M8 - Lymphatic System Flashcards
Lymphatic system functions
Maintains normal blood volume and interstitial fluid composition, provide alternative routes for hormones, nutrients, waste, lymphocyte production, immune response
Primary lymphatic structures
Thymus, red bone marrow
Secondary lymphatic structures
Tonsils, lymphoid nodules: lymph nodes, spleen, MALT - appendix, aggregated nodules
Lymphatic capillaries
Close ended tubes interspersed around blood capillary beds, smallest of lymphatic vessels, minivalves in clefts between cells, irregular outline, anchoring filaments connecting to surrounding CT, v permeable
Lymphatic vessels
3 tunics, difficult to distinguish tunics, widest lumen, thinnest wall thickness (permeability), contain more valves than veins
Lymph movement
Lymphatic capillaries –> vessels –> trunks –> ducts
Right lymphatic duct
Right clavicle, returns lymph from R side of head, neck, upper limb, thorax
Thoracic duct
Inferior to diaphragm, cisterna chyli, collects lymph from most of body
T cells
Thymus, cell mediated immunity - cell killers
B cells
Bone marrow, antibodies
NK cells
Natural killer, viruses and cancer
Diffuse lymphatic tissue
Lymphocytes loosely aggregated within CT, mucous membrane of respiratory, urinary, CT tracts
Lymphatic nodules
Lymphocytes aggregated within supporting framework of reticular fibers, germinal center that contains lymphocytes
Tonsils
Lymphatic nodule, crips - space where bacteria can enter deep and then destroyed by lymphocytes
Mucosa associated lymphoid tissue
In epithelia of digestive, respiratory, urinary, and reproductive systems, aggregated lymphoid nodules, appendix
Lymph nodes
Cleanse lymph
Afferent lymphatic vessels
Carry unfiltered lymph into lymph node
Efferent lymphatic vessels
Carry filtered lymph away from lymph node
Outer fibrous capsule
Ensures none of pathogens make way out, lymphatic fluid goes thru node and gets cleansed
Sinusoidal system
Exchange between lymphatic fluid and cellular debris and cells
Thymus
T cell maturation, superior to heart and deep to sternum, provides environment to ensure T cells know self from foreign
Spleen
Upper left quadrant, highly vascularized, red pulp 80%: erythrocytes, platelets, macrophages, plasma, white pulp: lymphoid tissue, lymphocytes, macrophages
Lymphedema
Accumulation of interstitial fluid, vascular capillaries depositing more than can suck up, caused by damage to lymphatic capillaries
Lymph nodes + metastasis
Cancer cells can become lodged in lymph nodes, lymphoma, drain to other parts causing metastasis
