Chapter 17- Spleen Flashcards
At what week of embryonic life does hematopoesis begin?
11
What does the spleen produce during embryonic life
red and white blood cells
What blood cells does the spleen produce after birth?
White blood cells
The spleen is considered an intraperitoneal organ. Why?
It’s completely covered by peritoneum except for the hilum
The length of the spleen varies, but about how long is it?
8-13 cm
What is the normal AP measurement of the spleen?
7-8 cm
What is the minumum length of a spleen with splenomegaly
13cm
The spleen is the largest organ in the ______ system
lymphatic
is the spleen required for life
no
The splenic vein joins the SMV to form what structure
Main Portal Vein
Where does the splenic artery come from
the left branch of the celiac axis
describe the echogenicity AND echotexture of the spleen
isoechoic/hypoechoic to the liver. homogeneous and smooth texture
The spleen is part of which body system that is responsbile for phagocytosis?
the reticuloendothelial system
The spleen has a true capsule. What does this mean
it is a fragile organ
What is phagocytosis
engulfing and destroying damaged and old cells and pathogens.
What are the 4 functions of the spleen
defense, hematopoiesis, blood cell and platelet distruction, blood reservor
when might a post-birth spleen produce red blood cells
in a case of severe hemolytic anemia
what is white pulp
it produces the white blood cells which ingest harmful pathogens that enter the bloodstream as an immune response
white pulp contains Malphigian corpuscles. what do these do?
they perform the lymphatic functions. lymph destroys bacteria and pathogens
Where is the white pulp located
it surrounds the smaller splenic arteries
when does red pulp form
after birth
what does red pulp do
destroys red blood cells through phagocytosis
red pulp is looser and more vascular. what is it made of?
splenic sinuses and splenic cords
What is a splenic sinus?
a long chennel that occupies the space that is not filled by white pulp
The spleen inspects red blood cells. why?
so it can destroy the abnormal cells.
to get through the splenic sinus, where must the blood pass through
the red pulp that acts as a filter for phagocytosis
The spleen’s phagocyte cells perform phagocytosis. what are the two parts of phagocytosis
pitting and culling
What is pitting
the removal of nuclei from old red blood cells without damaging the cell
what is culling
the removal of abnormal red blood cells
how does the spleen act as a blood reservoir
the red pulp can store red blood cells in the sinuses. this blood can quickly be released into the circulatory system when needed.
what is splenomegaly
an enlarged spleen
what is a common cause of splenomegaly
portal hypertension due to cirrosis of the liver causing a backup of blood into the spleen
what is the most common cause of splenomegaly in children
viral infections
how do you tell longitudinal and transverse sonograms of the spleen apart?
The long is an L shape and transverse is backward L
what complications may occur with asplenia
it may be associated with congenital heart defect. asplenia alone does not cause complications
what percent of people have an accessory spleen
10%
what is an accessory spleen
a globe shaped mass usually found around the hilum
define hematocrit
percentage of red blood cells in the blood
define bacteremia
percentage of bacteria within the blood
define leukocytosis
increase in the number of leukocytes
define leukopenia
abnormally low number of leukocytes in the blood
define thrombocytopenia
an abnormal decrease in platelets
the spleen is posteriolateral to what organs?
body and fundus of stomach, tail of pancreas
the spleen lies between the stomach and what other organ
the diaphragm
