Lec 25 Lymphatic System Flashcards
where are lymphatic vessels located?
they run alongside blood vessels within loose CT
where does the right lymphatic duct drain lymph from? where does it empty into?
right arm, right side of chest/abdomen area and head
drains into right subclavian
how do lymphatic vessels differ from blood vessels?
they are part of a drainage system, not a circulatory system so they transport their contents in one direction only.
where does the thoracic duct drain lymph from? where does it empty into?
majority of body
empties into left subclavian vein
what is lymph composed of?
- plasma [leaves capillaries]
- plasma proteins
- lipids
- lymphocytes
- misc [debris, bacteria, malignant cells]
in which direction does lymph travel? what are some factors that help control the flow of lymph
upwards
- contraction of skeletal muscles
- negative pressure in thorax
- valves preventing backflow
what do t-cells do?
destroy foreign material [direct]
what do b-cells do?
produce antibodies [indirect]
what are germinal centers?
area where b-lymphocytes develop and become plasma cells which produces antibodies
where is the spleen located?
upper left quadrant
what is red pulp?
blood flowing through a meshwork of fibers.
leaves blood vessels
what is white pulp?
clusters of lymphoid tissue (reticular fibers that trap debris)
takes away bacteria
what are sinusoids
irregular passageways through which blood passes
what are the functions of the liver?
- production of blood cells [adult - only lymphocytes]
- storage [platelets, wbc, rbc, iron]
- filtration [filters blood, destroys and disposes of old rbcss]
- immune function
describe the thymus and the location & function
deep to sternum but superficial to vessels of the neck
bilobbed mass of lymphoid tissue
during prenatal and postnatal development, it is responsible for the production of t-lymphocytes
is the thymus a functionally active organ in an adult?
no
where are lingual tonsils located
back of tongue [bumps]
where are pharyngeal tonsils aka adenoids located
located on roof of posterior wall of nasal pharynx
what happens when pharyngeal tonsils become inflamed?
they obstruct the passage of air from the nasal cavity and an infection can spread to the middle ear
where are palatine tonsils located
lateral
extend into soft palate on each side of oropharynx
