Knes360 Exam 1

The major difference between cardiac cells and skeletal muscle cells is that:

cardiac muscle cells have intercalated discs

Large increase in diastolic BP >20mmHg during exercise test on a treadmill is an indication of

coronary artery disease (myocardial ischemia?????)

Kyle McCabe

suffered cardiac arrest but survived because of screening. played youth football for years. found that he had a congenital form of long QT syndrome, a rare disorder that can disrupt the rhythm or rate of the heartbeat and cause sudden cardiac arrest

PWC: Physical Work Capacity

the ability to perform maximal physical work. As it is a function of the intensity and duration of work, each individual has many different capacities such as anaerobic, aerobic and endurance capacity

From the practical point of view as a coach, physical educator, or personal trainer it is important to know that Cardiovascular Drift is a hemodynamic phenomenon that occurs during prolonged moderately intense exercise, especially in a hot environment where there is a

- 10% increase in HR - 10% decrease in SV

The interesting conclusion(s) in the Patterson article on the heart transplant of a competitive cyclist was that

- lifestyle habits pre transplant may lead to increases in PWC after the transplant surgery - subjects exercise capacity was not limited by failure of HR to increase with exercise on test - a more aggressive treatment during recovery from heart transplant is possible in fit patients

Most accurate statement that explains Hemodynamic concept of Rate Pressure Product (RPP)

-RPP= HR X SBP during rest and exercise -RPP is used as a non invasive indicator of myocardial oxygen consumption (MVO2)

Exercise heart rate in humans is controlled by what mechanism(s)?

-Sympathetic Nervous System in the form of sympathetic cardiac nerves - Intrinsic Heart Rate set by the SA Nodes - Parasympathetic Nervous System via Left and Right vagus nerves

Factors that play a role in "snow storm angina" especially during the 1st major snowfall are

-static contraction of the arm muscles when lifting heavy snow -presence of coronary artery disease -low fitness level

The ability of endurance athletes CV system to transport oxygen to skeletal muscle can be increased significantly by:

-taking EPO -using RBC reinfusion technique (blood doping increase oxygen carrying capacity) -exercise training at moderate altitudes

High volume, heavy resistance training may not be a safe activity for individuals with hypertension because

-there is an exaggerated SBP and DBP response to this activity - Cardiac output may decrease with resistive exercise due to valsalva effect

During moderate intensity bout of aerobic exercise, Stroke volume is affected by 4 factors to increase venous return

1. Venous return- increase SV=increase venous return 2. Ventricular contractility- strength of ventricular contraction 3. Arterial/aortic blood pressure- increase in aortic pressure=decrease SV. It increases resistance of ventricles so aorta cant eject blood 4. Ventricular distensibility- stretchiness of heart (cardiac fibers)

4 mechanisms that explain how venous return is increased during exercise

1. valves in the large veins that prevent backflow 2. ventilator pump: when we go from rest to exercise, we breath more frequently and deeply. so, every time we breath inter-thoracic pressure increases and pressure compresses the vena cave, which enhances blood back to the right side of the heart 3. muscle pump: when skeletal muscle contracts, it compresses the veins and enhances blood flow coming back to the heart 4. sympathetic nervous system: increased sympathetic activity leads to mild venoconstriction that enhances venous return

While jogging at 50% of VO2max on the treadmill, we measure your heart rate with a heart rate watch to be 125 bpm and your cardiac output (Q) to be 18L/min. What is your SV?

144 mL/beat **Remember: Q=HRxSV and stroke volume always in mL (decimal 3 to R)

During a bout of incremental exercise where the intensity increases from low to maximal, the whole body a-VO2 difference increases from about 5mL O2/100mL of blood at rest to about ¬¬¬__________ mL O2/100mL during maximal exercise:

16-17

Your 65 yr old grandfather has just started a moderate exercise program at a fitness center and you want to give him an idea of what maximal heart rate is. What is the best estimate of his true maximal heart rate?

162 bpm 208- (.7 x age) OR 220- age

From the Colorado walking study article, the program goal was to increase walking behavior so that citizens were encouraged to walk ____steps per day more than usual for an added calorie expenditure of __kcal

2,000 steps/ 100 kCal

A moderate exercise training stimulus for a previously sedentary person is one that elicits ____ of the individuals V02 max

25-30%

Ejection fraction of the heart measured at rest in a sedentary healthy person is ~ ________ and __________ with acute exercise.

60% and increases

When administering a GXT to a subject on a treadmill and on a separate occasion using an arm ergometer, at similar work rates we would expect there to be:

A greater SBP and DBP response during arm exercise

The Blood Pressure in response to graded exercise in a normal, healthy person is:

ALL THE ABOVE: -large increase (60-80) in SBP -modest increase (10-20) in MAP -no change in DBP

Interpret the figure:

ALL THE ABOVE: - below HR of 100 the increase in HR is elicited by a decrease in parasympathetic (vagal) - exercise intensities above 50% cause the Sympathetic NS to increase HR - resting HR controlled mainly by Parasympathetic NS

A cardiologist who is interested in the size of the heart chambers and output of the ventricles before and after endurance training can use supine cycle ergometers and echocardiography to determine which of the following Variables

ALL: -EDV, ESV, and SV

Autoregulation is a physiological control mechanism that alters local blood flow to:

Active skeletal muscles via the production of tissue metabolites like NO, CO2, lactate and adenosine that stimulates vasodilation of the arterioles

In the CV exercise phys lab, researchers most frequently use which of the following techniques to measure cardiac output (Q) both at rest and during acute bouts of exercise?

CO2 Rebreathing

What vessel(s) delivers most of the blood flow to the left ventricle during exercise and are susceptible to narrowing via coronary artery disease:

Circumflex and left anterior descending artery (LAD)

A Case study in exercise physiology refers to

Clinical report that outlines an interesting medicinal condition and exercise results of a single individual

Which most accurately describes the physiology behind the blood flow redistribution that occurs when one goes from rest to incremental exercise

During exercise there is vasoconstriction of blood flow to visceral organs and dilation of vessels that bring more blood to active skeletal muscle, heart, and skin

MMSE: Mini Mental State Examination

Folstein test is a 30-point questionnaire that is used extensively in clinical and research settings to measure cognitive impairment. It is commonly used in medicine and allied health to screen for dementia.

The acute hemodynamic response to moderate and aerobic exercise that lasts 45-50 minutes include

Increase in EDV, decrease in ESV, no change in TBV

When one participates in an acute bout of aerobic exercise like jogging or cycling on a machine in a fitness center at a moderate intensity of 60-65% of VO2 max, the increase in exercise heart rate when the person increases intensity to 75% is due to?

Increase in Synmpathetic Nervous System Activity (SNS)

ST segment on a resting or exercise EKG is of primary importance because...

Its directly related to blood flow to myocardium

Ejection Fraction

SV divided by EDV. the fraction of blood that is ejected each time the heart contracts. usually get a resting EF of about 60%.

Blood doping by an endurance athlete like a New York Marathon runner or Tour De France cyclist where a unit of blood (~500mL) is withdrawn from the athlete and later reinfused into the vascular system would increase the O2 carrying capacity of the blood and also increase Stroke Volume (SV) and Cardiac Output (Q).

TRUE

During acute aerobic exercise up to an intensity of ~50% of VO2max in healthy subjects (not elite endurance athletes) the increase in cardiac output occurs as a result of increases in both Stroke Volume (SV) and Heart Rate (HR) while at higher exercise intensities the greater the cardiac output is due to increases in heart rate only.

TRUE

What is the mechanism for the BP results in this figure?

The arms show greater resistance because the muscle mass is less and the arterioles are smaller and fewer in number, thus BP is elevated to overcome this increased resistance

The Frank Starling mechanism as it applies to cardiovascular exercise physiology refers to...

The length/tension relationship in cardiac muscle that explains acute increases in contractility (only 1 answer!!!)

In healthy, young and old sedentary individuals heart rate (HR), stroke volume (SV), and Q all increase by about the same degree (2-4 fold) when going from rest to maximal aerobic exercise

True. don't put "T-but only in healthy individuals"

Prospective study

a longitudinal cohort study that follows over time a group of similar individuals who differ with respect to certain factors under study

The Middleton (2007) exercise fizz article on the effects of prolonged exercise on cardiac function showed that in healthy and endurance trained distant runners:

a significant decrease in ejection fraction (EF) occurred after the 3rd consecutive bout of running which suggests cardiac fatigue

2D Echocardiogram

bounce sound waves off of the heart to recreate a 2D picture of the heart; noninvasive and can be done during exercise. From the picture, cardiologists can measure the thickness of the ventricular walls, size of chambers and ventricular volumes

Total peripheral resistance is high at rest and ________ during an acute bout of incremental aerobic exercise

decreases

Stoke Volume (SV)

difference between EDV and ESV. amount of blood that is ejected from the left ventricle into the aorta in terms of mL per beat. SV increases significantly when we go from rest to exercise. typically about 60mL at rest.

venodilation

dilation/opening of veins

utilitarian walking

having a destination

recreational walking

having no destination

AMI: Acute Myocardial Infarction

heart attack

endothelial function

imbalance between vasodilating and vasoconstricting acting on/produced by the endothelium

The normal systolic blood pressure increase from rest to exercise during a graded exercise test is primarily due to

increase in HR

Normal SBP increase from resting to max exercise during a graded exercise test is DUE MOSTLY to...

increase in heart rate

During a graded exercise test (GXT) performed by a sedentary/active and healthy individual, stroke volume (SV):

increases linearly with exercise until about 50% of VO2 max, then levels off

What structures in the human heart allow the heart to act as a synctium? (PICTURES)

intercalated disks

arterial oxygen saturation

percentage of hemoglobin saturated with oxygen at the time of measurement

Informed consent

permission granted in the knowledge of the possible consequences

With regard to the conduct velocity of nervous impulses in the heart and its ability to function as a syncytium, the fastest velocities (in mm/sec) are found in the atria:

purkinje fibers

heart rate variability

variation in time variables between heartbeats

The QRS complex on an ECG represents the electrical activity of the :

ventricles

End-Systolic Volume (ESV)

volume of blood in mL that remains in ventricles after the heart contracts. typically about 40mL at rest. ESV decreases when we go from rest to exercise because the heart is contracting more forcefully

End-Diastolic Volume (EDV)

volume of blood left in the ventricles after a diastole. when we go from rest to moderate exercise the EDV increases because there is an increase in venous return. it's typically about 100mL at rest.

BMI: Body Mass Index

weight-to-height ratio, calculated by dividing one's weight in kilograms by the square of one's height in meters and used as an indicator of obesity and underweight

Normal Resting cardiac output values for sedentary individuals and endurance trained athletes are

~5-6L/min