Lecture 8: Lymphoid Flashcards
1
Q
List lymphoid tissues of the lymphatic system (6)
A
- Lymph node
- Spleen
- Thymus
- GALT
- BALT
- Bone marrow
2
Q
List immune cells (6)
A
- macrophages
- granulocytes
- NK cells
- T cells
- B cells
- dendritic cells
3
Q
Does the response time for innate immunity take days or hours?
A
hours
4
Q
Does the response time for adaptive immunity take days or hours?
A
days
5
Q
What is the specificity of innate immunity?
A
limited and fixed
6
Q
What is the specificity of adaptive immunity?
A
- highly diverse
- improves during course of immune response
7
Q
What is the response of innate immunity to repeat infection?
A
identical to the primary response
8
Q
What is the response of the adaptive immunity to repeat infection?
A
much more rapid than primary response = immune memory
9
Q
What are the two types of barriers of innate immunity?
A
- anatomical
- physiological
10
Q
What does innate immunity use to recognize PAMPS on antigens?
A
pattern recognition receptors (PRRs)
11
Q
Pattern recognition leads to _____ and _____.
A
- phagocytosis
- killing
12
Q
Adaptive immunity is different from innate immunity because it requires which type of cells?
A
lymphocytes
13
Q
What cells are involved in humoral immunity (3)?
A
- B cells
- antibodies
- serum mediators such as cytokines
14
Q
Which two cells does cellular immunity use?
A
- killer T lymphocytes (CD8+)
- phagocytes
15
Q
What do both humoral and cellular immunity require?
A
- T helper cells (CD4+ = MHC II)
- APC
16
Q
Is a Tc cell (cytotoxic T = CD8+ = MHC I) part of humoral immunity, cellular immunity, or both?
A
only cellular immunity
17
Q
What is the function of cellular immunity?
A
kills microbes (cytotoxicity)
18
Q
What is the function of humoral immunity?
A
generates plasma cells to produce antibodies
19
Q
What is an important feature of adaptive immunity? Why?
A
- memory
- future exposure elicits a faster/better response = have antibodies specific to antigen
20
Q
What are the results of inflammation and tissue damage during infection which leads to an influx of serum factors and cells?
A
- swelling, heat, pain, redness,
- allergy and asthma
- graft rejection and graft vs. host disease
- autoimmune disease
21
Q
Where are T cells located?
A
thymus
22
Q
Where are B cells located?
A
bone marrow & GALT
23
Q
List the secondary organs/tissues (5)
A
- diffuse lymphatic tissue (e.g. peyer’s patch, appendix, GALT)
- lymphoid nodules
- tonsils
- lymph nodes
- spleen
24
Q
Which organ is primary and secondary lymphoid organ?
A
GALT
25
**What are the 2 types of lymphoid nodules? What do they consist of?**
* **primary lymphoid nodule** = consist of small lymphocytes (inactive B cells) **with no germinal center**
* **secondary lymphoid nodule** = consist of large lymphocytes in the peripheral zone & large lymphocytes (active B cells) located in **germinal center**
26
**What are the characteristics of germinal cells (4)?**
1. located in the center of the nodule (follicle)
2. stains light due to large amount of cytoplasm and euchromatin
3. develop in response to antigens
4. site of active B cells (B cells proliferate = differentiate into plasma cells = produce antibodies)
27
**What is lymphadenitis? What causes it?**
* Enlargement/swelling of lymph nodes
* Caused by edema and hyperplasia of lymphatic nodules
28
**What are the symptoms of lymphadenitis? (4)**
1. swollen, palpable, and tender lymph nodes
2. fever
3. chills
4. general weakness
29
**What are the most common causes of lymphadenitis in the neck region (2)?**
tonsillitis and pharyngitis
30
Which organs/tissues (2) have a single nodule or aggregates with no capsule?
* Peyer's patch (ileum)
* Appendix
31
Which organ has nodules and a partial capsule?
tonsils
32
Which organs have nodules and a well-developed capsule (2)?
lymph node and spleen
33
**Recent evidence suggests that lymphatic tissue in the appendix is a site for what?**
B cells differentiation into immunocompetent cells
34
**What does the pharyngeal lymphoid tissue of the Waldeyer's ring comprise (4)?**
* Nasopharyngeal tonsil or adenoid
* The paired tubal tonsils
* The paired palatine tonsils
* The lingual tonsil
35
**What type of epithelium lines the adenoid (pharyngeal) tonsils?**
ciliated pseudostratified columnar epithelium
36
**Does the adenoid (pharyngeal) tonsil contain fewer or many primary and secondary lymphoid nodules (follicles)?**
fewer
37
**What type of epithelium lines the palatine tonsil?**
stratified squamous epithelium
38
**Does the palatine tonsil contain many or fewer primary and secondary nodules (follicles)?**
many
39
What is the function of **crypts** in the **palatine tonsil**?
increase tonsil surface area = allows antigens to hide
40
Lymph nodes are found in ______ throughout the body as ______ lymphoid structures
* **clusters**
* encapsulated
41
What is the function of the lymph nodes?
**filters and entraps antigens** from the lymph and supports the immune system
42
The lymph nodes are composed of (4)?
* **capsule**
* **cortex**
* **medulla**
* **sinuses** = interconnected channels (subcapsular, trabecular, medullary) where lymph travels and is filtered
43
**Lymph enters via ___ lymphatic vessel to ____ sinuses, percolates (filters) through tissue of lymph node and exits the ____ lymphatic vessel**
* **afferent**
* **subcapsular**
* **efferent**
44
What does the **outer cortex** of the lymph nodes contain?
**1° and 2° lymphoid nodules = B cell zones**
## Footnote
2°=germinal centers
45
What does the **inner cortex** (deep cortex, paracortex) of the lymph nodes contain?
**T cell zones**
46
Which structure of the brainstem contains a high number of plasma cells?
medulla
47
List the order of lymphatic flow (5)
1. Afferent vessel = lymphatic fluid (lymphocytes) arrive
2. Subcapsular sinus
3. Trabecular sinus
4. Medullary sinus
5. Efferent vessel = lymph fluid (lymphoytes) exit
48
Where are the majority of **T cells** located in the **lymph node**?
deep cortex
49
Where are **B cells** located in the **lymph node**?
germinal centers in superficial (outer) cortex
50
**What are high endothelial venules (HEV) and where are they found?**
* specialized postcapillary venules
* **lymph nodes**
* **tonsils**
* **aggregated or solitary lymph nodules (peyer's patches) (not in the spleen)**
51
**What is the function of HEV?**
support high levels of B and T lymphocyte migration from the blood
52
**What type of endothelium does HEV have and what is it able to do?**
* Cuboidal endothelium
* Has the ability to recruit large amounts of lymphocytes (possess receptors for antigen-primed cells)
53
**What type of fibers produce fibroblasts?**
reticular
54
**Which cells produce reticular fibers in lymphatic tissue?**
reticular cells
55
**How are reticular fibers arranged?**
arranged in a mesh-like network
56
Which type of collagen are reticular fibers?
Type III
57
**What type of endothelium lines lymphatic capillaries?**
simple sqaumous
58
**Do lymphatic capillaries have complete or incomplete basal lamina? Is this fenestrated or non-fenestrated?**
* Incomplete basal lamina
* Fenestrated
fenestrated capillaries = digestive organs and pancreas
59
**Where do lymphocytes enter major lymphatic vessels on the right side of the body?**
right lymphatic trunk
60
**Where do lymphocytes enter major lymphatic vessels on the left side of the body?**
thoracic duct
61
**What are the functions of the spleen (5)?**
1. filtration of blood
2. removal of aged or damaged RBCs, old platelets, and blood-born foreign matter
3. site of immune response
4. platelet storage
5. filters antigens out of the blood and promotes immune response = w/o spleen more susceptibility to blood-borne infections (e.g. post-splenectomy sepsis)
62
**What are the 6 structures of the spleen?**
1. capsule
2. trabeculae
3. reticular meshwork
4. red pulp
5. white pulp
6. lymphatic vessels
63
What does the reticular meshwork of the spleen contain?
reticular cells and reticular fibers
64
What does the red pulp of the spleen consist of?
splenic cords and splenic sinuses
65
What does the white pulp of the spleen contain?
* periarterial lymphatic sheath (PALS) (around central artery) = T cells
* lymphoid nodules = B cells
66
What does the lymphatic vessels of the spleen contain?
* efferent only
* present in white pulp, trabeculae, and capsule b/c lymphocytes enter through blood since spleen does not filter lymph
67
**What do discontinuous capillaries contain and where are they found?**
* gaps between endothelial cells
* discontinous basal lamina
* spleen and liver
68
**Explain open circulation in the spleen**
* Open circulation - blood empties from the sheathed capillaries into the splenic cords and then enters the sinuses through slits in the wall.
69
**Explain closed circulation in the spleen**
* Closed circulation - blood empties from the vessels of the white pulp into sheathed capillaries of the red pulp and then directly into the sinuses.
70
What is #1?
1° lymphoid nodule
| dark color, no germinal center
71
What is #2?
1° lymphoid nodule
| dark color, no germinal center
72
What is #3?
1° lymphoid nodule
| dark color, no germinal center
73
What is #4?
2° lymphoid nodule
| light color, has a germinal center
74
What is #1?
2° lymphoid nodule
| 2° is bigger than 1°, has germinal center
75
What is #2?
1° lymphoid nodule
| 1° is smaller than 2°, no germinal center
76
What structure is circled in red?
active 2° lymphoid nodule with germinal center
77
**What type of epithelium is the pink arrow pointing to?**
stratified squamous epithelium
78
**What structure is #1?**
lymphatic nodule
79
**What structures are #2?**
tonsilar crypts
80
**What structures are #3?**
lymphatic nodules
81
**What structure is circled in green?**
1° lymphoid nodule (inactive) = no germinal center
82
**What structure is #1?**
white pulp
83
What structure is #2?
red pulp
84
**What are the areas represented by RP?**
red pulp
85
**What structure is #3?**
white pulp
86
**What structure is #4?**
white pulp
87
**What structure is #5?**
white pulp
88
**What structure is #6 (pink arrow)?**
PALS
89
**What structure is circled in green?**
central artery
90
**What structure is #7?**
trabecular vein
91
**What structure is #8?**
capsule
92
**What structure is #9?**
PALS
93
**What structure is #10?**
trabecula
94
**What are the areas represented by WP?**
white pulp
95
What is #1?
white pulp
96
What is #2?
PALS
97
What is #3?
germinal center
98
What is #4?
marginal zone
99
What is #5?
central artery
100
What is #6?
red pulp
101
**What is #1 & #7 (same structure)?**
lymphatic nodule
102
**What is #2?**
red pulp
103
**What is #3?**
germinal center
104
**What is #4?**
marginal zone
105
Case: Hereditary Spherocytosis
A 25-year-old Japanese man was seen at the doctors office with mild anemia with reticulocytosis, increased serum unconjugated bilirubin and splenomegaly suggesting the presence of persistent hemolysis. The blood film showed a moderate anisocytosis (variability of size of erythrocytes), increased **spherocytes (small, globular erythrocytes)**. Additional tests were done and the results were consistent with a diagnosis of hereditary spherocytosis (HS). **The splenomegaly in this disease was associated with spleen’s involvement in active removal of abnormal red blood cells, spherocytes.**
**Question: Which of the following cells in the spleen were primarily involved in this process?**
A. Endothelial
B. Macrophages
C. Periarterial Lymphatic sheath
D. Reticular
E. Lymphoid nodule
B. Macrophages = phagocytosis of abnormal RBCs
## Footnote
Endothelial = gaps allow passage of RBCs
Periarterial Lymphatic sheath = T cells
Reticular = type III collagen = capsule
Lymphoid nodule = B cells
106
1. Identify this organ:
a. Adenoid tonsil
b. Lymphoid node
c. Thymus
d. Spleen
c. Thymus
107
2. What type of cell is located in the deep cortex of lymphoid nodes and is responsible for eliciting the adaptive immune response?
a. B-cell
b. Macrophage
c. T-cell
d. Plasma cell
c. T- cells
108
3. Identify the indicated structure:
a. Medulla
b. Lymphoid nodule
c. Periarterial lymphatic sheath
d. Red pulp
b. Lymphois nodule
109
4. Which secondary lymphoid structure contains T-cells?
a. Red pulp of the spleen
b. Outer cortex of the lymphoid nodes
c. Lymphatic nodules of the appendix
d. Periarterial lymphatic sheath of the spleen
d. Periarterial lymphatic sheath of the spleen
110
5. What are the two primary lymphoid organs in the body that undergo involution?
a. Appendix and spleen
b. Bone marrow and thymus
c. Spleen and thymus
d. Diffuse lymphatic tissue and bone marrow
b. Bone marrow and thymus
111
6. Identify the following organ:
a. Palatine tonsil
b. Spleen
c. Lymph node
d. Thymus
a. Palatine tonsil
