Chapter 16 Flashcards
What are the functions of the lymphatic system?
returns excess extracellular fluid to the cardiovascular system; provides immunity; aids in digestion of fats
Define Lymphatic capillaries.
microscopic, close-ended tubes that extend into interstitial spaces
How are lymphatic vessels formed?
by the merging of lymphatic capillaries
Lymphatic______ have walls similar to ________ only thinner, and possess valves that prevent _________ of the lymph.
vessels; veins; backflow
The ______ lymphatic vessels lead to lymph nodes and then merge into lymphatic _____.
larger; trunks
The function of lymphatic trunks?
to drain lymph from large body regions
Trunks lead to two collecting ducts— the ______ duct and the _____ ______ duct.
thoracic; right lymphatic
Where do the collecting ducts empty?
into the subclavian veins
What does lymph formation prevent?
prevents accumulation of excess tissue fluid
How is lymph created?
an increase of hydrostatic pressure forces some tissue fluid into lymphatic capillaries
Explain ways that move lymph.
contractions of skeletal muscles, contractions of smooth muscle in the wall of large lymphatic trunks, and low pressure in the thorax created by breathing movements
True or False?
Any condition that interferes with the flow of lymph results in edema
True
List 3 functions of lymph
lymph returns protein molecules and fluid to bloodstream; lymph transports foreign particles to lymph nodes; lymphatic capillaries in the small intestine absorb and transports lipids
Where are lymph nodes located?
Axillary, cervical, supratrochlear, inguinal regions, pelvic, abdominal, and thoracic cavities
Lymph nodes contain ___________ and ________-; what are those two responsible for?
lymphocytes and macrophages
lymphocytes act against foreign particles
macrophages remove foreign particles from lymph
Define Thymus.
a soft, bilobed organ within the mediastinum
Function of the spleen.
filters foreign particles and damaged red blood cells from the blood
What leaves the thymus and provides immunity?
T lymphocytes
Where is the spleen located?
in the upper left portion of the abdominal cavity
What is the text below describing?
It resembles a large lymph node encapsulated and subdivided into lobules by connective tissue
spleen
The body has immunity to infection that involves what two kinds of defenses?
innate (nonspecific) and adaptive (specific)
What are some examples of mechanical barriers?
skin and mucous membranes
(tears, saliva, sweat, and urine)
Define Inflammation.
a tissue response to damage, injury or infection
Natural Killer (NK) cells secrete…? What does that do?
NK cells secrete perforins
which destroy cancer cells and cells infected with viruses
Define autoantibodies.
an autoimmune disorder that attacks the body’s tissues
