Lymphatic System Flashcards
lymphoid tissue location
- abdomen
- pharynx
lymph composition
- plasma
- plasma proteins
- lipids
- lymphocytes
- miscellaneous debris (bacteria, malignant cells)
lymph function
- assists cardiovascular system in removal and transport of tissue fluid from extracellular spaces of body
- major role in the immunological defenses of the body against bacteria and viruses
lymphatic vessels location
- widely distributed throughout the body
- run alongside the blood vessels within the loose CT
lymphatic vessels structural characteristics
- varies in size
- anastomose
define amastomose
-joins each other forming a network
structural characteristics components
- lymphatic capillaries
- medium ducts
- lymphatic ducts
- lacteals
lymphatic capillaries
- begins to blind-ended tubes
- small thin walled
- very permeable
medium-large lymphatic vessels
- thicker walls
- smooth muscle fibers surround vessel
- have valves: permit fluid to flow in one direction only
what are lymphatic ducts?
- largest lymphatic ducts
- thicker walls, valves
lymphatic ducts components
- right lymphatic duct
- thoracic duct
lacteal location
-located in intestine
lacteal function
-transports products of fat digestion
what are lymph nodes?
-small, oval, aggregations or clusters of lymphoid tissue
lymph nodes location
- along the path of the lymphatic vessels
- throughout the body
- large clusters in cervical, axillary and inguinal regions
lymph nodes function
- filtration
- production of lymphocytes
lymph node filtration function
- filtration of lymph
- ->removal of foreign particles
lymph node production of lymphocytes function
-produces T-cells and B-cells
T-cells function
-destroys foreign material
B-cells function
-produces antibodies
lymph node structure
- enclosed in a fibrous capsule
- afferent vessels
- efferent vessels
- reticular fibers
- macrophages
- aggregations of T cells
- germinal centers
afferent vessels function
-brings lymph to node
efferent vessels function
-takes filtered lymph away from the node
reticular fibers function
-form a meshwork which traps debris
macrophages function
-engulfs and digests debris
germinal centers function
-area when B-lymphocytes develop and become plasma cells which produce antibodies
path of the transport of lymph**
(in order)
- tissue
- lymphatic capillaries
- large lymphatic vessels
- lymphatic ducts
- venous system
right lymphatic duct**
- drains upper right quadrant of the body
- empties its contents into the right subclavian vein
thoracic duct**
- drains lymph from lower extremities, abdomen, left thorax, left head, and neck
- empties into the left subclavian vein
what results from lymph not having an elaborate pump to push fluid towards its destination?
-must travel upward (against the force of gravity using different factors
what factors frontol the flow of lymph
- rhythmic contraction of skeletal muscles and smooth muscle of abdominal organs
- negative pressure in thorax
- valves
how do muscles control lymph flow?
-they massage the vessels and help ush fluid along
how do negative pressure control lymph flow?
-helps draw fluid up through thoracic duct
how do valves control lymph flow?
-prevents the backflow fo lymph
which lymphoid organs don’t transport lymph but contain lymphoid tissue(aka lymphoid organs)?
- spleen
- thymus
- tonsils
importance of having lymphoid tissue
- key role in body’s immunological defense mechanism
- makes them called lymphoid organs
spleen location
- upper left quadrant
- posterolateral to stomach
- level of 9th-11th ribs
spleen structure/contents
- red pulp
- white pulp
- reticular fibers
- sinusoids
spleen red pulp
-consists of blood flowing through a meshwork of fibers
spleen white pulp
-clusters of lymphoid tissue
spleen reticular fibers
- meshwork of fibers
- traps debris passing through so macrophages can negluf it
spleen sinusoids
-irregular passageways through which blood passes
spleen function
- production of blood cells
- storage
- filtration
- immune function
production of blood cells splenic function
- fetal life: all cell types
- adult: usually only lymphocytes
storage splenic function
- platelets
- WBC and RBC
- iron
filtration splenic function**
- filters blood
- destroys and disposes of old RBCs
immune function splenic function
-production of lymphocytes and antibodies
thymus location
- bi-lobed mass of lymphoid tissue
- located beneath sternum
thymus function
- during prenatal and postnatal development, it’s responsible for production of T-lymphocytes (“trade school for T-lymphocytes”)
- degenerates at puberty
tonsils general location
- clusters of lymphoid tissue
- deep to mucosa in 3 regions of pharnyx
tonsils function
- act as a barrier to infection (bc they contain lymphocytes)
- this destroys foreign material (like bacteria) as they enter the system
types of tonsils
- lingual tonsils
- pharyngeal tonsils (adenoids)
- palatine tonsils
lingual tonsil location
-located on posterior 1/3 of tongue
pharyngeal tonsil location
-located on root of posterior wall of nasopharynx
palatine tonsil location
-extend into soft palate on each side of oropharynx
