General Lymphatic System Flashcards
What is the lymphatic system responsible for?
Immune defense
What type of cells are responsible for support in the lymphatic system?q
Reticular cells
What do NK cells and T/B lymphocytes do in the lymphatic system?
Protect
What are two functions of vessels in the lymphatic system?
- return tissue fluid to circulating blood
- Create plasma
List the 4 organs of the Lymphatic System
- Thymus
- Spleen
- Lymphoepithelial structures (MALT, tonsils)
- Lymph and hemal nodes
Where are lymphocytes produced?
In germinal centers in cortex of LN
Filtration is the function of?
LN
Which organ of the lymphatic system stores blood, removes particles, produces lymphocytes and destroys used erythrocytes?
Spleen
Describe the function of the thymus and what happens to it during life
It involutes with age. Its function is to train and develop T-lymphocytes and produce thymosins
What are thymosins?
Antibody stimulating hormones
What is the function of the Circulatory System?
Transport blood and lymph to/from tissues
The heart, blood vessels and lymphatic vessels are all structures associated with which body system?
Circulatory System
Describe some similarities of the lymph vessels compared to blood vessels
- T. Adventitia
- One directional flow thanks to valves (like some veins)
- endothelium
What are 2 differences of lymphatic vessels compared to blood vessels?
- no T. Media
- All lymphatic vessels have valves
Lymph capillaries have adjacent cells joined by what 3 types of junctions?
Interdigitations, simple overlapping and adhering
What allows extra cellular fluid to flow in but not out in lymph capillaries?
Flap-like valves
Define Lymphedema
Acute or chronic build up of lymph fluid due to an obstruction in a vessel
The lymphatic system filters out before dropping back in the circulatory system where?
Right before the heart in a vein (caudal vena cava)
A lymph node will have multiple Afferent vessels and ____________ efferent
Only one with an artery and vein
What are 3 clinically significant issues associated with LN?
- Lymphadenopathy - enlargement
- Lymphadenitis - infection caused by an agent
- LN tumors
Which center is responsible for the parotid and mandibular center drainage?
Medial and Lateral Retropharyngeal Center behind the pharynx
What structures does the parotid center drain lymph from?
Dorsal head - skin, dorsal skull, orbit, masticatory m
The lower jaw (muzzle, salivary glands, tongue, etc) are drained by the ______________ center
Mandibular
What are the 3 centers that drain the neck from lymph?
Superficial cervical, deep cervical and tracheal trunk
The axillary center and right lymphatic duct drain what area of lymph?
Forelimb
What is the major lymph collecting channel?
Thoracic duct
Which forelimb lymph drainage arises from cisterna chyli?
Thoracic duct
What are the 3 lymph drainage centers of the hindlimb, pelvis, and abdominal wall?
Lumbar aortic
Medial iliac
Hypogastric
The lumbar, celiac, cranial/caudal mesenteric, cisterna chyli, popliteal and lumbar trunks drain lymph from which 2 areas?
Abdominal Viscera and Loins
List the 3 primary Lymphoid organs
- thymus
- Bone marrow
- Fabricius bursa in birds
What primary lymphoid organ is responsible for production of B-lymphocytes in birds?
Fabricius bursa
Describe where are T and B lymphocytes produces in primary lymphoid organs
T lymphocytes - Thymus
B lymphocytes - Bone marrow
Are the lymph nodes, tonsils, and spleen primary or peripheral lymph organs?
Peripheral
Where do lymphatic capillaries originate from?
Lacteals
What is another name for lymph and it is similarly composed to ?
Chyle. Similar composed to plasma
List the 5 structures of the lymph node
- Medulla
- cortex
- subscapular sinus
- follicle
- paracortex
List the 5 structures of the lymph nodes
- Medulla
- cortex
- subscapular sinus
- follicle
- paracprtex
In the lumen of the subscapular sinus of a LN, which structure slows lymph flow?
Stellate reticular
Which follicle of the LN has a germinal center?
Secondary follicle
Describe lymphocyte homing
When lymphocytes re-enter the lymphoid organs through endothelial vessels
What increases the chance of a lymphocyte of finding its target?
Circulation btw blood and lymph of lymphocytes
Which lymphoid organ is in charge of maturation and activation of lymphocytes?
Lymph nodes
The largest lymphatic organ is the _______________
Spleen
Which pulp in the spleen surrounds and follows central arteries?
White pulp
In white pulp of the spleen, what is the T-cell dominant tissue around the central Arterioles called?
Periarterial lymphatic sheath (PALS)
Describe the red pulp of the spleen
Spongy red mass composed of splenic sinuses and cords
What WBC is present in red pulp of the spleen?
Macrophages
Describe the primary role of macrophages
Remove damaged erythrocytes and iron metabolism
What is a common invasive cancer that can give way to splenic or cardiac tumors, is prevalent in large breed dogs, and causes blood vessel branching and even rupture?
Hemangiosarcoma
Which lymphoid organ is fully formed at birth and involutes with puberty?
Thymus
Multipotent T cell go through which 2 differentiating to become what in the thymus?
Thymic Nurse cells and Epithelioreticular cells
There are ____ Epithelioreticular cells
6
Which ERC of the thymus expresses MHC I and II antigens?
II
Which ERC regulates T-lymphocyte selection in the thymus?
V
Why are cortical capillaries impermeable to macromolecules in the thymus?
Blood Thymus Barrier in the thymus cortex
