Lymphatic System

Body’s 3 lines of defense are _____, _______, and _______________. What is bone marrow? Function of bone marrow is? What are WBC’s? Example of dz/condition with increased WBC (leukocytosis) Example of dz/condition with deceased WBC (leukopenia) What is pus?

What are RBC’s? What is RBC’s function? Why are they red? What is an antigen? What is an antibody? What are platelets?

What are some examples of Internal defenses to fight infection? What is an example of an external defense against infection? (Hint- it is the largest organ in the body)

Relate Lymphatic to Immune System Immune System– body’s defense system against infections (virus, bacteria, fungi) Lymphatic System– system of capillaries, vessels, lymph nodes, and lymphatic tissue Transports a fluid called LYMPH from the tissues as it returns to the bloodstream Lymphatic tissue filters (cleans) the lymph of abnormal cells and pathogens

So, what is lymph Thin, watery fluid that forms when plasma diffuses into tissue spaces (plasma is a straw colored liquid that is a component of blood) Lymph is composed of water, digested nutrients, salts, hormones, O2, CO2, and metabolic wastes (Ex. Urea)

Lymphatic vessels Located throughout the body in almost all tissues that have blood vessels

Lymph nodes AKA glands Located all over the body Small, round, oval masses – range in size Lymph vessels bring lymph to the nodes The nodes then filter the lymph and remove impurities (Ex. Cancer cells, pathogens, dead blood cells) The lymphatic tissue in the nodes produces lymphocytes (WBC) and antibodies (fight infection)

So, now the purified lymph (with its lymphocytes and antibodies) leaves the lymph node by a lymphatic vessel As the lymph vessels leave the lymph node they join together and form larger lymph vessels that drain into 1 of 2 ducts

1. Right Lymphatic Duct Short tube that receives purified lymph from the right side of head/neck/chest and right arm ** Purified lymph nodes enter into the right subclavian vein which returns purified lymph to the blood

2. Thoracic duct Larger tube that drains the rest of the body and empties into the left subclavian vein At the beginning of this duct is a pouchlike structure called the cisterna chyli---- a storage area for purified lymph before it returns to the bloodstream

Heart This is where the ducts drain into. They drain into the right and left subclavian veins of the heart.

Lymphatic tissue Produces lymphocytes (WBC) and antibodies (fight infection) Examples of lymphatic tissue 1. Tonsils– you have 3 pairs Palatine- located on each side of soft palate Pharyngeal (adenoids)- located in the nasopharynx Lingual- located back of tongue

2. Spleen- organ located just below your rib cage on left side Functions: Produces leukocytes, antibodies Destroys old RBC’s Stores erythrocytes to release into the bloodstream if excessive bleeding occurs Filters wastes from the tissues

3. Thymus Located center part of chest Goes away after puberty and is replaced by fat and connective tissue During early life, it produces antibodies and lymphocytes to fight infection - SO, why does it atrophy??

SUM IT UP

Diseases/Conditions 1. Adenitis Inflammation/infection of lymph nodes Happens because large quantities of pathogens enter lymph node and infect the tissue Sx: fever, swollen/painful nodes Tx: antibiotics, warm compresses If abcess forms- may have to incise and drain the node

2. Hodgkin’s disease (lymphoma) Chronic, malignant disease of lymph nodes Sx: painless swelling of nodes, fever, night sweats, weight loss, fatigue Tx: chemo/radiation, bone marrow transplant

3. Lymphangitis- inflammation of the lymphatic vessels, usually resulting from an infection in an extremity Sx: red streak extends up arm/leg from the source of infection, fever, chills, pain Tx: antibiotics, rest, elevate affected part

4. Splenomegaly—enlargement of the spleen Sx: swelling, abd. pain Can lead to anemia, leukopenia If spleen ruptures—Intraperitoneal hemorrhage and shock----death Can you remove spleen????

5. Tonsillitis– inflammation/infection of tonsils Sx: throat pain, dysphagia, fever, white spots of exudate on tonsils, swollen lymph nodes near mandible Tx: Antibiotics, rest, tylenol/advil for pain, warm gargles Chronic/frequent infections or enlargement that may cause an obstruction may need ?????

Other AIDS– caused by HIV (human immunodeficiency virus) Mononucleosis (MONO) Highly contagious (kissing disease)

Autoimmune diseases (immune system attacks its own healthy tissue) Rheumatoid arthritis Lupus

Vaccines and Immunity What is a vaccine? How does the vaccine provide immunity? Examples of “killed” vaccines Examples of “live” vaccines