Exam 4 Part I Flashcards
The hepatic portal circulation receives from the
digestive organs and spleen and delivers it to the liver.
Some advantages of having direct access (portal access) from the digestive organs and spleen to the liver are that:
glucose goes first to the liver, which contributes to the glucose buffer function of the liver.
Alcohol, etc., can get detoxified immediately.
Bacteria get phagocytized
In the spleen, old RBCs are trapped & Hb is broken down, the product goes to the liver & is processed for excretion there
In the liver (and also in the spleen, red bone marrow and other sites of reticuloendothelial cells), heme of old RBCs is converted [into biliverdin which is converted] into
bilirubin
In the blood, bilirubin, which is insoluble, is bound to
albumin
The liver conjugates the bilirubin (with glucuronic acid), making it soluble. Then conjugated bilirubin is excreted into the
duodenum
In the colon, some bilirubin is converted by bacteria to
urobilinogen
Jaundice
Jaundice = increased bilirubin in blood
Prehepatic jaundice–
Prehepatic– hemolytic – excessive breakdown, more non-conjugated form
hepatic jaundice
The jaundice of someone with liver disease, for example, from acetaminophen or other drug toxicity, alcohol consumption,, hepatitis or other causes of liver failure. May be a problem before or after conjugation.
n posthepatic jaundice, one would expect
increased conjugated vs. non-conjugated. If bile duct obstruction is total, no bilirubin reaches the intestines to be converted to urobilinogen, and thus none is found in the urine.
amino acid metabolism
deamination of excess amino acids → gluconeogenesis: amino acids converted to glucose (can also be from fats). In liver failure → hypoglycemia because can’t convert to glucose when needed.
transamination
allows synthesis of all non-essential amino acids. Liver has the ability to synthesize all. (Essential amino acids must be taken in in diet.)
carbohydrate metabolism
conversion of galactose and fructose to glucose
fat metabolism
beta-oxidation of fatty acids
synthesis of cholesterol
conversion of large quantities of CHOs and proteins to fats
synthesis of lipoproteins for transport of fats in the blood
vitamin storage
A, D, B12, one source says also E, K
mineral storage
Fe, Cu
phagocytosis
By Kupffer cells (RE cells = reticuloendothelial cells). Old red blood cells, bacterial cells, especially from colon.
65% of macrophages are in the
liver
synthesis of heparin
Synthesis of heparin: Mast cells around caps., also in lung, very important in places with many caps. = slow-flowing blood.
Liver produces __, so important to have an anti-coagulant handy.
Liver produces clotting factors, so important to have an anti-coagulant handy.
albumins
prevents circulatory shock by keeping blood volume up osmotically.
Alcoholic or other edema from liver’s not being able to produce enough plasma proteins →
ascites, low blood flow to kidneys causes fluid retention.
clotting factors and pathology
“fulminant (very quick, very serious) acute liver failure. Coagulopathy always present: International normalized ratio (INR) ≥ 1.5. What is INR? Do you remember?
alpha and beta-globulins
carriers for fats etc.