Lymphatics, Immune system Flashcards
Antigen vs Antibody
Antigen: suface cell marker (body may perceive as foreign)
Antibody: a protein that targets a specific antigen
Functions of the lymphatic system
Produces,maintains, distributes lymphocytes
Maintains net filtration pressure (to move blood from arteries into vessels)
Hormone/nutrient/waste distribution
Filters out foreign substances (aged/infected/cancerous cells)
Lymph pathway (arteries to veins) - acronym
A- Can I Come Vacuum The Den - V
Arteries
Bloodstream capillaries
Interstitial space
Lymphatic capillaries (some to veins)
Lymphatic vessels
Lymphatic trunks
Lymphatic ducts
Veins
Lymphatic capillaries:
What type of ends
Permeable?
Valves?
Anchored how?
Blind ended
Very permeable
One way valves
Anchored with collargen fibres
Lacteal
What kind of vessel?
Found where
What nutrient does it send straight to bloodstream?
Lymphatic capillary
Small intestine villi
Absorbs fat, send straight to bloodstream (as chyle) (skips first pass in liver)
Lymphatic vessels:
Do what frequently?
Travel alongside which vessels?
Anastomose frequently
Blood arteries and veins
Lymphatic trunks
Thoracic duct drains what
RIght Lymphatic duct drains what
Everything inferior to diaphragm + left side of body superior to diaphragm
Right side of body superior to diaphragm
(75/25 split)
Lymph transport
List ways that are similar to venous return
Other ways
Breathing helps change pressure, one way valves + skeletal muscle milking (squeezing)
Pulsation of nearby arteries
Smooth muscle contraction (in lymphatic walls)
3 classes of lymphocytes (antibodies)
T cells
B cells
NK cells
Macrophages: function (specific?)
“eat” anything that seems foreign
Presents info on foreign substances to T/B cells
Primary lymphoid organs: function + examples
Where B/T cells mature
Bone marrow + thymus
Secondary lymphoid organs: function + examples
Where B/T cells encounter antigens
Lymph nodes, spleen, etc
Lymphocyte development
Origin
Maturation
Seeding (dormant + circulate)
Antigen encounter
Proliferation/differentiation (what happens upon antigen encounter)
Origin: B/T cells in bone marrow
Maturation: B cells stay in bone marrow, T cells mature in thymus
Seeding: remain dormant in secondary lymphoid organs, circulate blood/lymph
Antigen encounter: lymphocyte antigen receptor binds to specific antigen
Proliferation/differentiation: effector cells make antibodies, memory cells wait for secondary response
Thymus:
What does it educate?
Positive selection?
Negative selection?
Rate of failure?
Larger in adults or children?
T cells
Positive selection: T cells must recognize self MHC
Negative selection: T cells must NOT recognize self-antigen
>99% of T cells fail, apoptose
Largest in children, gone by 25
Lymphoid tissue
Function, special regions?
Proliferation zone for lymphocytes
In areas of high-probability of antigen encounter
Diffuse lymphatic tissue: found in most organs
Lymphoid follicles/nodules: B-cell germinal centers (first line of defence for food/air)
Lymph nodes
Filter what?
Activate what when needed?
2 parts of structure
Filer LYMPH
Mount immune response (lymphocytes) if needed
Cortex: germinal centers for B cell proliferation
Medulla: contains B/T cells + macrophages
What slows down flow through lymph nodes?
Why
Hilium
To allow time for antigen scanning before sending lymph to next lymph node
Spleen
Filters what?
Stores what? Why?
2 components, contain what
(Largest lymphoid organ)
Filters BLOOD (takes out aged cells, pletelets, debris)
Stores broken down iron, platelets, monocytes for recycling in new cells
White pulp (white blood cells (B/T cells)
Red pulp (red blood cells, macrophage destroys old RBCs)
Mucosa associated lymphoid tissue (MALT)
Function
Locations
Protects digestive/respiratory systems from foreign matter
Tonsils, peyer’s patches, appendix (all secondary lymphoid organs)
1st line of defence:
examples, function
Skin: slightly acidic, keratin for extra protection
Mucous membranes (inside the body membranes): mucous (containing microorganisms) propelled by cilia to throat -> stomach acid for break down
2nd line of defence
Specific/non-specific?
Examples
Non-specific
Phagocytes: eat all foreign substances that break membrane
NK cells: use perforin to perforate + lyse foreign cells
Interferons: released by dying cell to warn surrounding cells (mobilize immune system)
Complement: use Membrane Attack Complex (MAC) to lyse microorganisms
Inflammation: sending more blood to area for healing + flushing out
Fever: stops microorganisms from growing, helps repair process
3rd line of defence
Specific/non-specific?
Examples
Specific (adaptive)
Humoral immunity: B cells
Cellular immunity T cells
Humoral immunity
acronym, brief explanation
PLAN
Precipitation: foreign cells are clumped for easier macrophage access
Lysis: complement uses MAC
Agglutination: like precpitiation
Neutralization: masking of dangerous parts of the pathogen (eliminates harm)
Primary response vs secondary response
Primary: firs encounter with antigen
B cells proliferate, make plasma cells, make antibodies + memory cells (DELAY, LOW # of ANTIBODIES)
Secondary: next encounter, up to years later
MEMORY B CELLS make plasma cells, make antibodies + more memory cells (NO DELAY, MORE ANTIBODIES, STRONGER RESPONSE)
2 Types of humoral response
Active immunity: sources
Passive immunity: sources
Active immunity: from infection/vaccination
Passive immunity: from placenta/breastfeeding (short term no memory cells), antibody injection (also no memory cells acquired)
Classes of B cells
IgM: present when?
IgA: found where?
IgD: found where on B cell?
IgG: crosses? during which humoral response?
IgE: present when?
IgM: primary response
IgA: in secretions
IgD: B cell surface
IgG: only one to cross placenta. during late primary/secondary response
IgE: present during inflammation/allergic reactions
Cellular immunity
Which type of cells? B or T
2 types of cells (present antigens)
T cells
MHC1/MHC2 cells
MHC1:
what message?
what is activated as result?
“I am infected, see something like me, kill it.”
Cytotoxic (specific) T cells activated
MHC2:
what message?
what is activated as result?
“Look at this infected cell, if you see one like it, kill it”
Helper T cells activates (very general immune response)
