Anatomy Test 3

returns fluids that leaked from blood vessels back to blood

lymphatic system

what three parts make up the lymphatic system?

lymphatic vessels, lymph, lymph nodes

-provide structural basis of immune system by housing phagocytic cells and lymphocytes
-structures include spleen, thymus, tonsils, lymph nodes, other lymphoid tissues

lymphoid organs and tissues

-return interstitial fluid and leaked plasma proteins back to blood
-3L/day

lymphatic vessels

Once interstitial fluid enters lymphatics, it is called \_______

lymph

the lymphatic system is a \_______________

one way system

lymph flows \_________ the heart

towards

Lymph vessels (lymphatics) include:

lymphatic capillaries, collecting lymphatic vessels, lymphatic trunks and ducts

Very permeable (take up proteins, cell debris, pathogens, and cancer cells)

lymphatic capillaries

\___________ travel throughout body via lymphatics

pathogens

what is lymph?

-composition like blood plasma
-contains white blood cells
-formed in the digestive system called chyle

lymph that leaves a lymph node is richer in \_________

lymphocytes

\______ is rich in triglycerides (fat) and looks milky white

chyle

specialized lymph capillaries present in intestinal mucosa

lacteals

\______________ drains right upper arm and right side of head and thorax

right lymphatic duct

\_____________ arises as cisterna chyli; drains rest of body

thoracic duct

lymph is propelled by....

Milking action of skeletal muscle
Pressure changes in thorax during breathing
Valves to prevent backflow
Pulsations of nearby arteries
Contractions of smooth muscle in walls of lymphatics

\_________ are main warriors of immune system

lymphocytes

where do lymphocytes arise from?

red bone marrow

what type of lymphocytes comes from the thymus?

T cells (T lymphocytes)

what type of lymphocutes comes from blood?

B cells (B lymphocytes)

protect against antigens (anything body perceives as foreign) ex. bacteria and bacterial toxins, viruses, mismatched RBCs cancer cells

lymphoid cells/lymphocytes

phocytize foreign substances; help activate T cells

macrophages

capture antigens and deliver them to lymph nodes; activate T cells

dendritic cells

produce reticular fiber stroma that supports other cells in lymphoid organs

reticular cells

What is lymphoid tissue?

-houses, and provides proliferation site for, lymphocytes
-"surveillance vantage point" for lymphocytes and macrophages
-largely reticular connective tissue (type of loose connective tissue)

-principal lymphoid organs of body
-embedded in connective tissue, in clusters along lymphatic vessels

lymph nodes

what are functions of lymph nodes?

1) filter lymph- macrophages destroy microorganisms and debris
2) immune system activation- lymphocytes activated and mount attack against antigens

what is the structure of a lymph node?

-vary in shape and size but most bean shaped
-external fibrous capsule
-trabeculae extend inward and divide node into compartments
-two histologically distinct regions (cortex, medulla)

TNM staging system:

(T) extent of the tumor
(N) spread to the lymph nodes
(M) presence of metastasis

what is N0?

no cancer found in the lymph nodes near the cancer

what is N 1-3?

depending on how many nodes are affected, how much cancerous tissue is in them, how large they are, and where they are

-largest lymphoid organ
-served by splenic artery and vein, which enter and exit at the hilum

spleen

what are functions of the spleen?

-site of lymphocyte proliferation and immune surveillance and response
-cleanses blood of aged cells and platelets, macrophages remove debris,
-stores breakdown products of RBCs (e.g. iron), plateletss and monocytes

it is\_______ around central arteries

white

there is \_______ pulp in venous sinuses and splenic cords

red

-found in inferior neck; extends into mediastinuml partially overlies heart
-increasses in size and most sctice during childhood
-stops growing during adolescence, than gradually atrophies

thymus

-simplest lymphoid organs
-form ring of lymphatic tissue around pharynx
-gather and remove pathogens in food or air

tonsils

There are approximately \_______ as many cells from bacteria, archaea, fungi, protists and viruses living in you than you have cells

3 times

there are only \________ known human pathogens

1400

resistance to disease

immunity

the immune system is comprised of the:

innate and adaptive

the \_______ defense system is nonspecific and fast

innate

the \_______ system is specific but slow

adaptive

what are innate defenses?

surface barriers and internal defenses

What are adaptive defenses?

-Humoral immunity (B cells)
-Cellular immunity (T cells)

\_______________ ward off invading pathogens

mechanical (physical) surface barriers

skin, mucous membranes, and their secretions provide:

-physical barrier to most microorganisms
-keratin resistant to weak acids and bases, bacterial enzymes, and toxins
-mucosae provide similar mechanical barriers

\____________ inhibit or destroy miroorganisms

protective chemicals

-acidity of skin and secretions (acid mantle) inhibits growth
-enzymes kill many microorganisms
-defensins are antimicrobial peptides and inhibit their growth
-other chemicals

chemical surface barriers

What are internal defenses?

cells and chemicals

what are types of internal defenses?

phagocytes, natural killer cells, antimicrobial proteins, fever, inflammatory response

\__________ are the most abundant WBC, but die fighting (they become phagocytic only on exposure to infectious material)

Neutrophils

\___________ develop from monocytes and are the chief phagocytic cells

macrophages

\_______ macrophages wander through tissue spaces eg. alveolar macrophages

free

\_____ macrophages permanent residents of some organs

fixed

What do macrophages not like to go into?

cartiliage: no phagocytes and few vessels

What are the events of phagocytosis?

1) phagocytes adgeres to pathogen or debris
2) Phagocyte forms pseudopods that eventually engulf the particles, forming a phagosome.
3) Lysosome fuses with the phagocytic vesicle, forming a phagolysosome.
4) Lysosomal enzymes digest the particles, leaving a residual body.
5) Exocytosis of the vesicle removes indigestible and residual material.

phagocyte must \_____ to particle

adhere

cytoplasmic extensions bind to and engulf particle in vesicle called \__________

phagosome

Phagosoe fuses with lysosome called \___________

phagolysosome

What is an inflammatory response?

-triggered whenever body tissues injured
-prevents spreaf of damaging agents
-diposes of cell debris and pathogens
-alerts adaptive immune system
-sets the stage for repair

What are the cardinal signs of inflammation?

1) redness
2) heat
3) swelling
4) pain
5) impairment of function

What are the inflammatory mediators?

kinins, prostaglandins, and complement

What do inflammatory mediators do?

-dilate local arterioles (hyperemia)
-make capillaries leaky
-many attract leukocytes to area
-some have inflammatory roles

What is histamine?

a compound that is released by cells in response to injury and in allergic and inflammatory reactions, causing contraction of smooth muscle and dilation of capillaries.

what does asprin do?

prostaglandins induce inflammation, pain, ad fever. this blocks an enzyme called cyclooxygenase effectively blocking the synthesis of prostaglandins. it relives some of the effects of pain, fever, and blood clotting.

What are interferons?

chemical messengers; they are viral-infected cells that secrete IFNs to "warn" neihboring cells

IFNs activate \______________ and indirectly fight cancer

NK cells and macrophages

\______________ are used to treat hepatitis C, genital warts, multiple sclerosis, hairy cell leukemia

Artificial IFNs

What are antimicrobial proteins?

interferons and complement proteins, some attack microorganisms directly, some hinder microorganisms' ability to reproduce

What is the complement system?

-proteins are produced by liver
-proteins circulate in inactive form in blood
-unleashes inflammatory chemicals that amplify all aspects of inflammatory response

the complement system is \_______ and \_______

passive and non-specific

the \_________________________ helps or "comeplements" the ability of antibodies and phagocytic cells to clear pathogens from an organism; there is greater than 30 blood proteins, its a mjory mechanism for destroying foreign substances

complement system

fever is apart of what system reacting?

innate immune system

fever is:

-abnormally high body temperature
-systematic response to invading microorganisms

leukocytes and macrophages exposed to foreign substances secrete \______

pyrogens

\__________ act on body's hermostat in hypothalamus, raising body temperature

pyrogens

The adaptive defense system includes:

-humoral immunity (B cells)
-Cellular immunity (T cells)

what are characteristics of adaptive defenses?

-triggered by inflammation
-highly specific: recognizes and targets specific antigens
-tolerance: ignores normal "self" tissue
-slow (compared to innate immunity)
-systematic: not restricted to initial site
-have memory: stronger attacks to "known" antigens: basis of vaccination

Adaptive immunity

antigen presentation triggers an immune response

Cell-mediated immunity

-phagocytes activates
-T cells activated

Direct Physical and Chemical Attack

activated T cells find the pathogens and attack them through phagocytosis or the release of chemical toxins

Antibody-Mediated Immunity

activated B cells give rise to cells that produce antibodies; attack by circulating antibodies

what does humoral mean?

related to body fluids

what does cellular mean?

related to cells

Steps of the Adaptive Immune Response: Cellular

1) Viral or bacterial infection of a body cell triggers antigen presentation by class I MHC proteins.
2) The infection results in the apperance of abnormal peptides in the cytoplasm
3) The endoplasmic retculum produces class I MHC proteins to which the abnormal peptides are attached
4) After export to the Golgi appartus, the MHC proteins with their bound abnormal peptides are transported to the plasma membrane
5) The abnormal peptides are displayed by class I MHC proteins on the plasma membrane

what are self-antigens?

-cell surface proteins that mark a cell as "self"
-MHC proteins (major histocompatibility complex)
-unique to each person (except identical twins)

what are MHC proteins?

major histocompatibility complex proteins

class \____ MHC proteins are on virtually all body cells

1

class \____ MHC proteins include certain immune cells

2

in the adaptive immune response: cellular, includes the destruction via \______

CD8- T cells

adaptive immune response: humoral

-antibody mediated- ABs produced by lymphocytes, circulating freely in body fluids ("humors")
-bind temporarily to target cell
-temporarily inactivate
-mark for destruction by phagocutes or complement
-hummoral immunity has extracellular targets

Steps of the adaptive immune response: Humoral

1) phagocytic APCs engulf the extracellular pathogens
2) lysosomal action produces antigenic fragments
3) the endoplasmic reticulum produces class II MHC proteins
4) antigenic fragments are bound to class II MHC proteins
5) antigenic fragments are diplayed by class II MHC proteins on the plasma membrane

in adaptve immune response: humoral, AP production happens via \______

CD4 T cells

What are antigens?

-substances that provoke an immune response
-the ultimate targets of the adaptive immune response
-often large, complex modules
-intruderes that are seen as "non-self"

what are antibodies shaped like?

Y

\_________ bind to antigen

antibodies

Does the body have all the antibodies it has for life or can it make/create new antibodies?

the body has all the antibodies it has for life; we can only fight what we have had before

Its estimated that humans generate about \_________ different antibodies, each capable of binding a distinct epitope of an antigen.

10 billion