chapter 22 Flashcards
lymphatic system
-4 components
- lymph
- lymphatic vessels
- lymphoid tissues and organs
- lymphocytes
lymph
- known as
- similar to what
- interstitial fluid
- similar to plasma but contains lower amounts of protein
lymphocytes
provide defense against infections and other environmental hazards
3 functions of lymphatic system
- fluid balances
- fat absorption
- defense
fluid balance
-entering and exiting
more fluids exit the capillaries than is reabsorbed
-extra fluid enters the lymphatics and is returning to the blood
fat absorption
-where does it absorb fat from
digestive system
defense
- what filters microorganisms
- what are defense cells called
microorganisms are filtered from lymph by lymph nodes and from blood by spleen
-lymphocytes
hydrostatic pressure
- definition
- what does high HP do
the pressure exerted by a liquid in response to an applied force
-tends to force H2O out of solution
what contributes to hydrostatic pressure of the capillaries
blood pressure
osmotic pressure
- definition
- what does indication of the force do
- what does high OP do
- the pressure is required to stop the flow of water by osmosis
- moves the water into a solution because of its solute concentration
- tends to draw H2O into a solution into a solution
what contributes to the osmotic pressure of the blood
plasma proteins (mostly albumins)
Arterial side
- water moves in or out
- hydrostatic pressure __ osmotic pressure
- fluid in capillary
- produces ___L/day of filtrates
- moves out
- greater than
- is forced out of capillary = filtration
- 24 L/day
Venule side
- water moves in or out
- hydrostatic pressure __ osmotic pressure
- fluid is
- produces ___ L/day of filtrates
- in
- less than
- forced into capillaries = reabsorption (occurs because of osmosis)
- 20.4 L/day
what is the difference in liters produced by the arterial side and the venule side
-what is done with it
- difference of ~3.6 L/day of fluid
- it is reabsorbed into lymphatics and returned to blood
Lymphatic vessels
-definition
carry lymph from peripheral tissues to the venous system
lymphatic capillaries
- definition
- present where
- absent where
- 1 component
- where the lymphatic networks begin
- present in almost every tissue and organ in body
- absent in areas that lack a blood supply
- lacteals
lacteals
- definition
- function
lymphatic capillaries in the small intestine
-transport of absorbed lipids
how is the lymphatic capillaries different from blood capillaries
-2
- they originate as pockets rather than forming continuous tubes
- have large diameters and thinner walls
2 major lymph-collecting vessels
- superficial lymphatics
2. deep lymphatics
superficial lymphatics location
located in the subcutaneous layers deep to the skin
deep lymphatics
-function
drains muscles, joints, and other deep structures
relationship between the lymphatic ducts and the venous system
large lymphatic vessels converge to form trunks which empty into 1 or 2 large ducts
2 types of ducts
- thoracic duct
2. right lymphatic duct
throacic duct
- base
- empties into what
- cisterna chyli which receives lymph from lower parts of the body
- left subclavian vein
right lymphatic duct
- delivers where
- empties into what
- lymph from right side of body above diaphragm
- empties into right subclavian vein
lymphoid tissue
- structure
- location
- each nodule has what
- densely packed lymphocytes within areolar CT
- deep to epithelium, digestive and urinary tracts
- each nodule has a “germinal center” which contain dividing lymphocytes
MALT
- what does it stand for
- definition
- component
- what does it have in it
- Mucosa, associated lymphoid tissue
- lymphoid tissue linked to digestive system
- aggregated lymphoid nodule
- areas of small intestine and appendix
tonsil
- definition
- 3 types
- what does it have
- contains what
- large lymphoid nodules in the wall of the pharynx
- pharyngeal, palatine and lingual
- multiple germinal centers
- crypts
crypts
- definition
- function
- invaginated outer edges
- trap material to be screened by lymphocytes for pathogens
locations of the lymph nodes
- typically found in together or separate
- function
- 4 main regions
- in clusters
- receive lymph from specific regions of the body
- cervical, axillary, lumbar and inguinal
cervical lymph nodes
drains lymph from head and neck
axillary lymph nodes
drains lymph from breast, axilla and upper arm
lumbar lymph nodes
drains lymph from abdominal organs
inguinal lymph nodes
drains lymph from pelvis and lower leg
what is the importance of lymph node clusters
lymph is filtered as it passes from node to node which insures adequate removal of antigens
the structure of a lymph node
-7
- afferent lymphatic
- subcapsular space
- outer cortex
- deep cortex
- medulla
- efferent vessel
- capsule
capsule
- made of
- definition
- dense CT covering
- separates node from surrounding tissues
afferent lymphatic
where lymph enters
subcapsular space
-what does it contain
-contains macrophages and dendritic cells
dendritic cells
involved in initiation of an immune response
outer cortex
-what does it contain
B cells within the germinal centers
deep cortex
-contains what
T cells
medulla
-contains what
B cells and plasma cells organized in medullary cords
efferent vessel
where lymph leaves
function of a lymph node -4
- filters lymph
- removes debris and pathogens
- antigens are presented B and T cells
- place where immune response is initiated
thymus
- location
- largest when?
- 2 components
- function
- in the mediastinum
- largest during childhood, decreases in size throughout adulthood
- cortex and medulla
- produces hormones called thymosins
cortex of the thymus
where T lymphocytes are dividing
medulla of the thymus
where the mature T cells are
thymosins
necessary for the maturation of T cells
spleen
- definition
- 3 components
- largest collection of lymphoid tissue in the body
- red pulp, white pulp of splenic nodule, hilum
red pulp of spleen contains what
large quantities of RBCs, macrophages and lymphocytes
white pulp of splenic nodule
- similar to what
- contains what
- lymphoid nodule
- large quanities of macrophages, dendrtitc cells and lymphocytes
3 functions of the spleen
- removal of abnormal blood cells and other blood components
- storage of iron recycled from RBCs
- initiation of immune response by B cells and T cells in response to antigens circulating in blood
hilum of the spleen
where vessels enters and exits
antigens
- definition
- 4 types of antigens
- chemical targets
- proteins
- lipids
- oligosaccharides
- nucleic acids
- proteins
foreign antigens
-location
on pathogens, donated tissues and cancer cells
self antigens
-location
on cells
2 general types of defense
- innate (nonspecific) defense
2. adaptive (specific) defense
innate defense
- definition
- present when
- does not distinguish one type of threat from another (same response regardless of pathogen)
- present at birth (genetic)
adaptive defense
- develops when
- responds when
- function
- develops after birth
- depends on activities of specific lymphocytes
- protects against particular threats
adaptive defenses
- 4 properties
- 2 forms
- specificity, versatility, memory and tolerance
- innate immunity and acquired immunity
specificity of immunity
a specific defense is activated by a specific antigen
-response targets that antigen and no others
versatility of immunity
- definition
- what does it insure
the immune systems consists of a large diverse population of lymphocytes
-insures the immune system can confront an antigen at any time
memory of immunity
- definition
- what is it able to
- can induce what
- the immune system has specific cells called “memory cells”
- able to remember antigens they have already seen
- can induce a stronger, faster response the next time the antigen is encountered
tolerance of immunity
- definition
- ex
- immune system does not respond to all antigens
- the immune system generally ignores normal tissues
innate immunity
- present when
- has no relationship to what
- response is generally
- at birth
- no relationship to previous exposure
- generally non specific
acquired immunity
- definition
- not present when
- 2 types
- acquire immunity against a specific antigen after exposure
- at birth
- active immunity and passive immunity
active immunity
- definition
- 2 types
- develops after exposure to an antigen
- naturally acquired active immunity
- induced active immunity
- naturally acquired active immunity
naturally acquired active immunity
- definition
- ex
- immunity develops because of natural exposure to antigens
- chicken pox
induced active immunity
- definition
- ex
- immunity develops because of deliberate exposure to antigens
- vaccines
passive immunity
- definition
- 2 types
- produced by transfer of antibodies from another source
- naturally acquired passive immunity
- induced passive immunity
- naturally acquired passive immunity
naturally acquired passive immunity
-definition
- mom’s antibodies given to baby through breast milk
- mom’s antibodies can cross the placenta
induced passive immunity
- definition
- example
- antibodies are administered to fight an infection or prevent a disease
- treatment of rabies
3 classes of lymphocytes
- T cells
- B cells
- NK cells
T cells
- ___ dependent
- how much %
- differentiates into 4 categories
- 80%
- thymus
- cytotoxic T cells
- Helper T cells
- Suppressor T cells
- Memory T cells
- cytotoxic T cells
Cytotoxic T cells
attack foreign cells or body cells infected by viruses
Helper T cells
stimulate the activation and function of both T cells and B cells
Suppressor T cells
inhibit the activation and function of both T cells and B cells
Memory T cells
are a subset of T cells that respond to a previously encountered antigen
B cells
- ____ dependent
- how much % of circulating lymphocytes
- 1 subdivision
- bone marrow
- 10-15%
- plasma cells
plasma cells
produce and secrete antibodies
NK cells
- how much % of circulating lymphocytes
- known as
- function
- 5-10%
- natural killer cells
- attack abnormal cells: cancer cells to bacteria
formation and distribution of lymphocytes
-3 steps
- thymus (thymic hormones)
- red bone marrow
- peripheral tissues
what does red bone marrow play a primary role in
maintenance of normal lymphocyte populations