AB-Spleen Flashcards
The spleen is part of what system
reticuloendothelial system
Spleens role before the 5th or 6th month of life
Role in the synthesis of blood proteins
After the 5th or 6th month, the spleens role is
Active in the body’s defense against disease; its major function is to filter the peripheral blood
The spleen is..
The largest single mass of lymphoid tissue
Location of the spleen
Lies in the left hypochondrium between the fundus of the stomach and diaphragm
The interomedial surface touches the stomach, left kidney, pancreas, and splenic flexure
The spleen is covered by a protective capsule except for..
the hilum where the vascular structures and lymph nodes are located
Ligaments
Splenorenal- attaches the spleen to the stomach and kidney; in contact with the posterior peritoneal wall, phreniocolic ligament, and gatrosplenic ligament
Gastrosplenic- composed of the two layers of the dorsal mesentery that separates the lesser sac posteriorly from the greater sac
Size of the spleen
Adult spleen:
8-13 cm in length
7 cm wide
3-4 cm thick
Decreases with age
Varies with nutritional status of the body
The spleen receives blood from
the splenic artery; travels horizontally along the superior border of the pancreas
After entering the hilum, the splenic artery branches into 6 smaller arteries
Splenic vein
Formed by multiple branches with in the spleen
Leaves the hilum to join the superior mesenteric vein to form the main portal vein
Travels along posteromedial border of the pancreas
What ligaments hold the spleen in place?
lienorenal, gastrosplenic, and phrenocolic ligaments
What causes the spleen to be displaced inferiorly?
A mass in the LUQ
Caudal displacement
Occurs secondary to a subclavian abscess, splenic cyst, or left pleural effusion
Cephalic displacement
Results from volume loss in left lung, left lobe pneumonia, paralysis of the left hemidiaphragm, or large intrabdominal mass
What is wandering spleen?
Embryologic anomaly
Results when the dorsal mesentery fails to fuse with the posterior peritoneum without supporting ligaments of the spleen
Patients may have an abdominal or pelvic mass, intermittent pain, and volvulus (splenic torsion)
Functional Characteristic of the Spleen
Maturation of the surface of erythrocytes
Reservoir
Culling
Pitting function
Disposal of senescent or abnormal erythrocytes
Functions related to platelet and leukocyte life span
Describe the location of the spleen in relation to the left kidney
anterior and superior
common location of accessory spleen
Splenic Hilum usually about 1cm -can enlarge like the rest of spleen
sonographic signs of histoplasmosis
echogenic areas -“starry night” appearance
major focal defects
◦Tumor (benign and malignant)
◦Infarction
◦Abscess
◦Cyst
splenic rupture
related to some sort of trauma or splenomegaly spleen is removed when this happens
subcapsular splenic rupture
spleen ruptures within the surrounding capsule that contains all of the blood
wandering spleen
a spleen that is not held in place because the stabilizing ligaments failed to develop or were not attached
a spleen is considered enlarged (splenomegaly) when is measures…?
>13cm
primary tumors that may metastasize to the Spleen
breast, lung, ovary, prostate, colon, kidney and melenoma
polycythemia vera
polycythemia: excess of red blood cells polycythemia vera:is a chronic disease of unknown cause that involves all bone marrow elements
erythropoeisis
red blood cell production
Red pulp
large number of red blood cells, fills remaining area of spleen
White pulp
tiny islands throughout spleen, contains lymphocytes, marphygian corpuscles
Pitting
removes nuclei from red blood cells
Culling
removes abnormal red blood cells
Situs solitus
normal
Situs inversis
mirror image
Situs ambiguous
halfway in-between
erythropoeisis
red blood cell production
clinical signs of polycythemia vera
weakness, fatigue, vertigo, tinnitus, irritability, splenomegaly and firmness, flushing of the face, redness and pain in extremities, blue-and-black spots
Within the lobules of the spleen are tissues called
pulps (red and white)
Lymphocytes of the spleen
help defend the body against infection
Functions of the spleen as an organ as the reticuloendothelial system
Production of lymphocytes and plasma cells
Production of antibodies
Storage of iron
Storage of other metabolites
Normal echotexture
The texture of the spleen is considered to be more echogenic than the liver. As the spleen enlarges, echogenicity further increases
Primary benign neoplasms
Hamartoma-both solid and cystic components, hyperechoic
Cavernous hemangioma-isolated inhomogeneous echogenic mass with multiple small hypoechoic areas
Cystic lymphangioma-mass with extensive cystic replacement of splenic parenchyma
Primary malignant neoplasms
Lymphoma-hypoechoic; diffuse involvement, focal small and large nodular, and bulky disease
Hemangiosarcoma-complex or solid, reembles cavernous hemangioma, but also can be hyperechoic
Metastases-hypoechoic but of higher echo amplitude than lymphoma; some are echodense
Hematopoeisis
blood cell production
The effect of cirrhosis to the spleen
congestive splenomegaly
Causes of splenomegaly
