chapter 20 lymphatic system

lymphatic system- a network of lymph vessels containing lymph and lymph nodes and its job is to maintain fluid balance.

lymphoid organs and tissues- are the structural basis of our immune system.

3 liters

capillary beds do not reclaim some of their lost fluids.

a clear watery fluid found in the the lymphatic vessels.

** has a much lower percentage of proteins than blood.

**only flows to the heart and does not clot.

tissue fluids, fats and proteins. to the general circulation.

** they begin blindly in intercellular spaces of soft tissues and do not form a closed circut.

blind ended vessels found in capillary bed and is made of simple squamous epithelium. the cells overlap each other and are anchored down by collagen fibers.

• **not found in bones teeth and cartilage cornea bone marrow and the central nervous system.
• **flaps open when interstitual pressure is high

• lymphatic capillaries 
• -larger lymphatic vessels
• -main lymphatic trunks
• -right lymphatic duct and thoracic 
• -juction between internal jugular and subclavian vein.

right, thoracic

• **throacic duct originates as the cisterna chyli
• under the lumbar reigon of abdominal cav

caused by proliferation of WBC in response to an underlying infection virus and all.

when the lymph vessels become inflammed and their vaso vasorum becomes congested with blood.

**seen thru skin and tender to touch

• almost like veins but...
• thinner walls and more valves and contain lymph nodes

as the capillaries increase in size the walls become thicker and have 3 layers.

**one way valves are seen sometimes in larger and often in the smaller.

proteins that accumilate in tissue spaces can only be returned to blood by lymphatics.

maintains osmotic pressure in the blood 

• lacteals absorb fats and neutrients 
• chyle milky fluid found in lacteals 1-2%

lymph moves through the system by the larger number of valves.

Breathing movements and skeletal muscle contractions establish a fluid pressure gradient.

• interstiual fluid pressure 
• pulsations of near by arteries & rhythmic smooth muscles contractions in lymph vessel walls.

**lymph pours into central veins at peak of inspiration.

caused by common flies and mosquitos which inject parasitic worms into host cells.

 it casues severe inflammation and pain and the skin develops ulcer like growths can cause fevers pain and chills.

**mostly effects legs and torso.

manage immune response & directly attack infected cells.

-produce plama cells that secrete antibodies and marks antigens for destruction by phagocytes.

macrophages phagocytize and help activate T cells.

reticular cells make reticular fibers.

dendric cells capture antigens and carry them to lymph nodes.

home for lymphocytes and and main spot for lymphocytes and macrophages also made or reticular CT

loosly arranged cells and reticular fibers and found in most organs

solid body of tightly packed cells and reticular fibers germinal centers where b cells prolifertate.

a cluster along thy lymph vessels. they filter and activate during immune attacks

macrophages remove micro organisims.

bean shaped and is a dense fiberous capsule.

the trabeculae divides nodes into compartments and have framework of reticular fibers.

the cortex is densley packed follicles and centers for B and T cells to divide.

• meduallary cords are inward extentions of cortex.
• lymph sinuses- lymph flows through the sinus and encounters macrophages.

it enters thru afferent vessels and travels thru from cortex to medulla and exits thru the efferent vessels at the hilum.

** there are less efferent vessels so that the lymphocytes and macro phages can do their work.

can be a sign of cancer, blocked lymph drainage, or other health conditions.

bubonic plague is bacterial infected lymph nodes and gangre.

composed of reticular tissue except the thymus and they all help protect the body.

**only lymph nodes filter lymph

the left hypochondrium directly below diaphragm on the left side of the stomach. its surrounded by inward extensions that divide the organ into compartments.

its a blood cleanser- it extracts old and defective blood cells and platelets from the blood.

Macrophages remove micro organisims from blood and phagocytose.

Mono and lymphocytes complete their development in the spleen.

takes iron and goblin from old RBC's and reuses

The pulp of spleen and sinus store blood.

B4 birth rbcs are made in the spleen after that it only makes RBC's in extreme hemolytic anemia.

W.Pulp- dense masses of developing lymphocytes and macrophages.

Red pulp- near outer region made up of fine reticular fibers submerged in blood site of blood cell and pathogen destruction.

removal of ruptured spleen. direct blow or injury causes it.

bone marrow and liver takes over in its absence but will have high risk of infections. IT REPAIRS ITSELF.

its the primary central organ of the lymphatic system.

highly active in first year and then it begins to atrophy.

• where t cells become imunocompetent(able to fight)
• has a cortex and medulla

cortex- rapidly dividing t cells and few macrophages.

medulla-less t cells and thymic corpusules.

no reticular fibers and no reticular fibers

secretes thymosin, enables lymphocytes to transform into tcells

lymphoid cells test the 5% of the tcells that mature each day  and to be relesed into the bloodstream.

lymphoid tissues located in the mucous membrane, protects us from germs that want to get in. and they

tonsils, peyers patches appendix and areas found in the respiratory and genitourinary organs.

form a entrance around the throat.

2 palatine make up the right and left side, they are the largest and most commonly infected.

pharyngeal tonsil- top of the mouth and called adenoids when its infected.

• lingual tonsil- base of tongue
• tubal tonsils- near openings of the Eustachian tubes.

protect against bacteria between nasal and oral cavities.

when bacteria is caught they are put into tonsillar crypts and thrown to the immune system to destroy them.

the immune cells also creates memories of these pathogens.

large clusters of lymphoid follicles almost like tonsils. 

located in the distal wall of the small intestine.

little piece off of the cecum and contains high volumes of lymphoid follicles.

destroys bacteria before the get into the wall

the immune cells develop memory so you can get long term immunity.