The Lymphatic System Flashcards
What does the lymphatic system consist of? (3)
- network of vessels
- tissues and organs
- red bone marrow
What are the 3 primary functions on the lymph system?
- drains excess interstitial fluid from tissue spaces and returns to blood
- transports dietary lipids and lipid-soluble vitamins absorbed from the GI tract
- initiates immunes responses against foreign cells and microbes
the lymphatic system in made up of minute ___ ____ capillaries which lie in the ____ ____ between body cells
blind-ending
tissue spaces
what are the two main lymphatic ducts?
- thoracic duct
- right lymphatic duct
What is the function of the lymphatic ducts?
To transfer the lymph from the lymphatic vessels back into the blood circulation
How is lymph moves through vessels?
Skeletal muscle contractions (which generate pressure)
What are lacteals and where are they found?
Tiny lymphatic vessels
In the villi of the small intestine
What is the function of lacteals?
Absorption of lipids from digestive tract
Lymph is collected in ____ and flows into progressively ___ lymph vessels, passing through a number of ___ ___
capillaries
larger
lymph nodes
What are the 2 types of primary lymphatic tissue?
- red bone marrow
- thymus
What happens in primary lymphatic tissue?
Stem cells divide
and become immunocompetent
What is the location and function of the thymus?
- located in mediastinum
- assists in maturation of T-cells which have migrated from bone marrow
What are the 3 secondary lymphatic tissues?
- spleen
- lymph nodes
- nodules
What is the function of secondary lymphatic tissues?
Main sites which initiate immune responses
What is the location and function of the spleen?
- Left hypochondriac region
- Immune functions relating to red blood cells
What is the location and function of lymph nodes?
- occur in groups along lymphatic vessels (in particular group and axilla)
- covered by capsule of connective tissue
- filter foreign substances
- illicit immune response (memory cells)
What is the location and function of nodules?
- masses of lymphatic tissue (not surrounded by capsule)
- found in connective tissue of mucous membranes in the GI, urinary, reproductive and respiratory tracts
What is an example of a lymph nodule?
Tonsils
What is the difference between innate and adaptive immunity?
Innate is non-specific, present at birth
Adaptive is an antigen specific response to invading microbe
What is the first line of defence against microbes? (2)
Skin
Mucous membranes
What is the second line of defence against microbes? (4)
- antimicrobial substances
- natural killer cells and phagocytes
- fever
- inflammation
What are the 5 stages of phagocytosis?
- chemotaxis (migration of cells towards pathogen)
- adherence
- ingestion
- digestion
- killing
What are the 3 stages of inflammation?
- vasodilation and increased permeability of blood vessels
- movement of phagocytes
- tissue repair
Adaptive immunity is mainly mediated by _-____ and _-____
B-cells
T-cells
