lymphatic system Flashcards
1
Q
beginnings of lymphatic vessels & main clusters of lymph nodes seen by __________ of embryonic development
A
week 5
2
Q
arises as ___________ from developing veins
A
lymph sacs
3
Q
jugular lymph sacs arises to form__________________ and ________________.
A
right lymphatic duct
thoracic duct
4
Q
lymphatic organs (except thymus) arises from _________.
A
mesoderm
5
Q
the lymphatic system is developmentally an off shoot of the ______________________.
A
venous system
6
Q
in the human embryo there are 6 lymph sacs from which the lymphatic vessels are derived:
A
jugular (paired)
posterior lymph (paired)
retroperitoneal
cisterna chyli
7
Q
lymphoid organs develop from __________________________.
A
mesodermal mesenchymal cells
8
Q
thymus (endodermal origin) forms as an ___________________.
A
outgrowth of pharnyx
9
Q
except for ________ and ________, lymphoid organs are poorly developed at __________.
A
spleen
tonsils
birth
10
Q
after birth, HIGH numbers of _______________ appear; their development parallels with what?
A
lymphocytes
maturation of immune system
11
Q
what does the lymphatic system do?
A
returns fluids leaked from blood vessels back to blood
12
Q
lymphatic system consists of 3 parts
A
- network of lymphatic vessels (lymphatics)
- lymph
- lymph nodes
13
Q
what is a lymph?
A
fluid in vessels
14
Q
lymph nodes
A
cleanse lymph
15
Q
what do lymphoid organs and tissues provide?
A
structural basis of immune system by housing phagocytic cells and lymphocytes
16
Q
structures include . . .
A
spleen, thymus, tonsils, lymph nodes, other lymphoid tissues
17
Q
lymphatic system returns interstitial fluid and leaked plasma proteins back to the blood via:
A
lymphatic vessels
18
Q
what are lymphatic vessels?
A
elaborate network of drainage vessels
19
Q
lymphatics circulates ________ interstitial fluid per day
A
~ 3 L
20
Q
____% via the ______ duct
A
75%
thoracic
21
Q
____% via the _____________ duct
A
25%
right lymphatic
22
Q
once interstitial fluid enters lymphatics it is called what?
A
lymph
23
Q
lymphatic vessels offer a _____________ ensuring lymph flows only toward the _________.
A
one-way system
heart
24
Q
lymph vessels include _____________ and _______________.
A
lymphatic capillaries
larger lymphatic vessels
25
what are lymphatic capillaries ?
blind-ended vessels that weave between tissue cells and blood capillaries
26
lymphatic capillaries are absent from ________, _________, & ________________.
bones
teeth
bone marrow
27
lymphatic capillaries are similar to blood capillaries, but are . . .
more permeable
28
lymphatic capillaries main function is to . . .?
absorb fluid in lymph formation
29
where do lymphatic capillaries originate?
in close proximity to blood capillaries in the interstitial spaces
30
lymphatic capillaries do NOT contain __________.
valves
31
what can lymphatic capillaries take up that blood capillaries CANNOT
larger molecules & particles
ex: proteins, cell debris, pathogens & cancer cells
32
can act as route for _________ or _________ to travel throughout the ______.
pathogens
cancer cells
body
33
lymphatic capillaries have increased permeability due to two specialized structures:
1. endothelial cells overlap loosely to form one-way minivalves
2. minivalves are anchored by collagen filaments to matrix, so increases in ECF volume opens minivalves even more
34
increased ECF causes
minivalves to open
35
decreased ECF causes
minivalve to close
36
what are lacteals?
specialized lymph capillaries present in intestinal muscosa
37
what do lacteal absorb?
digested fat & deliver fatty lymph (chyle) to the blood
38
lymph capillaries drain into increasingly larger vessels called . . .
collecting lymphatic vessels
39
larger lymphatic vessels consists of collecting . . .
vessels, trunks, and ducts
40
large lymphatic vessels have structures and tunics similar to veins except:
have thinner walls, with more internal valves
anastomose more frequently
40
collecting vessels in skin travel with ________________, but deep vessels travel with ________.
superficial veins
arteries
40
lymphatic trunks are formed by
union of largest collecting vessels, drain large areas of body
41
what region of the body do lumbar trunks drain?
lymph from the lower extremities, lower body quadrants, external genitalia
42
what region of the body do bronchomediastinal trunks drain?
lymph from the lungs, heart, trachea and mammary glands
43
what region of the body do subclavian trunks drain?
lymph from upper extremities, upper body quadrants, shoulder region, mammary glands
44
what region of the body do jugular trunks drain?
lymph from head and neck
45
what region of the body do intestinal trunk drain?
lymph from stomach and digestive system, liver and pancreas
46
where is cisterna chyli located?
abdominal origin of the thoracic duct
~ T11-L2 region
47
how long and wide is cisterna chyli?
~ 3-8cm long
~ 0.5-1.5cm wide
48
cisterna chyli receives lymph from where?
the lumbar trunks and the intestinal trunk
49
lymph is delivered from trunks into one of two large lymphatic ducts which are . . .?
right lymphatic duct
thoracic duct
50
what does the right lymphatic duct drain?
right upper arm and right side of head and thorax
51
what does the thoracic duct drain?
rest of the body
52
in about half of individuals, the thoracic duct starts out as what? and what is it called?
enlarged sac
cisterna chyli
53
where does the thoracic duct empty into?
the blood at the junction of the left internal jugular and subclavian veins
54
where does the right lymphatic duct empty into?
the blood at the junction of the right internal jugular and subclavian veins
55
what is the largest lymphatic vessel in the body?
thoracic duct
56
what is the length and width of the thoracic duct?
36-45 cm in length
1-5 cm in width
57
the thoracic duct perforates the __________ and runs through the _______________________.
diaphargm
chest to the left venous angle
58
where is the thoracic duct located?
to the left and anterior to the spine
59
the thoracic duct transport lymphatic loads from where?
right and left lower quadrants, left upper quadrant, left head and neck
60
how long is the right lymphatic duct in length?
1-2.5 cm in length
61
the right lymphatic duct is formed from where?
the confluence of the right jugular, supraclavicular, subclavian, & parasternal trunks
62
where is the right lymphatic duct located?
at the area of the right venous angle
63
what does the right lymphatic connect with?
the venous system at the right venous angle
64
the right lymphatic transports ______ of the daily lymphatic load
25%
65
the lymphatic duct transport lymph from where?
the right upper quadrant, right head and neck
66
lymphangitis:
condition in which lymphatic vessels appear as painful red lines under the skin
67
lymphangitis is inflammation of what?
the lymph vessels
68
why is lymphangitis potentially dangerous?
because it is uncontained infection that may lead to septicemia
69
lymphangitis is caused by what?
inflammation of larger lymphatic vessels that contain vaso vasora
70
what happens to the vaso vasora?
become congested with blood
71
larger lymphatics, like blood vessels, receive their nutrients from where
branching vasa vasorum
72
lymph system is a ___________ system like venous system
low-pressure
73
physical activity _________ flow of lymph; _____________ of area keeps needed inflammatory material in area for ____________.
increases
immobilization
faster healing
74
lymphedema:
severe localized edema
75
lymphedema is caused by what?
anything that prevents normal return of lymph to blood
76
what is the difference between regular swelling & lymphedema
protein rich fluid
77
common causes of lymphedema:
parasites
breast cancer surgery / radiation
primary lymphedema
78
what do lymphoid cells consist of what two types of cell?
immune system cells
supporting cells
79
where are immune system cells found?
lymphoid tissue
80
where are supporting cells found?
lymphoid tissue structures
81
immune system cells consists of what?
lymphocytes
82
what are lymphocytes?
cells of the adaptive immune system
83
lymphocytes mature into one of two main types of cells. . . what are they?
T cells
B cells
84
T cells and B cells protect against what?
antigens
85
what do T cells do?
manage immune response & some also attack & destroy infected cells
86
what do B cells do?
produce plasma cells, which secrete antibodies
87
what are some other lymphoid immune cells?
macrophages
dendritic cells
88
what are macrophages ?
phagocytize foreign substances and help activate T cells
89
what are dendritic cells?
capture antigens & deliver them to lmyph nodes; also help activate T cells
90
what is a supporting lymphoid cell?
reticular cells
91
what are reticular cells?
produce reticular fibers called stroma in lymphoid organs
92
what are stroma?
network-like support that acts as scaffolding for immune cells
93
what are the main functions of lymphoid tissue?
1. houses and provides proliferation sites for lymphocytes
2. offers surveillance vantage points for lymphocytes and macrophages as they filter through lymph
94
lymphoid tissue is largely composed of what ?
reticular connective tissue which is a a type of loose connective tissue
95
where do macrophages live?
on reticular fibers
96
reticular connective tissue dominates what?
all the lymphoid organs except the thymus
97
what the two main types of lymphoid tissue?
1. diffuse lymphoid tissue
2. lymphoid follicles (nodules)
98
what is diffuse lymphoid tissue?
loose arrangement of lymphoid cells and some reticular fibers
99
where is diffuse lymphoid tissue found?
in virtually every body organ
larger collections in lamina propria of mucous membranes
100
what are lymphoid follicles (nodules)?
solid, spherical bodies consisting of tightly packed lymphoid cells and reticular fibers
101
lymphoid follicles contain _________ of proliferating B cells
germinal centers
102
what are primary lymphoid organs?
areas where T and B cells matures ---- red bone marrow and thymus
103
where do T and B cells originate?
in bone marrow, but only B cells mature there; T cells mature in thymus
104
what are secondary lymphoid organs?
areas where mature lymphocytes first encounter their antigen and become activated
105
examples of secondary lymphoid organs . . .
nodes, spleen, MALT & diffuse lymphoid tissues
106
largest collections of MALT are found in?
tonsils
peyer's patches
appendix
107
what are lymph nodes?
principal secondary lymphoid organs of body
108
where are lymph nodes embedded?
deep in connective tissue in clusters along lymphatic vessels
109
lymph nodes can _______ or ________ in size during life
increase or decrease
110
examples of regional lymph nodes?
cervical, axillary, inguinal lymph nodes
111
two main functions of lymph nodes?
1. cleansing the lymph
2. immune system activation
112
macrophages ________ and ________ microorganisms and debris that enter lymph
remove and destroy
113
what is immune system activation?
offer a place for lymphocytes to become activated and mount an attack against antigens
114
what are lymph nodes surrounded by?
external fibrous capsule
115
capsule fibers extend inward as what ?
trabeculae that divide node into compartments
116
two histologically distinct regions of node:
cortex
medulla
117
what does the superfical area of cortex contain?
follicles with germinal centers that are heavy with dividing B cells
118
what does the deep cortex house?
T cells in transit
119
T cells circulate continuously among ________, __________, and _________
blood, lymph nodes, and lymph
120
abundant numbers of dendritic cells are closely associated with ?
both T and B cells
121
medullary cords extend inward from _________ and contain . . .
cortex
B cells, T cells and plasma cells
122
what are found throughout lymph node?
lymph sinuses
123
circulation in the lymph nodes:
1. lymph enters convex side of node via . . .
afferent lymphatic vessels
124
Circulation in the lymph nodes:
2. travels through large _________________ and then into smaller sinuses found throughout cortex and medulla
subcapsular sinus
125
circulation in the lymph nodes:
3. lymph then enters . . .
medullary sinuses
126
circulation in the lymph nodes:
4. finally exits concave side at _______ via _______________________.
hilum
efferent lymphatic
127
buboes:
inflamed, swollen, tender lymph nodes that result when nodes are overwhelmed by what they are trying to destroy
128
dark blotches = . . . . =
acral necrosis
black death
129
lymphadenopathy
enlargement of superficial lymph nodes
130
lymph nodes can become secondary what?
cancer sites if metastasizing cancer cells become trapped in node
131
what is the spleen?
blood-rich organ about size of fist
132
where is the spleen located?
in left side of abdominal cavity, just below stomach
133
the spleen is served by ____________ and _____, which enter and exit at the ________.
splenic artery
vein
hilum
134
spleen functions:
1. site of lymphocyte proliferation and immune surveillance and response
2. cleanses blood of aged blood cells and platelets; macrophages remove debris
135
three additional functions of spleen:
1. stores breakdown products of RBC for later resuse
2. stores blood platelets and monocytes for release into blood when needed
3. may be site of fetal erythrocyte production
136
spleen is encased by ________________ and also has ___________.
fibrous capsule
trabeculae
137
spleen consists of two components:
1. white pulp
2. red pulp
138
what is a white pulp?
site where immune function occurs
139
white pulp contains mostly . . .
lymphocytes on reticular fibers
140
what is a red pulp?
site where old blood cells and bloodborne pathogens are destroyed
141
red pulp is rich in . . .
RBCs and macrophages that engulf them
142
red pulp is composed of ___________ that separate blood-filled ____________________.
splenic cords
splenic sinusoids
143
the spleen has a ________ capsule, so direct blow or severe infection may cause it to . . .
thin
rupture, spilling blood into peritoneal cavity
144
splenectomy:
surgical removal of ruptured spleen
145
if spleen must be removed then ________ and ____________ take over most of its functions
liver
bone marrow
146
mucosa-associated lymphoid tissue (MALT)
lymphoid tissues in mucous membranes throughout body
147
what does the MALT do?
protects from pathogens trying to enter body
148
MALT is found in . . .
respiratory tract, genitourinary organs, and digestive tract
149
what are the simplest lymphoid organs?
tonsils
150
what do tonsils do?
form ring of lymphatic tissue around pharynx; appear as swellings of mucosa
151
palatine tonsils
at posterior end of oral cavity
152
which tonsil is the largest and most often infected?
palatine tonsils
153
types of tonsils:
palatine
lingual
pharyngeal
tubal
154
lingual tonsil
lumpy collection of follicles at base of tongue
155
pharyngeal tonsil
also called adenoids; located in posterior wall of nasopharynx
156
tubal tonsils
surround openings of auditory tubes into pharynx
157
what is tonsils function?
to gather and remove pathogens in food or air
158
tonsils are ___________ encapsulated
not fully
159
overlying epithelium invaginates, forming . . .
tonsillar crypts
160
peyer's patches
clusters of lymphoid follicles in wall of distal portion of small intestine
161
peyer's patch are also called . . .
aggregated lymphoid nodules
162
the number of peyer's patches peak at age ________ and then declines during ____________.
15-25
adulthood
163
peyer's patches location aids in which functions?
1. destroy bacteria, preventing them from breaching intestinal wall
2. generate "memory" lymphocytes
164
appendix:
offshoot of first part of large intestine
165
appendix contains a large number of . . .
lymphoid follicles
166
appendix location aids in functions that are the same as . . . .
peyer's patches
167
primary lymphoid organs :
thymus
red bone marrow
168
secondary lymphoid organs :
lymph nodes
tonsils
spleen
peyer's patches
appendix
169
thymus
bilobed lymphoid organ found in inferior neck
- extends into mediastinum and partially overlies heart
170
the thymus functions as ____________ where T cells ___________
lymphoid organ
mature
171
thymus is broken into lolubes that contain _________________ and ______________.
outer cortex
inner medulla
172
the cortex contains what?
rapidly dividing lymphocytes and scattered macrophages
173
medulla contains fewer _________ and ____________
lymphocytes
thymic corpuscles
174
thymic corpuscles are where ___________________ develop
regulatory T cells
175
regulatory T cells:
type of T cell that helps prevent autoimmunity
176
how does the thymus differ from other lymphoid organs:
1. has no follicles because it lacks B cells
2. does not directly fight antigens
3. stroma is made up of epithelial cells, not reticular fibers
177
thymus functions strictly in . . .
T lymphocyte maturation
178
T lymphocyte contains . . .
blood thymus barrier
179
blood thymus barrier:
keeps immature T lymphocytes isolated from any antigens to prevent premature activation
180
what is stroma made up of?
epithelial cells
181
