Chapter 16 Part 2 Flashcards
What can be confused for spleen
Extended liver
Potential pitfal of seeing spleen
Ribs
Gas
Diaphragm
Embryology of spleen
Arise from mesenchymal cells
Cells located between layers of dorsal mesentery
Cells differentiate to form
-splenic pulp
-splenic capsule
Base of the dorsal mesentery fuses with the posterior peritoneum
-Form splenorenal ligament
Normal variants/ congenital anomalies dealing with number
Accessory
Asplenia
Polysplenia
Normal variants/ congenital anomalies dealing with location
Wandering
Ectopic
Accessory spleen
AKA: “Splenule” Most common Homogenous isoechoic mass similar to the spleen Typically found hilum or inferior border of spleen
Asplenia
Complete absence
Rare
May occur as part of a major congenital abnormality
Polysplenia
Multiple small accessory spleen
Wandering splee n
migrated from its normal location in the left upper quadrant.
dorsal mesentery fails to fuse properly with posterior peritoneum
lack of support ligaments
Ectopic spleen
The spleen is located in the abdominal cavity outside of where it should be
Lymphatics contains
Lymph, lyphatic vessels, lacteals, lymph nodes and spleen, bone marrow and thymus gland
Lymphatics are distributed
Throughout the body and linked by lymphatic vessels
We typically have ________ lymph nodes
500-600
Locations we find clusters of lymph nodes
Inginual
Neck
Armpit
Abdomen
Function of lyphatics
Collect and transport excess fluids, lymph, from interstitial spaces back into the venous system
Absorb fats from small intestine and transport them to the liver
Utilize lymphoid tissue and organs to produce cells that fight (immune system) and dispose of foreign material
Common sites for abdominal lymph nodes
Paraaortic and paracaval areas near the great vessels
Peripancreatic area and porta hepatic area
Renal hilar area
Mesenteric
Lymph nodes usually are named based on
Vessel it follows
Size of lymph nodes
Less than 1 cm normally
Smaller than the tip of finger
Not normally imaged unless great scan and small patient
Typically seen when abnormal
Superficial vs deep nodes require change is
Frequency
Shape of LN
Ovoid shape
LN consist of
Cortex and hilum
Corts of LN is
Hypoechoic and concentric
Hilum of lymph node
Echogenic/hyperechoic
Multiple reflective interfaces of blood vessels, fat and the central sinus
Can see blood flow in this region
Sonogrpahic appearace of normal LN
Normally ovoid
AP is smaller than width or length
Have to see a fatty hilum
If abnormal (large, circular and lose fatty hilum): Hypoechoic masses and lots
If a person has an infection: Multiple and enlarged but still have fatty hilum and oval shape
Scanning LN I would first place probe
Epigastric for abd
