connective tissue skeleton of lymph nodes?
Stromal cells and extracellular products
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The lymph node contains an outer, fibrous _____ of dense irregular connective tissue
Capsule
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Grossly, lymphnodes have dense, outer, cellular ______ and a less cellular inner _____
Cortex; medulla
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What type of cells are found in the outer cellular cortex of lymph nodes?
B-cells, T-cells, & plasma cells
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The medulla of lymph node is less cellular than the _____.
Cortex
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Extensions of cortical tissue into the medulla of the lymph node
Medullary cords
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The medullary cords of the lymph node are separated by broad lymphatic channels called:
Medullary sinuses
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Interspersed throughout the cortex of the lymph node are very thin, collagenous:
Trabeculae
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Blood vessels enter and leave the lymph node at the:
Hilus
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Process of B- cells and T-cells leaving the blood stream and entering the lymph node
Diapedesis
37
Diapedesis is facilitated by complimentary:
Adhesion molecules
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The complementary adhesion molecules that facilitate diapedesis of b and t-cells:
Addressins
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Adressins are present on both:
Endothelial cells and lymphocytes
40
During diapedesis, the b and T cells migrates 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 junction or paracortical zone
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Space beneath the capsule where numerous afferent lymph vessels drain into:
Cortisol/subcapsular sinus
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The lymphatic vessels that drain into the cortical or subcapsular sinus are _____ lymph vessels
Afferent
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In the lymph node: The endothelium of sinus on the side adjacent to the capsule is ______ to prevent leakage, but _____ on the side adjacent to the parenchyma.
Continuous; discontinuous
47
The lymphatic sinuses are not open spaces like blood sinuses, but rather are filled with:
Reticular fibers and macrophage processes
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The sinuses of the lymph nodes that are located in the cortex:
Cortical sinuses, trabecular sinuses, peritrabecular sinuses
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broad lymphatic channels in the inner, less cellular medulla:
Medullary sinuses
50
The medullary sinuses contain what type of cells?
Lymphocytes, plasma cells, monocytes
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The medullary sinuses converge on the:
Hilus
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Lymph drains from the hilus of the node via:
Single efferent lymph vessel
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Eventually, lymph returns to the bloodstream via the:
Thoracic duct or right lymphatic ducts
54
Lymphatic drainage to regional lymph node is important in:
Metastasis of tumor cells
55
Within the cortex of the lymph node are densely packed, highly cellular:
Lymphoid follicles
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Lymphoid follicles can also be called:
Lymphatic nodules or primary follicles
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Lymphoid follicles may contain a paler, less dense ______.
Germinal center
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If a germinal center is present in a lymphoid follicle, the follicle is considered:
Secondary follicle
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A secondary follicle (germinal center present) 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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What cells are present at sites of B-cell proliferation (secondary hemopoiesis): (4)
Lymphoblasts, macrophages, immature b & T cells
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Proliferation of lymphocytes (within the lymph node) results in:
Englarment and swollen lymph node
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The dark staining rim around the germinal center of the lymph node is called the:
Mantle zone
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The mantle zone of the germinal center of the lymph node is the region of:
Antigen presentation
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The organization of lymphocytes in the cortex of the lymphnode is NOT:
Uniform
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The secondary follicle of lymph node is light staining due to:
Lots of cytoplasm
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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 and sinuses
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The thymus has a ______ of dense, irregular connective tissue:
Thin capsule
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The thymus contains slender _____ or _____ that divide the thymus into lobules
Interlobular septa or trabeculae
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The thymus has a darker staining ____ and a paler _____.
Cortex ; medulla
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The functions of the thymus: (4)
1. Production of mature immunocompetent Th (helper T cell) and Tc cells (cytotoxic T cells)
2. Clonal proliferation of cytotoxic T cells
3. Clonal deletion of self antibodies
4. Secretion of hormones regulating T cell development and maturation
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The clonal deletion of self antibodies of the thymus aids 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 mature they express: (3)
1. Antigen specific t-cell receptors
2. CD surface markers (cluster of differentiation)
3. Class 1 and 2 HLA (human leukocyte Ag) surface markers
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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 limitations resulting in only:
Local expansion of T-cells
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Place where t-cells migrate to become immune competent:
The thymic cortex
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In the thymus, the less cellular control medulla contains mostly:
B-cells, plasma cells & macrophages
85
Epithelial cells within the thymus that provide structural and physiological support:
Nurse cells
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_____ cells in the thymus secrete hormones that collectively regulate T cell proliferation & differentiation
Nurse cells
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What 3 hormones do nurse cells secrete?
1. Thymotaxin
2. Thymosin
3. Thymopoeitin
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Attract, regulate & promote t-cell proliferation and differentiation into cytotoxic T cells, helper T cells & suppressor T cells
Thymotaxin, thymosin, thymopoeitin
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Eosinophilic lamellated structures within both the cortex and medullary of thymus that represent degenerate reticular and epithelial nurse cells
Hassal’s corpuscles
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What type of cells to hassal’s corpuscles represent?
Degenerate nurse cells
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What organ degenerates at puberty and is vestigial in adults?
Thymus
92
The thymus undergoes: (in adults)
Fatty infiltration & lymphatic depletion
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The thymus undergoing fatty infiltration and lymphatic depletion is called:
Thymic inovlution
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The thymus contains contains an inner surface of capsule lined by ______ to isolate the thymus
Continuous epithelium
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because T-cells are not fully differentiated, there are 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:
Continuous antigenic barrier
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What isolates the thymus from immune cells:
Thymus barrier
99
The connective tissue sheath ) the blood-thymus barrier) consists of a wide variety of cells & fibers including:
Epithelioreticular cells
Reticular fibers
fibroblasts
Macrophages
Plasma cells
100
The blood thymus barrier surrounds the:
Endothelium and basement membrane of blood vessels
101
What is important in maintaining the integrity of the thymus?
The blood-thymus barrier
102
What is the largest lymphoid organ in the body?
Spleen
103
1. B & T cell replication, manufacture of antibody and antigen removal
2. Removal of particulate matter, aged or defective RBCs from circulation via phagocytosis
3. Recycling of Fe from Hb
4. Hemopoiesis in the fetus
Spleen function
104
1. Non-specific filtering of particulate matter & microorganisms from lymph
2. Interaction with circulating lymphocytes with antigen in lymph
3. Aggregation , activation, and proliferation of B cells with subsequent antibody production
4. Aggregation and proliferation of T cells & induction of cytotoxic immunity
Lymph node function
105
1. Production of mature immunocompetent helper, and cytotoxic T cells
2. Clonal proliferation of cytotoxic T cells
3. Clonal deletion of self antibodies
4. Secretion of hormones regulating T cell development and maturation
Thymus functions
106
If the spleen is removed, function is taken over by the:
Liver and bone marrow
107
Describe the capsule of the spleen:
Dense- fibro-elastic outer 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 red blood cells
110
Characteristic large thick bands of dense connective tissue that extend into the body of the spleen:
Trabeculae
111
The trabeculae of the spleen contain:
Trabecular arteries and veins
112
Unlike lymphnodes & thymus, the spleen lacks:
Cortex & medulla
113
The bulk of the spleen is composed of spongy matrix of:
Red pulp
114
Within the red pulp of the spleen are: (2)
Pulp cords and sinusoids
115
The sinusoids within the red pulp of the spleen contain:
Mostly blood
116
The pulp cords (cords of Bilroth) within the red pulp of the spleen are more cellular and contain:
Large #’s of macrophages & lymphocytes
117
The 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 #’s of _______.
White pulp; WBCs
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Areas of white pulp are considered ______ areas that may or may not have ______.
Follicular areas that may or may not have germinal centers
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The germinal centers of the follicular areas of white pulp contain primarily:
B-cells
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Located within the white pulp of the spleen is a:
Central artery
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The areas of white pulp are surrounded by a thin basophilic ____ which is further surrounded by a paler ____.
Mantle zone; marginal zone
123
The white pulp functions as a site of:
Antigen presentation & phagocytosis
124
The white pulp of the spleen contains large numbers of:
Macrophages, plasma cells & helper T cells
125
Enlarged germinal centers of the spleen visible to the naked eye
Splenic nodules
126
Central arteries of the spleen are surrounded by _____ and form ______.
T-cells; PALS
127
PALS:
Periarteriolar lymphatic sheaths
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PALS lack _____ because they have minimal ____.
Germinal centers; T-cell proliferation
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PALS are less well-developed in:
Humans
130
What term is used interchangeable with primary follicles in white pulp?
PALS
131
PALS should always be referring to ______ foci
T-cell
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Branches of splenic arteries 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 continue into the red pulp, where they branch into perpendicular:
Penicillar arteries
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The penicillar arteries of the red pulp branch into _____ and then terminate into 2-3 ______.
Arterioles ; sheathed capillaries
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Blind end capillaries that lack endothelial lining and are surrounded by macrophages.
Sheathed capillaries
136
The sheathed capillaries form a non-continuous:
Perivascular sheath or cuff
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The perivascular sheath act as part of the _____, active in phagocytosis
Filtering mechanism
138
Blood cells leave the sheathed capillaries via _____.
Diapedesis
139
Blood cells leave the sheathed capillaries via diapedesis and enter the ______ of ______.
Sinuses of red 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 through trabecular venules, it empties into:
Splenic vein
144
What type of circulation is found within the spleen?
Open circulation
145
Paired structures located at the junction of oral and pharyngeal cavities:
Palatine tonsil
146
The palatine tonsil is located within:
Tonsillar crypts
147
The tonsillar crypts that house the palatine tonsil are located between anterior and posterior _____.
Tonsillar pillars
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Anterior tonsillar pillar:
Palatoglossal arch
149
Posterior tonsillar pillar:
Palatopharyngeal arch
150
Tonsils located at the base of tongue:
Lingual tonsils
151
Pharyngeal tonsils are also called:
Adenoids
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Location of the pharyngeal tonsils/adenoids? What are they associated with?
Nasopharynx ; eustachian tubves
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Palatal, lingual, and pharyngeal tonsils are collectively referred to as:
Waldeyer’s ring
154
The ring of immunological protection around the GI and respiratory tracts:
Waldeyer’s ring
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Palatal and pharyngeal tonsils are collectively referred to as:
NALT
156
NALT
Nasal associated lymphoid tissue
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The palatine tonsil is similar to lymph nodes but it is:
Unencapsulated
158
The base of the palatine tonsil is supported by:
Collagenous hemicapsule
159
The palatine tonsil contains no distinct:
Cortex or medulla
160
In the palatine tonsil, lymphoid follicles are scattered through the _______, and may include ______.
Parenchyma; germinal centers
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Luminal surface of palatine and lingual tonsils is covered by:
Stratified squamous non-keratinized epithelium (SSNKE)
162
The stratified squamous non-keratinized epithelium invades the tonsils forming blind-ended:
Tonsilar crypts
163
Organ containing cortex with primary and secondary follicles & medulla with medullary cords and sinusoids
Lymph node
164
Organ containing mostly T-cells, not b-cells; hassal’s corpuscles; cortex and medullar present
Thymus
165
Organ containing robust capsule and trabeculae; no cortex & medulla, red and white pulp instead:
Spleen
166
Organ containing hemicapsule and skin-like epithelium with crypts, not cortex & medulla
Palatine tonsile
167
Blind ended sack, vestigial cecum
Appendix
168
The appendix ____ in adults
Atrophies
169
The appendix contains mostly _____ cells.
B-cells
170
_____ is 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:
GALT
173
MALT in respiratory tract:
BALT
174
MALT in pharynx:
NALT
175
Diffuse unencapsulated lymphoid aggregates associated with mucosal surfaces:
MALT
176
MALT is located in the ______ tissue of the _____.
Subepithelial connective tissue ; lamina propria
177
What type of cells are primarily present in MALT?
B-cells
178
MALT primarily produces:
IgA (secretory IgA)
179
Similar to lymph nodes, MALT may contain
Germinal centers
180
Samples antigenic material, produces lymphoblasts, and secretes antibody:
MALT
181
Malt in the gut contains specialized:
M-cells
182
M-cells of MALT in the gut are:
Squamoid enterocytes
183
M-cells (squamoid enterocytes) are located in surface epithelium with _____ on surface
Micro folds (NOT MICROVILLI)
184
MALT is responsible for antigen sampling and transfer from ______ into ______.
Gut lumen into lymphoid follicles
185
MALT is formed during:
fetal development
186
MALT distribution is maximum in _______ and progressively atrophies with ______.
Childhoood; age
187
Special type of MALT scattered throughout the small intestine:
Peyer’s Patches
188
Peyer’s Patches are most common in the ______ and least common in the _______.
Ileum ; duodenum
189
Peyer’s Patches project into the lumen of gut in _______ with cuboidal mucosa
Dome areas
190
Peyer’s patches also contain ______ cells.
M-cells
191
Peyer’s patches are histologically similar to:
MALT
192
Peyers’s patches are lymphoid aggregates that contain large numbers of:
B & T cells
193
Peyer’s patches ____ produce appreciable quantities of IgA
DO NOT
194
_____ are frequent in Peyer’s patches and are associated with foci of B-cells
Germinal centers
