spleen Flashcards
Normal measurements of the spleen
12 cm long, 7 cm wide, 3-4 cm thick
Spleen that has migrated from its normal position in the left upper quadrant
Wandering spleen
Small rounded mass found near hilum or inferior border of spleen in up to 30% of patients. May be confused with lymph nodes
Accessory spleen
Function of spleen
Production of lymphocytes, plasma cells, and antibodies. Storage of iron and other metabolites
Enters at splenic hilum; branches into six smaller arteries . Subject to infarction. Travels along superior border of pancreas
Splenic artery
Formed by multiple branches in spleen. Leaves hilum in horizontal direction to join superior mesenteric vein. Travels along posterior border on pancreas
Splenic vein
Main function of spleen
Filter peripheral blood
Spleen active in
Hematopoiesis
Proper patient position to evaluate spleen
Right lateral decubitus
Chronic disease of unknown cause that involves all bone marrow elements
Polycythemia vera
Results in massive splenomegaly
Myelofibrosis
Spleen lies in
Left hypochondrium
Spleen is a
Peritoneal organ
Tetrahedral or triangular part of spleen
Orange segment
Covers spleen with peritoneum
Protective capsule
Portion of splenic capsule firmly adhered to fused dorsal mesentery, anterior to upper pole of the left kidney
Bare area
Attaches spleen to stomach and kidney
Splenorenal ligament
Separate lesser sac posteriorly from greater sac
Gastrosplenic ligament
Returns unoxygenated blood from bowel to form main portal vein
Superior mesenteric vein
Emerge from splenic hilum, pass through outer lymph nodes along course of splenic artery
Lymph vessels
Largest lymphoid organ
Spleen
Accompany splenic artery and are derived from splenic plexus
Nerves
Diaphragm, left pleura, left lung, and ribs
Are above and behind the spleen
Fundus of stomach, lesser sac and panc tail are
Medial and anterior to splenic hilum
Left kidney and adrenal gland are
Inferior and medial to spleen
A mass in luq may displace spleen
Inferiorly
May be secondary to a subclavian abscess, splenic cyst, or Lt pleural effusion
Caudal displacement
May result from volume loss in Lt lung, Lt lobe pneumonia, paralysis of Lt hemidiaphragm, or large intrabdominal mass
Cephalic displacement
Absent spleen, rare, reversed position of AO and IVC
Asplenia or splenic aegenisis
Multiple spleens, absent GB, cardiac defects
Polysplenia
Anomalous placement or transportation of viscera or parts
Visceral heterotaxy
normal arrangment of asymmetric body parts
situs solitus
mirror image of situs solitus
situs inversus
disruption on the development of normal asymetric arrangement of abd organs and vessels
situs ambiguous
patients with asplenia may have _________ which means, two orphologic right lungs, midline location of the liver, reversed position of the AO and IVC, anomalous pulmonary venous return, and horshoe kidney
bilateral right sidedness
Patients with polyspenia have __________ which means two left lungs, left-sided azygos continuation of an interupted IVC, biliary atresia, absect GB, GI malrotation,and cardiovascular abnormalities
bilateral left sidedness
not essential to life, filters forgien materials from blood, forms antibodies
spleen
have elastic properties that allow the spleen to distend when filled with blood
venous sinuses
Spleen also functions as a
blood reservoir
within the lobules of the speen are tissues called
pulp
contains large numbers of lymphocytes, and helps protect the body from infection
white pulp
contains large numbers of red blood cells
red pulp
occurs throughout the entire reticuloendothelial system, but half of the catabolic activiy is localized to spleen
Phagocytosis of erythrocytes; breakdown of hemoglobin
the major portion of hemoglobin breakdown occurs in the spleen
splenomegaly
In anomalies such as the hemolytic anemias, the splenic phagocytes become engorged with _________ when erythrocyte destruction is accelerated
hemosiderin
process of removing nuclei from RBCs
pitting
process by which the spleen removes abnormal RBCs
culling
Indicates the percentage of RBCs per volume of blood. Abnormally low readings indicate hemorrhage or internal bleeding
hematocrit
indicates the presence of bacteria withing the body
bacteremia
indicates bacteria in the bloodstream
sepsis
increase in number of white blood cells
leukocytosis
decrease in white blood cells
leukopenia
decrease in platlets
thrombocytopenia
splenic parechyma should have fine uniform homogenous mid-to-low level echo pattern, as seen within the liver
normal texture
spleen has two components joined at the hilum
superomedial and inferomedial
diagnosed when spleen measures more than 13 cm
splenomegaly
Nonvizualization of the spleen may occur in:
atrophy
wasting diseases
chronich hemolytic anemias
autosplenectomy
What to look for sonographically in spleen:
contour
homogeniety
parenchyma
vascular patterns
The medial segment of the spleen may cross the midline and mimic a _________ inferior to the left lobe of the liver
mass
active hyperemia is a reaction in the moderately enlarged spleen
acute congestion
diffuse enlargement, may be of systemic origin cause by intrahepatic obs to portal veinous drainage or by obstructive venous disorders in the portal or splenic veins.
Chronic venous congestion
a disease that occurs when substances called amyloid proteins build up in the organs
amyloidosis
types of involvment seen in amyloidosis
nodular and difuse
sonographic findings of gaucher disease
splenomegaly
multiple nodules (irregulare, hyperechoic, or mixed)
diffuse inhomogeniety
Spleen enlarged with significant congestion of the red pulp in early stages of
sickle cell anemia
what are sonographic findings of sickle cell anemia
acute sickle cell crisis
subacute hemorrhage that appears as hypo echoic area in periphery of the spleen
Lifespan of the RBCs is short because they are destroyed by the spleen in large numbers. Two catagories are alpha-thalassmemia and beta-thalassemia
Thalassemia
Includes cases of acute hyperplasia
granulocytopoietic abnormalites
uncommon, may be the result of sepsis due to endocarditis or dental infection
splenic abscess
almost always the result of emboli that arise from the heart (valves from lt side of heart)
splenic infarction
sonographic findings of splenic infarction
fresh hemorrhage
healed infarction
localized hypoechoic area
spleen most commonly injured as result of
blunt abdominal trauma
if the patient has severe LUQ pain secondary to trauma ________________ or _____________ should be considered
splenic hematoma
subscapular hematoma
If the ______________, the outcome may be intraparenchymal or sub scapular hematoma
capsule is intact
it the _________________, a focal or free intraperitoneal hematoma may form
capsule ruptures
focal hematomas may have
intrasplenic fluid collections
is seen in patients with subscapular hematomas
perisplenic fluid
