Abdominal Anatomy Powerpoint Flashcards
(33 cards)
Aorta
-Largest artery in the body
-Originates at the Left Ventricle of the heart
-Positioned left of midline and anterior to the spine
-wall consists of three layers:
Tunica intima (inner most)
Tunica media (middle)
Tunica adventitia (outer most)
-function is to supply blood to the abdominal organs, pelvis, and lower extremities
Inferior Vena Cava (IVC)
-Largest vein in the body
-created by the union of the iliac veins
-enters the right atrium of the heart
-three layers:
tunica intima (inner most)
tunica media (middle, less smooth muscle than aorta)
tunica adventitia (outer most)
-marks posterior border of the caudate lobe of liver
-lies right of the abdominal aorta
-size varies with respiration
-3 hepatic veins drain into the IVC
Portal Venous System
- main portal vein created by the union of the superior mesenteric vein and the splenic vein
- referred to as the portal/splenic confluence
- confluence lies in the mid abdomen and collects blood from the intestines and spleen
- not connected directly to the IVC
- MPV enters the liver at the porta hepatis branches into right and left portal veins
- normal flow is toward the liver (supplies 80%) known as hepatopetal
Patient Prep Before Scanning
OUT PATIENTS -fat free, cream free evening meal, NOP after midnight INPATIENTS -NPO for 8 hours ER -Post Big Mac :0)
Liver
- Largest organ in the body next to the skin
- occupies almost all the R hypochondrium, the greater part of the epogastrium, and the L hypochondrium
- aorta lies posterior to the L lobe of the liver
- lies inferior to the diaphram
- the posterior border is in contact with the R kidney and inferior vena cava
Sub Phrenic Space
-between the liver and the diaphram is a common site for abscess formation
Right Subhepatic space
-includes Morison’s Pouch, a common space for periotoneal fluid or blood to collect
Main Lobar Fissure
- boundry between the right and left lobes of the liver
- on a longitudinal scan, it may seem as a hyperechoic line extending from portal vein to the neck of the gallbladder
- sonographoc landmark
Lobes of the Liver
- Right Lobe
- Left Lobe
- Caudate Lobe
Right Lobe of Liver
-Largest of the three
-Contains Three Fossae:
Porta Hepatis
Gallbladder
IVC
-A congenital varient, Riedels Lobe, can sometimes be seen as an anterior porjection of the liver. Sometimes extends down to the iliac crest
Left Lobe of the Liver
- Size varies from patient to patient
- men seem to have small left lobes
- can be found just under xiyphoid process
- if larger, makes a great acoustic window for pancreas and aorta
Caudate Lobe
- Small Lobe
- Situated inferior to the ligamentum venosum and superior to the IVC
Ligamentumteres
- appears as a bright echogenic triangle on the transverse scan
- separates the medial and lateral segments of the left lobe of the liver
Ligamentum Venosum
-appears as a hyperechoic line separating the left lobe from the caudate lobe of the liver
Vascular Supply
- Portal Venous System, supplies 80% of the blood flow to the liver from digestive system
- flow should be toward the liver (hepatopetal)
- main portal vein (MPV) enters the liver at the portahepatis, it divides into the right (RPV) and left (LPV) portal veins
- RPV is the largest and further divides into the anterior and posterior branches
Hepatic Veins
-Drain the blood from the liver back into the IVC
-Divided into three components
Right (RHV)
Middle (MHV)
Left (LHV)
-Can be distinguished from the portal veins by the lack of bright walls
Hepatic Arteries
- Supplies blood to the liver (About 20%)
- a branch of the celiac artery from the aorta
Primary Functions of the Liver
- Metabolism-carbohydrate and protein
- Digestion
- Storage
- Detoxification
Liver Funtions Tests (LFT’S)
- AST
- ALT
- LDH
- ALK phos
- Bilirubin
- PT
- Albumin and globulins
Liver Scanning
- TGC should be adjusted to balance the far gain and near gain echo signals
- over all gain should be adjusted to adequatley penetrate the entire right lobe of the liver as a smooth, homogenous echo pattern
- Depth- posterior right libe is positioned at the lower border of the screen
- focus- near the posterior border of the liver
- Transducer frequency- depends on the patient body habitus
Evaluate Liver for….
- the size of the liver in longitudinal plane
- the attenuation of the liver parenchyma
- texture
- presence of hepatic vascular structures, ligaments, and fissures
Gallbladder
- should be anechoic with a wall thickness less than 3mm
- should not have any fluid between wall and liver
- lies on the visceral surface of the liver
Should not be there
- polyps
- gallstones
- tumors
- thick walls with fluid around
- sludge
Pancreas
- Consists of the head, body, tail, uncinate process
- most easily seen in transverse scan
- GDA and CBD delineate the lateral border of the head
- the spenic vein delineates the posterior border
- sometimes can see the pancreatic duct
- body lies inferior to left lobe of liver
