survey of anatomy & physiology chap 14

The Lymphatic and Immune Systems: Your Defense Systems

14

INTRODUCTIONINTRODUCTION

Immune and lymphatic systems work to protect body from pathogens that can produce disease

Without these systems, you would not survive for long

THE DEFENSE ZONETHE DEFENSE ZONE

If a group of pathogens try to enter body, they must first get past barriers, such as intact skin and secretions of mucous membranes

PHYSICAL BARRIERS PHYSICAL BARRIERS

Anything that prevents invaders from getting inside your body prevents infection

Physical barriers act as first line of defense; located in areas most likely to be invaded

Skin and mucous membranes of eyes, digestive,

respiratory, reproductive systems

PHYSICAL BARRIERS PHYSICAL BARRIERS

Anything that prevents invaders from getting inside your body prevents infection

Physical barriers act as first line of defense; located in areas most likely to be invaded

Skin and mucous membranes of eyes, digestive,

respiratory, reproductive systems

THE DEFENSE ZONETHE DEFENSE ZONE

If pathogen does get into body, it is recognized as not belonging

Weapons in the form of specialized cells are engaged by immune and lymphatic systems to fend off the pathogens

THE DEFENSE ZONETHE DEFENSE ZONE

Weapons include specialized cells and powerful chemicals of immune and lymphatic systems

Chemicals stimulate inflammatory and clean up responses

Again, this is accomplished by combined and integrated efforts of immune and lymphatic systems

THE LYMPHATIC SYSTEMTHE LYMPHATIC SYSTEM

Both the transport system and barracks of immune system

Works closely with cardiovascular system

THE LYMPHATIC SYSTEMTHE LYMPHATIC SYSTEM

FOUR FUNCTIONS

STRUCTURES OF THE STRUCTURES OF THE LYMPHATIC SYSTEMLYMPHATIC SYSTEM

Smallest pipes of lymphatic system called lymph capillaries; run parallel to blood capillaries

STRUCTURES OF THE STRUCTURES OF THE LYMPHATIC SYSTEMLYMPHATIC SYSTEM

Lymph capillaries form network between cells of connective tissues, but

unlike blood capillaries, are open ended

THE LYMPHATIC SYSTEMTHE LYMPHATIC SYSTEM Proteins and fluids are lost from cardiovascular

capillaries and enter interstitial space.

THE LYMPHATIC SYSTEMTHE LYMPHATIC SYSTEM

Once this fluid enters lymph capillaries, it is known as lymphatic fluid (lymph)

Lymph: straw-colored, clear fluid; primary component is water

THE LYMPHATIC SYSTEMTHE LYMPHATIC SYSTEM

Lymph capillaries empty into lymphatic vessels, similar to veins including valves; body movement and contraction of smooth muscles propels lymph through system

FIGURE 14-1FIGURE 14-1THE LYMPHATIC SYSTEM AND THE RELATIONSHIP THE LYMPHATIC SYSTEM AND THE RELATIONSHIP BETWEEN BLOOD AND LYMPH CAPILLARIESBETWEEN BLOOD AND LYMPH CAPILLARIES

LYMPH NODESLYMPH NODES Large vessels empty into lymph nodes, ranging in size

from pinhead to an olive Lymph nodes: filters placed all along pathways or

vessels of lymphatic system

FIGURE 14-2FIGURE 14-2THE LYMPH NODE STRUCTURETHE LYMPH NODE STRUCTURE

Small, encapsulated bodies divided into sectionsConsist of sections of lymphatic tissue containing WBCs known as lymphocytes

LYMPH NODESLYMPH NODES

Lymphatic tissue surrounded by lymphatic sinuses filled with lymph fluid

Filter and destroy pathogens using WBCs

LYMPH NODES IN THE BODYLYMPH NODES IN THE BODY

Concentrated in cervical, axillary, inguinal, pelvic, abdominal, thoracic, and supra trochlear areas

Adenoids and tonsils also part of lymph system

LYMPHATIC TRUNKSLYMPHATIC TRUNKS

Lymphatic vessels exiting lymph nodes empty into one of several lymphatic trunks

COLLECTING DUCTSCOLLECTING DUCTS

Lumbar, intestinal, and intercostal trunks empty into thoracic duct the largest lymph vessel; more than two-thirds of lymphatic system drains into this duct

Lymphatic trunks empty into one of two collecting ducts

COLLECTING DUCTSCOLLECTING DUCTS

Bronchomediastinal, subclavian, and jugular trunks empty into right lymphatic duct; smaller duct within right thorax that empties into right subclavian vein

CIRCULATION OF CIRCULATION OF LYMPHATIC FLUIDLYMPHATIC FLUID

Lymphatic fluid flows in only one direction: from body tissues and organs to heart Blood to tissue Tissue to lymphatic

capillaries Lymphatic capillaries to

lymphatic vessels

CIRCULATION OF CIRCULATION OF LYMPHATIC FLUIDLYMPHATIC FLUID

1. Lymphatic capillaries to lymph nodes

2. Lymph nodes to lymphatic vessels

3. Lymphatic vessels to lymphatic trunks

4. Lymphatic trunks to collecting ducts

5. Collecting ducts to subclavian veins and then back to the blood

LYMPH ORGANSLYMPH ORGANS

Spleen Spongy saclike mass of

lymphatic tissue in upper left quadrant of abdomen

Structurally similar to lymph nodes but instead of lymphatic sinuses has blood sinuses

Surrounding blood sinuses are islands of white pulp containing lymphocytes and islands of red pulp containing both RBCs and WBCs

LYMPH ORGANSLYMPH ORGANS Spleen

Functions to remove and destroy old, damaged, or fragile RBCs

Also filters pathogens from bloodstream and destroys them like lymph node

Not vital organ; can be surgically removed; removal in children can severely compromise immunity, but has lesser effect on adults

LYMPH ORGANSLYMPH ORGANS

Thymus Soft organ located

between aortic arch and sternum

Very large in children because it must fend off new infections

Gets smaller; continues to have some activity in adults as immune system fully matures in its ability to fight infection

LYMPH ORGANSLYMPH ORGANS

Thymus Site of mature

type of WBC called a T lymphocyte (made in the bone marrow)

FIGURE 14-3FIGURE 14-3SPLEEN, THYMUS, TONSILS, AND SPLEEN, THYMUS, TONSILS, AND

LYMPHATIC VESSELSLYMPHATIC VESSELS

LYMPHATIC AND IMMUNELYMPHATIC AND IMMUNE

Nodes

Vessels

Organs

CellsChemicals

Barriers

Stores and Transports

THE IMMUNE SYSTEMTHE IMMUNE SYSTEM

Comprised of cells, chemicals, and barriers that protect body from invasion by pathogens

Some processes active, some passive, some inborn, and others change with experience

ANTIGENS-SELF OR FOREIGN?ANTIGENS-SELF OR FOREIGN?

Molecules on outer surface of cell membrane that identify them as friend or foe

Each living thing has unique cell surface antigens, allowing immune system to distinguish between cells that are naturally yours and cells that are not

ANTIGENSANTIGENS

Ability called self-recognition and non-self-recognition; is heart of how immune system functions

Well-functioning immune system ignores self antigens and attacks non-self antigens

ANTIBODIESANTIBODIES

Proteins the body makes that bind to antigens, eventually destroying them

One of most potent weapons of immune system

Called into action when foreign antigen invades the body

INNATE VERSUS ADAPTIVE INNATE VERSUS ADAPTIVE IMMUNITYIMMUNITY

Innate (natural) immunity First line of defense

against invasion Body's inborn ability to

fight infection Not affected by

environment Permanent

INNATE VERSUS ADAPTIVE INNATE VERSUS ADAPTIVE IMMUNITYIMMUNITY

Innate (natural) immunity Prevents invasion,

or if pathogens do get inside, takes steps to stop spread of infection

INNATE IMMUNITY-RECOGNIZES A INNATE IMMUNITY-RECOGNIZES A FOREIGN INVADERFOREIGN INVADER

The body’s first line of defense recognizes that invader is present but can’t identify it specifically

Like setting off a metal detector but not knowing exactly what the item is that did it

INNATE VERSUS ADAPTIVE INNATE VERSUS ADAPTIVE IMMUNITYIMMUNITY Innate (natural)

immunity Cannot improve with

experience Because it does not

recognize specific pathogens, it cannot "remember" an infection that body has encountered before

“ I CAN’T REMEMBER”

INNATE VERSUS ADAPTIVE INNATE VERSUS ADAPTIVE IMMUNITYIMMUNITY

Crude mechanism for defending body

Indiscriminately killing pathogens and healthy tissue alike

Take that, invaderI’m

one of you!!

INNATE VERSUS ADAPTIVE INNATE VERSUS ADAPTIVE IMMUNITYIMMUNITY Adaptive (acquired) immunity

Backs up innate immunity, specifically targeting invaders and sparing healthy tissue as much as possible

Remembers invaders from previous encounters and prepares for future invasion, improving response with experience by learning and changing

INNATE VERSUS ADAPTIVE INNATE VERSUS ADAPTIVE IMMUNITYIMMUNITY Innate and adaptive immunity work together Innate immunity prepares way for adaptive immunity,

weakening pathogens and stimulating components of adaptive immunity

INNATE VERSUS ADAPTIVE INNATE VERSUS ADAPTIVE IMMUNITYIMMUNITY Adaptive immunity, in turn, stimulates innate immunity

attacking pathogen on two fronts

INNATE VERSUS ADAPTIVE IMMUNITY-INNATE VERSUS ADAPTIVE IMMUNITY-HUMORAL* & CELLULARHUMORAL* & CELLULAR

*Humoral means found in body fluids

CELLS OF THE BODYCELLS OF THE BODY White blood cells

(WBC or leukocytes) are cells responsible for defending body against invaders

Red blood cells responsible for carrying oxygen throughout body

Platelets responsible for blood's ability to clot

CELLS OF THE BODYCELLS OF THE BODY

Leukocytes Form in bone marrow;

move to other parts of body to grow and mature

Not released into bloodstream unless infection present

Various types of white blood cells required to protect body in varying circumstances

LYMPHOCYTESLYMPHOCYTES T (for Thymus) and B

(for bone marrow) cells Form in bone marrow;

some move to other parts of body to grow and mature

T cells go to the thymus to mature

B cells stay, develop and mature in the bone marrow

LYMPHOCYTES-T AND B CELLSLYMPHOCYTES-T AND B CELLS

Specific T cells called T helper cells stimulate “killer T cells” which directly bind to antigen or pathogen and destroy it

T helper cells also stimulate B cells to make B plasma cells which produce antibodies and make B memory cells

LYMPHOCYTES-T AND B CELLSLYMPHOCYTES-T AND B CELLS

Both formed in the marrow both cells stimulated by the presence of a foreign antigen

B cells develop into plasma cells which forms antibodies to specific antigen and memory cells which “remember” it later

TABLE 14-1TABLE 14-1 WHITE BLOOD CELLS WHITE BLOOD CELLS INVOLVED IN IMMUNE RESPONSEINVOLVED IN IMMUNE RESPONSE

CHEMICALS TO PROTECT BODY CHEMICALS TO PROTECT BODY FROM INVADERSFROM INVADERS

Found in body; assist in destroying and neutralizing invaders

Cytokines: Involved in both innate

and adaptive immunity

CYTOKINESCYTOKINES

Cytokines are proteins produced by damaged tissues and WBCs that stimulate immune response in variety of ways:

Increasing inflammation

Stimulating lymphocytes

Enhancing phagocytosis

INTERFERONSINTERFERONS Cytokine produced

by cells that have been infected by virus

Binds to neighboring, uninfected cells and stimulates them to produce chemicals that may protect these cells from viruses

INFLAMMATIONINFLAMMATION

Also called inflammatory response

Typical symptoms: pain, swelling, heat, and redness

INFLAMMATIONINFLAMMATION

Deliberate action of body in response to tissue damage, whether mechanical or pathological injury

Response helps to wall off infected area to prevent further spread and allow battle to focus at site

INFLAMMATIONINFLAMMATION

When tissue is damaged, cells send out chemicals such as histamine, an inflammation modulator

INFLAMMATIONINFLAMMATION

These chemicals attract WBCs to site, increase permeability of capillaries, and cause local vasodilitation; extra fluid causes swelling

More blood comes to site, causing heat

INFLAMMATIONINFLAMMATION

WBCs destroy pathogens and clean away dead cells

Increase in fluid and cells coming to area increases pressure and creates pain

Innate immune mechanism, but plays important part in adaptive immunity

FIGURE 14-5FIGURE 14-5CAUSES AND CONSEQUENCES OF THE CAUSES AND CONSEQUENCES OF THE INFLAMMATORY RESPONSE.INFLAMMATORY RESPONSE.

FEVERFEVER During infection, immune

system releases cytokines that promote inflammation and immune responses

One of cytokine targets in brain is HYPOTHALAMUS responsible for setting and maintaining body temperature

FEVERFEVER Effect of cytokine is

elevated temperature set point, or fever

Rise in body temperature is deliberate attempt by immune system to destroy pathogens

INNATE IMMUNITY-BARRIERSINNATE IMMUNITY-BARRIERS

First, pathogens must get past physical and chemical barriers; most pathogens kept out by these barriers

Tears, saliva, urine, mucous secretions and sweat contain

chemical barriers

INNATE IMMUNITYINNATE IMMUNITY

INNATE IMMUNITYINNATE IMMUNITY

Release of cytokines and stimulation of inflammation attract macrophages to infection site

INNATE IMMUNITYINNATE IMMUNITY

Macrophages phagocytize infected cells

Release chemicals to further stimulate inflammation, activate more immune cells

INNATE IMMUNITYINNATE IMMUNITYPathogens are under attack from: PhagocytosisNoxious chemicalsMembrane ruptureClumpingAlteration to molecular structure

INNATE IMMUNITYINNATE IMMUNITY

Chemicals have specifically signaled hypothalamus to raise body temperature and you run a fever

INNATE IMMUNITYINNATE IMMUNITY

Remember: This is crude warfare, with innate immunity destroying anything non-self

Desperate attempt to defeat invaders, sometimes killing uninfected cells…

All leading to activation of adaptive immunity

INNATE IMMUNITYINNATE IMMUNITY

When phagocytic cells ingest pathogens, they display foreign antigen on cell membrane, essential for activation of B and T cells

ADAPTIVE IMMUNITYADAPTIVE IMMUNITY

Fights specific pathogens; has memory, "learns" from experience, recognizes specific pathogens

WHEN B CELLS ATTACKWHEN B CELLS ATTACK

ADAPTIVE IMMUNITYADAPTIVE IMMUNITY

Because of adaptive immunity, immunizations are able to prevent

illness

ADAPTIVE IMMUNITYADAPTIVE IMMUNITY

Innate and adaptive immunity work hand in hand; one cannot do its job without the other

ADAPTIVE IMMUNITY IS THEN ADAPTIVE IMMUNITY IS THEN ACQUIREDACQUIRED

Acquired immunity

occurs as the body

“adapts” to the

environment to which it is

exposed

Acquired immunity

occurs as the body

“adapts” to the

environment to which it is

exposed

Exposure is either

“passive” (nonspecific

antigen exposure) or

“active” (specific targeted

exposure)

Exposure is either

“passive” (nonspecific

antigen exposure) or

“active” (specific targeted

exposure) Exposure is “natural” or “artificial”

(created by humans)

Exposure is “natural” or “artificial”

(created by humans)

ACQUIRED ACTIVE IMMUNITYACQUIRED ACTIVE IMMUNITY

Daily Life

Acquired during

vaccinations

ACQUIRED PASSIVE IMMUNITYACQUIRED PASSIVE IMMUNITY

ACQUIRED ACTIVE IMMUNITYACQUIRED ACTIVE IMMUNITY

FIGURE 14-10TYPES OF IMMUNITIES

OUR IMMUNE SYSTEMOUR IMMUNE SYSTEM

http://www.youtube.com/watch?v=MI-BLaj5nFk

THE BIG PICTURETHE BIG PICTURE Army of pathogens wants to

invade body; first must get past body's barriers

If invader gets inside body, series of weapons stimulated by non-self-antigen

Cells (neutrophils, macrophages, and basophils) stimulated

Chemicals (cytokines) released that stimulate inflammation and phagocytosis

THE BIG PICTURETHE BIG PICTURE

Macrophages and other cells which have ingested some of invaders move to lymphatic system and search lymph nodes, looking for T and B cells that will recognize intruder

THE BIG PICTURETHE BIG PICTURE

Helper T cells activate and cause proliferation of B cells and cytotoxic T cells, as well as releasing chemicals to further stimulate phagocytosis and inflammation

T cells (green) infected with HIV (red)

THE BIG PICTURETHE BIG PICTURE

Cytotoxic T cells activated and proliferate

B cells produce antibodies that destroy invaders and further stimulate immune response

Cytotoxic T cells destroy invaders directly and release chemicals that further stimulate immune response

THE BIG PICTURETHE BIG PICTURE

Immune response, both innate and adaptive, will continue to be stimulated until feedback loop stopped, at least in part by regulatory T cells

Memory B cells and T cells stored in lymph nodes for later use if another army of same types of pathogens invade

THE BIG PICTURETHE BIG PICTURE

Macrophages and other phagocytic cells will clean up debris left by “warfare” waged by immune system and body will return to normal

FIGURE 14-11FIGURE 14-11THE BATTLE PLAN OF THE BODYTHE BATTLE PLAN OF THE BODY''S S DEFENSESDEFENSES

AUTO IMMUNE DISEASEAUTO IMMUNE DISEASE

It is believed that viruses can incorporate genetic material into human cells that changes it’s “ID CARD”, so that it is then identified as foreign, triggering an antigen-antibody reactionRead article “Auto Immune Diseases”Read article “Auto Immune Diseases”

AUTO IMMUNE DISEASESAUTO IMMUNE DISEASES

CHAP 14 TAKE HOME EXAMCHAP 14 TAKE HOME EXAM

Complete Worksheet No. 1 and the Labeling Activity

1 and 3 for credit (46 points) .

Questions #24 and #25

are EXTRA CREDIT (worth 7 points)

One ESSAY Question on the Lymphatic System will

appear on your FINAL EXAM

Complete Worksheet No. 1 and the Labeling Activity

1 and 3 for credit (46 points) .

Questions #24 and #25

are EXTRA CREDIT (worth 7 points)

One ESSAY Question on the Lymphatic System will

appear on your FINAL EXAM