KAAP310 Exam 2 (CH 20-23)

What are the functions of the lymphatic system?

fluid recovery, immunity, lipid absorption

How does the lymphatic system contribute to fluid recovery?

fluid is filtered from blood capillaries to the tissues and the lymphatic system is responsible for picking this water back up ad transporting it back to blood.

What could happen if there's even partial damage to the lymphatic drainage

lymphedema

How does the lymphatic system assist with immunity?

as the lymphatic system picks up fluid it also picks up foreign cells and chemicals from the tissues and takes them to the lymph nodes where an immune response will occur

What happens in the lymph nodes?

Lymphoid tissue destroys antigens and activates T and B cells

How does the lymphatic system help with lipid absorption?

in the small intestine small lymphatic vessels called lacteals absorb dietary lipids

What are the components of the lymphatic system?

lymph, lymphatic vessels, lymphatic tissue, lymphatic organs

What is lymph?

a colorless fluid containing white blood cells, that bathes the tissues and drains through the lymphatic system into the bloodstream.

What does lymph flow through?

lymphatic vessels (lymphatics)similar to blood vessels

How are blood capillaries and lymphatic capillaries different?

the lymphatic have dead-ends at the end of them whereas the blood cap connects to either the veins or the arteries.

What is the structure of a lymph vessel?

loosely overlapping endothelial cells (think like shingles on a roof) NOT joined by tight junctions and they do not have a continuous basal lamina. gaps are so large that the bacteria, lymphocytes and other larger molecules can enter.

how does lymph work with circulatory

draws excess fluid from the cells and deposits it into blood vessels

How does the lymph vessels diffuse fluid?

the overlapping edges of the cells next to each other act as valves that can open as pressure inside the vessel becomes too high and close as it drops back down

What are the layers of the lymphatic vessels?

tunica interna: endothelium and valves
tunica media: elastic fibers, smooth muscle
tunica externa: thin outer layer

What is the path the fluid takes through the lymphatic system?

lymphatic capillaries- collecting vessels-11 lymphatic trunks- two collecting ducts- subclavian veins

How is a collecting vessel formed?

as the lymphatic capillaries converge

What forms when the collecting vessels come together?

lymphatic trunks

What happens when lymphatic trunks converge?

collecting ducts are formed

How is the right lymphatic duct formed?

convergence of right jugular, subclavian and bronchomediastinal trunks. receives drainage from right arm, right thorax and right head

Where does the right lymphatic drain?

subclavian vein

How is lymphatic fluid moved?

by pressure in the interstitial space and the milking action of skeletal muscle contractions and respiratory movements

Neutrophils

are aggressively antibacterial leukocytes

natural killer cells

Large lymphocytes that attack and destroy bacteria, transplanted tissue, host cells infected with viruses or have turned cancerous; Responsible for immune surveillance

T lymphocytes

form in the thymus and other lymphatic tissue and attack cancer cells, viruses, and foreign substances

B lymphocytes

form in the bone marrow and release antibodies that fight bacterial infections

Macrophages

phagocytize tissue debris, dead neutrophils, bacteria, and other foreign matter. They also process foreign matter and display antigenic fragments of it to certain T cells, thus alerting the immune system to the presence of an enemy

dendritic cells

specialized white blood cells that patrol the body searching for antigens that produce infections

reticular cells

produce reticular fiber stroma that supports other cells in lymphoid organs

What is lymphatic tissue?

aggregations of lymphocytes in the connective tissues of mucous membranes and various organs

What is lym. diffuse tissue called when in respiratory, digestive, urinary, and reproductive tracts?

Mucosa assosiated lymphatic tissue (MALT)

WHen is the diffuse tissue called aggregated lymphoid nodules?

lymph nodes,tonsils and the appendix

What are the lymphatic organs?

red bone marrow, thymus, lymph nodes, tonsils, spleen

How does the red bone marrow contribute to the lymphatic system?

site of lymphocyte formation and T lymphocytes production

WHat is the thymus's role in the lymphatic system?

T lymphocytes are matured here and later get sent to the medulla. Thymus also secrete hormones that control the t lym as paracrine and systematically

What do lymph nodes do?

two functions; activate T and B cells and cleanse the lymph. MOST ABUNDANT LYMPHATIC ORGAN

What does the cortex of the lymph node do

when LN is fighting a pathogen, b cells multiply and differentiate

What does the medulla do?

branching network of medullary cords, composed of lymphocytes, plasma cells, macrophages, reticular cells and fibers.

What is the white pulp of the spleen?

lymphocytes and macrophages

What is the first line of defense?

skin and mucous membranes

What is the second line of defense?

inflammatory response

What is the third line of defense?

adaptive immunity- leaves body with a memory of the pathogen, so it can quickly defeat it if it comes across it again

innate immunity

The immunity that is present before exposure and effective from birth. Responds to a broad range of pathogens.

adapted immunity

constitutes the third line of defense and is distinguished by its capacity for immune memory. It adapts the body to the presence of a pathogen so we become less vulnerable to the illness it could otherwise cause.

Innate immunity has three characteristics:

Local, nonspecific and lacks memory

Nonspecific effects

each mechanism of innate immunity acts against a broad spectrum of disease agents, not just one specific pathogen

Lacking memory

the innate immunity lacks memory to any previous exposure to the pathogen, so it is no easier to attack a pathogen the second time

Neutrophils defense

phagocytosis and digestion, superoxide, hydrogen peroxide, and hypochlorite

Eosinophils defense

stand guard against parasites and allergens, that things too big to phagocytize

Basophils defense

secrete chemicals that aid the mobility and action of other leukocytes: heparin, histamines and leukotrienes

Lymphocytes defense

natural killer cells, T and B cells

Inferons

when an infected cell dies from infection it secretes this to help surrounding cells to better defend from viral replication from being altered by the virus

complement system

A group of about 30 blood proteins that may amplify the innate and adaptive response, enhance phagocytosis, or directly lyse extracellular pathogens.

What causes inflammation?

histamine, that is released when stimulated

What initiates a fever?

exogenous pyrogens

What is fever reducing called?

ANTIpyrexia

How does ibuprofen work?

inhibits prostaglandin synthesis

What further raises the temperature of a fever?

endogenous pyrogens

What to endogenous pyrogens do?

As neutrophils and macrophages attack pathogens, they secrete a variety of polypeptides that act as release it. These in turn stimulate neurons of the anterior hypothalamus to raise the set point for body temperature

Three characteristics of adaptive immunity

systemic effect, specificity, memory

what is the systematic effect

When an adaptive response is mounted against a particular threat such as a bacterial infection, it acts throughout the body to defeat that pathogen wherever it may be found.

What is specificity?

immunity directed against a specific pathogen

What does memory do?

the body quickly recognizes and responds to pathogen so that you do not even notice any response happened

cellular immunity

immune response that relies on T cells to destroy infected body cells

humoral immunity

specific immunity produced by B cells that produce antibodies that circulate in body fluids

natural active immunity

production of one's own antibodies or T cells as a result of infection or natural exposure to antigen

artificial active immunity

Production of one's own antibodies or T cells as a result of vaccination against disease

natural passive immunity

acquired by a child through placenta and breast milk

artifical passive immunity

temporary immunity that results from the injection of immune serum (antibodies) from another person or animal
treatment for snakebite, botulism, rabies, tetanus, and other diseases

What part of the antigen molecule reacts?

epitopes

What does the variable region do?

binds to antigen

What Antibodies are only monomers

IgD, IgE, IgG

What do epitopes do?

stimulate immune responses, each antigen only has one epitope but it can react with many

What is the structure of IGM

monomer and pentamer

Structure of IGA

monomer and Dimer, found in blood plasma, mucus, tears, milk

Development of T cells

Stem cells from bone marrow
migrate to thymus gland.
Second stage: T cells develop into activated T cells
Occurs when, and if, antigen binds to T cell's surface proteins
and a chemical signal is received from another T cell

Where does B cell maturation occur?

red bone marrow

T cells usually cant recognize and attack foreign antigens on their own they need the help of

antigen presenting cells

interlukins

Lymphocytes and APCs talk to each other through them

Cytotoxic T cells

the "effectors" of cellular immunity that carry out the attack on foreign cells

Helper T cells

promote the action of the killer T cells and play key roles in humoral immunity and nonspecific defense. All other T cells are involved in cellular immunity only

Regulatory T cells

limit immune response (when pathogen detected the concentration of these decreases)

Memory t cells

descended from Tc cells, responsible for immune systems memory

steps for cellular immunity

recognize, react, remember

recognize

two phases- antigen presentation and T cell activation.

How does attack happen?

TH cell recognizes an Ag-MHC protein complex, it secretes interleukins that exert three effects: (1) to attract neutrophils and natural killer cells; (2) to attract macrophages, stimulate their phagocytic activity, and inhibit them from leaving the area; and (3) to stimulate T and B cell mitosis and maturation.

What cells act like killer t cells and kill target cells

perforin and granzymes

What cells become memory cells?

T and B cells

What are the steps of attack

Neutralization, complement fixation, auugulation, precipitation

WHat is Neutralization?

masks dangerous parts of bacterial exotoxins; viruses

What is complement fixation?

Fc region of antibody binds complement proteins; complement is activated

What is agglutination?

clumping of enemy cells by antibodies

What is precipitation?

antigen molecules are clupped by adhesion to antibodies

Which cells are involved in secondary responses memory?

Memory B

Type 1 (acute) hypersensitivity

Common allergies and asthma
Begin immediately following exposure, but are short lived
IgE antibodies found in basophils and mast cells can bind to allergens
Triggers basophils and mast cells to release chemicals associated with inflammation
Anaphylaxes or anaphylactic shock could occur

Type 2 antibody dependant hypersensitivity

IgG or IgM attacks antigens bound to cell surfaces. The reaction leads to complement activation and either lysis or opsonization of the target cell.

Causes toxic goiter

Type 3 immune complex

causes auto immune diseaqses

Type4 delayed

happens about 12-24 hours after exposure, like posion ivy, cosmetic reaction

Cross-reactivity

The ability of antibodies to react with other compounds other than the target antigen

abnormal exposure of self-antigens to blood

Some of our native antigens are not exposed to blood
Blood-testes barrier isolates sperm from blood

change in structure of self antigens

viruses and drugs may change the structure of self-antigens and cause the immune system to perceive them as foreign