Peritoneum & Retroperitoneum

Question 0

Describe the location of two different peritoneum layers.

Answer 0

Visceral- membrane covering organs

Parietal- membrane covering abd walls.

Question 1

What is the peritoneum?

Answer 1

Is a thin serous membrane lining the walls of the paritoneal cavity and viscera. It is made up of a single layer of epithelial cells called the mesothelium and a thin layer of connective tissue.

Question 2

Where is and what is the Peritoneal cavity?

Answer 2

It is the most anterior potential space in the abdominal cavity, two sacs in it is the greater and lesser sac. It is normal for there to be a little bit of fluid.

Question 3

Where are the greater an lesser sac in relation to each other where do they communicate?

Answer 3

Greater sac takes up most of the peritoneal cavity and mostly is anterior to lesser sac

Lesser sac is smaller and located anterior to pancreas, Lt kidney and adrenal gland, posterior to the stomach.

These sacs communicate by the epiploic foramen

Question 4

What is the mesentery?

Answer 4

Double layer of peritoneum, with variable number of fat cells, surrounding the organs and connecting them to the abdomen wall. It surveys as a conduit for nerves, blood vessels/nodes which go to and from organs.

Question 5

What is and name the Omenta?

Answer 5

Double layer fold or sheet of the perituneum.

2 Omentas: greater and lesser.

Question 6

What is the location and connections of the greater Omenta?

Answer 6

The greater Omenta is laden with fat and drapes down from the greater curvature of the stomach and loops back on itself attaching to the transverse colon, 4 layers thick.
It connects the stomach with the diaphragm, spleen, and transverse colon.

Question 7

What is the location and connections of the lesser Omenta?

Answer 7

It lies posterior to the LLL and attaches by the fissure for the ligamentum venosum.

Lesser omentum connects the lesser curvature of the stomach and proximal duodenum to the liver.

Question 8

What are the most common cause of peritoneal fluid-Ascites?

Answer 8

• Cirrhosis
  
  • cancer
  • congestive heart failure

Question 9

Name the spaces from first to last that fill with asites before the peritoneal cavity and what space is where the major amount of fluid flows between abdomen and pelvis?

Answer 9

1. pouch of Douglas
   
   2. Paravesical spaces
   3. Paracolic gutters

The major flow between pelvis and peritoneal cavity happens in the paracolic gutters.

Question 10

What are the clues for Ascites?

Answer 10

Bowls may sink or float in anechoic fluid.

Appears anechoic fluid that takes the shape of its container.

Question 11

What to do if peritoneal fluid is found?

Answer 11

• Look for inflammation an/or malignancy in fluid, these signs include:
-fine or course internal echoes
-loculations
- unusual distribution
- matting or clumping of bowl loops
- thickening of interface between
fluid and adjacent structures

Question 12

Describe the Retroperitoneum location and what protects it.

Answer 12

Area veteran the posterior peritoneum and the posterior abdominal wall muscles. Extends from diaphragm to pelvic brim. Protected by spine, ribs, pelvis and muscles.

Question 13

What does the Retroperitoneum enclose?

Answer 13

The Great vessels… aka the AO & IVC

Question 14

Name the Retroperitoneum’s subdivisions.

Answer 14

• Anterior pararenal space (space anterior to renals)
  
  • Peritenal space (space containing renals)
  • posterior pararenal space (space posterior to renals)

Question 15

What is the anterior Pararenal Space?

Answer 15

Fat laden space between the posterior parietal peritoneum and Gerota’s fascist.

Question 16

What are the organs in the Anterior Pararenal space?

Answer 16

• Pancreas
  
  • duodenal sweep
  • Ascending & descending Colon
  • superior mesenteric vessels
  • Portion of CBD

Question 17

Describe the Perirenal space.

Answer 17

It is surrounded by Gerota’s fascia which separates it from the pararenal space.

Question 18

What organs/structures are in the perirenal space?

Answer 18

• Kidneys adrenal glands
• Perirenal fat
• Ureters
• Renal vessels
• Retroperitoneal lymph nodes

Question 19

What medially fusses connective tissue surrounding the great vessels?

Answer 19

Anterior renal fascia

Question 20

How do you know a massis Retroperitoneal?

Answer 20

Anterior renal displacement or of dilated ureters (of those that can be seen).
Displacement ventrally and cranially by mass.

Question 21

Hepatic & subhepatic masses causes displacement _________ & _________.

Answer 21

Inferior & posterior

Question 22

Pleural vs subphrenic for fluid collections?

Answer 22

Coronary ligament does not allow for fluid to collect in right posterior subphrenic space to collect between bare area of liver and diaphragm. If there is fluid it is superior to diaphragm (pleural effusion- distribute posterior medially in chest.

Question 23

Subcapsular vs intraperitoneal fluid collection?

Answer 23

Subcapsular (liver or spleen)- is seen unilaterally & conform to shape of capsule.

Question 24

What is the purpose of adrenal glands?

Answer 24

Endocrine gland-secretes steroid hormones & catecholamines (epinephrine/norepinephrine).

Question 25

What function does the medulla of the adrenal glands give us, and what hormones does it produce?

Answer 25

Gives us our fight or flight response Norepinephrine and epinephrine

Question 26

What does norepinephrine do?

Answer 26

* Dilates coronary blood vessels, •Constricts skin and renal vessels * Increase heart rate

Question 27

What is the does epinephrine do?

Answer 27

* Regulate blood pressure * Dilates coronary arteries-to regulate blood pressure * Constricts other arteries * Aids in the break down of glycogen and lipides

Question 28

Name the 3 zones of the cortex from outer to inner.

Answer 28

1. Zona glomerulosa 2. Zona fasciculata 3. Zona reticularis

Question 29

What does the zona glomerulosa make?

Answer 29

Mineralcorticoids (regulated salts) aldosterone & deoxycorticsterone.

Question 30

What does the zona fasciculata make?

Answer 30

Make glucocorticoids (sugar regulating steroid) cortisol & corticosterone.

Question 31

What does the zona reticularis make?

Answer 31

Gonadocorticoids (sex hormones)

Question 32

Name the lab tests for adrenal glands.

Answer 32

* ACTH * aldosterone * Cortisol * Catecholamines

Question 33

What secretes ACTH what does it do & what is it indicative of when in increased amounts?

Answer 33

It's a adrenocortictropic homone secreted by pituitary gland, stimulates the release of cortisol and androgens and aldosterone Increase indicates adrenal hypo function (Addison's disease) or hyper function (Cushing's disrase).

Question 34

What is the purpose and indications for Aldosterone?

Answer 34

Maintains blood pressure & volume Increase indicates adrenal cortical hyperplasia, an adenoma or adrenal carcinoma Decrease indicates Addison's disease

Question 35

What is the purpose and indications for Cortisol?

Answer 35

Metabolizes nutrients, mediates stress and regulates immune system Increase indicates Cushing's disease, hyperthyroidism, stress and obesity Decrease- indicates Addison's disease, hypothyroidism, liver disease

Question 36

What are the indications of Catcholamines?

Answer 36

Increase indicates malignant neuroblastoma, pheichromocytoma (if elevated 100x normal), or strenuous exercise.

Question 37

Describe the shapes of the right and left adenals.

Answer 37

Rt- triangular Lt- crescent

Question 38

Describe the echo geniality of a under 1yr old's adrenal.

Answer 38

Echogenic medulla (center) & hypochoic cortex (edge).

Question 39

Describe the appearance of an adrenal of those over 1 yr old.

Answer 39

Hypochoic

Question 40

What are the diaphragmatic Cruda (rt & lt crus)? And how do they appear on ultrasound?

Answer 40

Muscular/tendinous structures that extend from diaphragm downward to attach to the vertibral column On US appear as hypoechoic linear structures surrounded by dobro fatty tissue.

Question 41

What are some lymph node sights?

Answer 41

``` Abdomen -para-aortic chain - mesenteric and celiac Pelvic - iliac chain -hypogastric Intraperitoneal - splenic hilum -parapancreatic - hepatic hilum ``` Lymph from adrenals and renals drain in to para-aortic nodes.

Question 42

Describe the normal sonographic appearance of a lymph node.

Answer 42

<1cm not normally visualized but when they are... Homogeneous & often hypoechoic with low to medium internal echoes with no posterior enhancment (can have a hyperechoic center. Para-aortic can be enlarged,lobulated or sheet-like.

Question 43

Describe an enlarged lymph nodes

Answer 43

- can sound aorta "donut" like - para aortic can elevate superior celiac an mesentery vessels anteriorly - posterior aortic lymnodes can elevate aorta away from spine "floating AO"

Question 44

What can lymph nodes be confused with?

Answer 44

Para-aortic nodes can stimulate aneurysms. Nodes surrounding vessels can be sandwich like. Enlarged nodes at hepatic hilum can cause intrahepatic duct dilation.

Question 45

If enlarge lymph node is seen what should you do?

Answer 45

If adenopathy is seen look for primary tumor or inflammation Check for splenomegaly Scan iliac vessels for enlarged nodes