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Definition
Liver is the largest members of the human body
and iS located in the upper right part of the
abdominal cavity under the diaphragm behind
the ribs.
Liver consists of two main lobes lobe and
right lobe of the left and others small. At
the bottom of the right lobe and the
gallbladder is located that relate to the
liver through the bile duct, which stores
bile secretion by the liver.
Role Of Liver In Immunity
Cellular Elements of the Innate Immune System of
the Liver :
In the liver, the hepatocytes comprise
approximately 80% of all cells. Liver sinusoidal
endothelial cells make up most of the
nonparenchymal liver cells,( ~50% of
nonhepatocytes). The remaining cells in the liver
belong to the adaptive immune system (T and B
lymphocytes) and the innate immune system
(KC, NK cells, and NKT cells).
Liver Damage and Impaired Regeneration
in C3−/− Mice after PHx
The three pathways of complement activation
(classical, alternative, and lectin) converge at the
central complement component C3. Therefore,
C3 deficiency not only eliminates C3 activation
and cleavage into active C3 fragments but it also
largely prevents the downstream activation of C5
and the release of C5-derived activated
fragments (29).This central role of C3 was the
basis to study the regenerative phenotype of the
corresponding deficient mice (C3−/−).
In contrast to their wild-type littermates, C3−/−
mice displayed an abnormal regenerative
response with a markedly compromised clinical
postoperative course. The clinical deterioration
of the C3−/− mice became evident between 15
and 24 h after PHx and resulted in a high
mortality of 40% (21:52 mice) as compared with
15% (3:20) for their wild-type littermates (P <
0.05). This clinical impairment was associated
with disruption of the lobular architecture of the
liver and the presence of randomly distributed
necrotic areas throughout the parenchyma.
Ballooning degeneration was evident in the
cytoplasm of hepatocytes
adjacent to the necrotic areas
This prominent presence of
necrosis and hepatocyte
degeneration in C3−/− mice
correlated with lower BrdU
incorporation at 44 h after
hepatectomy and with
reduced liver weight recovery
in the surviving C3−/− mice
Complement Component C5 Is Required
for Normal Liver Regeneration.
C5, the initial component participating in the
assembly of the membrane attack complex, is
activated through cleavage by the classical or
alternative pathway C5 convertase, a protein
complex containing activated C3 molecules
(C3b). Complement activation occurring during
liver regeneration would lead to cleavage and
activation of native C5. Having shown that C3
was required for a normal regenerative
response, we investigated whether C5, the
downstream activation target of C3,
might be essential for liver regeneration
too.Similar to C3−/− mice, C5−/− animals
exhibited an abnormal regenerative response
and increased mortality after hepatectomy as
follows: 23% (9:30) for C5−/− mice as compared
with 4% (1:23) for C5+/+ mice (P < 0.05).
However, the livers of the surviving C5−/− mice
showed less parenchymal damage than those of
C3−/− mice and the rate of BrdU incorporation
into C5−/− hepatocytes over time revealed a
delayed rather than severely diminished DNA
synthetic response after PHx when compared
with that of wild-type littermates It should be
noted that this delayed proliferative response of
C5−/− livers had a significant impact on the
recovery of liver weight As in the case of
C3−/− mice, analysis of aminotransferase and
total bilirubin serum levels in C5−/− mice at 44
h after PHx confirmed the higher incidence of
liver failure and more pronounced liver
damage
Combined C3/C5 Deficiency Induces a
More Severe Regenerative Defect than
Single C3 or C5 Deficiency after PHx
Given that the absence of both C3 and C5
caused defective regeneration after PHx, it
was important to establish whether C3 merely
serves as an intermediate activator of C5 or
whether both components mediate distinct
functions; this was explored, for example, by
activating different pathways via their
anaphylatoxins C3a and C5a and their
downstream receptor-mediated interactions.
Acute-phase protein of liver in
immune
Acute-phase proteins are a class of protein whose
plasma concentrations increase (positive acutephase proteins) or decrease (negative acute-phase
proteins) in response to inflammation
Inflammatory cells and red blood cells
• In response to injury, local inflammatory cells
(neutrophil granulocytes and macrophages)
secrete a number of cytokines into the
bloodstream, most notable of which are the
interleukins IL-1, IL-6 and IL-8, and TNF-α.
• The liver responds by producing a large number
of acute-phase reactants. At the same time, the
production of a number of other proteins is
reduced; these are, therefore, referred to as
"negative" acute-phase reactants. As such,
increased acute phase proteins from the liver
may also contribute to the promotion of sepsis.
Cytokinesis of liver in immune
Cytokinesis, from the greek cyto- (cell) and kinesis
(division), is the process in which the cytoplasm of a
single eukaryotic cell is divided to form two
daughter cells. It usually initiates during the late
stages of mitosis, and sometimes meiosis, splitting a
mitotic cell in two, to ensure that chromosome
number is maintained from one generation to the
next. In animal cells, one notable exception to the
normal process of cytokinesis is oogenesis (the
creation of an ovum in the ovarian follicle of the
ovary), where the ovum takes almost all the
cytoplasm and organelles, leaving very little for the
resulting polar bodies,
function
1. Get rid of toxins.
2. Regulate the level of sugar in the blood.
3. Composition of bile (gall bladder juice).
The liver is the largest manufacturer of
CHEMICAL liver cells in the body represents
about 60% of liver tissue is carried out by any
group other cells in the body is turning most of
the food you eat into a form the body can use,
such as:
1. Conversion and storage of sugar until it is needed
and there is a planning level in the blood.
2. Break down fat and convert them to cholesterol.
3. To get rid of ammonia and the formation of
absorbed proteins for blood clotting.
4. To get rid of toxins and alcohol.
5. Composition of bile and you break down what
people eat fat.
There is another type of cells in the liver is the
hepatic Kupffer cells, which is concerned with the
following documents:
1. Get rid of old red blood cells.
2. Destroy microbes and waste from cells
Preparation / Abdul Rahman Abdullah ALTariki &Muhannad Abdul Aziz Al-Melhem
Supervision / d.Abd-Rheim Abdel-Alim