Nutritional Pathology 1 Flashcards
anemia
condition in which blood does not have enough healthy red blood cells
atrophic gastritis
associated with pernicious anemia - chronic inflammation of stomach mucosa, leading to loss of gastric glandular cells that then get replaced
decrease in chief and parietal cells
intestinal metaplasia -a change from normal gastric epithelium to that of the small intestine
pernacious anemia components
MEGABLASTOMIC anemia w/
- atrophic gastritis
- complete achlorhydria -absence of hydrochloric acid in gastric secretions
- malabsorption of vitamin b12
- deficiency of intrinsic factor
fundus secretion
chief cells and parietal cells
parietal cells
HCL and IF secretion
absorption of Vit b12
R-binders in saliva, Intrinisc Factor from stomach - into the duodeunum
IF receptors in the ileum
enzyme reactions with vit b12
- methyltransferase in conversion of homocysteine to methionine
- isomerization of methyl malonyl CoA to succinyl CoA
cobalamin
we cannot make this - get it from environment like Vit b12
corring ring + cobalt =cobalamin
major causes of vitamin B12 deficiency
dietary lack of vit b12
lack of intrinsic factor (PA and gastrectomy)
competition for vit B12
impaired ileal absorption of Vit b12
- chrohns and illeal resection
congenital deficiency of TC II - transcobalamin
most common cause of Vit b12 deficiency + the other two main causes
lack of IF - intrinsic factor
Impaired ileal absoorption
Congenital deficiency of of TII - part of the absorption process
chronic gastritis
lymphocytes (T-cells) histiocytes - destruction of the glandular epithelium of the stomach
T/F Pernicious anemia is an auotoimmune disease
T
90% of the time - there are antibodies produced against the parietal cells (which function in secreting the intrinsic factor)
70% of the time there are antibodies against the intrinsic factor
50% of the time there are anibodies to thyroid tissue
antibodies attack what?
the complex of vit b12 and intrinsic factor
atrophic glossitis
strawberry tongue - tongue with b12 deficiency
‘beefy red’ tongue
causes of megoblastomic anemia
vitamin b12 deficiency
folate deficiency
erythroleukemia (proliferation of immature red and white blood cells)
vit b12 role in methyltrasnferase
makes homocysteine –> methionene
vit b12 converts…
malonyl CoA to –> succinyl CoA
Chrohns and ileal resection will result in?
impaired ileal absorption of vit b12
description of hematopoietic system in anemia?
hypercellular marrow
erythroid hyperplasia
MEGABLASTOSIS
giant metamyelocytes
peripheral smear in anema
macro-ovalocytes (abnormal RBC’s)
hypersegmented polys - neutrophils are hypersegmented
giant platalets
neurological disorders associated with PA
Symmetric numbness and tingling of extremities, impaired vibratory and position sense, spastic ataxia
degeneration of the posterior and lateral columns of the spinal cord (fatty tissue / myloid undergoes lysis/degeneration)
75% of untreated patients
could occur in absence of anemia
what can the schillings test do?
determine if vit b12 is being absorbed or not - checks level of excreted urine (if less than normal - repeat test but give oral IF before Vit b12 - if excretion is increased - patient most likely has PA
Folic acid deficiency vs PA
LACKS THE NEUROLOGICAL FINDINGS - but results in megaloblastic anemia similar to B12 defciency
T/F humans are entirely dependent on dietary sources like green vegetable, fruits, liver for folate?
TRUE - humans need to ingest and folic acid is tricky in that it is lost due to heat / overcooking food
FH4
tetrahydrofolate acid
derivative of folic acid and used to transfer 1 carbon unit (formyl, methyl groups) in the synthesis of various compounds (purines, methionine, dTMP)
hypercellular marrow
1 neutrophil will look like 3
what FH4 does
tetrahydrofolate (derivative of folic acid) acts as an INTERMEDIARY in the transfer of one-carbon units (formyl, methyl groups) in the synthesis of various compounds (purines, methionine, dTMP)
connection between B12 and DNA synthesis
Cobalamin (b12) w/ circulating folate –> FH4
FH4 w/ Thymidylate synthetase takes dUMP –>dTMP
dTMP –> DNA
carbon transfers with folate
FH4 takes one carbon–> becomes derivative –> gives up carbon –> FH2
one carbon fragments used in synthesis of?
Purines, METHIONENE
dTMP
Causes of decreased folic acid?
decreased intake
increased need during pregnancy
inflammation of bowel
drugs
dihydrofolate reductase
turn FH2 back to FH4
primary site of iron absorption?
duodenum (stores it as well)
microcytic anemia
small red cells with iron deficiency
hypochromic anemia
red blood cells lack the coloration
typical of iron defcicency as well as PA
storage of iron
Transferrin (in blood bound)
Ferririn (storage of iron in cells)
