clinical biochemistry

1. The spleen
Prepared by :
Aveen Rasul muhammed
Sumaya Ramadhan Nabi
College of health sciences /
Clinical Biochemistry Department
2nd stage 2016-2017
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2. The spleen :
It’s secondary lymphoid
organ , brownish in color
and located in the left
upper quadrant of the
abdomen .
it acts primarily a blood
filter .
Develops from
mesenchymal cells in the
dorsal mesogastrium
during the fifth weeks of
gestation .
%30 of RBCs are
present in spleen . 2

3. Structure :
It composed of ( capsule , hilum , trabeculae , reticular networks
, splenic pulp , white pulp , red pulp , and sinusoid )
- spleen is enclosed in a well-developed capsule : ( dense
irregular C.T. , elastic fibers are present between bundles of
collagen fibers and are most abundant in the deeper layers of the
capsule , smooth muscle fibers also maybe present in small
groups )
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4. Hilum ;
on the medial
surface of the spleen ,
the capsule is indented
to form a cleft-like
hilus through which
blood vessels , nerves ,
and lymphatics enter or
leave the spleen
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5. Trabeculae ;
Trabeculae is broad bands
of C.T. the (spaces
between trabeculae are
filled by a reticular
network of fibers and
associated reticular cells )
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6. Splenic pulp ;
The scattered gray areas
form the white pulp and
consists of diffuse and
nodular lymphatic tissue ,
the white pulp synthesize
antibodies .
The dark red tissue is the
red pulp consists of
diffuse lymphatic tissue
that is suffused with blood
(RBCs present )
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7. the red pulp contains large ,
branching , and thin walled
blood vessels called splenic
sinusoids that supplies the
areas of the spleen .
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8. Function ;
• Filtration of blood , distract old and abnormal RBCs .
• Recycles iron .
• Pitting-removal of granular inclusions from RBCs ,e.g. .
HJ bodies .
• Immune infection :
• Contributes to CMI and humoral immunity .
• Source of lymphoreticular cells and sometimes hematopoietic
cells .
• Infection control :
• Clearance on unopsonized , non ingested bacteria from
circulation .
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9. Fate of RBCs ;
Globin
Release of hemoglobin
Iron + Apo ferritin Porphyrin (heme )
bilirubin
Amino acids
Stored & reused
Excreted
Ferritin
Stored & reused
Destruction of RBCs in spleen
(biliverdin reductase )
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10. Extrinsic hemolytic anemia ;
Also known as autoimmune hemolytic anemia , this type of
anemia develops when the spleen the spleen traps and destroys
healthy RBCs . It can also come from RBCs destruction due to
infection .
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11. References ;
• William, J.K . Krause's Essential Human Histology For Medical
Students . 3rd edit. p.; 140-142
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12. Thank u
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