m e t a b o l s m p a r t2
TRANSCRIPT
- 1. METABOLISM PART2
2. The Liver and Gallbladder
3. Liver
The largest glandular organ in the body
Weight: 1.5 kg
Reddish brown and has four unequal lobes
Supplying vessels: 1. hepatic and portal vein
Location: right upper quadrant, below the diaphragm
the only internal human organ capable of natural regeneration of
lost tissue
4. Functions:
Gluconeogenesis the synthesis of glucose from certain amino acids,
lactate or glycerol
Glycogenolysis the breakdown of glycogen into glucose
Glycogenesis the formation of glycogen from glucose
Protein metabolism
Lipid metabolism: Cholesterol synthesis
Lipogenesis, the production of triglycerides (fats).
5. The liver produces coagulation factors
. The liver produces and excretes bile
The liver also produces insulin-like growth factor 1 (IGF-1), a
polypeptide protein hormone that plays an important role in
childhood growth and continues to have anabolic effects in
adults.
The liver is a major site of thrombopoietinproduction,a
glycoprotein hormone that regulates the production of platelets by
the bone marrow.
6. The breakdown of insulin and other hormones
The liver breaks down hemoglobin, creating metabolites that are
added to bile as pigment (bilirubin and biliverdin).
The liver breaks down or modifies toxic substances , methylation
and most medicinal products in a process called drug metabolism.
This sometimes results in toxication, when the metabolite is more
toxic than its precursor.
The liver converts ammonia to urea.
7. The liver stores a multitude of substances, including
glucose
The liver is responsible for immunological effects- the
reticuloendothelial system of the liver contains many
immunologically active cells, acting as a 'sieve' for antigens
carried to it via the portal system.
The liver produces albumin, the major osmolar component of blood
serum
The liver synthesizes angiotensinogen a hormone that is responsible
for raising the blood pressure when activated by renin, an enzyme
that is released when the kidney senses low blood pressure.
8. Liver functions
include liver enzymes, are groups of clinical biochemistry
laboratory blood assays designed to give information about the
state of a patient's liver.
9. Albumin is a protein made specifically by the liver, and can be
measured cheaply and easily. It is the main constituent of total
protein; the remaining fraction is called globulin .
The half-life of albumin is approximately 20 days.
Albumin is not considered to be an especially useful marker of
liver synthetic function; coagulation factors
10. Alaninetransaminase (ALT), also called Serum
GlutamicPyruvateTransaminase (SGPT) or Alanineaminotransferase
(ALT) is an enzyme present in hepatocytes (liver cells).
Aspartatetransaminase (AST) Aspartatetransaminase (AST) also called
Serum GlutamicOxaloaceticTransaminase (SGOT) or
aspartateaminotransferase (ASAT) is similar to ALT in that it is
another enzyme associated with liver parenchymal cells.
11. Alkaline phosphatase (ALP) Alkaline phosphatase (ALP) is an
enzyme in the cells lining the biliary ducts of the liver. ALP
levels in plasma will rise with large bile duct obstruction,
intrahepaticcholestasis or infiltrative diseases of the
liver.
12. Bilirubin is a breakdown product of heme, a part of hemoglobin
in red blood cells. The liver is responsible for clearing the blood
of bilirubin.
Bilirubin is taken up into hepatocytes conjugated to make it
water-soluble, and secreted into the bile, which is excreted into
the intestine.
13. Coagulation test
The liver is responsible for the production of coagulation factors.
The international normalized ratio (INR) measures the speed of a
particular pathway of coagulation, comparing it to normal.
If the INR is increased, it means it is taking longer than usual
for blood to clot. The INR will only be increased if the liver is
so damaged that synthesis of vitamin K-dependent coagulation
factors has been impaired: it is not a sensitive measure of liver
function.
14. HEPATITIS
15. Hepatitis
inflammation of the liver characterized by the presence of
inflammatory cells in the tissue of the organ
can be self-limiting, healing on its own, or can progress to
scarring of the liver.
is is acute when it lasts less than six months and chronic when it
persists longer.
16. 17. Causes of acute hepatitis
Viral hepatitis: Hepatitis A through E (more than 95% of viral
cause), Herpes simplex, Cytomegalovirus, Epstein-Barr, yellow fever
virusadenoviruses.
Non viral infection: toxoplasma, Leptospira, Q fever,rocky mountain
spotted fever
Alcohol
Toxins: Amaniia toxin in mushrooms, carbon tetrachloride,
asafetida
Drugs: Paracetamol, amoxycillin, antituberculosis medicines,
minocycline and many others
Ischemic hepatitis (circulatory insufficiency)
Pregnancy
Auto immune conditions, e.g., Systemic Lupus Erythematosus
(SLE)
Metabolic diseases, e.g., Wilson's disease
18. symptoms
flu-like symptoms, common to almost all acute viral infections and
may include malaise, muscle and joint aches, fever, nausea or
vomiting, diarrhea, and headache.
More specific symptoms, which can be present in acute hepatitis
from any cause, are: profound loss of appetite, aversion to smoking
among smokers, dark urine, yellowing of the eyes and skin and
abdominal discomfort.
19. Jaundice can be a late feature and may indicate extensive
damage. Other features include abdominal fullness from enlarged
liver or spleen, low grade fever and fluid retention
Extensive damage and scarring of liverleads to weight loss, easy
bruising and bleeding tendencies.
Acne, abnormal menstruation, lung scarring, inflammation of the
thyroid gland and kidneys may be present in women with autoimmune
hepatitis
20. Causes of chronic hepatitis
Viral hepatitis: Hepatitis B with or without hepatitis D, hepatitis
C causes chronic hepatitis
Autoimmune: Autoimmune hepatitis
Alcohol
Drugs: methyldopa, nitrofurantoin, isoniazid, ketoconazole
Non-alcoholic steatohepatitis
Heredity: Wilson's disease, alpha 1-antitrypsin deficiency
Primary biliary cirrhosis and primary sclerosingcholangitis
occasionally mimic chronic hepatitis[4]
21. Stages of Chronic hepatitis
Pre-icteric stage- with early symptoms that are non-specific,
flu-like symptoms, that include malaise, fatigue, headache,
myalgia, anorexia, nausea and vomiting and diarrhea
Icteric- occurs a few days to weeks after the icteric stage and
include jaundice, dark colored urine, light colored stools and
steatorrhea
Post-icteric stage- a convalescent stage lasting a few weeks
jaundice resolves and appetite returns
22. Hepatitis A
Accounts for 20-25% of cases of clinical hepatitis in the
world
Formerly called infectious hepatitis
Caused by an RNA virus
Mode of transmission: oral-fecal, sexually
Incubation period:15-50 days, average of 30 days
Confers immunity against itself
23. Symptoms
Asymptomatic, mostly
Flu-like upper respiratory symptom
Low grade fever
Anorexia, indigestion
Jaundice and dark urine
24. Diagnosis
Large liver and spleen
HAV antibodies in the serum
Hepatitis A antigen in the stool
25. Prevention
Proper hygiene
Vaccine (Havrix and Vagta)
Administration of globulin
26. Management
Bed rest
Small frequent feedings
27. Hepatitis B
Can be found in blood, saliva, semen and vaginal secretions
Can be transmitted by blood, through mucous membranes and breaks in
the skin and the placenta
Develops into a more chronic type or within 6 months
28. Symptoms
Resembles hepatitis A but has a longer incubation period
Symptoms are insidious and variable
Loss of appetite, dyspepsia
Generalized aching, malaise, weakness
Enlarged liver and spleen
Jaundice
Diagnosis: prsence of HBsAg and antibodies
29. Treatment and Prevention
Interrupt chain of transmission
Active and passive immunization
Antiviral agents
Bed rest
Adequate nutrition
30. Hepatitis C
Formerly referred to as non-A, non-B hepatitis
Mode of transmission: blood and body fluids
Incubation period: 15-160 days
Symptoms appear milder than HBV
31. Hepatitis D
Occurs in some cases of hepatitis B because the virus requires the
hepatitis B surface antigen for its replication
Mode of transmission: blood and body fluids
Symptoms and treatment are almost the same with hepatitis
B