(034 - MMB) Control of Fuel Selection in Muscles Flashcards
The soleus muscle mainly contains … muscle fibers
Red slow
…(numb) extra-ocular eye muscles control movement of the eye, & …..(numb) controls elevation of eyelid
Six 6 , one
extra-ocular eye muscles Contain predominantly….. muscle fibers
fast contracting
The soleus muscle Reaches peak tension in….. minutes
80-200mins
The extra-ocular muscles Reaches peak tension in….. minutes
7-8 mins
Muscle can use a variety of fuels to produce energy to perform work:
- glycogen
- adipose fat
- Plasma lipoproteins & plasma Non-esterified fatty acids (NEFA)
- Ketone bodies
- Amino acids (from degraded muscle tissue): during starvation
When does the Muscle use Plasma glucose as fuel ?
during the fed state (during exercise or at rest)
When does the Muscle use Muscle & liver glycogen (by glycogenolysis) as fuel ?
during fasting (<18 hrs.)
and high intensity exercise.
When does the Muscle use Muscle & adipose fat (TAG) as fuel ?
during fasting and low intensity exercise
When does the Muscle use Plasma lipoproteins & plasma NEFA as fuel ?
during fasting & not exercising
When does the Muscle use Ketone bodies as fuel ?
during prolonged exercise, or very prolonged fasting
how muscle fuel chnages from fed to strarving ?
In the fed state, and during high intensity exercise: -carbohydrate (glucose) being the preferred fuel
During fasting:
-Muscle starts by using glycogen & continues by using TAGs & KBs
During prolonged starvation:
-muscle uses amino acids by breaking proteins
Give a summary of how muscle fuel chnages from fed to strarving ?
fuels change from glucose to fatty acids to ketone bodies to amino acids
Summarize effect of insulin on different metabolic pathways ?
• ++ glycogenesis
• – gluconeogenesis
• ++ glycolysis
• ++ lipogenesis
• – lipolysis.
The main target organ of glucagon is….
the liver
Summarize effect of Glucagon on different metabolic pathways ?
(Anti-Insulin Action):
• ++ glycogenolysis
• – glycogenesis
• –lipogenesis
• ++gluconeogenesis
• –glycolysis
After prolonged fasting for more than … hours , GLUCONEOGENESIS takes over after glycogenolysis in the liver.
> 12 hrs
Fuel Choice During Exercise is Determined by….
Intensity and Duration of Activity
During high intensity exercise:….. is the preferred fuel
blood glucose
(External/internal) sources of fuel are used at rest ,
While (External/internal) are used at exercise
External ,, Internal
Examples on external fuel sources used at rest ?
blood glucose, TAG
Examples on internal fuel sources used at rest ?
muscle glycogen – TAG
RQ value of 0.7 indicates that lipids are being metabolized, 0.8 for proteins, and
1.0 for carbohydrates
