Ch:22 Lymphatic System- Notes
Fluid balance, fat absorption, and defense are functions of the ___________________.
Lymphatic system helps to absorb fat and other substances from the digestive system with the help of specialized vessels called ______________
______________ is a fluid similar to plasma or interstitial fluid but does not have plasma proteins.
Lymphatic capillaries have _________________ which are loosely attached and are therefore more permeable.
Lymph capillaries merge to form _____________ which have valves and are similar in structure to veins.
Lymph moves through the vessels with the help of milking action carried out by the _________________ and pressure changes created by the respiration
____________ is bean-shaped clusters of B and T cells found at intervals along the length of the vessels
As lymphatic vessels exit from lymph nodes, they merge and form _____________.
__________________ is the main collecting duct of the lymphatic system.
- Receives lymph from the left side of the head, neck, and chest, the left upper extremity, and the entire body below the ribs.
- Drains lymph into venous blood at junction of the left subclavian vein and internal jugular vein.
_________________ drains right side head, arm and chest. Empties into venous system at junction of right subclavian vein and right jugular vein.
Right lymphatic duct
_________________ make up 20–30% of circulating leukocytes
Most are stored, not circulating
_____________ make up 80% of circulating lymphocytes.
________________ attack cells infected by viruses. Produce cell-mediated immunity
Cytotoxic T (TC) cells
_______________ is formed in response to foreign substance. Remain in body to give “immunity”
Memory T cells TM:
______________ stimulate function of T cells and B cells
Helper T (TH) cells:
________________ inhibit function of T cells and B cells
Suppressor T (TS) cells:
_______________ Make up 10–15% of circulating lymphocytes
___________ differentiate (change) into plasma cells which produce and secrete antibodies (immunoglobulin proteins).
_______________ responsible for immunological surveillance and attack foreign cells, virus-infected cells, and cancer cells
The spleen, lymph nodes and nodules are __________________________ (sites where the mature lymphocytes reside and carry out immune response)
Secondary Lymphatic organs
Red bone marrow and thymus gland are ____________________________. (where the lymphocytes originate and mature to become immunocompetent)
Primary Lymphatic organs
_____________________ are scattered throughout the lamina propria of mucous membranes lining the GI tract, respiratory airways, urinary tract, and reproductive tract.
Mucosa associated lymphatic tissue (MALT):
_______________ are aggregates of lymphatic tissue in appendix and small intestines for protection
__________ large groups of nodules in the mucosa of the pharynx. Provide protection against bacteria entering the body through the mouth or nasal cavities.
A __________________ capsule surround each lymph node. Capsule extends in the lymph node as trabeculae.
dense connective tissue
Outer part of the node is called ____________ which is made up of lymphatic nodules containing lymphocytes and macrophages
Inner medulla is made up of irregular strands of lymphatic tissue called ________________.
Destroys defective RBCs, Detects and responds to foreign substances, Limited reservoir for blood are functions of the __________.
The spleen is often damaged in abdominal trauma. A _____________ may be required to prevent excessive bleeding.
__________ is lymphatic tissue around arteries in the spleen.
___________ is Lymphatic tissue associated with the veins in spleen
The depression on the Spleen where the splenic blood vessels enter and leave is called ________.
______________ Is defined as the ability to resist damage from foreign substances such as microorganisms and harmful chemicals.
_______________ is lack of resistance.
__________________ prevent entry, limit the spread of microorganisms or other environmental hazards.
Innate (nonspecific) defense mechanisms
Mucous membrane that lines the digestive respiratory and urogenital tract secrete a viscous mucus that prevents entry of potentially harmful microbes is a ________________.
In addition many of the secretions like saliva, tears etc. also contain proteins like __________ which digest cell wall of microbes and destroy it.
________________ are specialized cells that perform phagocytosis. Phagocytosis takes place in 5 steps chemotaxis, adherence, ingestion, digestion, and killing.
Neutrophils and monocytes are cells involved in ______________________.
____________________ Is carried out by natural killer (NK) cells. They attack cancer cells and body cells infected with viruses.
_______________ are chemicals released by virus infected cells.
- They cannot save the infected cell, but they diffuse to neighboring healthy cells, where they stimulate the production of antiviral proteins that inhibit viral replication in these cells. Thus an infected cell helps to protect uninfected cells.
- There are three known types of interferons, alpha, beta, gamma. - are most effective in controlling short term infections, such as cold and influenza.