BMS 302 Exam 4

The source of calcium in cardiac muscle is:

the sarcoplasmic reticulum and extracellular sources

Starling's law of the heart

states that, within physiological limits, the heart pumps out the blood that returns to it within each cycle; is the result of the length-force relationship also observed in skeletal muscle; can also be described as autoregulation; is demonstrated by a decreased force of contraction with decreased stretch of cardiac muscle

Starling's law of the heart holds that the _____, the greater the force of contraction.

greater the venous return, edv, and longer myocardial fibers

What parts of the heart are innervated by both the Parasympathetic and Sympathetic nervous systems?

the SA and AV nodes and the atria

The ventricles are innervated by:

the Sympathetic nervous system only

The ______ Nervous System increases the intracellular Ca++, which permits a more rapid & forceful contraction, _____ the rate of re-uptake of Ca++ by sarcoplasmic reticulum following contraction, which _____ plateau phase of ventricular fast response action potential or QT interval making it possible to cause a _____ heart rate.

Sympathetic; increases; shortens; faster

The flow chart shown below best represents:

The turtle heart experiment in which the temperature of the fluid bathing the sinus venosus is decreased.

The flow chart shown below best represents:

The turtle heart experiment in which the temperature of the fluid bathing the sinus venosus is increased.

Decreasing the temperature of the fluid bathing the sinus venosus:

decreases heart rate; decreases the rate of diffusion of ions across the membrane during the prepotential; makes the prepotential slope more shallow; follows ficks law

Increasing the temperature of the fluid bathing the sinus venosus:

increases heart rate; increases the rate of diffusion of ions across the membrane during the prepotential; makes the prepotential slope steeper

Vagal tone

affects the heart rate during rest and repose conditions; reduces the inherent rate of contraction by about 20-30 beats per minute in humans; is a tonic stimulation by the PANS of the SA-node

Cutting the right vagus nerve:

eliminates vagal tone; causes the heart rate to increase

Stimultion of the right vagus nerve innervating the turtle heart:

causes the heart rate to decrease

Vagal arrest is the result of:

continuing vagal stimulation that causes the prepotential slope of action potentials in the sinus venosus to approach zero; binding of large quantities of acetylcholine to cholinergic receptors in the sinus venosus

Vagal stimulation following the addition of atropine results in

no change

The effect of atropine is the result of:

cholinergic receptors being blocked by the atropine so acetylcholine cannot alter heart function.

The flow chart shown below best represents:

 The turtle heart experiment in which the ventricle is injected with epinephrine.

With an injection of epinephrine into the heart, heart rate and force of contraction (stroke volume) both increase, leading to an increased cardiac output. This is because

increased heart rate helps compensate for the decreased stroke volume that can be the result of an increased heart rate which decreases filling time and ejection fraction increases when the ventricles are stimulated by the SANS and that helps keep stroke volume from falling due to the increased heart rate

Which of the following statements are true for both increasing the temperature of the fluid surrounding the sinus venosus and stimulating the heart with epinephrine?

HR increases and filling time decreases

During the cardiac cycle, an extra systole can be induced by electrical stimulation during:

 the relative refractory period.

The compensatory pause is seen because:

the wave of depolarization from the sinus venosus reaches the ventricular muscle during the absolute refractory period of the extra-systole.

When Stannius Ligatures I and II are tied on a turtle heart, the ______ the lowest (shallowest) prepotential slope, the ______ an intermediate prepotential slope and the ______ the greatest (steepest) prepotential slope.

 ventricles have; atria have; sinus venosus has

When taking a blood pressure, the first sound that you hear represents the _____, and is the pressure that is generated during _____.

systolic reading; contraction of the ventricles

Mean arterial pressure must be homeostatically maintained why?

to insure adequate perfusion of all vascular beds, to insure sufficient pressure so that the forces of gravity can be overcome, to prevent one from passing out if the brain is insufficiently perfused, to allow one to change positions such as going from reclining to standing without feeling faint, through the baroreceptor reflex.

As the heart to brain distance becomes greater, the MAP at the level of the heart _____ , while the MAP at brain level _____ when compared with different species.

increases; remains about the same

Systolic blood pressure is reflected or influenced by _____, whereas diastolic pressure is reflected by _____.

cardiac output; peripheral resistance

You are measuring the blood pressure in a patient using a sphygmomanometer. You could detect an increase in venoconstriction by observing _____________, and you could detect an increase in vasoconstriction of the arterioles by observing ______________.

 an increase in systolic pressure; an increase in diastolic pressure

if heart rate doubles and stroke volume doubles, cardiac output will:

quadruple (4X).

what factors can affect stroke volume?

end diastolic volume, venous return, heart rate, ejection fraction, ventilation, sympathetic stimulation and excersize

List three mechanisms the body has developed to maintain the return of blood (venous return) to the heart from the extremities.

skeletal muscle pump, thoracic pump, venoconstriction

What facilitates venous return?

increase in venous tone, skeletal muscle pump, thoracic pump, postural changes, fainting

skeletal muscle pump

muscle contraction squeezes veins forcing blood back toward the heart past one way valves

thoracic pump

negative pressure in chest "pulls" blood into the thorax (and heart) with each inhalation

venoconstriction

smooth muscle in the elastic venous vessels contracts forcing blood from the venous system back toward the heart

What branch of the Autonomic Nervous System innervates the veins?

Sympathetic

What autonomic output leads to venoconstriction?

Increased Sympathetic

What is the effect of venoconstriction on venous return?

increases

What autonomic output leads to venodilation?

Decreased Sympathetic

What is the effect of venodilation on venous return?

decreases

Increased sympathetic activity stimulates the smooth muscle (effector) in the wall of the veins to ________ and therefore ______ the diameter of the vessel.

contract; decrease

List three factors that can alter peripheral resistance.

viscosity, length, diameter

What vessels play the most important role in altering peripheral resistance?

arterioles

Decreased sympathetic activity stimulates the smooth muscle (effector) in the wall of the veins to ________ and therefore ______ the diameter of the vessel.

relax; increase

What branch of the Autonomic Nervous System innervates the arterioles?

Sympathetic

What is the effect of arteriolar vasoconstriction on peripheral resistance?

increases

What autonomic output leads to arteriolar vasoconstriction?

Increased Sympathetic

What autonomic output leads to arteriolar vasodilation?

Decreased Sympathetic

What is the effect of arteriolar vasodilation on peripheral resistance?

decreases

Increased sympathetic activity stimulates the smooth muscle (effector) in the wall of the arterioles to ________ and therefore ______ the diameter of the vessel.

contract; decrease

Decreased sympathetic activity stimulates the smooth muscle (effector) in the wall of the arterioles to ________ and therefore ______ the diameter of the vessel.

relax; increase

Sympathetic tone

Veins and arterioles are in a partially contracted state under rest and repose conditions which is the result of a tonic sympathetic stimulation of the smooth muscle in the walls of the vessels.

baroreflex arc stimulus

decreased MAP

baroreflex arc receptor

baroreceptors located in carotid artery and aortic arch

baroreflex arc Afferent Pathway

decreased frequency of impulses along sensory neurons

baroreflex arc integrator

cardiac and vasomotor centers of medulla

baroreflex arc efferent pathways

sympathetic neurons to heart & vessels and parasympathetic neurons to heart

baroreflex arc effectors

cardiac muscle and smooth muscle of vessels

baroreflex arc response

increased MAP

During moderate exercise, systolic pressure increases because cardiac output _____ and diastolic pressure is maintained close to resting levels or decreases as blood flow to exercising skeletal muscle _____, and blood flow to the digestive tract _____.

increases; increases; decreases

Hypertension (high blood pressure)

can be diagnosed with repeated blood pressure measurements using a sphygmomanometer and stethoscope, is diagnosed when blood pressure readings exceed 140/90, has no symptoms in the early stages of development and goes unnoticed until damage to the cardiovascular system has occurred

Total Lung Capacity formula (6.0 L in men, 4.6 in women)

IRV + TV + ERV + RV

vital capacity formula

IRV + TV + ERV

Functional Residual Capacity formula

ERV + RV

Inspiratory Capacity formula

IRV + TV

Tidal volume

amount of air inhaled per breath during normal breathing, at rest 0.5 L

Inspiratory reserve volume

amount of air that can be inspired above and beyond that inspired during a normal quiet inspiration

Expiratory reserve volume

maximal amount of air that can be expired following a normal quiet expiration

FEV1 and FEV3

75-85%, >97%

BTPS refers to

body temperature, standard pressure (760 mm Hg)

Evaluate this subject's airway resistance.

Airway resistance is less than expected.

In subjects with normal lung function at sea level or moderate altitudes, ___________ has the greatest effect on increasing ventilation.  

 

hypocapnia

Hyperventilation results in _____ levels.

decreased blood carbon dioxide, no change in blood oxygen

What is the effect of hypocapnia on ventilation?

decreases

What is the effect of hypercapnia on ventilation?

increases

What is the effect of hypoxia on ventilation?

increases

Typical values for an end-expiratory sample of gas collected following a one minute breathold might be:

5-6% CO2

The data in the table below was collected from a subject using a small balloon to collect an Haldane-Priestly end-expiratory gas sample. Sample___ represents an end-expiratory sample collected following a breath-hold, sample ___ represents an end-expiratory sample collected following hyperventilation, and sample ___ is the control resting sample

Y, Z, X

What happens to oxygen levels in the blood during a breath-hold?

decrease

What happens to carbon dioxide levels in the blood during a breath-hold?

increase

Hyperventilation results in _____blood CO2 levels, which ____ breath-hold time, while breath-holding ______ blood CO2 levels resulting in _____ urge to breath.

decreased; increases; increases; an increased

The Sympathetic Nervous System _____ smooth muscle contraction, which _____ diameter and _____ airway resistance.

decreases, increases, decreases

The Paraympathetic Nervous System _____ smooth muscle contraction, which _____ diameter and _____ airway resistance.

increases, decreases, increases

What is the most appropriate type (cholinergic or adrenergic) of agonist and/or antagonist for decreasing airway resistance? Select all appropriate drug classes.

Cholinergic Antagonists and Adrenergic Agonists

Prevention of bronchitis

remove source of irritation

Prevention of asthma

anti-inflammatory drugs and bronchodilators

A Calorie or kilocalorie unit is used to measure food energy and is equal to the amount of heat needed to raise the temperature of a __________ of water by ______________.

kilogram; 1^o Centigrade

Conversion factors for metabolism

1L-1000 mL; 1 kg- 1000 g; 1kcal- 1000 cal

What statements best describes the approximate efficiency of the body in utilizing energy?

initially 80% converted to thermal energy, 20% converted to work energy, eventually all (100%) energy is converted to thermal energy

The amount of energy put into a system is _____ the energy put out by the system.

the same as

In the laboratory _____ was used to measure the metabolism of the Mr. Faust, the laboratory mouse and _____ was used to determine the metabolism of the human subject.

indirect calorimetry, indirect calorimetry

When we measure actual heat produced by a subject to determine metabolic rate, we are using_____ calorimetry, and if we measure oxygen consumption, we are using _____ calorimetry.

direct; indirect

The _____ gives us a relationship between heat production and oxygen consumption in the body that allows us to indirectly determine metabolic rates.

energy equivalent of oxygen

The energy equivalent of oxygen is:

4.8 kcal heat produced for every liter of oxygen utilized

As age increases, metabolic rate____ .

decreases

Ingestion of food:

consisting primarily of proteins has a greater effect on metabolism than lipids or carbohydrates, increases resting metabolic rates.

As circulating thyroxine (thyroid hormone) levels increase, metabolic rate ______.

increases

Metabolic rate increases following the ingestion of caffeine because caffeine:

inhibits phosphodiesterase activity causing more cAMP to be present and therefore enhance sympathetic pathways

What is required for the measurement of a Basal Metabolic Rate (BMR)?

fasting subject (12 or more hours), reclining subject, early morning testing, quiet and thermoneutral room

metabolic rate (units used in human measurements)

kcal/m2 x hr

metabolic rate (all species)

volume O2 /time or kcal/time