Lymphatic System Flashcards
3 main functions of the lymphatic system
- drains excess interstitial fluid
- transports dietary lipids ( vit. A, D, E, K)
- carries out immune response
collect excess tissue fluid and return it to venous blood
- without a “drainage system” edema in tissues increases and high fluid pressure causes tissue damage or tissue death
lymph vessels
Lymph vessels absorb excess _____ and ____ to return to blood.
interstitial fluid and plasma proteins
the 6 components of the lymphatic system
- lymphatic fluid
- lymphatic vessels
- lymph nodes
- tonsils
- thymus
- spleen
clear, watery-appearing fluid found in the lymphatic vessels
lymph/lymphatic fluid
complex fluid that fills spaces between the cells and part of the extracellular matrix
interstitial fluid
both lymph and IF resemble _____ in composition.
blood plasma
Lymphatic vessels resemble veins in structure with these 3 exceptions:
- they have thinner walls
- they contain more valves
- they contain lymph nodes
the capillary wall of lymphatic vessels is formed by a single layer of thin, flat, ______ cells.
As the diameter increases from capillary size, the walls become thicker and have 3 layers.
endothelial cells
function of lymphatic vessels:
transportation of fluid, proteins, fats, and other substances to the general circulation
______ do not form a closed circuit. Lymphatic capillaries begin blindly in intercellular space
lymphatic vessels
Lymphatic capillaries have _____ permeability than blood capillaries
greater
As lymph pressure increases, the cells of the capillary wall overlap so that…
lymph does not move out
Lymphatic capillaries are attached to surrounding cells by _______.
connective tissue filaments
As interstitial fluid increases, the tissue filaments are pulled –> _____________ –> fluid flows into the capillary
space between cells increases
Virtually all capillary beds contain lymphatic capillaries. Lymphatic vessels follow the ____ system. Lymphatic vessels of the viscera follow _____.
- venous system
2. arteries
Lymphatic capillaries merge to form larger lymphatics and eventually form the main lymphatic trunks = 2 main ducts:
- right lymphatic duct
- thoracic duct (left lymphatic duct)
Most of the lymphatic system has to overcome ____.
gravity
2 pumps that aid in flow of lymph:
respiration pumps: pressure changes in thoracic and abdominal cavities with respiration
skeletal muscle pumps: “milking” action of muscle contractions
During exercise, lymph flow may increase as mush as ____ times
10 - 15 times
oval/bean-shaped structures enclosed by a fibrous capsule that occur in clusters in certain areas
lymph nodes
afferent lymph vessels carry lymph ____ lymph nodes
to
efferent lymph vessels carry lymph ____ lymph nodes
away from
6 group locations of greatest clinical importance of lymph nodes:
- preauricular lymph nodes
- submental/submandibular group
- superficial cervical lymph nodes
- axillary lymph nodes
- superficial cubital (subtrochlear) nodes
- iliac and inguinal lymp nodes
2 functions of lymph nodes:
- defense: filtration, phagocytosis
- hematopoieses
physically stops particles from progressing further in the body
mechanical filtration of lymph nodes
biological activity of cells destroys and removes particles
biological filtration of lymph nodes
cells remove microorganisms and other particles (biological filtration)
phagocytosis
If overwhelmed, ______ can become infected or damaged
lymph nodes
______ of lymph nodes serves as the site of the final stages of maturation for some types of lymphocytes and monocytes that have migrated from the bone marrow
lymphoid tissue
masses of lymphoid tissue like lymph nodes but without the afferent vessels. Located in a protective ring under the mucous membranes in the mouth and back of throat
tonsils
the 5 tonsils:
- palatine tonsils (2) on each side of the throat
- pharyngeal tonsil (adenoid) near posterior opening of nasal cavity
- lingual tonsils (2) near base of the tongue
2 functions of tonsils
- protect against bacteria that may invade tissues around the openings between the nasal and oral cavities
- serve as first line of defense from exterior and are subject to chronic infection or tonsilitis
a primary organ of the lymphatic system along with red bone marrow. Located in the mediastinum
thymus
3 main functions of the thymus
- plays critical role in body’s defenses against infections
- source of lymphocytes before birth
- after birth, thymus secretes thymosin and other regulators, which enables lymphocytes to develop into mature T cells
Located directly inferior to the diaphragm, superior to most of the left kidney, and posterior to the stomach. Is roughly an ovoid shape and enclosed in a fibrous capsule
spleen
The spleen is divided into 2 compartments:
white pulp: dense masses of developing lymphocytes
red pulp: near outer regions, made up of network of fine reticular fibers submerged in blood
4 functions of spleen
- defense
- hematopoeisis
- red blood cell and platelet destruction
- blood reservoir
As blood passes through the spleen, _____ lining the sinusoids of the spleen remove microorganisms and destroy them.
macrophages
capillary beds that have large fenestrations to allow for passage of large proteins
sinusoids
____ and _____ complete their development and become active in the spleen
monocytes and lymphocytes
Macrophages in the lining of the spleen remove worn out red blood cells and imperfect platelets from the blood and destroy them.
Macrophages also break apart _____ molecules and salvage their iron and globin by returning them to the bloodstream for storage in bone marrow and liver
hemoglobin
At any given point in time the _____ of the spleen contains a considerable amount of blood
pulp
Significant internal bleeding could occur if the spleen is accidentally ruptured. ______ can stop the blood loss and save a life.
splenectomy
The spleen can be removed and is not considered a vital organ, but an individual without a spleen has increased _______________.
susceptibility to blood infection and is immunocompromised.
1 in 8 women will develop __________ in their lifetime.
breast cancer
cancerous cells from the primary tumor can spread via ________ system
the lymphatic system
The breast is drained by 2 sets of lymphatic vessels:
- lymphatics that drain the skin over the breast with the exception of areola and nipple
- lymphatics that drain the underlying substance of breast, as well as skin of areola and nipple
more than #% of the lymph from the breast enters the lymph nodes of the axillary region
85%
the lymphatic system benefits the whole body by:
maintaining fluid balance and promoting freedom from disease
