Abdomen - Spleen

Question 1

most vulnerable abdominal organ:

Answer 1

spleen

(left hypochondrium = protection of lower thoracic cage)

*most frequently injured*

Question 2

largest lymphatic organ:

Answer 2

spleen

(lymphocyte (WBC) proliferation + immune surveillance/response)

Question 3

Functions of the spleen:

(pre- & postnatally)

Answer 3

Prenatally: hematopoietic (blood-forming) organ

Postnatally: identifying, removing, + destroying old RBCs & broken-down platelets; recycling iron + globin

*useful, but NOT a vital organ*

Question 4

Spleen has a relatively delicate fibroelastic capsule, entirely surrounded by peritoneum except for…?

Answer 4

splenic hilum

splenic branches of the splenic artery + vein enter/leave

Question 5

location of spleen:

Answer 5

• rests on Left Colic Felxure
• associated posteriorly with **left 9th - 11th ribs; **separated by diaphragm + costodiaphragmatic recess
• varies in size, weight, + shape;

**normally: **approx. 12 cm long, 7 cm wide (weighs 7 ounces)

Question 6

The large size of the splenic artery (or vein) indicates what about the organ?

Answer 6

… the volume of blood that passes through the spleen’s capillaries and sinuses

• normally contains large quantity of blood
• expelled periodically into circulation by action of smooth muscle in its capsule + trabeculae

Question 7

Splenic capsule:

Answer 7

• dense, irregular, fibroelastic connective tissue

(can expand + contract)

• capsule is thickened at the splenic hilum
• Internal trabeculae (deep aspect of the capsule) carry blood vessels to/from the parenchyma (splenic pulp) = substance of the spleen

Question 8

Splenic Rupture:

Answer 8

causes:

• punctures by fractured rib (left 9th-12th)
• sudden, marked increase in intra-abdominal pressure = thin capsule + overlying peritoneum of spleen burst

- rupture = intraperitoneal hemorrhage and shock

Question 9

Splenectomy

Answer 9

• **Sub-total (partial) splenectomy: **(when possible); followed by rapid regeneration

- total splenectomy: (usually no serious effects); most functions are assumed by other reticuloendothelial organs (e.g., the liver and bone marrow)

• greater susceptibility to certain bacterial infections

CONDITIONS IN WHICH THE SPLEEN MUST BE REMOVED:

Warm autoimmune hemolytic anemia:

• Spleen recognizes RBC as foreign bodies and attacks them

Question 10

Splenomegaly

Answer 10

spleen is diseased (ex. granulocytic leukemia) may enlarge 10X or more its normal size

• sometimes accompanies hypertension
• occurs in some forms of **hemolytic or granulocytic anemias **(RBCs or WBCs destroyed at abnormally high rates); splenectomy may be life-saving
• not usually palpable in the adult; *if it is, *enlarged 3x

Question 12

Accessory Spleen(s)

Answer 12

• common (10%) + usually small
• 1+ small accessory spleens may form near splenic hilum
• embedded partly or wholly in tail of pancreas (b/t layers of gastrosplenic ligament, in infracolic compartment in mesentery, or in close proximity to ovary or testis)
• if not removed during splenectomy, symptoms that indicated removal of the spleen (e.g., splenic anemia) may persist

Question 13

Splenic Needle Biopsy + Splenoportography

Answer 13

relationship of the costodiaphragmatic recess to the spleen is clinically important

• • *potential space descends to level of 10th rib in midaxillary line
• keep in mind for needle biopsy, or injecting radiopaque material into spleen for visualization of the portal vein (splenoportography)
• material may enter the pleural cavity, causing pleuritis

*inject below rib 10 level*