Exam 3: Lymphatic System Flashcards
(179 cards)
1
Q
What lymphatic organ is only in ruminants?
A
Hemal (lymph) nodes
2
Q
What lymphatic organ is only in avians?
A
Cloacal Bursa
3
Q
How many lymph nodes do Avians have?
A
few to none
4
Q
What are the 3 functions of the Lymphatic System?
A
- Protect from endogenous/exogenous substances
2.Primary defense system
3.Secondary defense system
5
Q
How does the Lymphatic System function as a Primary Defense System?
A
Epithelial barriers prevent exogenous substances from getting in
6
Q
Gives examples of the epithelial barriers in the lymphatic primary defense system
A
Skin (epidermis)
CT of skin (dermis)
Epithelial lining of GI, resp, urogenital
7
Q
What is the Lymphatic System’s Secondary Defense System?
A
Lymphatic / Immune System
kicks in if substances get past primary defense
8
Q
Which embryonic tissue are most lymphatic structures derived from?
A
Mesoderm
9
Q
What lymphatic structure is derived from endoderm?
A
Epithelial Reticular Cells
10
Q
Lymphocyte function
A
immune response
11
Q
Immunocompotent
A
lymphocytes “remember problem”
leads to stronger effect next time
12
Q
Antigen
A
substance that causes immune response
13
Q
Examples of antigens
A
bacteria, virus, toxin, tumor cells
14
Q
What are the 2 types of lymphocytes?
A
T cells
B cells
15
Q
What lymphatic structure are T cells modified by?
A
Thymus
16
Q
What is the function of T cells?
A
cell-mediated immune response
17
Q
What occurs when T cells contact an antigen?
A
Produces lymphokines
lead to cell membrane lysing –> death
18
Q
What lymphatic structure are B cells modified by in birds?
A
Cloacal Bursa
19
Q
What 2 lymphatic structures are B cells modified by in mammals?
A
bone marrow
Ileal Peyer’s Patch
20
Q
What is the function of B cells?
A
humoral immune response
21
Q
Where do lymphocytes go after development?
A
secondary lymphatic organs
(lymph nodes, spleen, tonsils)
22
Q
Primary/Central Lymphatic Organs of Avians
A
Thymus
Cloacal Bursa
23
Q
Primary/Central Lymphatic Organs of Mammals
A
Thymus
Bone Marrow
Ileal Peyer’s Patch
24
Q
What is special about the development of lymphocytes in primary lymphatic organs?
A
Shielded from outside antigens
so don’t recognize bad things as normal
25
Examples of Secondary/Peripheral Lymphatic Organs
lymph nodes, spleen, tonsils
26
What are four cell types that are normally in every secondary lymphatic organ?
plasma cells
macrophages
reticular cells
lymphocytes
27
Stroma
network of reticular cells + reticular fibers in lymphatic organs
"supportive framework"
28
Reticular Cells
specialized fibroblasts that produce reticular fibers
29
Involution
concept that thymus gets smaller over time/with age b/c fewer cells
30
What are the functions of the thymus?
T cell production
Humoral factors
31
What are two humoral factors in the thymus?
Thymosin
Thymopoietin
32
What is the function of humoral factors in the thymus?
stimulate bone marrow stem cells --> T cells
33
Septa
sheet of tissue
make up capsule of thymus
34
Thymus has (complete/incomplete) lobules
incomplete lobules
35
What are the two parts of a thymic lobule?
Cortex (outer/darker)
Medulla (inner/lighter)
36
List the structures in the cortex/medulla of thymus
T cells
Macrophages
Stroma (with epithelial reticular cells)
Thymic (Hassall's) Corpuscles
37
Are there more T cells in the cortex or medulla of the thymic lobules?
Cortex - because they are leaving!
38
Epithelial Reticular Cells
cells in stroma of thymic lobules
connected by desmosomes
surround T cells
39
What is the function of epithelial reticular cells?
produce thymopoietin to influence T cell development
40
Are there reticular fibers in the stroma of the thymic lobules?
NO
41
Thymic (Hassall's) Corpuscles
laminated masses of epithelial reticular cells
unknown function
Larger = older animal
42
What two structures are characteristic of the Avian Thymus?
Thymic Corpuscles
Myoid Cells
43
What is different about Thymic Corpuscles in the Avian compared to mammals?
"loose" aggregates of epithelial reticular cells
NOT tightly adhered
44
Myoid Cells
in medulla of thymic lobule
unknown function
look like skeletal muscle in cross-section
45
What kind of capillaries are in the cortex of the thymus and what do they have?
continuous cortical capillaries
have blood-thymus barrier
46
What allows the thymus to shield developing T lymphocytes?
Blood-Thymus Barrier
47
List Layers of Blood-Thymus Barrier
capillary endothelium
basement membrane
connective tissue
basement membrane
epithelial reticular cells
48
Lymph Vessels are ONLY (Afferent/Efferent)
Efferent
49
Cloaca
common chamber where GI, repro, urinary tracts empty in avians
50
What is the function of the Cloacal Bursa?
development of B lymphocytes
51
What are the "folds" within the Cloacal Bursa?
Plicae
52
What is the term for the cortex + medulla in the Cloacal Bursa?
Follicles
53
Does diffuse lymphatic tissue encounter antigens or not?
No recent antigen encounter, waiting to respond
54
Primary Nodule
no germinal/active center
even texture, small lymphocytes
55
Secondary Nodule
responds to antigen
germinal center (immature center where lymphocytes react to antigen)
corona (darker, outer ring)
56
Peyer's Patch
aka mucosal aggregated lymphatic nodules
have pseudovilli domes
57
Ileal Peyer's Patch
in ileum of ruminants
primary lymphatic organ in ruminants
ONLY developing B cells
58
What lymphocytes are in tonsils and are they in contact or independent of antigens?
T & B cells
contact antigens
59
Fossula
depressions in tonsil
60
Crypt
openings on tonsil after fossula
61
Follicle (or Tonsil)
= fossula + crypt
62
List 3 types of tonsils
Palatine
Pharyngeal
Lingual
63
What tissue type is palatine tonsil covered by?
Non-Keratinized Stratified Squamous Epithelium
64
Where are palatine tonsils located?
oral part of pharynx (dog)
65
What tissue type covers the pharyngeal tonsils?
Pseudostratified Columnar Epithelium w/ cilia
66
What is the location of the pharyngeal tonsils?
nasal part of pharynx
67
What tissue type covers the lingual tonsils?
Keratinized Stratified Squamous Epithelium
68
Where are lingual tonsils located?
root of tongue
69
Where is tubal tonsil located?
nasopharynx where auditory tube goes
70
What is lymph?
fluid that leaks into interstitial spaces
71
Which 3 structures have no lymph?
brain
spinal cord
retina of eye
72
Name 2 ducts in the lymph vessel system
Thoracic duct
Right Lymphatic duct
73
Lymph Nodes are (primary/secondary) lymphatic organs
secondary
74
What are the two functions of lymph nodes?
Filter lymph
Immune response
75
What is different about swine lymph nodes?
Opposite lymph flow
flows from center --> periphery
76
What 2 tissue types are lymph node capsules made of?
DICCT or Loose CT
77
What is the term for spicules/indentations of capsule into the lymph node?
Trabeculae
78
Apart from cortex/medulla, what other layer is in the lymph node?
Paracortex
79
What the paracortex of the lymph node?
area of more distributed T cells
80
What are two unique structures in the medulla of the lymph node?
medullary cord
medullary sinuses
81
What is present in the medulla cord of the lymph node?
lots of plasma cells
82
What is the medullary sinus in the lymph node?
space between cords where lymph is located
83
What is the hilus of the lymph node
indentation where vessels come & leave
84
Explain lymph flow in a lymph node
afferent lymph nodes --> subscapular sinus --> cortical sinus --> medullary sinuses --> efferent lymph node
85
What causes enlargement of lymph nodes?
proliferation of T & B cells during infection
86
What is different about equine lymph nodes?
have many, smaller lymph nodes
87
What is the only lobulated lymphatic organ?
thymus
88
(T/F) The thymus has lymphatic nodules.
False
89
What are areas in the Peyer's Patch with T cells called?
Thymus-dependent zones
90
Where are M cells located?
Peyer's Patch (aggregated lymphatic nodules)
91
What is the function of M cells?
"sampling" antigens from lumen selectively for lymphocytes to test
92
Which lymphatic organ is the only one which afferent lymph vessels?
lymph node
93
What are the sinuses in the lymph node lined by? What is unique about them for their function?
endothelium
big gaps so lymph percolates
94
Paracortex (thymus-dependent zone)
region where cortex is continuous with medulla and T cells predominate
95
What is the function of reticular cells in lymph node?
span sinuses to slow lymph flow and divert it to contact other cells within lymph node
96
What do macrophages contain in lymph nodes on occasion?
hemosiderin
97
What is hemosiderin?
product of hemoglobin broken down by macrophages in lymph nodes (recycled RBC)
98
What kind of tissue surrounds the lymph node (outside capsule)? And what structures are within it?
adipose tissue
lymph vessels
99
Foreign Body Giant Cells
multinucleated, pale-staining macrophages in lymph node that ingest foreign material
100
What is significant about plasma cells near foreign body giant cells?
negative golgi image
basophilic cytoplasm
101
What type of animals are Hemal Nodes found in?
ruminants only
102
Hemal nodes have _____ instead of lymph vessels.
RBC | large blood supply
103
What two types of tissue make up the hemal node capsule?
DICCT + smooth muscle
104
Function of lymph node
"surveillance system"
filters/monitors what's in lymph before going back into vasculature
105
Where are hemal nodes located?
any place where lymph nodes are
most common- paralumbar fossa
106
(T/F) Hemal Nodes have lymphatic nodules
True
1-2 scattered nodules
107
Function of Hemal Nodes
filter blood
immune response to antigen in blood
108
(T/F) Hemal Nodes have a cortex and medulla
False
only lymphatic nodules, not organized into cortex/medulla
109
What are the 3 functions of the spleen?
Produce blood cells in embryo
RBC/platelet reservoir
Blood filter
110
The spleen is a (primary/secondary) lymphatic organ that is (independent/dependent) of antigen.
Secondary
Dependent
111
How is the spleen filter blood? (2 ways)
destroy old RBC (recovery iron)
immune response (T + B cells)
112
What structure covers the spleen?
tunica serosa
113
What's another name for tunica serosa on spleen?
visceral peritoneum
114
What two layers is the tunica serosa of the spleen made up of?
mesothelium + lamina propria (CT layer)
115
What two tissues is the capsule of spleen made of?
DICCT + smooth muscle
116
White pulp of spleen
where lymphocytes are
117
periarterial lymphatic sheath
(where T cells are) where T cells infiltrate artery/arteriole in spleen
118
Red pulp
everything around white pulp in spleen
119
Splenic Cords
everything between venous sinuses in the red pulp of the spleen
120
Venous sinuses
spaces in red pulp
121
Marginal Zone
junction of red & white pulp in spleen
122
Function of Marginal Zone in spleen
where blood flow slows so T & B cells can contact antigen in white pulp
123
Where does antigen-cell interaction take place in spleen?
marginal zone
124
What two cell types are in the marginal zone?
macrophages + lymphocytes
125
Order of Splenic Circulation
aorta --> celiac A --> splenic A --> trabecular A --> artery of the white pulp
126
Which lymphocyte dominates in the white pulp?
B cells
127
(T/F) The spleen has lymphatic nodules.
True
128
Once the splenic artery branches, it becomes ______ artery.
trabecular
129
Open theory
blood enters right into splenic cord from terminal capillaries and blood percolates to get to venous sinuses
130
Closed theory
terminal capillaries empty directly into venous sinuses
131
Fusiform Endothelial Cells
very long endothelial cells lining of venous sinuses with gaps so RBC can get into venous side of circulation
132
The spleen has only (afferent/efferent) lymph vessels. It (receives/produces) lymph.
efferent
produces
133
Differences in avian spleen
no lymphatic nodules form (unless diseased state)
134
What two cell types are present in the splenic cord?
plasma cells + macrophages
135
What occurs in the spleen when B lymphocytes are stimulated?
nodules form
136
What occurs in the spleen when T lymphocytes are stimulated?
thickening of periarterial lymphatic sheath (where T cells predominate)
137
(T/F) Macrophages are immunocompetent (can remember).
False
138
Arterial Penicillus
terminal portion / branching from artery of the white pulp
139
Ellipsoid (sheathed capillary)
reticular cells + macrophages
RBC forced through space between and pulls out anything abnormal for macrophages to degrade
140
Thick smooth muscle in capsule + trabeculae contracted indicates the ______ theory.
closed (because so close to venous sinuses)
141
When smooth muscle in capsule + trabeculae is relaxed, this indicates ____ theory.
closed (percolates b/c further from venous sinuses)
142
Annular Reticular Fibers
supportive fibers that surround fusiform endothelial cells in venous sinus
143
What cell type is in the venous sinuses that help degrade RBC if they cannot get through the fusiform endothelial cell gaps?
macrophages
144
Venous side of circulation in spleen (mechanism of movement)
red pulp vein --> trabecular vein --> splenic vein --> portal vein to liver
145
Sinusal vs. Nonsinusal Spleen
smooth muscle in sinuses in ruminants = not technically sinusal so NONSINUSAL
146
What is different about the avian spleen?
on right side of stomach
NO lymphatic nodules or trabeculae from capsule
ellipsoid has simple cuboidal lining
147
Mononuclear phagocytes
phagocytic cell with consistently shaped nucleus
148
Polymorphonuclear Phagocytes
= neutrophil | many forms of the nucleus
149
Mononuclear Phagocytes
macrophages (have consistently shaped nucleus
149
Two cell times that derived from the monocyte-macrophage system
mononuclear phagocytes
polymorphonuclear
150
Monocytes derive sinus-associated cells which can differentiate into what 4 types of macrophages?
splenic
lymph node
bone marrow
liver
151
Monocytes derive into what 4 cell groups?
Sinus-associated cells
Free cells
Antigen processing cells
Tissue cells
152
What 2 macrophages types arise from "free cell" lineage of monocyte?
Serous membrane
alveolar
153
What cells arise from antigen processing cells from monocyte lineage? (5)
M cells
interdigitating cells
follicular dendritic cells
reticular dendritic cells
veiled cells
154
What 4 cell types derive from tissue cell category of monocyte lineage?
connective tissue macrophages
mesangial cells (kidney)
microglia (CNS)
osteoclasts
155
Term for elevation in monocytes
Monocytosis
156
Dendritic cells
"tree-like" branching dendritic processes
157
Dendritic cell functions (2)
-bind antigen on surface
-retain antigens for long periods
158
Follicular dendritic cells location
B cells areas (germinal centers)
159
Interdigitating cells location
T cell areas (proliferating)
160
Veiled cells location
afferent lymph vessels + sinuses of lymph nodes
161
Reticular dendritic cells ("clear cells" or Langerhans) location
stratified epithelia
162
M cell location
aggregated lymphatic nodules (Peyer's patches) + tonsils
163
M cell function
upside-down cup open to lymphocyte/macrophages and bring antigens in for "sampling"
164
T cells make up __% circulating lymphocytes in blood, B cells __% and the other __% are made up by ___.
70
20
Natural Killer (NK) cells
165
Natural Killer (NK) Cell Function
recognize body's own cells that become tumors / abnormal growth
produce chemicals similar to T cells
166
(T/F) NK Cells are immunocompetent.
False
167
What is prominent in NK cells?
azurophilic granules on the lymphocyte
168
Killer (cytotoxic) T cells
produce lymphokines when in contact with antigen (destroy abnormal cells)
169
T cell reverts into ________ when it comes into contact with antigen and becomes _______.
Lymphoblast
immature
170
List the 4 "clones" a lymphoblast divides into.
Killer (cytotoxic) T cell
T memory cell
Helper T cell
Suppressor T cell
171
T memory cells
recognize antigen so when encountered again, faster/greater response at next encounter
172
Helper T cells
help B cells when they encounter antigen
173
Suppressor T cell
make chemical suppressor substances which keep immune system from going overboard and harming body
174
Blast transformation
when T & B lymphocytes undergo process back to immature form when encounter antigen
175
B cells when encounter antigen form what 2 cell "clone" types?
plasma cells
B memory cells
176
B memory cells
remember antigen, faster/greater response
177
Lymphocytopoiesis
process of lymphoblast to get progressively smaller
178
Antigenic/immunological surveillance
circulation and recirculation allow lymphocytes to go anywhere in body
"lymphocyte patrol"
