nutritional disorders

Question 1

anemia
risk factors
pathogenic classification of rbc production

Answer 1

[Hb] lower than reference value
risk: age, gender, ethnicity, pregnancy, other disease
- decreased rbs production (nutrients, hormones , bone marrow, chronic disease, renal insufficiency)
- increased destruction of RBC
blood loss

Question 2

morphological classification

Answer 2

complete blood cell count
- Hb, RBC, WBC.
hematocrit = how much of total volume = rbc
mean corpuscular volume (MCV) = hematocrit/RBC
- microcytic (small cell, low rbc count) normocytic, macrocytic (large cell)

mean corpuscular hemoglobin concentration (MCHC) [hemoglobin/hematocrit] - chromicity = low value = fewer Hb , more pale.

Question 3

iron metabolism

Answer 3

Fe2+ bioactive, absorbable. Fe3+ is not. ferritin stored in cells. bound to transferrin in blood to be transfer.
taken to bone marrow to make rbc. hb taken to macrophage to breakdown, or iron taken to hepatocyte/muscle to store.

Question 4

iron deficiency anemia (IDA)

Answer 4

no iron = cant make rbc

• limited supply of iron - malabsorption or malnutrition.
• increased loss - bleeding, phlebotomy (drawing too much blood in hospital)

Question 5

clinical presentation of IDA

Answer 5

fatigue, pallor, weak, dizzy, increase HR, breathing, impaired immune, reduced cognitive and physical performance

Question 6

microcytic anemia & iron

Answer 6

lack of iron - unstable rbc, smaller than normal.
low MCV, low MCHC
test: iron test isnt great because it fluctuates.
t-sat: transferrin saturation = how much iron bound at any given time
TIBC - total iron binding capacity = max amount of iron bound.

Question 7

treating iron deficiency

Answer 7

oral iron therapy - nutrients and meds to influence bioavailability. vit C - good, antacids, calcium = bad.

parenteral iron - may cause anaphylactic reaction
recombinant human erythropoietin (EPO) - in patient w chronic kidney disease
blood transfusion - immediate

Question 8

vit b12

Answer 8

cobalamin
water-soluble vitamin
sources: microbial synthesis, meat, dairy

Question 9

vit b12 metabolism

Answer 9

bound to food, released by pepsin &HCl. haptocorrin binds b12, travels to small intestine. intrinsic factor interacts w b12 to allow recognition and absorption by enterocyte in small intestine. transferred to transcombalamin then as b12 into blood.
stored in liver or excreted thru urine..

Question 10

bio actions of vit b12

Answer 10

co-enzyme carries out its actions with folate for cell grwoth, DNA syntehsis, RBC production, neuro function.
helps in methionine and succinyl coa production. their precursors (homocysteine & methylmalonyl coA will be high in vitb12 deficient

Question 11

causes of anemia of b12

Answer 11

deficiency of IF - pernicious anemia (autoimmune)
decreased GI absorption - crohn’s
inadequate intake - vegetarians
prolonged medication use - proton pump inhibitor
rare congenital disorder - transporter deficiency

Question 12

clinical presentation of b12 deficiency

Answer 12

neuropsychioatric - development delay, hypotonia, cognitive impair
GI - feeding difficulty, decreased appeptite

Question 13

macrocytic anemia and b12

Answer 13

impaired DNA synthesis = increase RBc growth without cell division.
high MCV, inadequate RBC production
- low serum b12, high homocysteine, methylmalonic acid. anti-IF/parietal cell = pernicious anemia. liver and thyroid function - rule of other disease causing b12 anemia.

Question 14

treatment of b12 deficiency

Answer 14

supplements
intramuscular injection (when cant absorb naturally)

Question 15

bone remodeling

Answer 15

balance btw bone form (osteoblasts) and bone resorption (osteoclasts)

Question 16

bone metabolism

Answer 16

regulation of vit D, calcium & other hormone, mineral, unmineralized matric and mineralized matrix
absorption of vit D - derived from cholesterol, carried by binding protein, cleared from liver.
ca 2+ dependent on vit Dto be absorbed. then can be transferred to bone where stored and calcified.

Question 17

endocrine regulation of calcium

Answer 17

PTH - regulated by negative feedback loop to maintain Ca2+ levels in body. released when low Ca2+ levels. = increased reabsorption in kidney (phosphate follows), vit D reabrsorption from kidney, absorption from gut.

Question 18

hypercalcemia

Answer 18

high Ca2+

moans, bones, groanes, stones

Question 19

hypocalcemia

Answer 19

muscle pain
seizure
tetany
arrythmia

Question 20

risk factor for bone disease

Answer 20

lifestyle
malabsorption
increased demands
aging 
ethnicity, sun exposure
endocrine disorder
rheumatological disorder
drugs obestity

Question 21

rickets and ostomalacia

Answer 21

• deficient mineralization of growth plate (rickets) or bone matric (osteomalacia)
  cause: nutritional deficiency
  vit d resistance
  renal phosphate wasting

Question 22

osteoporosis

Answer 22

systemic skeletal disorder.
compromised bone strength
osteoclasts break down too much bone before it can be replaced by osteoblasts

Question 23

osteoporosis diagnosis

Answer 23

personal history of fragility fracture
measurement of bone mineral density.
osteoporosis t-score

Question 24

osteoporosis treatment

Answer 24

balance diet, smoking alcohol cessation. exercise, calcium vit D supplement. drugs for bone or menopause