Lymphatic System Flashcards
1
Q
general functions of the lymphatic system
A
- picks up fluid left behind in interstitial space so it doesnt accumulate –> gets it back into circulation
- assists immune system in making sure we get rid of foreign things causing us illness
2
Q
components of the lymphatic system
A
lymph
lymphatic vessels
lymphoid tissues and organs
3
Q
lymph
A
fluid component of lymphatic system
4
Q
lymphatic vessels
A
contain/carry lymph
some go through lymphatic organs to be filtered
branch from smaller to larger
5
Q
lymphatic vessels branch from ___ to ____
A
smaller to larger
6
Q
3 possible functions of lymphoid tissues and organs
A
filter lymph
filter blood
filter things we are swallowing/breathing
7
Q
how is edema caused?
A
if fluid leaks out in capillary bed and isn’t taken up by lymphatic vessels, there is a continual leakage of that fluid which causes edema
8
Q
primary objective of lymph; secondary objective of lymph
A
- maintain fluid volumes
2. filter the fluid to assist immune system
9
Q
difference between lymphatic circulation and blood circulation
A
lymphatic circulation only goes in one direction
from the body to the thoracic cavity
10
Q
t/f there is a pump that helps lymph move back to the thoracic cavity
A
false
11
Q
lymph is the ____ components of plasma
A
escaped
12
Q
how does plasma fluid become lymph?
A
some plasma escapes circulation, accumulates in interstitial spaces, and is taken up by lymph vessels which take it back to circulation
13
Q
why may lymph have proteins in it?
A
because it doesn’t just come from plasma; it comes from cells and extracellular transports too
picks up proteins from interstitial fluids
14
Q
how do proteins enter into circulation
A
fluid picks up proteins from interstitial fluids, then gets into lymph
lymph is dumped into circulatory system, then proteins enter circulation
15
Q
t/f lymphatic vessels deliver lymph to and from the thoracic cavity
A
false! lymphatic vessels are only involved in one-way flow toward the heart
16
Q
smallest of all lymphatic vessels
A
lymphatic capillaries
17
Q
characteristics of lymphatic capillaries
A
formed by a single layer of loosely overlapping endothelial cells (like shingles on a roof)
anchored by collagen filaments/fibers
dead-ended structures that allow lymph to move in; start pushing by pressure
18
Q
why are lymphatic capillaries anchored by collagen filaments?
A
so that they can pivot, which creates an opening which allows fluid to move into capillaries
19
Q
why are lymphatic capillaries said to be “dead-ended”?
A
there is no capillary bed
they can only move things in and go in one direction
20
Q
what is the minivalve system?
A
lymph movement mechanism in lymphatic capillaries
21
Q
how does the mini valve system work?
A
Fluid coming into capillary creates pressure, which pushes lymph along vessels:
- lymphatic capillaries pivot, creating an opening for fluid to move into capillaries
- accumulation of pressures of fluids cause things to enter or be moved through lymph capillary
- once enough fluid is inside, it pushes those back closed
22
Q
lacteals
A
lymphatic capillaries of the intestinal walls (in villi)
23
Q
chyle
A
lymph in lacteals (intestinal lymph)
composition of chyle is different than the lymph in the rest of the body because it has a different fat composition
24
Q
villi
A
fingerlike projections into lumen of intestine
contain lacteals
25
why does the intestinal "tube" have villi?
villi increase the surface area so we can absorb more nutrients
26
we can move *which nutrient* into lymph system at a higher rate than other things from the intestines?
digested fats!
27
how does nutrient digestion work? (generally)
- we absorb fluid and digested nutrients out of intestines
- nutrients are are absorbed into lacteals
- nutrients become part of lymph (esp digested fats)
28
lymphatic capillaries merge into ________
lymphatic collecting vessels
29
how many tunics are in lymphatic collection vessels?
3
30
walls of lymphatic collecting vessels are ____ than veins
thinner
31
lymphatic collecting vessels are most similar to which circulatory vessel?
veins
32
t/f lymphatic collecting vessels contain valves
true! they contain more valves than veins!
33
why do lymphatic collecting vessels have more valves than veins?
because lymph is under VERY low pressure
34
lymphatic collecting vessels empty into ______
lymphatic trunks
35
lymphatic trunks
lymphatic vessels which drain relatively large areas of the body
all lymphatic collecting vessels empty here
36
t/f lymphatic trunks drain and supply large areas of the body
false! they only DRAIN
37
all lymphatic trunks empty into 2 major _______
lymphatic ducts
38
major lymphatic trunks are named based on _______
the part of the body that they drain
39
5 major lymphatic trunks
```
1 bronchomediastinal
2 subclavian
3 jugular
4 lumbar
5 intestinal
```
40
bronchomediastinal lymphatic trunk drains which area of the body?
thoracic cavity
41
subclavian lymphatic trunk drains which area of the body?
upper limbs
42
jugular lymphatic trunk drains which area of the body?
head/neck
43
lumbar lymphatic trunk drains which area of the body?
lower extremities
44
intestinal lymphatic trunk drains which area of the body?
abdominal cavity
45
2 lymphatic ducts
right lymphatic duct
| thoracic duct
46
right lymphatic duct drains which areas of the body?
head
upper arm
thorax
47
thoracic duct drains which parts of the body?
everywhere OTHER THAN WHERE R LYMPHATIC DUCT DRAINS
| rest of body EXCEPT head, upper arm, thorax
48
t/f thoracic duct drains the thorax
false! the r lymphatic duct drains the thorax, along with the head and upper arm
49
cisterna chyli
saclike structure that is basically the beginning of thoracic duct, lower in the body
50
the right lymphatic duct and thoracic duct are located where?
on opposite sides of the neck
51
the right lymphatic duct and thoracic duct both feed into the same spot; where is it?
junction between the jugular vein and subclavian vein
52
where does lymph empty into the veins?
junction between jugular vein and subclavian vein
| this is where lymphatic ducts feed into
53
why do the lymphatic ducts empty into circulation at the junction between jugular and subclavian veins?
this is the place where pressure of blood in veins is lower than pressure of lymph
just before getting to the heart, so vein bp is reallllyyyyy low
54
factors assisting lymphatic flow (what helps push lymph toward junction drain)
```
1 valves
2 muscular pump
3 respiratory pump
4 arterial pumping
5 smooth muscle contraction
```
55
which vessel in the lymphatic system contains valves?
lymphatic collecting vessels
56
order of lymphatic vessels from smallest to largest
lymphatic capillaries
lymphatic collecting vessels
lymphatic trunks
lymphatic ducts
57
if you have a cold, why is it good to increase physical activity?
movement of skeletal muscles pumps the lymph more, so it gets filtered more, which is good for the immune system!
58
lymphedema
if lymph is not circulating properly, lymph may accumulate in an area because it is not moving
59
muscular pump of lymphatic system
action of skeletal muscle
as we move skeletal muscle, the muscle pushes against lymphatic vessels and squeezes/pushes lymph toward the thoracic cavity
60
lymphedema is caused by failure to utilize which factor in assisting lymph flow?
muscular pump
61
respiratory pump of lymphatic system
change in pressure in thoracic cavity causes fluids to move in
62
arterial pumping mechanism
pumping of blood in arteries helps flow of lymph in lymphatic vessels:
- the heart pushes blood out during systolic ejection
- the blood goes through arteries in waves
- when blood pushes into lymphatic vessels, it can push the lymph because of this force
63
how does smooth muscle contraction help with lymphatic flow?
in lymphatic trunks and thoracic duct, smooth muscle contracts in peristaltic waves
this milks the vessels to push lymph in one direction
64
all blood cells are produced where?
bone marrow
65
types of lymphocytes
b cells
| t cells
66
lymphatic system accumulates ______ and can do its immune function by finding and attacking antigens
lymphocytes
67
what type of cell is a lymphocyte?
white blood cell
68
where are b cells produced?
| where do b cells become immunocompetent?
produced in red bone marrow
| become immunocompetent in bone marrow
69
where are t cells produced?
| where do t cells become immunocompetent?
produced in red bone marrow
| leave bone marrow; become immunocompetent in thymus
70
primary lymphatic organs
bone marrow and thymus
71
primary lymphatic organs are where ________ occurs
immunocompetence of B cells and T cells
72
secondary lymphatic organs are where _____ occurs
where cells go after becoming immunocompetent to "hang out"
73
immunocompetency
an immature naive lymphocyte gets a receptor on its surface, which is specific to be able to grab hold of a certain thing (antigen)
aka maturing
74
what does it mean that lymphocytes are "genetically programmed" to grab hold of a certain antigen?
we do not need to come into contact with the specific antigen to have made the cells that fight them
75
how do we get the receptors which make lymphocytes immunocompetent?
- receptors are proteins, which are products of DNA
| - the wbc's DNA contains program to produce the protein that gets incorporated into surface of cell
76
types of lymphoid cells
lymphocytes
macrophages
dendritic cells
reticular cells
77
macrophages
lymphoid cells which started as monocytes, then went through diapedesis and became a phagocytic cell
78
which lymphoid cells directly interact with the "invading cells"
macrophages and dendritic cells
79
phagocytic cells
macrophages and dendritic cells
80
why are macrophages and dendritic cells considered "active, functional cells?"
they get rid of cellular debris and attack/consume foreign things
81
t/f reticular cells directly interact with the antigen
false
82
what type of tissue are reticular cells made of?
reticular tissue
83
function of reticular cells
they make a lattice/mesh to hold all other cells in space
| this mesh is called a stroma
84
stroma
a network of reticular fibers that supports other cells
occurs in localized places in lymphatic organs
has different names in different places
85
t/f reticular cells produce a lattice that covers the entire lymphatic organ
false; it is confined to localized places in lymphatic organs
86
most tissue in lymphatic structures is ________
diffuse lymph tissue
87
what is embedded in diffuse lymph tissue?
clusters of reticular fibers, which allow the accumulation of active cells
88
clusters of reticular fibers are also known as
nodes
germinal centers
stroma
89
functions of lymphoid tissue
proliferation site for lymphocytes
| allows detection of infection or damage
90
what does it mean that lymphoid tissue is the proliferation site for lymphocytes?
lymphocytes are attracted to this area and accumulate here
91
which lymphocytes proliferate in lymphoid tissue?
macrophages and dendritic cells
92
how does lymphoid tissue allow for detection of infection/damage?
lymph passes by nodes (area where all the cells are hanging out)
if anything foreign is in the lymph, the cells can attack it and get rid of it
93
_____ are like TSA security
nodes
94
what does the node look like?
reticular fibers create web to hold all other cells in place
macrophages are attached and held in place by reticular fibers
lymphocytes are in between fibers, but unattached
95
lymphoid organs
```
lymph nodes
spleen
thymus
tonsils
peyers patches
```
96
principal lymphatic organs of the human body
lymph nodes
97
how many (ballpark) lymph nodes are in the human body
100s to 1000s
98
vessels pass through many ____ before being dumped into circulation
lymph nodes!
99
what do lymph nodes filter?
lymph!
100
how do lymph nodes filter lymph?
while the lymph flows through, a bunch of immune-type cells are hanging out in reticular centers to detect and act on any antigens
101
3 reasons why we can live without the spleen
- filtering lymph can be handled by lymph nodes
- recycling RBCs can be handled by liver
- storage of things (like platelets) can occur in other areas of body
102
largest lymphatic organ
spleen!
| it is the size of ur fist :)
103
how is lymph supplied to the spleen?
by blood!
104
what does the spleen filter? how?
blood!
- blood moves into spleen
- plasma moves out of circulation and gets filtered by spleen
- then plasma moves back into circulation
105
the spleen filters ___ by filtering ____
blood; lymph
106
which works more on blood: spleen or lymph nodes?
spleen
107
what is in the spleen to help it filter?
lymphocytes, macrophages, etc
| all hanging out
108
secondary functions of the spleen
- recycling RBCs (breaking down and removing old/defective RBCs and platelets)
- storing things like platelets
- embryo's site of RBC production
109
site of RBC production in embryo? why?
spleen! because it does not have bone marrow!
110
what does the thymus filter?
NOTHING! (tricked ya lolz)
111
how does thymus activity change as we age?
functions most early in life, then deteriorates with age
112
major function of thymus
promote immunocompetence in T lymphocyte cells
113
how long can immunocompetence last in T cells?
over 70 years :)
114
t/f we have one set of tonsils
false! we have several ~
115
where is the major set of tonsils located? do they get infected most or least?
palatine tonsils- in back of mouth next to uvula
| they get infected the most
116
function of tonsils
filter food/drinks we are swallowing and air we are inhaling
117
where are Peyers patches located?
in distal (far) portion of small intestine, into the large intestine (even into the appendix!)
118
what do peyer's patches do?
food we are eating could be contaminated with bacteria
as we absorb that food, it passes through peyers patch
if bacteria present --> immune system activated
119
what happens when peyer's patches activate B and T immune cells?
B and T cells produce memory cells
120
memory cells
cells produced by B and T immune cells that give us long term immunity for the things we came into contact with that could be infectious
121
lymph node action
1. lymph enters node via afferent lymphatic vessels
2. lymph filters through sinuses/germinal centers
3. lymph exits through efferent lymphatic vessels at hilus
122
afferent vessels on lymph node
where lymph arrives
empty lymph into lymph node
more than 2 on each node
123
after lymph ultimately passes out of lymph node, efferent vessels may become ______ for another lymph node
afferent vessels
124
hilus
indentation part of lymph node's bean-like structure
| where efferent vessels exit node
125
areas where lymph nodes accumulate
neck
maxilla
armpits
inguinal region (between legs)
126
when lymph moves into nodes, if it has antigens what happens?
it initiates an immune response and lymph node inflames
127
spleen action
1. blood delivered directly to spleen via splenic artery
2. lymph filtered by lymphocytes in white pulp
3. lymph then filtered by macrophages in red pulp
4. cleansed fluid returns to splenic vein
128
blood leaks out of blood vessels in spleen and gets filtered by _______
white pulp
129
white pulp
found immediately surrounding arteries supplying spleen
consists mostly of lymphocytes
filters lymph first
130
red pulp
found immediately surrounding white pulp
made of mostly RBCs, also macrophages
filters lymph after white pulp
131
blood path from heart to spleen to heart
```
heart
abdominal artery
~ (not directly)
splenic artery
spleen
splenic vein
inferior vena cava
heart
```
132
thymus action is most prominent in _____
newborns
133
thymus action
secretes thymosin and thymopoietin
| causes t lymphocytes to become immunocompetent
134
role of thymosin and thymopoietin
stimulate hemocytoblast to start producing WBCs
| cause t lymphocytes to become immunocompetent
135
immunocompetent t lymphocytes help us fight against _______
antigens we have never seen before
136
tonsils are named after ____
their location
137
when is taking tonsils out a good thing?
if tonsils are the site of constant infection, then they're the problem
138
palatine tonsils
paired set found near uvula
| largest; get infected most often; get removed most often
139
largest tonsils
palatine tonsils
140
which tonsils get removed most often?
palatine
141
lingual tonsils
paired set
found at base of tongue (further back than palatine)
along food/drink path
142
pharyngeal tonsil (adenoids)
only 1 tonsil! (NOT PAIRED)
| on posterior wall of nasopharynx
143
if palatine tonsils are taken out, what other tonsil(s) is also usually removed?
adenoids/pharyngeal tonsil
144
pharyngeal tonsil is also known as
adenoids
145
tubal tonsils
found along passageway that connects middle ear to pharynx (eustachian tube)
146
tonsil histology
follicles with germinal centers
| crypts
147
tonsil crypts
dead end pathways
| food/air we swallow goes through here --> if pathogens, they pass through here
148
tonsil action
1. crypts trap bacteria and particulates
2. bacteria pass through epithelium into lymphoid tissue
3. lymphoid tissue destroys pathogens
4. memory cells formed
149
what are peyer's patches
isolated clusters of lymphoid follicles in intestines
they destroy bacteria
they generate memory lymphocytes
150
lymphatic development (process)
1. developing veins bud off lymph sacs at fifth week
2. these form branching system of lymphatic vessels
3. connection of jugular lymph sac with jugular veins become right lymphatic duct and thoracic duct
4. lymphoid organs develop from mesodermal mesenchyme that become reticular tissue (except thymus!)
151
first lymph sacs to form
jugular lymph sacs
| this is where it'll all eventually connect
152
where do lymph sacs form from?
developing veins
vena cava
iliac veins
153
first lymphatic to appear in development
thymus
154
development of thymus
```
endodermal origin (started as part of pharynx, then detached/moved)
thymus secretes chemicals to develop other lymph organs
```
155
when do lymphocytes start to populate at secondary lymph organs?
after birth
156
when do lymphocytes start to populate at thymus?
before birth
