lympth Flashcards
what is the lymphatic system
a drainage system that returns extracellular fluid to the body circulation
how many types of extracellular fluid is there and what are they
3
plasma
interstitial
lymph
what is plasma
the colorless fluid component of blood that seeps through the capillary walls
what is interstitial
the plasma that has seeped through the capillary walls and circulates among the body tissue
what is lymph
when interstitial fluid drains out of the tissues and enters the lymph ducts
it is similar to the circulatory system but what are the three differences
lacks a pump
travels only in one direction
contains lymph nodes
what does it consist of
capillaries
vessels
ducts
nodes
where does it course along
circulatory system
what are capillaries
blind ended structures in the interstitial spaces
consist of single endothelial layer
what do capillaries join together to form
larger vessels
what controls the direction of flow in capillaries
valves
capallaries are superfical vessles at what level and where do they drain into
subcutaneous drain into deep lympthatics
what passes through nodes on the way to the chest
deep vessels
in the chest what happens to lymph
re-enters the bloodstream
what are lymph nodes an important component of
RE system
are lymph nodes distributed throughout the body
YES
what is the shape of lymph tissue that is scattered along the lymphatic vessels
bean/ovoid
what is the measurements of lymph nodes
1mm- 1/2 cm
what are lymph nodes surrounded by
A connective tissue capsule
what do afferent vessels do
drain into the node
carry lymph through the sinuses
filter out/ destroy bacteria and malignant cells
has germinal centers
what are germinal centers and what do they do
sponge like centers
produce lymphocytes
empty into the lymph prior to leaving the node
what are the sinuses lined with
phagocytic cells
what do efferent vessels do
leave only at the hilum
lymph nodes are rarely the site of what
primary disease
the secondary disease may be seen with
systemic infections
many neoplasms
what are the two major node-bearing areas in the retroperitoneum
pelvis- iliac + hypogastric
upper retroperitoneum- paraaortic
the lymph chain follows the course of what
thoracic aorta
abdominal aorta
iliac arteries
what are other lymphatic tissues
tonsils
thymus
spleen
what do tonsils protect
oral region
what does the thymus produce and manufacture
produces antibodies before puberty
manufactures lymphocytes
what does the spleen do
filters blood and produces lymphocytes
what does lymphatic circulation consist of
deep and superficial channels of drainage
what are the group of nodes at key locations
axillary- upper limbs
cervical- neck
inguinal- lower limbs
intestinal nodes-digestion
what is another name for the intestinal nodes
peyer’s patch
what does the right lymphatic duct drain
right upper quadrant
what does the left lymphatic ducts drain
remaining 3/4 of the body
what is another name for the left lymphatic duct
thoratic duct
what is the physiology of lymph
extracellular fluid formation similar to blood plasma-higher albumin ratio low leukocyte count no erythrocytes digestive enzymes
what is the physiology of lymph flow
slow under resting conditions
depends on the kneading action of skeletal muscles
contains valves in larger vessels to prevent backflow
what are the functions of lymphatic system
phagocytosis
immunity
tissue drainage
excretion
what is excreation
adsorpation and circulation of end products of fat digestion
what is the sonographic appearance of abdomen
not usually visualized
what is the abdominal nodes measurement
<1cm
what is the appearance of lymph nodes
homogenous
low level echoes
what are the pitfalls of lymph nodes in US
enlarged para-aortic lymph nodes may mimic aneurysm
bowel gas may obscure our visulization off abnormal nodes
enlarged lymph nodes surrounding vessels may make evaluation of these vessels and their bifurcations difficult
fluid filled areas may obscure enlarged nodes
