BMS 302 final exam

Ca2+ in skeletal muscle

SR

Ca2+ cardiac muscle

SR + extracellular

long plateau phase fast response action potential

1. is responsible for long refractory period seen in cardiac muscle.

2. allows the heart to serve as a pump because the ventricles have time to fill with blood before another contraction can be induced.

3. keeps cardiac muscle in the depolarized state so another contraction cannot be initiated until the heart has had time to contract and refill.

Which ion is responsible for the long plateau phase of the ventricular muscle action potential?

Ca++

Starlings law

1. the principle that the strength of heart contractions is directly related to the initial length of the cardiac muscle fibers. This means that the more the heart fills with blood, the stronger the subsequent contraction.

2. Auto regulation

3. is the result of cardiac fiber length being proportional to end-diastolic volume.

SA node, Av node, atria innervated by

both the Parasympathetic and Sympathetic nervous systems

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

Decreasing the temperature of the fluid bathing the sinus venosus

Decreases HR (deceases rate of diffusion Ca++ and Na++) making potential slope more shallow

Increasing the temperature of the fluid bathing the sinus venosus

Increases HR (increases the rate of diffusion of ions Ca++, Na++) making slope steeper

vagal tone

1. is a tonic stimulation by the Parasympathetic Nervous System of the SA-node.

2. reduces the inherent rate of contraction by about 20-30 beats per minute in humans

3. affects the heart rate during rest and repose conditions.

Cutting the right vagus nerve

1. eliminates vagal tone

2. causes the heart rate to increase

Stimulation of the right vagus nerve innervating the turtle heart:

causes the heart rate to decrease

Vagal arrest is the result of

1. continuing vagal stimulation until the heart stops beating

2. continuing vagal stimulation that causes the prepotential slope of action potentials in the sinus venosus to approach zero.

3. binding of large quantities of acetylcholine to cholinergic receptors in the sinus venosus.

Vagal stimulation following the addition of atropine results in 

 

no change in the heart rate

The effect of atropine is the result of

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

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

1. increased heart rate helps compensate for the decreased stroke volume that can be the result of an increased heart rate which decreases filling time

2. 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

1. Increases HR

2. Decreases fill time

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

You are given a turtle heart preparation with the Stannius Ligatures I and II tied properly. You count the ventricular rate and find it to be 12 beats per minute. Based on what you've learned, what rates might you expect to find for sinus venosus and atria, respectively

Increase (20 beats/min, 15 beats/min)

Stannius Ligature I

between sinus venous and atria

Stannius Ligature II

between atria and ventricle

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.

entricles 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

1. to insure adequate perfusion of all vascular beds

2. to insure sufficient pressure so that the forces of gravity can be overcome

3. to prevent one from passing out if the brain is insufficiently perfused.

4. to allow one to change positions such as going from reclining to standing without feeling faint.

5. 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)

quadruple (4X)

In the reclining position, gravity has little influence on blood pressure homeostasis

true

In the standing position, blood tends to pool in the extremities

ture

Venous return decreases when one moves from a reclining to a standing position

true

Mean arterial pressure must decrease in order for perfusion of the brain to be maintained in the standing position as compared to the reclining position

false

The baroreceptor reflex is responsible for adjusting mean arterial pressure on a moment to moment basis

true

Venous valves1.

1. prevent blood from pooling in the extremities.

2. assist in reducing the effect of hydrostatic pressure on blood returning to the heart.

3. when impaired are the cause of varicose veins.

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

1. skeletal muscle pump

2. thoracic pump

3. venoconstriction

facilitates venous return

1. increase in venous tone

2. skeletal muscle pump

3. thoracic pump

4. postural changes such as lying down with feet elevated

5. fainting

facilitates venous return - standing from a reclining position

false

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

List three factors that can alter peripheral resistance

1. viscosity

2. length

3. diameter

Which of the following vessels play the most important role in altering peripheral resistance

arterioles

What branch of the Autonomic Nervous System innervates the arterioles

Sympathetic

What is the effect of arteriolar vasoconstriction on peripheral resistance

increases

Veins and arterioles are in a partially contracted state under rest and repose conditions

1. This state is called sympathetic tone

2. The partially contracted state is the result of a tonic sympathetic stimulation of the smooth muscle in the walls of the vessels

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

Total Lung Capacity

IRV + TV + ERV + RV

Vital capacity

IRV + TV + ERV

Functional Residual Capacity

ERV + RV

Inspiratory Capacity

IRV + TV

Tidal volume

amount of air inhaled per breath during normal breathing

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

Residual volume

amount of air left in the lungs after a maximal expiratory effort

BTPS refers to

body temperature, ambient pressure, saturated gas

The composition of room air

20.93% O2, 0.04% CO2, and 79% N2.

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

hypercapnia

Hyperventilation results in _____ levels

1. no change in blood oxygen

2. decreased blood carbon dioxide

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

What is the effect of hyperoxia on ventilation

has no effect

Which of the following statements are true

1. Haldane-Priestly end-expiratory samples can be used to estimate pulmonary capillary blood levels of CO2.

2. Blood gases diffuse across the cell membranes in the lungs so rapidly that at any point in time CO2 and O2 levels in the alveoli and pulmonary capillaries are in equilibrium.

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

5-6% CO2

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

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

1. Adrenergic Agonists

2. Cholinergic Antagonists

Bronchitis

inflammation of airways caused by pollution, smoking or chronic infection

Asthma

inflammatory response accompanied by bronchoconstriction

Emphysema

smoking (in 90% of all cases) ultimately leading to a loss of surface area and air way collapse especially during exhalation

Lung Cancer

heredity and smoking

Bronchitis (treatment)

remove source of irritation

Asthma (treatment)

anti-inflammatory drugs and bronchodilators

Emphysema (treatment)

stop smoking, supplemental oxygen

Lung Cancer (treatment)

surgery

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

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 energy equivalent of oxygen is:

4.8 kcal heat produced for every liter of oxygen utilized

oxygen consumption

total oxygen (ml or liters) utilized per unit of time (minutes, hours, days)

metabolic rate (all species)

volume O2 /time or kcal/time

metabolic intensity

volume O2 /(time x kg) or kcal /(time x kg)

V_E

ventilation, L of air per min

VO₂

oxygen consumption (volume oxygen / min)

Oxygen consumption measurements are converted to _____, which stands for _____.

STPD, standard temperature and pressure of a dry gas

Measurements in the laboratory needed for the Haldane transformation include:

1. F_ECO₂

2. F_EO₂

3. V_E

On a per kilogram basis (metabolic intensity or mass specific metabolic rate), the metabolic rate of smaller mammals is _____ larger mammals.

greater than

In Experiment #12 (Energy Metabolism), we compared the oxygen consumption, heat production and metabolic rate of a human and a mouse. Which of the following conclusions were you able to make?

The human has a higher total O₂ consumption (liters /min), but lower metabolic rate measured in kcal/(kg × hr).

As the size of an animal _____, the surface area:mass ratio _____ and therefore the organism loses heat to the environment at a ____ rate and must consequently produce _____ heat per unit of body mass to compensate for the _____ heat losses.

1. decreases, increases, faster, more, increased

2. increases, decreases, slower, less, decreased

direct

actual heat produced by subject to determine metabolic rare

indirect

oxygen consumption