Starvation and Malnutrition

Question 1

How does your body get its energy in the fed state?

Answer 1

glycolysis, aerobic respiration

Question 2

How does your body get its energy fasting b/w meals?

Answer 2

4-6 hours gluconeogenesis begins
glycogenolysis persists until 10-18 hours after meal

a little bit of FFA release from adipose tissue

**glucagon and epinephrine stimulate

Question 3

What is the main source of energy after fasting 1-3 days?

Answer 3

Fatty Acids

also get some glucose (solely from gluconeogenesis) and ketone bodies

Question 4

Starving after 5 days, what is the main energy source?

Answer 4

adipose–ketone bodies

also some glucose and fatty acids

Question 5

Once again, when are the glycogen stores depleted?

Answer 5

after 1 day

really after 10-18 hours

Question 6

Main source of energy for brain and muscles:
1 day of fasting
2 days of fasting
5 days of fasting

Answer 6

1 day of fasting: brain-glucose, muscles–mainly fatty acids, some glucose
2 days of fasting: brain-glucose, some ketone bodies, muscles–mainly fatty acids, some ketones
5 days of fasting: brain-ketone bodies, muscle–mainly fatty acids, some ketone bodies

Question 7

Once again, when does the ketone body formation begin?

Answer 7

after 2 days of fasting

Question 8

What is the one part of the body that can’t use ketones?

Answer 8

RBCs, lack mitochondria

Question 9

Describe the circumstances that favor ketone formation?

Answer 9

oxaloacetate has been all used up b/c of gluconeogenesis

so now acetyl CoA can’t enter TCA. Instead, it goes on to make ketone bodies.

Acetyl CoA increases b/c of beta oxidation of fatty acids

Question 10

Describe ketogenesis.

Answer 10

Fatty Acids and amino acids–>acetoacetate + beta hydroxybutyrate

Rate limiting enzyme: HMG CoA synthase

Question 11

What type of ketone does the urine test detect?

Answer 11

only detects acetoacetate

Question 12

Why does a patient in diabetic ketoacidosis have fruity breath?

Answer 12

b/c of acetoacetate–>acetone (fruity smell)

Question 13

Why does EtoH on an empty stomach set you up for fasting hypoglycemia?

Answer 13

b/c alcohol causes the formation of NADH.
the increase in NADH favors the formation of pyruvate–>lactate and oxaloacetate–>malate
these then can’t be used for gluconeogenesis.

Basically, the liver can only metabolized ETOH or give body glucose. not both. Fasting hypoglycemia.

Question 14

What are 4 possible fates of acetyl CoA?

Answer 14

TCA cycle
Fatty acid synthesis
cholesterol synthesis
ketone synthesis

Question 15

What are the important features of kwashiorkor?

Answer 15

FLAMES
fatty liver (b/c of lack of ApoB100)
anemia
malnutrition (of protein, may have adequate calories)
Edema (distended abdomen)
Skin lesions and depigmentation of hair and skin

Question 16

What are the key features of marasmus?

Answer 16

muscle wasting
totally energy malnutrition
also get variable edema, and loss of subcutaneous fat

Question 17

What is refeeding syndrome?

Answer 17

happens after 5 days of fasting
start low and go slow!!

cells gobble up all the new ions and nutrients etc–get serum depletion of potassium, magnesium. Can get arrhythmias and neuro problems.

depletion of ATP phosphorylating things inside the cell

**during fasting–cells sacrificed their ions for the good of the serum oncotic pressure.