H: Lymphatic System Flashcards
(115 cards)
1
Q
What are the 7 components of the lymphatic system
A
- diffuse lymph tisse
- lymph nodules
- lymph nodes
- spleen
- bone marrow
- thymus
- lymphatic vessels
2
Q
What are the 3 major functions of the lymphatic system?
A
- drain excess interstitial fluid (and return to blood)
- provide alternative route for hormones, nutrients, waste
- immune response (produce, maintain, distribute lymphocytes)
3
Q
After draining excess interstitial fluid, it must return to the blood to help maintain normal ____
A
blood volume
4
Q
Lymphatic vessels are the connection between ___
A
circulatory system and lymphatic system
5
Q
Describe the difference between hydrostatic pressure and osmotic pressure in a capillary bed
A
hydrostatic pressure - pushes plasma out of capillary bed into interstitial area
osmotic pressure - brings fluid back into capillary bed
6
Q
Which is stronger, hydrostatic pressure or osmotic pressure at capillary beds? is it even?
A
not even - hydrostatic is stronger
this is why we need lymph system – to bring interstitial fluid back into circulatory system
7
Q
Because hydrostatic pressure > osmotic pressure, what builds up around capillary beds?
A
large blood proteins and excess fluid
8
Q
the build up of large blood proteins and excess fluid around capillary beds leads to ____
A
edema (swelling)
9
Q
Lymphatic capillaries are found around ___
A
capillary beds
10
Q
Describe lymphatic capillaries
A
blind ended
porous
endothelial lined
discontinuous basal lamina
11
Q
Lymphatic capillaries are found in ___
A
connective tissue
12
Q
Lymphatic vessels get progressively ____ while moving superiorly in the body
A
larger
13
Q
Lymphatic vessels have a discontinuous ___
A
basal lamina
14
Q
What are the 2 final lymphatic ducts of the lymph system
A
- thoracic duct
2. right lymphatic duct
15
Q
Thoracic duct enters into the ____; located between ___
A
left venous angle
between left internal jug v and left subclavian v
16
Q
Right lymphatic duct enters into the ____; located between ___
A
right venous angle
between right internal jug v and right subclavian v
17
Q
Thoracic duct drains ____
Right lymphatic duct drains ___
A
Thoracic duct - drains waste down, abdomen, left thorax, left upper limb, left head/neck
Right lymphatic duct - drains right thorax, right upper limb, right head/neck
18
Q
Lymphatic system doesn’t have a pump (like circulatory system). So what controls lymph movement?
A
compression from skeletal muscles
aka us moving around
19
Q
Lymphatics drain in a ___ direction movement
A
one
20
Q
Why do lymphatics drain in one direction?
A
lymphatics have VALVES (endothelial cells folded)
21
Q
____ are the definitive cell of the lymphatic system
A
lymphocyte
22
Q
Name the 3 types of lymphocytes
A
- b cell
- t cell
3 Natural killer (NK) cells
23
Q
B cells are ____%
T cells are ___%
NK cells are ____%
of circulating lymphatic system
A
B cells = 20-30%
T cells = 60-80%
NK cells = 5-10%
24
Q
B cells were first recognized in ____
A
bursa of fabricus birds
25
B cells produce/secrete ____ along with ____
antibodies
their derivative cell (plasma cells)
26
B cells are involved in ____ immunity
T cellsa re involved in ____ immunity
B cells = humoral immunity
T cells = cell mediated immunity
27
T cells differentiate in the ___
thymus
28
What is the function of T cells
attach and destroy cells
29
What is the function of NK cells?
kill certain transformed cells
30
What are other supporting cells of the lymphatic system
```
reticular cells
neutrophils
dendritic cells
epithelioreticular cells
monocytes
basophils
follicular dendritic cells
macrophages
eosinophils
langerhan cells
```
31
reticular cells produce ___
reticular fibers (type 3 collagen)
32
Epithelioreticular cells create ___
stroma for thymus
33
Diffuse lymphatic tissue is an accumulation of _____. Where?
accumulation og lymphocytes
in LAMINA PROPRIA of alimentary canal, respiratory, urinary, reproductive tracts
34
Where is diffuse lymphatic tissue found
accumulation of lymphocytes
in LAMINA PROPRIA of aliminetary canal, respiratory, urinary, reproductive tracts
35
Do diffuse lymphatic tissue have a surrounding capsule?
no they are loosely organized
36
Diffuse lymphatic tissue contains loosely organized lymphocytes as well as ____ and ___
plasma cells and eosinophils
37
Lymphatic nodules aka ____
lymphatic follicles
38
Lymhatic nodules (lymphatic follicles) are an accumulation of ____. Where?
lymphocytes
wall of alimentary canal, respiratory, urinary, reproductive tracts
39
Do lymphatic nodules have a capsule?
no
| but they ARE sharply defined
40
How are lymphatic nodules (lymphatic follicles) defined?
sharply defined
meshwork of reticular fibers
41
Lymphatic nodules are composed of a meshwork of ___
reticular fibers
42
Lymphatic nodules (follicles) contain lymphocytes and __ and ___
plasma cells
| eosinophils
43
What are the 2 types of lymphatic nodules (follicles)
1. primary nodule
| 2. secondary nodule
44
What is the main difference between a primary lymphatic nodule and secondary lymphatic nodule
these are both lymphatic nodules (follicles)
primary - small, and WAITING to respond to an antigen
secondary - larger, responding to an antigen
45
Aggregation of primarily small lymphocytes
| primary or secondary nodule
primary
46
Describe the layers of a secondary lymphatic nodle
GERMINAL CENTER (central, lighter staining bc of large lymphocytes)
MANTLE ZONE / CORONA / CORTEX - darker staining, small lymphocytes
47
Describe the staining differences between the germinal center and the mantle zone of the secondary lymphatic nodule
Germinal center = stains lighter due to large lymphocytes in center
Mantle zone (cortex / corona) = stains darker because small lymphocytes present here
48
Normally, lymphatic nodules (follicles) are found randomly dispersed and by themselves
This is called ____
solitary lymphatic nodules
49
Sometimes, lymphatic nodules (follicles) in certain locations of the alimentary canal are grouped togethe ros that they are touching or almost touching
This is called ____
aggregated lymphatic nodules
50
Aggregated lymphatic nodules (follicles) are found in 3 main locations in the alimentary canal. Where?
1. tonsils
2. peyer's patches
3. appendix
51
Aggregated lymphatic nodules in the tonsils create a ring around ____
creates a ring around the entrance to the oropharynx and the nasopharynx
52
Aggregated lymphatic nodules in peyer's patches are found in ___
the ileum
53
Aggregated lymphatic nodules in the appendix arise off of the ___
cecum of the large intestine
54
Does everyone agree that the lymphatic nodules in the appendix are aggregated?
no
because they don't technically touch
but we know they are there and we know there are lots of them
55
Diffuse lymphatic tissue and lymphatic nodules are BOTH accumulation of lymphocytes in the walls of the alimentary canal, respiratory, urinary and reproductive tracts.
So they have special naming of _____. Why?
MALT - mucus-associated lymphatic tissue
because they are BOTH associated with mucus-lined tracts
56
MALT (mucus-associated lymphatic tissue) refers to what 2 types of lymphatic tissue?
diffuse lymphatic tissue
lymphatic nodules (follicles)
57
MALT can be named according to the region/organ in which it appears
- GALT = ____
- BALT = ____
GALT - gut associated lymphatic tissue (associated with alimentary canal)
BALT - bronchus associated lymphatic tissue (assocated with respiratory system)
58
Lymph nodes are found along ____
the lymphatic vessels pathway
59
____ are capsulated organs found along the pathway of lymphatic vessels
lymph node
60
Lymph node function is to ____
filter!
therefore they have phagocytosis here
61
Lymph nodes
____(#) in average adult
____ mm in diameter
___ shaped
500-600 in adult
1-25mm
bean shaped
62
Lymph nodes are sites for initiation of ____
immune response
63
Lymph nodes cluster in certain areas. Where do these clusters filter lymph from?
Cervical =
Axilla =
Inguinla =
Mesenteries =
Cervical = filter from head/neck
Axilla = filter form upper ilmb
Inguinal = filter from lower limbs
Mesenteries = filters from serous membrane coming from organs
64
2 parts of the lymph node
- What is the stroma?
- What is the parenchyma?
stroma - supporting connective tissue of lymph node
Parenchyma - functional part of lymph node
65
The stroma of a lymph node is made up of what 3 things
1. capsule
2. trabeculae
3. reticular connective tissue
66
STROMA of lymph node
| the capsule of lymph node is made up of ___ connective tissue
dense
67
STROMA of lymph node
| the trabecuae are __ connective tissue. they are extensions of ___
dense
capsule
68
STROMA of lymph node
reticular connective tissues are from ____ origin
produced by ___ cells
mesenchymal origin
reticular cells produce it
69
PARENCHYMA of lymph node
| The cortex is just deep to the ___
capsule
70
PARENCHYMA of lymph node
| Comes all the way around the lymph node except at the ___
hilum
71
PARENCHYMA of lymph node
| Cortex is made up of 2 parts. What are they?
superficial (nodular cortex) = primary adn secondary lymphatic nodules
deep cortex (paracortex) = no lymphatic nodules
72
PARENCHYMA of lymph node
| Medulla is made up of 2 parts. What are they?
medullary sinus = for lymph flow, converge near hilum
Medullar cords = tissue pieces w/ cells
73
What are the 4 cell types made up by the reticular meshwork of lymph nodes?
1 reticular ells
2 dendritic cells
3 macrophages
4 follicular dendritic cells
74
Dendritic cells are __ derived
bone marrow
75
Follicular dendritic cells
| - are these true antigen presenting cells
no
76
Follicular dendritic cells have multiple thin cytoplasmic processes that are associated with
lymphocytes
because on the lymphocytes = antigens
77
IN LYMPH NODE:
Primary cell found in nodular cortex ____
Primary cell found in deep cortex ____
Primary cell found in medulla ____
b lymphocytes = nodular
t lymphocytes - deep
b cell = medulla
B --> T --> B
78
Where can lymph enter the lymph node?
Where can lymph exit the lymph node?
afferent lymphatic vessels = anywhere along capsule of lymph node
efferent lymphatic vessels = must exit @ hilum
79
When lymph enters along the capsule, it immediately enters the ____
subcapsular (cortical) sinus
80
When lymph is in the subcapsular (cortical) sinus in the lymph node, it turns and drains into the ____
trabecular sinus (along the trabeculae)
81
When lymph is in the trabecular sinus in the lymph node, it then drains into the ____
medullary sinus
82
From the medullary sinus, the lymph drains into the ___
efferent lymphatic vessel at the hilum
83
___% of lymphocytes enter lymph node via lymph pathway
__% of lymphcotes enter lymph node through high endothelial venules
10% = through lymph pathway
90% = through high endothelial venules
84
What are high endothelial venules?
ENDOTHELIAL VENULES
- except lined with cuboidal/columnar instead of simple squamous
- found in deep cortex
- leave through medullary sinus --> efferent lymphatic vessels
85
Thymus gland is __-lobed
Located in ___
Posterior to ___
Anterior to ____
bi lobed
in mediastinum
posterior to sternum
anterior to trachae/greatr vessels
86
What happens to the thymus as we age?
thymus is very important in childhood
it atrophies w/ age and is replaced by adipose tissue
87
What is the function of the thymus gland?
thymic cell education
| t cellls mature and differentiate into immunocompetent t cells
88
Where does thymic cell education take place?
What happens during thymic cell education?
thymus gland
this is when t cells mature and differentiate into immunocompetent t cells
89
The thymus is an organ (so it has a capsule)
Capsule sends off trabeculae which sections the thymus into ____
thymic lobules
90
Each thymic lobule has a an outer ___ region and an inner ___
outer cortex
inner medulla
91
T/F: Each thymus gland has 1 cortex and 1 medulla
false
| 1 cortex and 1 medulla PER THYMIC LOBULE
many thymic lobules per thymus gland
92
What are thymocytes? Where are they found?
thymocytes = immature t cells found in cortex of thymic lobules
93
Thymic lobule:
why does the cortex stain dark?
why does the medulla stain light?
cortex stains dark bc contains thymocytes
medulla stains light because contains more mature t cells (more cytoplasm)
94
What is the pathway of thymocytes?
begin in cortex if thymic lobule
move towards medulla for education
once matured, leave thymus gland altogether to aggregate in other areas
95
Is the stroma of thymus glands made up of reticular fibers?
no!
96
What is the stroma of the thymus gland made up of?
epitheleoreticular cells create a framework for lymphocytes to hang from
97
Epitheleoreticular cells make up what?
What are the 6 diff types of these cells/where are they found?
make up stroma of thymus gland
types 1, 2, 3 - in cortex of thymic lobule
types 4, 5, 6 - in medulla of thymic lobule
98
Epithelioreticular cells form _____
extensive meshwork in thymus
99
Type 6 epithelioreticular cells form ____
thymic (hassal's) corpuscles
100
Describe thymic (hassal's) corpuscles and how they are formed
type 6 epithelioreticular cells arrange in concentric flattened circles
fill with keratinohyoid granules -- fill with keratin! the are dying
101
Thymic (hassal's) corpuscles are found ____
in the medulla of thymic lobules of thymus
102
What is the function of the spleen
filter and monitor blood immunologically just as the lymph node monitors lymph
103
___ is the largest mass of lymphatic tissue in the body
spleen
104
The capsule of the spleen contains myofibroblasts.
Why are myofibroblasts here?
fibroblasts - produce dense ct
myo - actin, to contract/expel things from spleen
105
What are the 2 main parts of the spleen?
1. red pulp
| 2. white pulp
106
What are the 2 main parts of the red pulp of spleen?
1. splenic sinuses
| 2. splenic (billroth's) cords
107
Splenic sinus of red pulp of spleen.
What kind of sinus?
Surrounded by __?
blood-filled venous sinus
surrounded by cords
108
Splenic (billroth's) cords of red pulp of spleen
consist of what kind of cells?
consists of red blood cells, macrophages, lympocytes, plasma cells, granulocyte
109
what is the main role of splenic (billroth's) cords of red pulp of spleen
filtration!
removal of particulate materials, removal of antigens, removal of worn-out or defective RBCs, WBCs, platelets
(red pulp and white pulp split these functions)
110
The white pulp of the spleen is ___ tissue consisting mostly of ____
lymphatic tissue
mostly lymphocytes
111
Lympocytes in the white pulp aggregate around ____
central arteries (branches of splenic arteries)
112
Branches of splenic arteries are called ____
What aggregates around these? Where/
central arteries
lymphocytes aggregate around these in teh white pulp of the spleen
113
The aggregation of lymphocytes around central artery are called ____
periarterial lymphatic sheaths (PALS)
114
What are periarterial lymphatic sheaths (PALS)? where are they found?
aggregation of lymphocytes around the central artery in the white pulp of spleen
115
What is the function of the white pulp of the spleen?
carry out immune functions similar to lymph nodes
