CH 22 Flashcards
function of lymph
- Lymph node’s location of many immunity responses
- Return blood
i) Drainage of excess interstitial fluid
ii) Transport of dietary lipids
iii) Immune Response
Innate immunity:
The immunity u are born with (Healthy skin, mucous lining, sweat, digestive linings)
Adaptive immunity
Acquired immunity (As exposed to new pathogens throughout life)
- Basis of vaccines
Flow of lymph
- Begins as interstitial fluid.
- Ends up in lymphatic system.
- Eventually up in subclavian system lymph fluid is put back in venous system
Lymphatic tissue
Structures and organs that are part of the lymphatic systems (Lyph nodes, spleen etc.)
Red Bone Marrow:
Where the first part of much of the lymphatic system and immunity begins.
iii) Immune Response of lymph system
- Lymphatic system is one of the locations where the immune response takes place
- General AND/OR specific response
i) Drainage of excess interstitial fluid
- When pressure builds up, interstitial fluid should be returned to the bloodstream
- Edema: Excess interstitial fluid
Edema
Excess of interstitial fluid
ii) Transport of dietary lipids
- Some of the fats are not absorbed from the gut to bloodstream.
- They go from gut to lymphatic THEN back into the bloodstream.
- Water soluble go from water to bloodstream
iii) Immune Response
- Lymphatic system is one of the locations where the immune response takes place
- General AND/OR specific response
How many lymph nodes in body
600 Lymph circulation is a closed circuit
lymphatic trunks
multiple lymph vessels form lymph trunks
Lymph capilleries compared to blood caps
Lymph vessels are larger
Formation of lymph
- Starts as plasma then eventually it becomes interstitial fluid and then once it moves from interstitial spaces into lymphatic vessels it is called lymph
- When interstitial fluid builds up it causes anchoring filament to pull on the capillary allowing interstitial fluid to flow in, increasing the formation of lymph (Only flows in, SHOULD NOT flow out of capillary)
- Capilleries and vessels do not have smooth muscels, make use of skeletal muscle pump – when muscles contract it pushes lymph uphill against gravity, aiding in returning lymph to venous system
- Breathing pushes lymph uphill towards subclavian
How much lymph produced and reabsorbed per day
- Abt 3L per day produced (AND 3L per day reabsorbed)
How does the flow of lymph go
- Lymph vessels generally follows pathways of blood vessels
If doctors are to increase lymph flow they must massage it upwards NOT downwards
sequence of lymph
Blood capillaries → interstitial spaces → lymphatic capillaries → lymphatic vessels → nodes and trunks → L & R lymphatic ducts → subclavian veins/jugular
Flow of lymph assisted by which two pumps?
Skeletal muscle pump and respiratory pump (breathing moves lymph)
Edema
Excesssive interstitial fluid ( part of body gets puffy)
Two classifications of lymphatic organs and tissues
Primary lymphatic organs and tissues
Secondary lymph organs and tissues
Primary lymphatic organs and tissues
where stem cells (proliferate AKA) divide and become immunocompetent (Capable of producing immune response)
- Ex. Red bone marrow (key site), Thymus gland
- Where immune cells are produced
Secondary lymphatic organs and tissues
sites where immune response takes place (thymus, nodes, spleen, and lymphatic nodules (Very small lymph node without outer capsule))
- Locations where immune response takes place
Thymus
- BEST know for site of where Pre T Cells become mature and learn job description of immunity
- Component of both primary and secondary lymphatic organs
- Thymus gland atrophies over time and thus immunity system declines over time
Trabeculae of thymus
- An extension of the capsule that descends to the interior, separating the thymus into rooms (Lobules)
Cortex of thymus
T-cells (Most are pre T cells – not mature enough for an immune response)- Maturing means learning what cells in body to leave alone and what cells to attack,
dendritic cells (Educators: Help pre T cells become mature T cells),
epithelial cells (Produce hormones that help T cells mature)and
macrophages (Clean up Pre T cells that fail the course and die off – Only 2-3% of T cells mature)
Medulla of thymus
Part of outer region of lobule
more mature T-cells (Will eventually leave thymus and go into lymph system and travel through the body),
Epithelial cells of thymus
Part of the outer region of the lobule
(Continue to help secrete hormones for maturation of T cells), dendritic cells (Function as APC [Antigen presenting Cells] this cell identifies pathogen in body and marks it so immune cell knows what to attack) and macrophages
Thymus size
- Thymus abt 70g in infants
- In older adults could be less than 3g
Most superfiical lymph nodes
Neck and axilla
How many lymph nodes in body
Around 600
Function of lymph nodes
- Trap pathogens and attempt to kill them off in the lymph node (Lymph fluid flows in afferent lymphatic vessels, pathogens get trapped inside the node, T cells will kill them off – this is why lymph nodes swell)
Capsule of lymph nodes
Outer connective tissue with fibroblasts
Stroma of node
- Structural portion of lymph node (Trabecula is a part)
- The frame in the house
Parenchyma of node
- Portion of lymph node that trap and kill
Divisions of parenchyma of node
Superficial cortex and deep medulla
Superfiical cortex consists of
Outer cortex and inner cortex
Outer cortex of node
- Some B cells
- Follicular dendritic cells ATC
- Macrophages
Inner cortex of node
Mainly T cells that are mature, secondary there are dendritic cells that are ATC
- B cells become plasma sells that produce antinbodies
Deep medulla of node
- B cells
- Plasma cells
- Macrophages
Direction of lymph flow through a lymph node?
Afferent lymph vessel (Incoming only)
Subcapsular sinus
Trabecular sinus
Medullary sinus
Efferent lymph vessel
Characteristics of lymph in efferent vessel
(Cleaner, healthier, lymph fluid exits node)
Spleen
- Very good blood supply
- Capsule - serous membrane (visceral peritoneum)
- Lots of fibroblasts
- Stroma: Structtural
- Outer connective tissue (capsule)
- Trabecula : Internal portioin divided into lobules
Parecgyma of the spleen
Containing white pulp and red pulp
White pulp of the spleen
lymphocytes (WBC of many kinds)
Macrophages
Central arteries
Surrounds major blood vessesl coming in
Red pulp of parencyma in spleen
Venous sinuses
splenic (Billroth’s) cords (lympatic tissue
(All 5 found in splenic cord)
RBC
Macrophages
Lymphocytes
Plasma cells
Granulocytes
3 Additional jobs of spleen to immunity
- Important for removing old worn out RBCS (typical lifespan is 120- days) and platelets (7-9 days till broken down and rebuilt) (Macrophages help)
- Stores 30-35% of bodies platelets (Big part of blood control in homeostasis)
- Key location in the production of RBCs
If spleen is removed, what takes over?
Liver and bone marrow must take over jobs of spleen
Where are lymphatic nodules found
Lamina propria (connective tissue) of mucous membranes lining the GI, urinary and repro tracts and respiratory airways
MALTS
(Mucosa- Associated Lymphatic Tissue)
Lymphatic nodules found in the mucous membrane tissue
Peyers patches
Congregation of whole bunch of lymphatic nodules (i.e tonsils)
Nonspecific resistance AKA
Innate immunity
What is nonspecific resistance
First line of defence
Wide variety of body responses
- Mechanical protection
- Chemical protection in loose connective tissue (sebum, lysozyme in sweat, gastric juice in stomach)
Second line
internal antimicrobial substance, phagocytic and natural killer cells, inflammation, and fever.
Antimicrobial proteins
proteins that fight against pathogens/microbes
Body cells infected with viruses produce proteins called interferons
IFNs also enhance the activity of phagocytes and natural killer (NK) cells, inhibit cell growth
transferrins inhibit cell growth
What doe interferons and transferrins work againss
Bacteria and viruses
Interferon
stop viruses from replicating also enhance the activity of phagocytes and natural killer (NK) cell
Transferrin
proteins that inhibit cell growth by reducing the amount of iron available to certain bacteria
NK cells
Natural killer cells are lymphocytes that lack the membrane molecules that identify T and B cells.
MHC
major histocompatibility complex (marker on membrane of own cells saying “Please do not attack”) – protein markers on cell membranes
have the ability to kill a wide variety of infectious microbes plus certain spontaneously arising tumor cells.
2 ways that NKs kill cells
. Release perforins (chemicals) into the plasma membrane of a microbe cytolysis occurs – chemicals that insert a hole into pathogen causing cytolosis (rupturing)
Bind to a target cell and inflict damage by direct contact (apoptosis).
Neutrophils and macrophages are type sof
Phagocytes
Wandering macrophages
(neutrophils and macrophages)
- Hop into blood stream and travel to problem area (most are neutrophils (smaller than macrophages)
Fixed macrophages
(lung tissue, liver, lymph nodes
Phases of phogocytosis
- Chemotaxis
- Adherence
- Ingestion
- Digestion
- Killing and residual bodies
When does inflammation occur?
occurs when cells are damaged by microbes, physical agents, or chemical agents. The injury may be viewed as a form of stress.
Fever is caused by
infection from bacteria (and their toxins) and viruses. The high body temperature inhibits some microbial growth and speeds up body reactions that need repair.
3 basic stages of inflammation
Vasodilation/increased permeability:
Emigration of phagocytes
Tissue repair
First stage of inflammation
Vasodilation/increased permeability:
Blood vessels expand
- More ease of things in bloodstream exiting
Chemotaxis
A process that makes a location more attractive to phagocytos (tell phags where to travel)
What is the role of Histamines, kinins, prostoglandins, leukotrienes and complment protein systme in vasodialtion/increasing permeability
- Histamines
- Enhance permeability and dilation
Kinins
- Enhance permability, vasodilation, and chemotaxis agent
- Prostaglandins
- Usually chemicals relwased by cells that have been damaged enhance dialation and permeability
Leukotrienes
- Enhance permeability and dilation and also chemotaxic agent
- complement protein system
- Help in multiple places in the immunity system
Second stage of inflammation
) Emigration of phagocytes
Phagocytes emigrate to where the problem is
leukocytosis:
After phagocytes engulf damaged tissue and microbes, they eventually die, forming a pocket of dead phagocytes and damaged tissue and fluid called pus. Pus must drain out of the body or it accumulates in a confined space, causing an abscess.
Last stage of inflammation
Tissue repair
What is a fever
An elevation of the hypothalamus caused by interleukins
Purpose of fever
elevate body temperature causing it to be less hospitable to bacterial and infection
What is immunity
the ability of the body to defend itself against specific invading agents.
Antigens
substances recognized as foreign and cause the immune responses
Distinguishing properties of immunity
specificity and memory.
T cells and B cells derive from what
pluripotent stem cells in bone marrow
Where do B cells complete their development
Bone marrow
Where do T cells develop
develop from pre-T cells that migrate to the thymus.
Types of adaptive immunity
Cell mediated
Anti-body mediated (humoral) (AMI)
Clonal Selection
Cell mediated immunity
(CNI)
Destucion of antibodies by T cells, particularly effective against intracellular pathogens, such as fungi, parasites, and viruses;
Cells attacking cells
Antibody mediated immunity
(AMI)
Destruction of antigens by antibodies
Mainly against antigens dissolved in body fluids and extracellulalr pathogens,, primaryly bacteria
Rarely enter body cells
Clonal selection
process of a lymphocyte going through proliferation and differentiation → population of similar cells (clone).
Effector cells examples
helper T cells, cytotoxic T cells and plasma cells
Antigens are both
Immunogenic and reactive
Most often proteins
Immunogenicy
the ability to provoke an immune response by
stimulating the production of specific antibodies, the proliferation
of specific T cells, or both.
Reactivity
the ability
of the antigen to react specifically with the antibodies or cells it
provoked.
The specifc part of antigen molecules that trigger immune responses are
antigenic determinants, or epitopes
Why do antigens exhibit great diversity
genetic recombination.
Major hisocampatibility complex antigns OR HLA antigens
MHC
Unique to each persons body cells
Aid in detection of foreign invaders
. All cells except red blood cells display MHC class I antigens
What does the success of organ/ tissue transplants depend on?
histocompatibility.
What is neccessary for an immune response to occur
, B and T cells must recognize that a foreign antigen is present.
How does a B cell react to a foreign antigen
binds to antigens in extracellular fluid
How does a T cell react to an antign
can only recognize fragments of antigenic proteins that first have been processed and presented in association with MHC self-antigens.
APCs
antigen-presenting cells
process exogenous antigens (antigens formed outside the body) and present them together with MHC class II molecules to T cells.
Examples of APCs
macrophages, B cells, and dendritic cells.
How is an antigen processed and presented by APCs
ingestion of the antigen, digestion of antigen into peptide fragments, fusion of vesicles, binding of peptide fragments to MHC-II molecules, and insertion of antigen-MHC-II complex into the plasma membrane.
Cytokines
small protein hormones needed for many normal cell functions
Types of T cels
Help T cells (CD4 pattern)
Killer T cells (Tc)
Memory T cells (Tm)
Memory T cells
- Programmed to recognize the original invading antigen, allowing increased rate of immunity response if same pathogen invades again.
Killer T ccells recognize what on antigens
antigen fragments associated with MHC-1 molecules.
3 ways that killer T cells work
Perforin and Granulysin
- insert into the target cell membrane to form pores
ii) Lymphotoxin: Activates damaging enzymes inside the target cell. iii) Granzymes: Killing infected virus cells or tumor cells with granzymes
3 parts of antigen structure
Immunoglobulins
Binding site
Constant region
5 Antibody actions
i) Neutralizing Antigen
ii) Immobilizing Bacteria
iii) Agglutinating and Precipitating Antigen
iv) Activating Complement
v) Enhancing Phagocytosis
Role of complement system
group of about 30+ proteins present in blood plasma and on cell membranes
when activated, these proteins “complement” or enhance certain immune, allergic, and inflammatory reactions
Classical is direct route
Membrane attack complex
creates channels in the
plasma membrane that result in cytolysis, the bursting of
the microbial cells due to the inflow of extracellular fluid
through the channels
Constant region of antigen
The middle, is a region of structure that does not change for all immunoglobulins
Agglutinating and Precipitating Antigen
When an antibody joins with an antigen it clumps together, causing it to fall out of the solution for phagocyte to deal with
Immobilizing Bacteria antibody action
attack flagella or motor of cell thus rendering antigen immobile
How does enhancing phagocytosis occur
once antibody jois to antigen causing Chemotaxis (attracting phagocytes)
Neutralizing antigen antibody action
prevent attachment of antigen cells to healthy cells
Opsonization
- Process to enhance phagocytosis
- Puts coating on microbe, attracting phagocyties and allows for beter binding
Primary response of immunological immunity
(hopefully vaccine)
- IgG and IgM respond similarally at around 14 days
- Secondary Response in immunological immunity
- Tremendous spike in IgG: Bc of memory cells produced in primary response
- Relative spike in IgM
Self recognition
- self recognition: immunity cells recognize cells that belong in your body (MCH class one) as acceptable cells in the body and therefore do not react to them
- self tolerance:
- self tolerance: Once imunity system recognizes those cells it will recognize tose cells and not produce a reaction
Lack of cell tolerance
Immunity cells attack own cells
auto immune disease
Agining afects on immune system
- Young kids haven’t hadenough exposure
- Older peoples immunity system decreases (Speed and strengthreduced over time)
- Vaccines don’t produce the same response in older adults
- B Cells and T cells are less responsive
- Stress, smoking also influence immunity response
Allergic reactions and immune syystem
- Overactive immunity response: anaphylactic (nut allergy)
- Treatment is antihistamines if mild
infectious mononucleosis
- When B cells are infected, malaise, desire to sleep a lot, spleen is greatly enlarged, brain affects
- Lupus – systematic lupus erythematous
- Chronic inflammatory autoimmune disease
- Most common in females and 15-55 age group
- Joint pain, bed ridden
- Stress works against it
- Genetic and environmental cause
Specific disease response
for every specific disease encounters, the body will responds in a specific way
Hapten
a substance that can combine with a specific antibody but lacks antigenicity of its own.
All cells except ________ cells display MHC class I antigens.
RBCs
Examples of APCs
Dendritic cells, B cells, Macrophages
Cytokines
small protein hormones needed for many normal cell functions
Participate in immune functions
Which cells display display CD4 pattern
Helper T cells
Diff bw cytoxic T cells and Killer T cells
Cytotoxic T-cells are part of your adaptive immune response. Natural killer cells are part of your innate immune response
trypsin
chymotrypsin
carboxypeptidase
A part of pancreatic secretions
(finish up digestion of proteins)
What stimulates CCK production
Chime entering small intestine
Paneth Cells
Part of intestinal glands/brush border
- secrete lysosomes
- Brunner’s Glands (Duodenal Glands)
- Important, secretes alkaline secretion
- Important for neutralizing acidic environment coming from the stomach
