Exam 1 Flashcards
 how do you measure metabolic rate?
Direct calorimetry
How do you measure oxygen consumption today?
Open circuit spirometry
Test this by clipping the nose to prevent nasal breathing 
What is the biological control system and how does it work?
To trigger the operation of a control system, a stimulus representing a change in the internal environment must be present. The stimulus excites a sensor that is a receptor in the body capable of detecting change in the variable in question. The excited sensor then sends a message to the control center. The control center integrates the strength of the incoming signal from the sensor and sends a message to the effectors to bring about the appropriate response to correct the disturbance (i.e., desired effect). The return of the internal environment to normal (i.e., homeostasis) results in a decrease in the original stimulus that triggered the control system into action. This type of feedback loop is termed negative feedback and is the primary method responsible for maintaining homeostasis in the body
What is the game of a control system?
Game is the capability of the control system the more gain, the easier it is to correct a disturbanc
Intracrine signaling
When a chemical messenger is produced inside a cell, that triggers, a signaling pathway within the same cell that leads to a specific
Juxracrine signaling
Cells communicating cell to cell contact in example of this is when both cells constrict to ensure heart contracts and smooth and effective manner
Autocrine signaling
A cell produces and releases a chemical messenger into the extra cellular fluid that acts upon the cells producing the signal. Example of this would be when a cell triggers DNA to produce a contractile proteins, which increases the size of the muscle cell.
Paracrine signaling
When a cell produces signal in a nearby, cell helps. For example, immune cells attacked in, protect the body from infection
Endocrine signaling
When a cell releases, chemical signals (hormones) into blood, and these are carried throughout the body
Cycle ergometer
Measure work performance of your legs
Bench Step
Measure work capacity of humans
What are normal blood sugar level?
4.0 to 5.4 mmol /L
Cholesterol levels? 
Less than 200 MG/DL
borderline high 200-239
high at or above 240
Blood pressure reading?
Normal is 120/80 or lower
High stage one is 130/80
Stage two high blood pressure is 140/90 or higher
CVD
An assessment used to evaluate a patient’s risk of developing cardiovascular disease
How is ATP produced at rest?
Aerobic metabolism (blood lactate levels are low)
Rest to exercise transitions
ATP production increases immediately
Oxygen up take increases rapidly
Initial ATP production is through anaerobic pathways (ATP-PC, Glycolysis)
There is an oxygen deficit
How is ATP produced in the first 5 seconds of short term, high intensity exercise
ATP-PC system
Intense exercise longer than 5 seconds
Shift to ATP production via glycolysis
Events lasting longer than 45 seconds
ATP production through ATP-PC, Glycolysis, and aerobic systems
High intensity exercise lasting longer than 20 seconds
Anaerobic glycolysis produces ATP
High intensity exercise lasting longer than 45 seconds
Combination of ATP-PC, Glycolysis, and aerobic metabolism
Events lasting longer than 10 minutes
ATP production primarily from aerobic metabolism
Prolonged exercise in a hot or humid environment at high intensity
Results in upward drift in oxygen uptake due to increase in body temperature and blood levels of epinephrine and norepinephrine
From rest to moderate exercise, oxygen uptake…
Oxygen increases rapidly, generally reaching a steady state in one to four minutes
Oxygen deficit
Lag in oxygen uptake at the beginning of exercise
Why is a steady state not reached in a hot or humid environment
The upward drift in oxygen consumption over time does not allow the steady state to be achieved
Why do trained subject have a lower oxygen deficit
Better developed aerobic bioenergetic capacity due to cardiovascular or muscular adaptations
Oxygen debt
The amount of oxygen required after physical exercise to convert accumulated lactic acid to glucose
Removal of lactic acid following exercise
70% is oxidized and used as substrate by heart and skeletal muscle
20% converted to glucose
10% converted to amino acids
Physiological factors influencing Vo2 max
Maximum ability of cardiorespiratory system to deliver oxygen to the muscle
Ability of muscles to use oxygen and produce ATP aerobically
Lactate threshold
The point at which blood lactic acid rises systematically during incremental exercise
Bioenergtics
Converting macronutrients into energy
Exergonic reaction
A chemical reaction that releases energy
Endergonic reaction
Reaction that requires input of energy
Protein synthesis
Synthesizing proteins based on the body going through stress
Coupled reactions
Energy given off by the exergonic reaction in turn powers the endergonic reaction
Oxidation
Removing an electron
Reduction
Adding an electron
Enzymes
Lower activation energy
Enzyme levels in the blood indicate
Disease or tissue damage
