LYMPHATIC Flashcards
The Lymphatic System
Consist of two semi-independent parts:
1.Lymphatic vessels
2.Lymphoid tissues and organs
Semi independent parts that
- consist of excess tissue fluid and plasma proteins carried by lymphatic vessels
- If fluids are not picked up, edema occurs as fluid accumulates in tissues
- also pick up excess fluid (lymph) and return it to the blood
Lymphatic Vessels
Weave between tissue cells and blood capillaries Walls overlap to form flaplike minivalves
Fluid leaks into this
also anchored to connective tissue by filaments
Higher pressure on the inside closes minivalves Fluid is forced along the vessel
Lymphatic capillaries
It collect lymph from lymph capillaries
Carry lymph to and away from lymph nodes
Return fluid to circulatory veins near the heart Right lymphatic duct drains the lymph from the right arm and the right side of the head and thorax
Thoracic duct drains lymph from rest of body
Lymphatic collecting vessels
Lymphatic vessels are similar to veins of the
cardiovascular system
Thin-walled
Larger vessels have valves
Low pressure, pumpless system
Lymph transport is aided by: Milking action of skeletal muscles
Pressure changes in thorax during breathing Smooth muscle in walls of lymphatics
Lymphatic vessels are similar to veins of the
cardiovascular system
Thin-walled
Larger vessels have valves
Low pressure, pumpless system
Lymph transport is aided by: Milking action of skeletal muscles
Pressure changes in thorax during breathing Smooth muscle in walls of lymphatics
Lymphatic nodes filter lymph before it is returned to the blood
Harmful materials that are filtered:
Bacteria
Viruses
Cancer cells
Cell debris
Lymphatic nodes filter lymph before it is returned to the blood
Harmful materials that are filtered:
Bacteria
Viruses
Cancer cells
Cell debris
WHAT
Defense cells within lymph nodes:
it - engulf and destroy bacteria, viruses, and other foreign substances in lymph
Macrophages
Defense cells within lymph nodes
It - respond to foreign substances in lymph
Lymphocytes
Most lymph nodes are kidney-shaped, less than 1 inch long, and buried in connective tissue
Surrounded by a capsule
Divided into compartments by trabeculae
Most lymph nodes are kidney-shaped, less than 1 inch long, and buried in connective tissue
Surrounded by a capsule
Divided into compartments by trabeculae
PART OF LYMPHATIC NODES
(outer part)
•Contains follicles - collections of lymphocytes
•Germinal centers enlarge when antibodies are released by plasma cell
Cortex
PART OF LYMPHATIC NODES
Contains phagocytic macrophages
Medulla (inner part)
Flow of lymph through nodes
Lymph enters the convex side through afferent lymphatic vessels
Lymph flows through a number of sinuses inside the node
Lymph exits through efferent lymphatic vessels
Flow of lymph through nodes
Lymph enters the convex side through afferent lymphatic vessels
Lymph flows through a number of sinuses inside the node
Lymph exits through efferent lymphatic vessels
Several other lymphoid organs contribute to lymphatic function (in addition to the lymph nodes)
what are these organs?
Spleen
Thymus
Tonsils
Peyer’s patches
Appendix
WHAT LYMPHOID ORGAN
- it is Located on the left side of the abdomen
Filters and cleans blood of bacteria, viruses, debris
Provides a site for lymphocyte proliferation and immune surveillance
Destroy worn-out blood cells
Forms blood cells in the fetus
Acts as a blood reservoir
Spleen
WHAT LYMPHOID ORGAN:
Found overlying the heart
Functions at peak levels only during youth
Thymus
WHAT LYMPHOID ORGAN
-Small masses of lymphoid tissue deep to the mucosa surrounding the pharynx (throat)
Trap and remove bacteria and other foreign pathogens
Tonsillitis results when the tonsils become congested with bacteria
Tonsils
WHAT LYMPHOID ORGAN:
Found in the wall of the small intestine
Similar lymphoid follicles are found in the appendix
Macrophages capture and destroy bacteria in the intestine
Peyer’s Patches
Mucosa-associated lymphoid tissue (MALT)
Includes:
Peyer’s patches
Tonsils
Appendix
Acts as a sentinel to protect respiratory and digestive tracts
Mucosa-associated lymphoid tissue (MALT)
Includes:
Peyer’s patches
Tonsils
Appendix
Acts as a sentinel to protect respiratory and digestive tracts
What are the wo mechanisms that make up the immune
system defend us from foreign materials
- Innate (nonspecific) defense system
- Adaptive (specific) defense system
- specific resistance to disease
Immunity
is a functional system rather than an organ system in an anatomical sense
Immune system
TYPE OF DEFENSE SYSTEM
Mechanisms protect against a variety of invaders Responds immediately to protect body from foreign materials
Innate (nonspecific) defense system
TYPE OF DEFENSE SYSTEM
Fights invaders that get past the innate system
Specific defense is required for each type of invader
The highly specific resistance to disease is immunity
Adaptive (specific) defense system
Innate body defenses are mechanical barriers to
pathogens (harmful or disease-causing
microorganisms) and include:
Body surface coverings
•Intact skin
•Mucous membranes
Specialized human cells
Chemicals produced by the body
Innate body defenses are mechanical barriers to
pathogens (harmful or disease-causing
microorganisms) and include:
Body surface coverings
•Intact skin
•Mucous membranes
Specialized human cells
Chemicals produced by the body
Surface membrane barriers, such as the skin and
mucous membranes, provide the first line of
defense against the invasion of microorganisms
Protective secretions produced by these membranes
Acidic skin secretions inhibit bacterial growth
Sebum is toxic to bacteria
Mucus traps microorganisms
Gastric juices are acidic and kill pathogens
Saliva and tears contain lysozyme (enzyme that destroy bacteria)
Surface membrane barriers, such as the skin and
mucous membranes, provide the first line of
defense against the invasion of microorganisms
Protective secretions produced by these membranes
Acidic skin secretions inhibit bacterial growth
Sebum is toxic to bacteria
Mucus traps microorganisms
Gastric juices are acidic and kill pathogens
Saliva and tears contain lysozyme (enzyme that destroy bacteria)
Cells and chemicals provide a second line of
defense
Natural killer cells and phagocytes Inflammatory response
Chemicals that kill pathogens
Fever
Cells and chemicals provide a second line of
defense
Natural killer cells and phagocytes Inflammatory response
Chemicals that kill pathogens
Fever
SECOND LINE OF DEFENSE
Lyse (burst) and kill cancer cells, virus-infected cells
Release chemicals called perforin and granzymes to degrade target cell contents
Natural killer (NK) cells
SECOND LINE OF DEFENSE
Triggered when body tissues are injured
Four most common indicators (cardinal signs) of acute inflammation
1. Redness
2. Heat
3. Pain
4. Swelling (edema)
Inflammatory response