Lymphatic System and Immunity

Key Terms Lymph Lymph nodes Lymph vessels Lymphocytes Spleen Standard precautions Thoracic duct Tonsils Vaccination Natural Immunity Passive acquired immunity Acquired immunity Active immunity Allergern Anaphylaxis Hypersensitivity Incubation period Interstitial fluid Artificial acquired immunity

Objectives Describe the general functions of the lymphatic system Identify structures of the lymphatic system. Identify locations of major lymphatic pathways Explain the lymphatic circulation. Describe the lymph node and it’s function. Discuss the functions of the spleen and thymus gland.

Objectives Differentiate between specific and non specific defenses and give examples of each. List 6 non specific defense mechanisms and the actions of each. Differentiate between primary and secondary immunity and active and passive immunity

Functions of lymphatic system Carry excess fluid and waste from interstitial spaces in most tissue and return it to the blood stream. Launches generalized and targeted attacks against foreign particles which allows the body to destroy these particles

Lymph Straw colored fluid Interstitial fluid – tissue fluid because it is in the spaces between the cells. Composed of water, lymphocytes, some granulocytes, oxygen digested nutrients, hormones, salts, carbon dioxide and urea It does not contain RBC’s or protiens (too large)

Lymph Carries wastes back to the capillaries for excretion The lymphatic system has no pump. The lymph is moved along in the lymph vessels by the action of the skeletal muscle action..

Lymph Vessels Closely parallel veins Valves similar to those in veins prevent backflow Located in almost all tissues and organs that have blood vessels

The Lymphatic Pathway Lymphatic Capillary Lymphatic Vessel Lymph Node Lymphatic vessel Lymphatic trunk Collecting ducts Subclavian vein

The Lymphatic Pathway There are two large main lymphatics Thoracic Duct- Collects lymph from left side of chest, left head and neck, left upper limb, abdominal area and lower limbs and empties into the left subclavian vein. – It is larger and longer of the two ducts

The Lymphatic Pathway Right Lymphatic Duct- collects lymph from right head and neck, right upper limb, right thorax and empties into the right jugular vein Lymph only flows in one direction from the body organs back to the heart.

Lymph Nodes Small, oval shaped- size of a pinhead to size of an almond Located alone or grounded Site for lymph production and filter for screening out harmful substances If substance can’t be destroyed, node becomes inflamed

Tonsils Masses of lymphatic tissue Produce lymphocytes Filter bacteria Get smaller as person ages Adenoids- tonsils on upper part of the throat.

Spleen Sac like mass of lymph tissue LUQ just below diaphram Forms lymphocytes and monocytes Filters blood Stores RBC Contract during activity or blood loss to release RBCs Destroys or removes old RBCs

Thymus Gland Upper anterior thorax above the heart Also considered an endocrine gl and

Immunity the body’s ability to resist bacterial invasion and disease Natural At birth Inherited Permanent Includes – Unbroken skin – Chemical barriers – Blood phagocytes – Local inflammation – Fever – Species resistance

Immunity Passive Acquired Immunity – Acquired artificially by injecting antibodies to protect from specific disease – Immediate immunity – Lasts 3-5 weeks – Mother provides newborn with some passive immunity – Used when someone exposed Tetanus Infectious hepatitis

Immunity Active Acquired Immunity Natural Results from having had and recovered from a disease – A child who gets measles will usually not get them again – Child’s body has manufactured antibodies Artificial Comes from getting vacinated Immunization – Artificial resistance to a particular infection by artificial means – Antigen injected into a person to stimulate antibody production

Disorders Adenitis- swelling in the lymph gland Lymphadenitis – enlargement of the lymph nodes which occurs when infection is present and body is trying to fight off infection Tonsillitis- inflammation of the tonsils – Become enlarged, infected and difficult swallowing – Surgery in extreme cases

Disorders Hodgkin’s Disease Cancer of the lymph nodes – Symptoms – painless swelling of lymph nodes – Tx- Chemotherapy and radiation Infectious Mononucleosis Virus Young adults and children Spread by oral contact Symptoms – Enlarged lymph nodes – Fever – Physical and mental fatigue – Elevated leucocytes – Tx- Bedrest

Hypersensitivity Immune system fails to protect against foreign material, Antibodies formed irritate certain body cells An abnormal response to drug or allergen Allergen- an antigen that causes an allergic response – Ex: ragweed, penicillin, bee stings, foods, etc

Anaphylaxis Severe, sometimes fatal allergic reaction Antigen-antibody reaction stimulates a massive secretion of histamine –chemical that triggers inflammatory response Symptoms – Breathing difficulties, headache, facial swelling, falling blood pressure, stomach cramps, vomiting – Tx- Adrenaline-Epinephrine- relaxes muscles and constricts blood vessels

Autoimmune Disease Immune system fails to recognize self from nonself Attacks and damages tissue and organs Juvenile diabetes Rheumatoid arthritis Systemic lupus thermatosus – body attacks healthy tissue – Butterfly rash