Chapter 16: Lymphatic and Immune System

What is the first function of the lymphatic system?

transports excess interstitial fluid away from spaces and return to bloodstream

What is the second function of the lymphatic system?

absorbs lipids from digestive system and transports them to the bloodstream (lacteals)

What is the third function of the lymphatic system?

Defends body against diseases and allows humans to live in world with other organisms

What is the lymphatic system?

a collection of cells and biochemicals that travel in lymphatic vessels

The lymphatic system contains a network of vessels that do what?

assist in circulating fluids

The term “immune system” refers to the fact that many cells of the lymphatic system provide both what?

defense against disease and permanent immunity against future infections

Lymphatic pathways include what?

capillaries, vessels, nodes, larger lymph vessels, trunks, collecting ducts, subclavian veins in thorax

Lymphatic capillaries are microscopic and are?

closed ended tubes and also thin walled

What does the lymphatic capillaries do?

networks parallel blood capillaries throughout the body

What type of epithelium tissue is lymphatic capillaries form?

simple squamous

What is it called when the tissue that is interstitial fluid enter lymphatic capillaries?

the fluid is now called lymph

Lymphatic vessels are similar to veins but what about them is different?

they are thinner

What are the 3 layers of the lymphatic vessels?

inner (endothelial), middle (smooth and elastic), and outer (CT)

Lymphatic vessels contain what type of valves that allow one way flow?

semilunar

Larger vessels lead to lymph nodes and then to what?

larger lymphatic trunks

Lymphatic trunks does what?

drain lymph from lymphatic vessels

Lymphatic trunks are named for the regions they serve which are?

lumbar, intestinal, intercostal, bronchomediastinal, subclavian, jugular

What do lymphatic trunks drain INTO?

lymphatic collecting ducts

Lymphatic collecting ducts drain from lymph from?

trunks

The lymphatic collecting ducts there are two for the entire lymphatic system. What are those two?

thoracic and right lymphatic duct

Thoracic duct is longer and wider of the two ducts and drains majority of the?

body

Thoracic ducts begins as a?

sac called cisterna cyliii and then enters left subclavian vein

The right lymphatic duct is much smaller than the thoracic duct and drains the?

upper right portion of the body

Where does the right lymphatic duct begin?

right thorax and empties into the right subclavian vein

What is the order of the lymphatic pathway?

capillary

afferent lymphatic vessel

lymph node

efferent lymphatic vessel

lymphatic trunk

collecting duct

subclavian vein

What is lymph?

tissue fluid that has entered a lymphatic capillary

What does lymph formation depend on?

tissue fluid formation

What is tissue fluid formation?

capillary blood pressure filters water and small molecules from the plasma

The resulting tissue fluid in tissue fluid formation has the same composition as?

blood plasma

What does the resulting tissue fluid contain?

water and dissolved nutrients, gases, and hormones

What is the exception to resulting tissue fluid?

tissue fluid does not contain large plasma proteins which remain in blood plasma so to maintain osmotic pressure it is needed to draw fluid back to blood capillaries

Tissue fluid=

blood plasma- plasma proteins

Lymph formation explained is the filtration from the plasma normally exceeds reabsorption that leads to?

net formation of tissue fluid

Forming lymph is the increase of tissue fluid throug hydrostatic pressure within interstitial spaces that force?

fluid into lymphatic capillaries and forms lymph

Prevention of accumulation of excess tissue fluid or what is called?

edema

What is an example of edema?

a woman has axillary lymph nodes removed during breast cancer surgery and the lymphatic drainage is obstructed from the upper limb resulting in the edema

Lymph inside lymphatic vessels has low?

hydrostatic pressure like venous blood

Muscle activity influences the movement of lymph through the?

lymphatic vessels

Muscle activity include the?

contraction of skeletal muscles, respiratory process, and smooth muscle in the larger lymphatic vessels

Contraction of skeletal muscles compresses lymphatic vessels moving the?

lymph

Respiratory process creates low pressure in the thorax and high pressure in?

abdomen during inspiration and sends lymph from abdomen to thorax

Smooth muscle in the larger lymphatic vessels contracts to aid in?

flow of lymph

Valves in lymphatic vessels prevent what?

backflow

When is lymphatic flow the highest in?

during physical exercise

What are the roles of lymphatic capillaries?

Absorb dietary fats in small intestine, return small proteins, collect excess fluid, deliver excess fluid, deliver foreign particles, valves easy entry of tissue fluid

Lymphatic tissue contain several cell types including?

lymphocytes and macrophages

Lymphatic organs consist of encapsulated lymphatic tissue. This includes?

lymph nodes, thymus, and spleen

Lymph nodes are usually bean shaped that are?

greater than 2.5 cm long

Where are lymph nodes located?

along lymphatic vessels and they filter pathogens from lymph

What do lymph nodes contain?

lymphocytes and macrophages

What do the lymphocytes do for lymph nodes?

attack viruses, bacteria, and parasitic cells

What do macrophages do for lymph nodes?

engulf and destroy foreign substances and damaged cells and cellular debris

Lymph nodes are found in groups or chains along the paths of?

larger lymphatic vessels throughout the body

Major locations of lymph nodes include?

cervical region, axillary, supratrochlear, inguinal, pelvic cavity, abdominal, thoracic cavity

Lymph nodes are not found in?

central nervous system

2 primary functions of lymph nodes are?

filter harmful particles from lymph and immune surveillance (macophages and lymphocytes)

Along with the red bone marrow the lymph nodes are centers for?

lymphocyte production

Where is the thymus located?

in mediastinum posterior to the upper portion of the body of the sternum

What is the function of the thymus?

houses lymphocytes and differentiates thymocytes into T lymphocytes

The spleen is located where?

in upper left portion of the abdominal cavity and is inferior to the diaphragm and posterior and lateral to the stomach

What is the function of the spleen?

houses macrophages that remove foreign particles, damaged red blood cells, and cellular debris from blood and contains lymphocytes

The spleen has 2 tissue types which are?

white (lymphocytes) and red pulp (red blood cells, lymph and macro)

Innate which is?

nonspecific defense

Innate defense is the general defense and protect against?

many types of pathogens

Adaptive specific defense is more specific and precise it targets?

specific antigens

Adaptive defense is carried out by?

lymphocytes that recognize certain foreign molecules

Innate defenses include what?

species resistance and mechanical barriers, inflammation, chemical barriers, natural killer cells, phagocytosis, and fever

What is species resistance?

certain species are resistant to diseases that affect other species

For species resistance what are some things species can lack?

receptors, temperature, chemical environment

What are mechanical barriers?

considered the first line of defense and prevent entrance of pathogens

What forms mechanical barriers?

skin and mucous membranes

What are some examples of mechanical barriers?

epidermis sloughed off or ciliated epithelium in respiratory tract traps and sweeps away pathogens, hair trap, tears, saliva, urine

Inflammation produces local redness and also what?

swelling, heat, and pain

Swelling results from increased capillary permeability and?

fluid entry into tissue spaces

Inflammation is a process that walls off infection site and inhibits the?

spread of infection

Inflammation response sequence is?

blood vessels dilate

capillary permeability increases

fluid leaks into tissue

white blood cells invade

tissue fluid-clotting

fibroblasts arrive

phagocytes active

cells divide

Chemical barriers include what?

enzymes, interferons, defensins, collectins, complement

Enzymes in body fluid provide a chemical barrier to pathogens what is a good example of this?

pepsin in gastric juice and lysozyme in tears destroy microorganisms

Interferons block vital replication and act against?

growth of tumors and stimulate phagocytosis

Defensins are peptides produced by neutrophils and other granulocytes they can cripple?

microbes by making openings in cell membranes or walls

Collectins are proteins that protect against many?

bacteria, yeast, and some viruses

Complement is a group of proteins in plasma and other body fluids that stimulates?

inflammations, attracts phagocytes, and enhances phagocytosis

Natural Killer or NK cells are a small population of lymphocytes and are different from?

B cells and T cells that provide adaptive defenses

NK cells defend against viruses and cancer cells by doing what?

secreting cytolytic substances called perforins that lyse cell membrane

NK cells can also enhance?

inflammation

Phagocytosis removes what?

foreign particles from the lymph

Phagocytes in the blood vessels and the tissues of what remove particles from the blood?

speen, liver, bone marrow

Most active phagocytic cells are?

neutrophils and monocytes

Monocytes that leave the blood become what to be free or fixed in tissues?

macrophages

Mononuclear phagocytic system consist of?

monocytes and macrophages of the body

A fever begins when a viral or bacterial infection stimulates what?

lymphocytes to proliferate this produces cells that secrete a substance called interleukin (thermoregulatory set point)

IL-1 is also called?

endogenous pyrogen

Elevated body temperature indirectly inhibits microbial growth that causes the liver and spleen to?

take up iron that makes it not available for bacteria and fungi to use in their normal metabolism

Characteristics of adaptive defenses is the?

third line of defense in resistance to particular pathogens or to their toxins or metabolic by products

Characteristics of adaptive defenses is based on the ability to?

distinguish molecules that are part of the body (self) from non self

Adaptive responses are carried out by lymphocytes and macrophages that can do what?

recognize specific antigens

There are 2 types of adaptive defenses which are?

cellular immune response (immune) and humoral immune response (antibodies)

Cellular and humoral are both considered what?

third line of defense

Antigens may be what?

proteins, polysaccarides, glycoproteins, and glycolipids

Lymphatic system responds to what but not self antigens?

non self antigens