Chapter 16: Lymphatic System and Immunity

What are the functions of the lymphatic system?

fluid balance

lipid absorption

defense

What is fluid balance?

transport of fluid from interstitial spaces in blood

What is lipid absorption?

lacteals in the small intestine

What is defense?

helps defend the body against infection

The lymphatic pathways begin as ________________ that merge to form larger __________________.

lymphatic capillaries;

lymphatic vessels

lymphatic capillaries are _______-ended tubes, and extend into ______________. They form a single layer of what?

closed ended tubes;

interstitial spaces;

squaemous endothelium

List the lymphatic pathway.

lymphatic capillaries

lymphatic vessels

lymphatic trunk

What are the characteristics of lymphatic vessels?

-endothelial layer

-smooth muscle-elastin fiber layer

-outer layer of CT

-have semilunar valves

-transports fluid to lymphnodes

List the layers of the lymphatic vessels from outside in.

Outer layer CT >

Endothelium, smooth muscle, elastin fiber > endothelial layer >

semilunar-valve

Lymphatic Trunk:

vessels empty ______ into trunks.

fluid

Lymphatic Trunk:

Trunks are named for the regions they serve. Name the trunks and where they serve.

Lumbar trunk - lower limbs

Intestinal trunk (abdominal viscera)

Intercostal trunk (thorax)

Bronchromediastinal trunk (thorax)

Subclaian trunk (upper limbs)

Jugular trunk (neck and head)

Lymphatic Trunk:

Fluid is then transported to...

collecting ducts

Collecting Ducts:

The __________ collects lymph from the lymphatic duct.

thoracic duct

The thoracic duct originates in the _______, passes through the __________, and empties into the ________________.

abdomen; diaphragm; left subclavian vein

The _________ duct collects lymph from the lymphatic trunks.

right lymphatic duct

The right lymphatic duct originates in the ____________, passes through the __________, and empties into the ____________.

right thorax;

diaphragm;

right subclavian vein

TISSUE FLUID AND LYMPH FORMATION:

1. Begins in the blood capillaries

2. Blood pressure pushes fluid, nutrients, gases, and hormones into capillary walls.

3. Albumin reabsorbs water back into blood plasma by osmosis.

4. Filtration exceeds reabsorption creating tissue fluid.

5. Pressure from excess fluid in the tissue move the tissue fluid into he lymphatic capillaries forming lymph

TISSUE FLUID AND LYMPH FORMATION:

1. Begins in the...

blood capillaries

TISSUE FLUID AND LYMPH FORMATION:

2. BP pushes (4) _____________ into __________.

fluid, nutrients, gases, and hormones

capillary walls

TISSUE FLUID AND LYMPH FORMATION:

3. ________ reabsorbs water back into blood plasma by _______.

albumin; osmosis

TISSUE FLUID AND LYMPH FORMATION:

4. Filtration exceeds reabsorption creating ____________.

tissue fluid

TISSUE FLUID AND LYMPH FORMATION:

5. Pressure from excess fluid in the tissue move the tissue fluid into the _____________ forming lymph

lymphatic capillaries

What is lymph flow dependent on?

-Hydrostatic pressure of the tissue fluid

-contracting skeletal muscles

-valves in the lymphatic vessels

-contraction of smooth muscles

-inhalation

________________________ drives lymph into lymphatic capillaries.

Hydrostatic pressure of tissue fluid

contracting skeletal muscles happens in...

the limbs

__________________ prevent backflow similar to veins.

valves in the lymphatic vessels

_________________ in the walls of larger lymphatic vessels and lymphatic trunks.

contraction of smooth muscles

_________ creates pressure in the thorax and abdominal cavity to move the lymph

inhalation

movement causes tissue fliud to accumulate interstitial fluid, producing...

edema

List the characteristics of the lymph node structure

-2.5 cm long (1-inch), bean shaped

- Hilum; indented region were blood vessels and nerves enter.

-multiple entry sites for afferent vessels, one site for efferent vessels

-capsules: outer covering, dense CT

-nodules: masses of b-lymphocytes and macrophages

-sinuses: pathway for lymph to travel

Alternate lymph nodes:

Lymph nodules are also found...

singlely, or

in groups associated with the mucous membrane

What does MALT stand for?

mucosa-associated-lymhnoid tissue

What tissues fall under MALT?

-appendix

-deyer's patches

-tonsils

-digestive mucosa

-respiratory mucosa

-genitourinary tract

Lymph nodes are NOT located in the...

Central nervous system.

List the locations of lymph nodes.

cervical region

axillary region

supratrochlear region

inguinal region

pelvic cavity

abominal cavity

thoracic cavity.

List the regions the node serves: Cervical region

filters lymph from scalp, face, pharynx, and nasal cavity

List the regions the node serves:

Axillary region

Upper limbs, mammary glands, thorax and upper abdoman

List the regions the node serves:

Supertrochlear regions

elbow

List the regions the node serves:

Inguinal region

lower limbs, external genitals, lower abdominal wall

List the regions the node serves:

pelvic cavity

follows the illiac blood line; filters lymph from filter area

List the regions the node serves:

abdominal cavity

filters lymph from abdominal cavity

List the regions the node serves:

Thorasic cavity

filters lymph from thoracic cavity.

What are the functions of lymphnodes?

-filtering potentially harmful particles from lymph before it returns to the blood stream

-surveillance by lymphocytes and macrophages for pathogens

-lymphatic production

What diseases affect lymph flow?

lymphedema

lymphagitis

lympnaentis

What is lymphedema?

obstruction that does not allow proper drainage of lymph from the body tissue

What is Lymphagitis?

caused by an acute strephococcus infection of the skin, resulting in inflammation and red streaking at the location of the infection

- This could develop into a systemic infection

What is lymphnadentis?

Bacterial infection in the nodes causing the nodes to enlarge and may be painful (swollen glands)

What is lymphoma?

Cancer of the lymph nodes

What is the thymus?

A soft, bilobed gland located in the mediastinum anterior to the aortic arch

The thymus is _______ in infancy and becomes ________ as an adult.

large; smaller

The thymus contains many ______ that houses lymphocytes made in the __________.

lobules; red blood marrow

maturation of cells that occurs in the thymus become...

t-lymphocytes

What is the hormone that is secreted to stimulate...

t-lymphocyte maturation

The _______ is the largest lymphatic organ, and resembles a large ___________.

spleen; lymph node

The white pulp nodules contain _________ while the red pulp nodules contain ___________.

lymphocytes; red blood cells

The spleen acts as a....

blood reservior

In the spleen, macrophages are responsible for...

monophages are responsible for...

macrophages - destruction of red blood cells

monophages - surveillance of pathogens

What are the seven innate defenses of the lymphatic system?

1. Species resistance

2. mechanical barriers

3. chemical barriers

4. natural killers (NK cells)

5. inflammation

6. phagocytosis

7. fever

Species resistance:

Species maybe resistant to diseases that affect other species because it's cells do not have ________ for the pathogens or it's tissues do not provide the __________ environment that a particular pathogen requires.

receptors;

temperature or chemical

Mechanical barriers is the _____ line of defense.

1st

Mechanical barriers:

Prevents the ______________ of some infectious agents.

What are these mechanical barriers, internal and external?

entrance;

external mechanical barriers: skin, hair, tears, saliva urine

internal mechanical barriers: mucous membranes that line the respiratory, digestive, urinary, and reproductive systems

What are the 2nd lines of defense?

3. chemical barriers

4. natural killers (NK cells)

5. inflammation

6. phagocytosis

7. fever

Give examples of chemical barriers

pepsin (in the stomach), lysozyme (enzymes)

acids, salt, interferon, defensins, collectins, complements

Interferon is produced by __________ and _________ in response to viruses and tumor cells

lymphocytes and fibroblasts

Differins are produced by _______________ in the epithelium of passageway linings. It makes holes in bacteria _________ and ___________.

granular white blood cells

cell walls; membranes

Collectins bind to a variety of _________ in order to be recognized by __________.

microbes; phagocytes

Complements work in a cascade to stimulate _______ and attracts phagocytes for __________.

inflammation; phagocytosis

Natural killer cells recognize cells that contain _______ or cells that have changed into ________.

viruses; cancer cells

Natural killer cells secrete __________ that _______ the cell membrane, destroying the infected cells.

perforins; lyse

All natural killer cells secrete chemicals that enhance _____________.

inflammation

Inflammation is activated by ___________ or by __________ or _____________ defenses.

infection; physical or chemical defenses

Inflammation results in increased ________ and _____ at the infection site because of the dialation of the ___________, which brings blood to the affected area

redness and heat

Inflammation:

Permeability of vessels ___________ during inflammation so that ________________ leak into surrounding tissue and may activate ____________.

increases; fluid cells; pain receptor

During inflammation, _____ may be created.

pus

Inflammation:

The site of infection can be separated from the rest of the body by....

a web of fibrin

What cells are involved in phagocytosis? What is this process known as?

monocytes and neutrophils

Known as the reticuloendothelial system

Phagocytosis:

monocytes and neutrophils are recruited to the site of infection by...

positive chemotaxis

Phagocytosis:

Macrophages engulf ______ bacteria while neutrophils neutrophils only engulf _____.

100; 20

Fever is...

elevated body temperature indirectly through microbial growth and increases phagocytic activity

Fever:

Low fevers of short duration may be a __________ response, not a symptom to be treated aggressively with ___________.

desired response; medication

What is the third line of defense?

Adaptive defenses

What is adaptive defense?

Immunity is resistance specific pathogens or to their toxins or metabolic by-products

What is agglutination?

The reaction between antigens and antibodies

What are antibodies?

soluble, globular proteins that constitute the gamma globulin fraction of plasma proteins

List the types of antibodies.

IgG

IgA

IgM

IgD

IgE

Describe IgG.

defends against bacteria, viruses, and toxins, and activates complements

Describe IgA.

defends against bacteria and viruses found in breast milk

Describe IgM.

reactions with antigens on red blood cells

Describe IgD.

activation of B-cells for immunity

Describe IgE.

Promotes inflammatory and allergic reactions

Each person has millions of varieties of ________________ where each variety originates from single cell forming clones.

T and B cells

What is the makeup of T-lymphocytes and B-lymphocytes in circulating blood?

T: 70-80%

B: 20-30%

Activated T-cells (helper T-lymphocytes) bind to a ______________ that is presented on one of the listed cells.

foreign antigen

Helper T lymphocytes stimulate the production of other T-lymphoytes and b-lymphocytes to kill...

foreign invaders

What are release cytokines?

colony-stimulating factors (produces lymphocytes)

interferon, interleukin (lymphocyte differentiation) and

tumor necrosis factor

Helper T-lymphocyte production of...

cytotoxic T-cells

Supressor T-cells

Memory T-cells

Supressor T-lymphocytes are produced when...

interferon is nearly cleared.

B-lymphocytes can bind antigen directly from...

pathogen/toxins

Helper T-lymphoctes can stimulate production of...

B-lymphocytes

B-lymphocytes reside in the...

What do they bind to?

lymph nodes and spleen

Bind to antigens