Lymphatic system and hematopoietic organs Flashcards
(212 cards)
1
Q
What is the lymphatic system?
A
Tissues and organs which produce, store and carry white blood cells
2
Q
What does the lymphatic system do?
A
Fight infections and other diseases
3
Q
What does the lymphatic system include?
A
Bone marrow
Spleen
Thymus
Lymph nodes
Lymphatic vesels
4
Q
What does the lymphatic system filter?
A
Pathogens from the blood
5
Q
3 parts of the lymphatic system
A
Lymphatic
Lymph nodes
Lymphoid organs
6
Q
What fluid does the lymphatic system clean?
A
The interstitial fluid/extracellular fluid
7
Q
What is extracellular fluid similar to?
A
Plasma
8
Q
Different name for white blood cells
A
Lymphocytes
9
Q
Which are our infection-fighting cells?
A
White blood cells
10
Q
Is the lymphatic system one way/unidirectional or bi-directional?
A
Unidirectional
11
Q
Primary function of the lymphatic system
A
Transport excess interstitial fluid from the intertital space back to the blood circularion
12
Q
What does the lymphatic system use to transport the interstitial fluid back to the blood circulation?
A
Thoracic duct
13
Q
Does the blood circulation have a one way or bi-directional course?
A
Bi-directional
14
Q
What are the lymphatic vessels that come before the lymph nodes called?
A
Afferent lymphatic vessels
15
Q
What are the lymphatic vessels that come after the lymph nodes called?
A
Efferent lymphatic vessels
16
Q
Do lymphatic capillaries have a continuous basal membrane?
A
No it has a discontinuous basal membrane
17
Q
Where are the elastic fibers found?
A
Only the capillaries
18
Q
What kind of junction I found in the lymphatic cappilaires?
A
Button like junction
19
Q
What kind of junction I found in the lymphatic ducts?
A
Zipper like junctions (has to be tight)
20
Q
Are there valves in the lymphatic vessels?
A
Yes
21
Q
What is the part of the vessels between two valves called?
A
Lymphangion
22
Q
Different name for Lymphangion
A
Primitive hearts
23
Q
4 types of external compression of the lymphatic vessels
A
Skeletal muscles
Cardiac muscle
Smooth muscles
Intestinal peristalsis
24
Q
What happens when there is lymphatic pump dysfunction?
A
Lowered lymph flow
Increased Edema formation
Increased inflammatory cytokines and cells retention and local immune deficiency
25
Does the lymphatic system have a central pump?
No
26
What does the right lymphatic duct drain?
The right upper part of the trunk, right upper limb and right side of the head and neck
27
What are lymphoid organs classified as?
Primary or secondary organs
28
Which are the primary lymphoid organs?
Thymus and bone marrow
29
What are the primary lymphoid organs responsible for?
The production and maturation of lymphocytes
30
Which are the secondary lymphoid organs?
Spleen
Peyer's patches
Appendix
Tonsils
Lymph nodes
31
What are the secondary lymphoid organs responsible for?
Further maturation of lymphocytes and initial of immune
32
What kind of organs are lymph nodes?
Full organs
33
Where are lymph nodes located?
Along the course fo the lymphatic collectors
34
What do the lymph nodes contain?
Lymphocyte B
Lymphocyte T
35
Shape of lymph nodes
Ovoid/bean shape
36
Size of lymph nodes
few mm - 1 cm
37
Where does lymphocyte B originate?
Bone marrow
38
Where does lymphocyte T originate?
Thymus
39
Are lymph nodes solid or hollow organ?
Solid organ
40
What is the lymph node built up of?
Capsule
Parenchyma
Trabecular of the capsule hilum
41
What is the stroma of the lymph node made up of?
Dense connective tissue and reticular stroma
42
Where in the lymph node are the plasma cells found?
In the medulla
43
Where in the lymph node are the macrophages cells found?
The medulla
44
Where in the lymph node are the lymphocytes cells found?
The medulla
45
How many efferent vessels from each lymph node?
1
46
How many afferent vessels in each lymph node?
Several
47
When does the follicles goes from primary to secondary?
When the b-cells go from naive to memory b-cells
48
What does the cortex of an unstimulated lymph node consist of?
Primary follicles composed of naive B cells
49
What are naive B cells?
Small, mature lymphocytes with condensed chromatin and scant cytoplasm
50
What is the location of the maturation of T-lymphocytes?
Thymus
51
Where is the thymus located?
Mostly in the anterior mediastinum and small part in the neck
Retrosternal
52
Is the thymus paired or unpaired?
Unpaired
53
What is each lobe of the thymus formed by?
A cortex and a medulla
54
Name of the neck of the thymus
Cornua of the thymus
55
Name of the lobes of the thymus
Thymic lobes
56
What is found inside the capsule of the thyroid?
The parenchyma (lymphoid tissue)
57
4 cells types of the thymus
T lymphocytes
TEC (thyme endothelial cells)
Macrophages
Dendritic cells
58
What allows for thymus homing?
Markers of the cell surfaces
59
What is positive selection?
Survival signal
60
What is negative selection?
Death signal
61
2 types of early fatal TEC
cTEC (cortex)
mTEC (medulla)
62
In which bones is there bone marrow?
Long bone
63
How much of total body weight is made of bone marrow?
3-5%
64
Where does hematopoiesis take place?
Bone marrow
65
What does the spleen consist of?
Large encapsulated mass of vascular and lymphoid tissue
66
Where is the spleen situated?
Upper left quadrant of the abdominal cavity
67
Which is the largest secondary lymphoid organ?
The spleen
68
Main spleen function
Destroy aged erythrocytes, aged platelets and repair young erythrocytes
69
What is the color and consistency of the spleen?
Dark red
Soft
70
What takes over hemocatheresis if the spleen is removed?
The liver
71
2 surfaces of the spleen
Diaphragmatic surface (external)
Visceral surface (internal)
72
Which surface of the spleen is convex?
The diaphragmatic surface
73
Which ribs does the spleen project on?
9-11th
74
Which rib is at the mid axis of the spleen?
10th
75
4 impressions on the visceral surface of the spleen
Gastric impression
Renal impression
Pancreatic impression
Colic impression
76
3 borders of the spleen
Superior/anterior border
Inferior/posterior border
Internal border
77
How much is the spleen covered by the peritoneum?
Entirely
78
Which artery supplies the spleen?
Splenic artery
79
Which vein drains the spleen?
Splenic vein
80
Which is the largest branch of the celiac trunk?
The splenic artery
81
What is white pulp in the spleen made of?
Lymphoid tissue
82
What does the white pulp in the spleen do?
Immune response
83
What does the red pulp in the spleen do?
Filtration of the blood (hemocateresis)
84
What does the splenic artery branch into when entering the hilum?
Trabecular arteries
85
What does the trabecular arteries in the spleen branch into when entering the white pulp?
Central arterioles
86
What are the central arterials in the spleen covered by?
Seath of lymphocytes
87
What does the central arterioles branch into when entering the red pulp?
Penicillar arterioles
88
What do the penciller arterioles branch into?
Terminal capillaries
89
What does the sinusoid of the spleen do?
Removal of damaged and aged erythrocytes
90
Where in the spleen does immune screening happen?
White pulp
91
What does the interstitial fluid enter the lymphatic system through?
Small lymphatic capillaries (internal or terminal lymphatics)
92
What are the larger vessels in the lymphatic system called?
Pre-collectors
Collectors
Trunks
Ducts
93
What is the interstitial fluid called when inside the lymphatics?
Lymph
94
What prevents retrograde flow in the lymph vessels?
One-way valves (like in veins)
95
What can lymph contain?
Proteins
Minerals
Fats
Nutrients
Cancer cells
Foreign invaders
Infection-fighting white blood cells
96
What does the lymphatic vascular system regulate?
Tissue fluid
Homeostasis
Immune cell trafficking
Absorption of dietary fats
97
Primary function of the lymphatic system?
Transport excess interstitial fluid from the interstitial space back to the blood circulation via the thoracic duct
98
Does the lymphatic system play an important role in the dissemination of cancer cells?
Yes
99
At which level does the lymphatic circulation start?
At the capillary level
100
Do pre-collector vessels have valves?
Yes
101
Which vessels have propulsive activity?
Afferent and efferent lymphatic vessels
102
5 places where the major lymphatic trunks can be found
Intestinal
Lumbar
Bronchomediastinal
Subclavian
Jugular
103
Name of 2 lymphatic ducts
Thoracic and right lymphatic
104
Are lymphatic capillaries blind ends?
Yes
105
How much are lymphatic endothelial cells covered by basement membrane?
Only partially
106
What facilitates interstitial fluid and cellular entry into the lymphatic capillaries?
The button structures
107
What anchors the lymphatic epithelial cells to the elastic components of the extracellular matrix?
Button structures
108
2 routes of entry for interstitial fluids to the lymphatic capillaries
Paracellular
Transcellular
109
What do lymphatic capillaries converge into?
Precollectors
110
What do precollerctors converge into?
Lymphatics
111
Where are zippers located?
Among the collector lymphatic epithelial cells
112
Which lymphatic vessels have complete basement membrane and smooth muscle cell layers?
Lymphatics
113
What allows for unidirectional lymph flow?
Lymphatic valves
114
Which junctions are continuous, button or zipper?
Zipper
115
What acts as primary valves for fluid and cell entry into lymphatics ?
Button junctions
116
Which endothelial cells have button-like junctions?
Endothelial cells of initial lymphatics
117
Which vessels have zipper-like junctions?
Collecting lymphatics and blood vessels
118
Which junctions create the endothelial barrier in collecting lymphatics and blood vessels?
Zipper-like junctions
119
What makes it possible for lymphangions to perform rhythmic contractions?
The fact that they are innervated with sympathetic and parasympathetic nerves
120
What does the rhythmic contractions of the lymphangion do?
Pushes the lymph forward
121
What is the propulsion of lymph a result of?
The combination of both active and passive mechanisms
122
Do lymphatic capillaries have basement membranes?
No they lack basement membranes
123
Are larger collecting lymphatics permeable?
No impermeable
124
What transport lymph back to the venous circulation?
Collecting lymphatics
125
Does the collecting lymphatics transport the lymph at high or low pressure
Low as it operates without a central pump
126
Since the collecting lymphatic are a low pressure transport system what have they developed to facilitate fluid transport?
Features such a valves and smooth muscle cells which provide an intrinsic pumping force
127
Which are the 2 largest lymphatic vessels?
Trunks and ducts
128
Which lymphatic duct drains the most, the right lymphatic duct or the thoracic?
The thoracic (3/4th of the body)
129
Which trunks drains the lymph of the abdomen and pelvis?
Left and right lumbar trunks
Intestinal trunk
130
Which trunks drains the lymph of the head and neck?
Right and left jugular trunks
131
Which trunks drains the lymph of the upper limb?
Right and left subclavian trunks
132
Which trunks drains the lymph of the thoracic viscera?
Right and left broncomediastinal trunks
133
Which is the largest duct in the body?
The thoracic duct
134
Where does the thoracic duct originate?
The cisterna chyli
135
Where is the cisterna chyli?
In the abdomen at level of T12
136
How does the thoracic duct pass into the thorax?
Through the aortic hiatus of the diaphragm
137
Where does the thoracic duct run?
Between the aorta (on the left) and the azygos vein (on the right) and posteriorly to the oesophagus
138
Where does the thoracic duct end?
At the confluence of the internal jugular vein with the left subclavian vein
139
How much of the whole body lymph does the thoracic duct drain?
3/4ths
140
Is the right lymphatic duct constant?
No
141
Where does the right lymphatic duct empty?
Into the right subclavian vein
142
What do high endothelial venules allow for?
The entry of the lymphocytes into the node
143
What happens to the lymph once its inside the lymph node?
It is filtered by immune cells of the parenchyma (mainly B and T lymphocytes)
144
What does the cortex of an UNSTIMULATED lymph node consist of?
Primary follicles composed of naive B cells with an underlying meshwork of follicular dendritic cells
145
What happens when a lymph nodes becomes activated by being exposed to antigen?
Germinal centers form in the center of B cell follicles
Primary follicle cells are pushed to the periphery where they form a mantle zone around the germinal center
146
What makes up the mantle zone?
Primary follicles and a few memory B cells
147
What is a secondary follicle made up of?
A germinal center and surrounding mantle zone
148
What is a sentinel lymph node?
The first lymph node to which cancer cells are most likely to spread from a primary tumor
149
Can there be more than one sentinel lymph node?
Yes
150
Which organ controls and harmonises the entire immune system and the immune functioning of the organism?
The thymus
151
Where do T-progenitor cells replicate and undergo maturation?
In the thymus
152
What is the thymus covered by on the side?
Mediastinal part of the pleura parietalis
153
Which large vessels and nerves run behind the thymus?
Aortic arch
Brachiocephalicae vein
Superior vena cava
154
Where do large vessels and nerves run in relation to the thymus?
Behind
155
What is the thymus connected to the thyroid gland by?
The thyrothymic ligament
156
What moulds the shape of the thymus?
Adjacent structures
157
What lies anteriorly to the thymus?
Sternohyoid and sternothyroid muscles and fascia
Manubrium sterni
158
Which vein might be partly embedded in the thymus?
The left brachiocephalic vein
159
What is the thymus in contact with posteriorly?
Vessels of the superior mediastinum
Upper part of the thoracic trachea
Anterior surface of the heart
160
What cells types are found in the thymus?
Maturing T lymphocytes
Thymic endothelial cells (TEC)
Macrophage
Dendritic cells
161
What is positive selection?
Survival signal
162
What is negative selection?
Death signal
163
Which cells enter the thymus to begin commitment to the T cell lineage?
Bone marrow derived lymphoid progenitor cells
164
What does positive selection delineates selection of thymocytes into?
CD4, T-helper
CD8, cytotoxic T cell lineage
165
Where do the cells migrate in the thymus after positive selection?
To the medulla
166
What mediates negative selection in the thymus?
mTECs
167
What happens to the cells in the thymus when they after positive selection go to the medulla?
They go through negative selection
168
What does the process of thymopoiesis result in?
A population of peripheral blood and lymphoid sites with naive CD4+ and CD8+ T cells and CD4+ regulatory T cells (tregs)
169
What does the establishment of self-tolerance in the thymus depend on?
Promiscuous gene expression (pGE) of tissue-restricted antigens (TRAs) by TECs
170
What does the spleen consist of?
A large encapsulated mass of vascular and lymphoid tissue
171
Which quadrant of the abdominal cavity is the spleen situated in?
Upper left/left hypochondrium
172
Between what is the spleen located?
Between the fundus of the stomach and the diaphragm
173
Which position is the spleen in?
Supramesocolic
174
Is the spleen entirely lined by the peritoneum or only partly?
Entirely
175
What is the supralateral aspect of the spleen shaped by?
The left dome of the diaphragm
176
What is the inferomedial aspect of the spleen shaped by?
The splenic flexure of the colon, the left kidney and the stomach
177
2 main functions of the spleen
Destroying aged erythrocytes (hemocatheresis) and aged platelets (catharsis of the platelets)
Repair young erythrocytes (pitting)
178
What does the spleen process, blood or lymph?
Blood (its a second lymphoid organ)
179
What does the spleen have reservoirs for?
Granulocytes and platelets
180
Which is the external surface of the spleen?
Diaphragmatic surface
181
Which is the internal surface of the spleen?
Visceral surface
182
Which ribs does the projection of the spleen on the thoracic cage correspond to?
9th, 10th and 11th rib
183
Which ligaments hold the spleen to the abdominal wall?
Folds of peritoneum:
Splenorenal
Phrenicocolic
Phrenicosplenic
Gastrosplenic ligament
184
What attaches the spleen to the stomach?
The gastrosplenic ligament
185
Which is the largest branch of the celiac trunk?
The splenic artery
186
Where is the fibrous capsule of the spleen thick?
At the level of the hilum
187
2 main components of the spleen
Red pulp
White pulp
188
What is the white pulp of the preen composed of?
Lymphoid tissue
189
What does the splenic artery divide into when it enters the hilum?
Trabecular arteries
190
What does the trabecular arteries follow?
The course of the trabeculae
191
What are the branches of the trabecular arteries that enters the white pulp called?
Central arterioles
192
What are the central arterioles surrounded by?
A sheath of lymphocytes
193
What happens to the death of lymphocytes that surround the central arterioles when they leave the white pulp and enter the red pulp?
It is lost
194
What are the branches of central arterioles in the red pulp called?
Penicillar arterioles
195
2 routes of blood flow though the splenic red pulp?
Open circulation
Closed circulation
196
What is blood enclosed by in the closed circulation of the red pulp?
Epithelium cells
197
What is the sinusoid of the human spleen like?
Barrel-like
198
What does the sinusoid of the human spleen do?
Remove damaged or aged erythrocytes
Permits migration of leukocytes from the cords of billroth into the circulation
199
How much of the blood in the spleen goes through the open circulation?
90%
200
In which circulation of the spleen does immune screening take place?
Both
201
What does the blood drain through in the open circulation of the spleen?
Through the walls of the capillaries
202
What does the blood undergo when crossing the wall of the sinusoids to reenter the circulation in the open circulation?
Macrophage selection
203
What happens to the capillaries in the closed circuit of the spleen?
It does directly into the sinusoids
204
What lines the sinusoids?
Incomplete endothelium that is unique to the spleen
205
What are the endothelial cells of the sinusoids called?
Stave cells
206
What are stave cells connected by?
Intercellular junctions which alternate with intercellular slits
207
What doe white pulp have the same organisation as?
Lymphnodes
208
What is the term for unencapsulated lymphoid tissue that exists in the walls of the alimentary, respiratory, reproductive and urinary tracts and the skin?
Mucosa-associated lymphoid tissue (MALT)
209
Subclasses of mucosa-associated lymphoid tissue
Gut-associated lymphoid tissue (GALT)
Bronchus-associated lymphoid tissue (BALT)
210
Where are the lymphoid cells of MALT located?
In the lamina proprietor and the submucosa as discrete follicles or nodules
211
What is the Waldeyer's ring?
Circumpharyngeal ring of MALT which surrounds the openings into the digestive and respiratory tracts
212
What is the Waldeyer's ring made up by?
The tonsils and smaller collections of lymphoid tissue
