Term
| Substrate metabolism efficiency |
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Definition
1) 40% of substrate energy -> ATP
2) 60% of substrate energy -> heat |
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Term
| heat production _________ w/energy production |
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Definition
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Term
| What are the pros of measuring energy expenditure with direct calorimetry? |
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Definition
1) Accurate over time
2) Good for resting metabolic measurements |
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Term
| What are the cons of measuring energy expenditure with direct calorimetry? |
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Definition
1) expensive, slow
2) exercise equipment adds extra heat
3) sweat creates errors in measurements
4) not practical or accurate for exercise |
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Term
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Definition
| estimates total body energy expenditure based on O_2 used, and CO_2 produced |
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Term
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Definition
1) allows V of inspired air (unknown) to be directly calculated from V of expired air (known)
2) Based on constancy of N_2 volumes |
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Term
| V of inspired O_2 may not... |
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Definition
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Term
|
Definition
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Term
| During metabolism O_2 usage depends on what? |
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Definition
type of fuel being oxidized
1) More Carbon atoms in molecule=more O_2 needed
2) Glucose < palmitic acid |
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Term
| Respiratory exchange ration |
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Definition
ration btw. rates of CO_2 production, O_2 usage
1) RER = VCO_2/VO_2 |
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Term
| Lactate build up increases |
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Definition
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Term
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Definition
| element w/atypical atomic weight |
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Term
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Definition
| rate of energy used by body |
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Term
| What is metabolic rate based on? |
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Definition
| whole-body O_2 consumption and corresponding caloric equivalent |
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Term
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Definition
| rate of energy expenditure at rest; minimum energy requirement for living |
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Term
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Definition
| body surface area, age, stress, hormones, body temperature |
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Term
| metabolic rate _______ w/exercise intensity |
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Definition
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|
Term
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Definition
| will increase w/exercise duration even though the amount of work didn't change |
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Term
| VO_2 max (maximal O_2 uptake) |
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Definition
| point at which O_2 consumption doesn't increase w/further increase in intensity |
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Term
| What is the best single measurement of aerobic fitness? |
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Definition
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Term
| Max. anaerobic exercise: estimates of anaerobic effort involve |
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Definition
1) excess postexercise O_2 consumption
2) lactate threshold |
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Term
| O_2 demand > O_2 consumed in early exercise |
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Definition
1) body incurs O_2 deficit
2) O_2 required - O_2 consumed
3) occurs when anaerobic pathways used for ATP production |
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Term
| O_2 consumed > O_2 demand in early recovery |
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Definition
1) excess postexercise O_2 consumption (EPOC)
2) replenishes ATP/PCr stores, converts lactate to glycogen, replenishes hemo/myoglobin, clears CO_2 |
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Term
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Definition
point at which blood lactate accumulation increases markedly
1) lactate production rate > lactate clearance rate
2) interaction of aerobic and anaerobic systems
3) good indicator of potential for endurance exercise |
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Term
| How is lactate threshold usually expressed? |
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Definition
| as a percentage of VO_2max |
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Term
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Definition
fatigue
1) ability to exercise hard w/out accumulating lactate beneficial to athletic performance
2) higher lactate threshold=higher sustained exercise intensity=better endurance performance |
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Term
| Higher lactate threshold predicts... |
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Definition
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Term
|
Definition
| use less energy for given pace |
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Term
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Definition
1) decrements in muscular performance w/continued effort, accompanied by sensations of tiredness
2) inability to maintain required power output to continue muscular work at given intensity |
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Term
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Definition
1) inadequate energy delivery/metabolism
2) accumulation of metabolic by-products
3) failure of muscle contractile mechanism
4) altered neural control of muscle contrition |
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Term
| PCr depletion coincides w/fatigue |
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Definition
1) PCr used for short-term, high intensity effort
2) PCr depletes more quickly than total ATP |
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Term
| What helps to defer PCr depletion? |
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Definition
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Term
| What is the cause of Glycogen depletion happening very quickly? |
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Definition
1) High intensity
2) During first few minutes of exercise versus later stages |
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Term
| What fiber type depletes the fastest? |
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Definition
| Fibers recruited first or most frequently |
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Term
| When are type 1 fibers depleted? |
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Definition
| After moderate endurance exercise |
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Term
| Recruitment depends on exercise intensity |
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Definition
1) Type I fibers recruit first (light/moderate intensity)
2) Type IIa fibers recruit next (moderate/high intensity)
3) Type IIx fibers recruit last (maximal intensity) |
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Term
| Depletion and blood glucose |
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Definition
1) Muscle glycogen insufficient for prolonged exercise
2) Liver glycogen -> glucose into blood
3) As muscle glycogen decreases, liver glycogenolysis increases
4) Muscle glycogen depletion + hypoglycemia = fatigue |
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Term
| A certain rate of muscle glycogenolysis is required to maintain |
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Definition
1) NADH production in Krebs cycle
2) Electron transport chain activity
3) No glycogen = inhibited substrate oxidation |
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Term
| With glycogen depletion, what happens to FFA metabolism |
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Definition
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Term
| Fatigue and its causes: Metabolic by-products |
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Definition
1) Pi : from rapid breakdown of PCr, ATP
2) Heat: retained by body, core temp. increases
3) lactic acid: product of anaerobic glycolysis
4) H+ lactic acid -> lactate + H+ |
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Term
| Heat alters metabolic rate |
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Definition
1) increases rate of carbohydrate utilization
2) hastens glycogen depletion
3) high muscle temp. may impair muscle function |
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Term
| How is lactic acid beneficial? |
|
Definition
Serves as a source of fuel:
1) directly oxidized by type I fiber mitochondria
2) shuttled from type II fibers to type I for oxidation
3) converted to glucose via gluconeogenesis (liver) |
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Term
| Possible causes of neural transmission fatigue |
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Definition
1) decrease in ACh synthesis and release
2) altered ACh breakdown in synapse
3) increase in muscle fiber stimulus threshold
4) Altered muscle resting membrane potential |
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Term
| Fatigue of neural transmission may inhibit what? |
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Definition
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|
Term
| Failure may occur at _____________ ____________, preventing muscle activation |
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Definition
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Term
| Central Nervous System: fiber recruitment has conscious aspect |
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Definition
1) Stress of exhaustive exercise may be to much
2) Subconscious or conscious unwillingness to endure more pain
3) Discomfort or fatigue = warning sign
4) Elite athletes learn proper pacing, tolerate fatigue |
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Term
| Major functions of the Cardiovascular system: |
|
Definition
1) Delivers O2, nutrients
2) Removes CO2, other wastes
3) Transports hormones, other molecules
4) Temperature balance and fluid regulation
5) Acid-base balance
6) Immune function |
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Term
| What are the 3 major circulatory elements in the cardiovascular system? |
|
Definition
1) A pump (heart)
2) Channels or tubes (blood vessels)
3) A fluid medium (blood) |
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Term
|
Definition
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Term
|
Definition
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Term
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Definition
| pumps oxygenated blood from lungs to body |
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Term
|
Definition
| pumps deoxygenated blood from body to lungs |
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Term
| Blood flow through the heart |
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Definition
| Superior/Inferior vena cavea -> RA -> tricuspid valve -> RV -> Pulmonary valve -> pulmonary arteries -> lungs -> pulmonary veins -> LA -> mitral valve -> LV -> aortic valve -> aorta |
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Term
|
Definition
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|
Term
| Why does the LV have the most myocardium? |
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Definition
| Must pump blood to the entire body |
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Term
|
Definition
Similar to Type I:
1) High capillary density/ number of mitochondria
2) Striated |
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Term
| What are cardiac muscle fibers connected by? |
|
Definition
Intercalated discs:
1) Desmososmes
2) Gap junctions |
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Term
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Definition
|
|
Term
|
Definition
| rapidly conduct action potentials |
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Term
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Definition
1) large, long, unbranched, multinucleate
2) intermittent, voluntary contractions
3) Ca2+ released from SR |
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Term
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Definition
1) small, short, branched, one nucleus
2) continuous, involuntary rhythmic contractions
3) calcium-induced calcium release |
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Term
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Definition
| fluid filled area for heart protection and removal of friction |
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|
Term
|
Definition
|
|
Term
|
Definition
1) large, long, unbranched, multinucleated
2) Intermittent, voluntary contractions
3) Ca2+ released from SR |
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Term
|
Definition
1) Small, short, branched, one nucleus
2) Continuous, involuntary rhythmic contractions
3) calcium-induced calcium release |
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Term
| Myocardial Blood Supply: Right Coronary Artery |
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Definition
1) Supplies right side of heart
2) Divides into marginal, posterior interventricular |
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Term
| Myocardial Blood Supply: Left (main) Coronary Artery |
|
Definition
1) Supplies left side of heart
2) Divides into circumflex, anterior descending |
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Term
| Atherosclerosis leads to... |
|
Definition
|
|
Term
|
Definition
| special heart cells generate and spread electrical signal |
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Term
| Flow of electrical signal through the heart |
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Definition
1) Sinoatrial (SA) node
2) Atrioventricular (AV) node
3) AV bundle (Bundle of His)
4) Purkinje fibers |
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Term
| How does the electrical signal in the heart spread? |
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Definition
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|
Term
|
Definition
|
|
Term
| What does the AV node allow? |
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Definition
| A delay which allows for the RA/LA to contract before RV/LV ; relays signal to AV bundle after delay |
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Term
| What is released in the heart to hyperpolarize the cells? |
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Definition
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|
Term
| When the heart is hyperpolarized what happens? |
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Definition
| Decreases HR, force of contraction |
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Term
| What is released in the heart to help facilitate depolarization? |
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Definition
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|
Term
| When the heart is depolarized what happens? |
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Definition
| Increases HR, force of contraction; Increases HR above intrinsic HR |
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Term
|
Definition
| recording of heart's electrical activity |
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Term
| What are the 3 basic phases measured in the ECG? |
|
Definition
1) P wave
2) QRS complex
3) T wave |
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Term
|
Definition
|
|
Term
|
Definition
| ventricular depolarization |
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Term
|
Definition
| ventricular repolarization |
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Term
|
Definition
| slow HR; lower than 60 beats/min. |
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Term
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Definition
| fast HR (when not working out) ; can lead to decreased blood flow |
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|
Term
| Premature ventricular contraction |
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Definition
| a common cardiac arrhythmia that results in the feeling of skipped or extra beats caused by impulses originating outside the SA node |
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Term
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Definition
| a serious cardiac arrhythmia consisting of three or more consecutive premature ventricular contractions |
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Term
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Definition
| a serious cardiac arrhythmia in which the contraction of the ventricular tissue is uncoordinated, affecting the heart's ability to pump blood |
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Term
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Definition
| blood pumped out per contraction - measured in mL ; difference btw. EDV and ESV |
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Term
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Definition
| the fraction of blood pumped out of the left ventricle with each contraction, determined by dividing SV by EDV ; clinical index for heart contractile function |
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Term
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Definition
| volume of blood pumped out by the heart per minute |
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Term
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Definition
| the period that includes all events btw. 2 consecutive heartbeats |
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Term
|
Definition
relaxation phase
1) chambers fill w/blood
2) twice as long as systole |
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Term
|
Definition
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|
Term
| Cardiac cycle: Ventricular Systole |
|
Definition
QRS complex to T wave
1) Ventricular pressure rises
2) Atrioventricular valves close
3) Semilunar valves open
4) Blood ejected
5) At end, blood in ventricle = end systolic volume |
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Term
| Cardiac cycle: Ventricular Diastole |
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Definition
T wave to next QRS complex
1) Ventricular pressure drops
2) Semilunar valves close
3) Atrioventricular valves open
4) Fill 70% passively, 30% by atrial contraction
5) At end, blood in ventricle = EDV |
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Term
|
Definition
| carry blood away from heart |
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Term
|
Definition
| control blood flow, feed capillaries ; control system R ; site of most potent VC and VD |
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Term
|
Definition
| site of nutrient and waste exchange |
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Term
|
Definition
| collect blood from capillaries |
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Term
|
Definition
| carry blood from venues back to heart |
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Term
|
Definition
1) highest pressure in artery (during systole)
2) top number : 110 to 120 mmHg |
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|
Term
|
Definition
1) lowest pressure in artery (during diastole)
2) bottom number : 70 to 80 mmHg |
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|
Term
| Mean arterial pressure (MAP) |
|
Definition
1) average pressure over entire cardiac cycle
2) MAP = 2/3 DPB + 1/3 SBP |
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Term
| Blood flows from region of _____ ____ to region of ____ ____ |
|
Definition
| high pressure (LV, arteries) ; low pressure (veins, RA) |
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|
Term
| What is the easiest way to change flow? |
|
Definition
Change resistance
1) Vasoconstriction (VC)
2) Vasodilation (VD)
Diverts blood to regions most in need |
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Term
|
Definition
| blood flows from region of high pressure (LV arteries) to low pressure (veins, RA) |
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|
Term
| cardiac output is related to |
|
Definition
| change in pressure and resistance (radius of vessels) |
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Term
| Distribution of blood at rest |
|
Definition
1) liver, kidneys receive 50% of Q
2) Skeletal muscle receives 20% of Q |
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|
Term
| Distribution of blood during heavy exercise |
|
Definition
1) exercising muscles receive 80% of Q via VD
2) flow to liver, kidneys decreases via VC |
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|
Term
| Three types of intrinsic control of blood flow |
|
Definition
1) metabolic
2) endothelial
3) myogenic |
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|
Term
| What is the intrinsic control of blood flow? |
|
Definition
| ability of local tissues to constrict or dilate arterioles that serve them ; alters regional flow depending on need |
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Term
| Intrinsic control of blood flow : Metabolic mechanisms (VD) |
|
Definition
1) build up of local metabolic by - products
2) decrease O2
3) increase CO2, K+, H+, lactic acid |
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|
Term
| intrinsic control of blood flow : endothelial mechanisms (mostly VD) |
|
Definition
1) substances secreted by vascular endothelium
2) nitric oxide (NO), prostaglandins, EDHF |
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|
Term
| Intrinsic control of blood flow : myogenic mechanisms (VC, VD) |
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Definition
1) local pressure changes can cause VC, VD
2) increase pressure -> increases VC, decrease pressure -> increases VD |
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Term
| Sympathetic nervous system innervates |
|
Definition
smooth muscle in arteries and arterioles
1) baseline sympathetic activity -> vasomotor tone
2) increase sympathetic activity -> increases VC
3) decrease sympathetic activity -> decreases VC (passive VD) |
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Term
| Integrative control of blood pressure is maintained by |
|
Definition
|
|
Term
|
Definition
1) sensitive to changes in arterial pressure
2) afferent signals from baroreceptor to brain
3) efferent signals from brain to heart, vessels
4) adjust arterial pressure back to normal |
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|
Term
| Where are chemoreceptors and mechanoreceptors located? |
|
Definition
|
|
Term
| Three mechanisms that assist with venous return |
|
Definition
1) one-way venous valves
2) muscle pump
3) respiratory pump |
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|
Term
| Blood : three major functions |
|
Definition
1) transportation (O2, nutrients, waste)
2) temperature regulation
3) acid-base (pH) balance |
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Term
|
Definition
| total precent of volume composed of formed elements |
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Term
|
Definition
1) no nucleus
2) cannot reproduce
3) replaced regularly via hematopoiesis
4) produced and destroyed at equal rates |
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Term
|
Definition
| oxygen-transporting protein in RBC |
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|
Term
|
Definition
1) thickness of blood (due to RBC)
2) viscosity increases as hematocrit increases
3) plasma volume increases as RBC increase |
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Term
| Purpose of the respiratory system |
|
Definition
| carry O2 and remove CO2 from all body tissues |
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Term
| 4 processes of the respiratory system |
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Definition
1) pulmonary ventilation (external respiration)
2) pulmonary diffusion (external respiration)
3) transport of gases via blood
4) capillary diffusion (internal respiration) |
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|
Term
| Flow of pulmonary ventilation |
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Definition
| nose/mouth -> nasal conchae -> pharynx -> larynx -> trachea ->bronchial tree -> alveoli |
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Term
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Definition
| active process, expands thoracic cavity in 3 dimensions, expands volume inside thoracic cavity/lungs, lung volume increases - intrapulmonary pressure decreases, air passively rushes in |
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|
Term
| muscles involved in inspiration |
|
Definition
1) diaphragm (flattens)
2) external intercostals move rib cage and sternum up and out |
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|
Term
| muscles involved with forced breathing |
|
Definition
1) scalenes, sternocleidomastoid, pectorals
2) raise ribs even farther |
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Term
|
Definition
1) lung volume decreases, intrapulmonary pressure increases
2) air forced out of lungs |
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|
Term
| Expiration (active/forced breathing) |
|
Definition
1) internal intercostals pull ribs down
2) abdominal muscles force diaphragm back up |
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Term
|
Definition
1) changes in intra-abdominal, intrathoracic pressure promote venous return to heart
2) pressure increases -> venous compression/squeezing
3) pressure decreases -> venous filling |
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|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
| Total lung capacity (TLC) |
|
Definition
|
|
Term
|
Definition
gases dissolve in liquids in proportion to partial P
1) also depends on specific fluid medium, temperature
2) solubility in blood constant at given temperature |
|
|
Term
| What is the most important factor for determining gas exchange? |
|
Definition
| partial pressure gradient |
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