Midterm 3 - Lecture 21 Flashcards
What must food be converted to to get energy?
Cells don’t get energy directly from food, it must be first converted to: Adenosine Triphosphate
ATP (Adenosine Triphosphate)
A form of energy one can immediately use, it is needed for cells to fxn and muscles to contract
How is glucose stored?
Glycogen (muscle and liver)
How are fatty acids stored?
body fat
How are amino acids stored?
growth, repair or excreted as waste
What are the 4 predominant energy pathways?
- ATP (2-3 s)
- ATP-CP Energy System (8-10 s)
- Anaerobic Energy System (2-3 min)
- Aerobic Energy System (3+ min)
What is the ATP-CP energy system?
ATP is stored in the muscle and liver for “quick energy”
- Never impulses trigger breakdown of ATP into ADP; splitting of the phosphate bond = energy for work
What type of activity is the ATP-CP energy system used for?
- muscle contraction
- moving hand from a hot stove
- jumping and throwing
The usefulness of ATP-CP vs ATP is not the AMOUNT of energy, what is it?
- quick and powerful movements
- only small amounts of ATP are stored = only 2-3 sec of energy
- ATP-CP = 8-10 sec. of energy
For longer periods of work, what energy systems must be used?
The Aerobic and Anaerobic Energy System
ATP is broken down into ADP + energy for biological work + P; how is it immediately resynthesized?
by CP!
- CP = creatine + energy for resynthesis of ATP + P
- ATP = ADP + energy from CP + P
Anaerobic energy system
- without O2
- activities that require a large burst of energy over a short period of time
Anaerobic Glycolysis
production of ATP from CHOs without oxygen (aka breakdown of glucose)
Where is glycogen stored?
stored in the muscle and liver, it is available quickly
What system provides ATP when ATP-CP runs out?
Anaerobic Glycolysis
How much work does the anaerobic energy system allow for?
2-3 minutes
What makes muscle contraction slower?
the process to produce ATP is not as fast as ATP-CP
Anaerobic glycolysis is less efficient in producing ATP than Aerobic glycolysis, so why is it used?
- needed for a large burst of energy lasting a few minutes
Why do the muscles fatigue after 2-3 minutes of work using anaerobic glycolysis?
when O2 is not present the end produce of glycolysis is lactic acid, which causes the muscles to fatigue
What is body fat the greatest source of? Why?
ENERGY!
Fatty acids + O2 = 129ATP
Glucose + O2 = 36ATP + H2O + CO2
Glucose = 2ATP + 2LA
Glycogen = 3ATP + 2LA
How much ATP does a glucose molecule produce during anaerobic glycolysis vs aerobic glycolysis?
Glucose = 2ATP + 2LA
Glucose + O2 = 36ATP + H2O + CO2
What is an oxygen deficit?
the body can not supply enough O2 to the muscles that the muscles demand
- when the muscle does not get enough oxygen, exhaustion is reached causing immediate and involuntary reduction in intensity
What is oxygen debt?
“pays back” the deficit
Aerobic energy system
with O2 = using large muscle groups continuously over a period of time
How does the aerobic energy system stop breakdown of glycogen into lactic acid?
- O2 enters the system, stopping the breakdown of glycogen to lactic acid
- With O2, glycogen breaks down into: ATP + CO2 + H2O
- These byproducts are easier to get rid of
- CO2 expelled by the lungs
- H2O is used in the muscle - with prolonged exercise, CHOs are the first fuel choice, as exercise continues, FAT becomes predominant
- protein is not a main fuel source except in an emergency
What is the only fuel source for anaerobic energy systems?
Carbohydrates
What does the cardiac system do to respond to increased requirements for O2 during exercise to maintain aerobic respiration?
- alter blood composition
- increase blood flow
- alter priority of flow
What is the most common rhythm irregularity in racehorses?
second-degree partial atrioventricular block
- missed ventricular beats
- disappears during exercise
What is the spleen a reservoir for?
RBC
* liver, gut and lungs can also sequester RBC
What are RBC released in response to?
Exercise
What is VO2 max?
maximum rate of O2 consumption as measured during incremental exercise
What do catecholamines dilate?
bronchial tree
- mechanism to increase O2 delivery
- open up the bronchi to bring more air in
During mild aerobic exercise, is the anaerobic:aerobic ratio high or low?
low
As intensity of exercise increases, what system is used more?
- anaerobic is used and lactate starts to build up
What is the anaerobic threshold?
the point where lactate begins to accumulate in the bloodstream
Can the body be trained to remove lactate more efficiently?
Yes
- in untrained individuals, anaerobic threshold happens at ~55% VO2 max, but 80-90% in elite endurance athletes
Can anaerobic threshold or VO2 max be increased with training?
both
Exercise-induced pulmonary hemorrhage
- edema in gas exchange region of lung
- horses
- not clear how
- treated with furosemide and nasal strips
What is elevated heart rate controlled by?
- sympathetic stimulation and catecholamines
What is erythrocyte (RBC) mobilization controlled by?
- neural (sympathetic) and hormonal control
What 3 hormones increase in response to exercise?
- cortisol
- epinephrine
- norepinephrine
