Normal Anatomy (Test 1) Flashcards
Borders of Abdominopelvic Cavity
Superior: diaphragm
Inferior: pelvic floor
Posterior: back muscles and spine
Anterior: abdominal core muscles
2 Layers of Peritoneum
1) visceral- covers organs
2) parietal- lines cavity wall
Function of Peritoneum
- protection
- secretes fluid, so the organs do not rub when moving
Intraperitoneal
- within peritoneal cavity
- spleen, stomach, sm intestine (except duodenum), liver, gall bladder, ovaries
Retroperitoneal
- behind or inferior to peritoneal cavity
- kidneys, ureters, prostate, rectum, pancreas, uterus, bladder, duodenum
Congenital means…
at birth
Size of Aorta
- 2cm (prox)
- 1.5cm (distal)
- should not be more than 3cm
Shape of Aorta
- tubular, highly pulsatile, cylindrical
- the proximal portion appears curvilinear
Echogenicity of Aorta (wall and lumen)
lumen-anechoic
walls-bright, echogenic
3 differences between veins and arteries are…
Veins:
1) carry blood that is low in oxygen from body to heart
2) larger
3) thinner walls
4) affected by respiratory compressibility
Arteries:
1) carry oxygen rich blood from heart to body
2) smaller
3) thicker walls
4) pulsatile
What level does the aorta bifurcate at?
L4
How does the aorta appear on US?
- lumen is anechoic (black)
- homogeneous (smooth)
- walls are echogenic
- parallel walls
- tubular shape
3 Branches of Celiac Trunk
- left gastric artery (smallest)
- splenic artery (largest and most tortuous)
- common hepatic artery
Which artery can we not usually see in US?
-left gastric
How does the SMA appear in US?
- echogenic walls
- runs parallel to aorta
- 1cm below celiac trunk
Why do we scan the IVC?
-clots
Where do the Rt and Lt renal arteries originate from?
- laterally from aorta
- just inferior to SMA
- Rt renal artery is longer than Lt renal artery
- courses posteriorly to IVC
What are 4 sonographic parameters?
- size
- contour
- echotexture
- echogenicity
Echogenic
-bright
Anechoic
-black
Hypoechoic
-darker than the surrounding tissue
Hyperechoic
-brighter than the surrounding tissue
Isoechoic
-same as the surrounding tissue
Homogeneous
-smooth
Heterogenous/Inhomogenous
-not smooth
Contour
-smooth or irregular border
How is the IVC different from the aorta?
- inner lumen is larger
- expands and contracts with respiration
Gastroesophogeal (GE) Junction
- donut/target appearance
- anterior to aorta
- superior to celiac trunk
- seen in SAG PROX AO
Diaphragmatic Crura (Crus)
- linear muscular portions of diaphragm
- right crus is seen in SAG PROX AO, inferior to GE Junction and anterior to aorta
Common Congenital Variations
- 3 renal arteries
- common hepatic artery can come off SMA
- right hepatic artery can come off SMA
- left hepatic artery originates from left gastric artery
- transposition
What is the location of the IVC?
-right of midline
Where does the IVC bifurcate?
-approx L5
What are the tributaries of the IVC
- hepatic veins
- renal veins
- right gonadal vein (left gonadal vein comes off left renal vein)
- common iliac veins
What divides the liver into right and left halves?
-mid hepatic vein
Appearance of IVC
- 2.5cm
- anechoic lumen
- thin, echogenic walls
Interface
-area between 2 organs/structures
Specular Reflectors
-bright echoes
What is another name of the abdominopelvic cavity?
-peritoneal cavity
Parietal Peritoneum
- portion of the peritoneum that forms a closed sac
- closed in males
- open to fallopian tubes in females
- separates intraperitoneal and retroperitoneal organs
Sonographic Appearances of the Diaphragm
- curvilinear
- echogenic
- hypoechoic
- smooth
3 Layers of Arteries and Veins
- tunica intima (inner)
- tunica media (mid)
- tunica externa (outer)
