Gilead -Topics in Human Pathophysiology Fall 2009 Drug Safety and Public Health.
Hepatic Pathology and Respiratory System Topics in Human Pathophysiology Fall 2011 Gilead Drug...
Transcript of Hepatic Pathology and Respiratory System Topics in Human Pathophysiology Fall 2011 Gilead Drug...
Hepatic Pathology and Respiratory SystemTopics in Human Pathophysiology Fall 2011Gilead Drug Safety and Public Health
Outline
Hepatic Pathophysiology Digestive System Overview Placement and role of liver Liver microstructure Pathologies of liver
Respiratory Structure and Function
Digestive system
The Liver
Part of digestive system
Located in upper right abdominal quadrant
Is served by two blood vessels: the hepatic portal vein, the hepatic artery
Has one duct that carries bile away from it to the gall bladder for storage
Composed of lobules that contain hepatocytes
Blood moves easily from the external vessels, in porous capillaries past the hepatocytes to a central vein
Hepatocytes do the work of the liver
Figure 14.11
Hepatic Portal System
Liver Functions
Secretes bile – which emulsifies fats within small intestine
Metabolizes bilirubin - a breakdown product of hemoglobin
Produces albumin, and clotting factors
Metabolizes fats, proteins, carbohydrates, stores glycogen, makes HDLs and LDLs
Inactivates many biologically active chemicals including alcohol, medicinal and recreational drugs, hormones, poisons
Stores fat soluble vitamins and iron
Converts ammonia (NH3) into soluble urea to be excreted by kidneys
Hepatitis
• Inflammation of the liver• Causes include:
• Viruses and other pathogens
• Drug and alcohol toxicity
• Environmental toxins• Obesity, autoimmune
disorders
Viral Hepatitis
Hepatitis A (HAV)
Hepatitis B (HBV) Hepatitis C (HCV)
Etiology Causes mild acute illness- hepatocyte injury
Causes acute illness and chronic liver disease, can lead to liver cancer
May cause acute illness, acts long term leading to chronic liver disease and risk of liver cancer
Mode of transmission
Fecal-oralprimarily in children, young adults
Contact with infected body fluids – blood, semen; contaminated needles, mother to newborn
Contact with infected blood, mostly through contaminated needles
Vaccination Hep A vaccine Hep B vaccine No vaccineFrom http://www.cdc.gov/hepatitis/index.htm
Figure 9.20
Reverse transcriptase required
Pathophysiology of Hepatitis
Destruction of hepatocytes (necrosis) by inflammation
Altered blood flow through and to liver
Edema – both peripherally and in portal vessel area
Blockage of bile ducts leading to reduced bile in small intestine and problems with fat absorption
Reduction of ability to make blood proteins including albumin, clotting factors, complement
Buildup of blood toxins including urea and ammonia
Symptoms of Hepatic Damage Jaundice
Dark amber colored urine
Nausea/vomiting
Abdominal pain - R upper quad
Fatigue
Also- ascites, hepatic encephalopathy, coma, death
Cirrhosis Long term
result of liver damage
Liver Tests – Liver Panel
AST– liver enzyme, elevated with damage to cells
ALT - liver enzyme, elevated with damage to cells
ALP – enzyme related to bile ducts, levels elevate if there is a blockage
total bilirubin (blood)– may be elevated with liver damage or excessive RBC destruction
Albumin (blood) – checks on synthetic ability of liver cells
prothrombin time - decreased synthesis of clotting factors by liver
See labtestsonline for more information
CT Scan of the Liver
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Nodular cirrhotic liver with ascitesNormal liver
www.integris-health.com
Drug Induced Hepatotoxicity More than 900 drugs, toxins
and herbs cause drug induced hepatotoxicity,
20-40% of all fulminant liver failure cases are caused by drug induced hepatotoxicity
It is the most common reason a drug is withdrawn from approval
Damage to liver can be hepatocellular or cholestatic
Drug-Induced Hepatotoxicity from http://www.emedicine.com/Med/topic3718.htm
Figure 10.1
Respiratory System
Gas exchange
Protection
Speech
Compression of abdomen and spine stiffening
Acid-Base balance
Respiratory Functions
Figure 10.8
Respiratory Interface
Alveolar wall
Capillary wall
Surfactant
Gas Exchange occurs by diffusion