Lymphatic System Flashcards
Define the Lymphatic system
consist of lymphatic vessels and lymphoid organs
Describe lymphatic capillaries
absorb fats and transport them to the blood stream
What is the function of the lymphatic system
help with immunity to defend body against disease
Which way does lymph flow
one way from lymphatic capillary system to subclavian vein, join venous circulation to go back to heart
Does all fluid return to the heart via cardiovascular system
most, not all leftover, go into lymphatic capillary flow to lymphatic vessel
What is the function of lymphatic capillaries
take plasma fluid that has not been reabsorbed by circulatory system
fluid bathes cells assisting capillaries in delivering glucose, O2, salts, amino acids and other nutrient
What is the excess fluid entering lymphatic capillaries called
lymph
Where does lymph flow
from lymphatic capillaries into larger lymphatic vessels until eventually empty into venous blood
Describe lymphatic vessels
extend throughout the body
have one way valve: structure similar to veins
return lymph dependent on squeezing action of skeletal muscles
Where do all lymphatic vessels merge before enter venous circulation
thoracic duct-> Left/Right Lymphatic Duct
Where does the L+R lymphatic drain
Left lymphatic duct goes to L subclavian Vein
Right lymphatic duct goes to R subclavian Vein
Where does larger duct drain fluid from
both lower extremities, abdomen, L arm, L side Head and neck
Where does R thoracic duct drain from
is smaller and drain from R arm, R side of head and neck and R thoracic area
Which organs are considered lymphoid
lymph nodes, spleen, thymus, tonsils
what is a lymph node encapsulated in
encapsulated in fibrous connective tissue with many incoming and few outgoing lymph vessels
What are afferent vessels
incoming vessels flows through network of sinuses contain cells
What are the efferent vessels
allow lymph to flow out of lymph node
How is the interior of lymph node divided
nodules
What do nodes contain
lymphocytes and macrophages
what is function of lymph node
filter center, rid flowing lymph of infection organism and other debris as it passes through sinuses( cortical, orbital, medullary)
Where do lymph nodes tend to be grouped
together in regions of the body: groin, axilla
Where is spleen located
upper left abdomen
What is spleen function
extract old/defect blood cells and platelets
remove debris, foreign matter, bacteria, viruses, toxins
What is spleen encapsulated
thin fibrous connective tissue with incoming splenic artery and outgoing splenic vein
How is interior spleen divided
lobules, open spaces, contain lymphocytes and macrophage carry out function of spleen
How does blood enter and leave spleen
enter splenic artery, leave splenic vein flows to Hepatic Portal vein
Where does hepatic portal system drain to and from what
carries blood drained from vein of spleen, intestine, stomach and pancreas to liver
liver take blood and detoxifies before return to general circulation
Where is Thymus gland located
anterior surface of heart
what does Thymus secrete
thymosin and thymopoietin hormones
enable T lymphocytes( T cell) to mature and function as part of immunity
How do T cells aid in immune defense
attack body cells which are cancerous or infected with pathogens
What is noted about thymus as human grow
prominent in newborn: larger during childhood
growth of thymus stop in teen years and whither away by old age
What are the tonsils( palatine tonsils)
group small lymphoid organ in lateral posterior portion of throat
How do the tonsils function
gather and destroy bacteria inhaled in air or food
What are the channels in tonsils called
crypt:
What is the function of crypts
to trap bacteria and foreign matter
bacteria then go into lymphoid tissue where destroyed
What is the function of the immune system
ID foreign, invading particles and eliminate them
What is a non-specific immune system
innate immune system
serves as first line defense through physical and chemical barriers to prevent pathogen entering the body
acts the same to all threats, rapidly destroy large # of pathogens
What is specific immune system
takes several days to activate
extremely effective against pathogens
main lymphocytes: T and B cells
The skin is a part of which immune response system
non- specific
very few pathogens penetrate the skin
What is normal flora
good bacteria growth in environment from tear and sweat
produce lactic acid inhibit pathogenic bacteria
Define inflammatory response
localized response in the tissue
What are the 3 parts of the inflammatory response process
- inflammation increase blood flow to infection region
- tissue swelling dilates vessel in affected area to help increase # of immune cell response to infection
- Increased blood cause redness and pain: brings awareness
What are cytokines
secreted proteins
regulate and signal both specific and non-specific immune system
What are the 2 main groups of cytokines
interferon: inhibit viral replication, assist natural killer cell
interleukin: chemical activator, sends signal throughout body to increase immune response
What does pyrogen do
reset body thermostat in hypothalamus
is a subtype of interleukin
What is a fever
raise body temp set point
help body fight infection, interfere with
What is the function of a fever
help body fight infection, interfere with growth and replication of pathogen
cause lysosome to break down
lysosome release enzyme that lyse cell infected by virus
promote activity of wbc
when in short duration assist recovery
How are WBC divided
granulocyte: have granules in cytoplasm
Agranulocyte: don’t have granules in cytoplasm
What are included as granulocyte
neutrophil, eosinophil, basophil
Describe a neutrophil
most abundant WBC
responsible for fighting infect that involve bacteria
use phagocytosis to invest foreign material
has a short life, die quickly after pathogen eaten
after death exit body as pus
multi-lobed nucleus: when stained is light pink
What is phagocytosis process
cell recognize pathogen by cell surface receptor
neutrophil bind to pathogen, bring into cell, form vacuole
vacuole fuses with cell lysosomes, released digestive enzymes to destroy pathogen
once pathogen destroyed, contents released from cell
Describe Eosinophil structure and function
respond to allergic reaction and parasitic infection
similar in appearance to nuetrophil except granules stain dark pink to red
Describe Basophil structure and function
rarest form of granulocyte
involved with release histamine and heparin same shape of neutrophil and eosinophil: granules stain dark blue/purple
What is histamine
vasodilator: increase blood flow through dilation vessels and capillaries
What is heparin
blood anticoagulation: help prevent formation of blood clots
What are the 2 types of agranulocytes
Monocytes and Lymphocytes
Describe monocytes
Lg WBC: “U” shaped nucleus
move into tissue to become macrophage
What are the 3 types of lymphocytes
T-cell, B-cell, Natural Killer cell
specific immune response depends on activity of lymphocytes
What are the functions of lymphocytes
make antibodies, attack foreign cells, destroy body cells that have lost normal function
What is the structure of lymphocytes
large dark nucleus w/little cytoplasm
Where are B-cells produced
Millions produced in bone marrow
What is the function and structure of B-cells
genetically program produce glycoprotein receptor as part of cell coat
each receptor bind with antigen
becomes active when antigen binds with specific receptor
What is an antigen
molecule specifically recognized as foreign by immune system
what is B-cell called when activated
plasma cell
What is function of plasma cell
produce antibodies( immunoglobulins) soluble form of glycoprotein from B-cell surface
What are the 5 categories of immunobloulins
IgG, IgE, IgD, IgM, IgA
What do some activated B-cell become
memory B cell
What is function of memory B cell
continue to produce small amount of antibody even after infection
allows product of antibody faster if some pathogen comes again
What is an antibody
mediated immunity- defend body against pathogen through secretion of antibodies
bind to pathogen, mark for phagocytosis and make it unable to do more damage
What are T-cells
thymus-dependent: originate in bone marrow and mature in thymus gland
what is function of T-cells
work through cell-mediated immunity: locally releases content: cytokines or enzyme to kill pathogen
What is a killer T cell
cytotoxic: recognize and destroy cell contains foreign antigen
attack virus infected cell or cancer cell by release cytotoxin and lyses cell
What is a helper T-cell
secrete substance activates immune response
B-cell require interact with T cell before rapid division
What are Natural killer cells
originate in bone marrow
seek out abnormal body cells and destroy them
highly effective against tumor cells
What is a graft rejection
rejection of transplanted organ by organ donor
tissue donated usually originate in other body
What is MHC
major histocompatibility complex
glycoprotein surface receptors on all cells of body
enable immune system to determine what cells are body and what are foreign
What is the process of graft rejection
MHC on surface of graft is recognized as foreign pathogen
to help host accept graft, immunosuppressant drugs are used to suppress immune system: makes patient more susceptible to infection due to lower immune
What is an autoimmune disease
lymphocyte attack own body: antibodies and T-cells
What is RA
rheumatoid arthritis
T cells attack synovial lining inside joints
T cell produce interleukin cause inflammation inside joint systemically
What is MS
Multiple sclerosis
antibodies attack/prevent formation myelin sheath around nerve cells produces muscular weakness
what are allergies
antibodies produced against mild antigen( allergen)
common: environmental
Sx: red/watery eyes, sneezing, runny nose, headache
What is anaphylaxis
excessive immune response
severe life threatening reaction against pathogen, insect bug bite
antibody overproduced by B-cell- capillary permeability cause reaction in minutes
What are the symptoms of anaphylaxis
swelling/hives, narrow respiratory pathway,
severe: lowered BP could lead to anaphylaxis shock which could be fatal due to severely dilated capillaries causing heart to stop or airway to close
What is an Epi-pen
pen that injects epinephrine into thigh at beginning of anaphylaxis; epinephrine offsets symptoms
What is edema
accumulation of fluid
What is lymphedema
lymph vessel can become blocked or have difficulty with lymph drainage
fluid slowly accumulate become swollen and distended
serious if not treat as vulnerable to infection, connective tissue could be permanent stretch or distention
What is tonsillitis
inflammation of the tonsils
become infected and appear white and swollen from a viral/bacterial infection
