EXAM 3 Practice test Flashcards
You are given an isolated turtle heart preparation with the sinus venosus, atria,and ventricle separated. You count the ventricular rate and find it to be 12 beats per minute. What rates might you expect to find for the sinus venosus and atria, respectively?
12 beats/min, 12 beats/min
15 beats/min, 20 beats/min
20 beats/min, 15 beats/min
9 beats/min, 6 beats/min
20 beats/min, 15 beats/min
Acetylcholine __________ heart rate. This is accomplished partly by _____ the rate of Ca++ influx through leakage channels into cardiac pacemaker cells.
increases, increasing
increases, decreasing
decreases, decreasing
decreases, increasing
decreases, decreasing
During the cardiac cycle, an extra systole can be induced by electrical stimulation during:
the latent period
the absolute refractory period
the relative refractory period
systole
the relative refractory period
Following the addition of atropine to the pericardial cavity of a turtle heart preparation, stimulation of the vagus nerve:
decreases heart rate
increases heart rate
has no effect on heart rate
decreases, then increases the heart rate, as parasympathetic stimulation continues
has no effect on heart rate
Which of the following parts of the heart is well supplied with sympathetic neurons and a limited number of parasympathetic neurons?
atria
ventricles
sino-atrial node
intercalated disks
ventricles
Read the the following two statements and determine the most appropriate assessment.
A. Heart rate in the presence of epinephrine
B. Heart rate in the presence of atropine
Opinions:
A is greater than B
B is greater than A
A is approximately equal to B
A is greater than B
Hypertension:
Options:
is commonly called “a silent killer.”
is often diagnosed because of severe headaches and dizziness
can be treated and permanently cured.
is diagnosed by a single elevated blood pressure reading.
is commonly called “a silent killer.”
Systolic blood pressure is reflected or influenced by ____, whereas diastolic pressure is reflected by ______.
Options:
heart rate; stroke volume
peripheral resistance; cardiac output
cardiac output; heart rate
cardiac output; peripheral resistance
cardiac output; peripheral resistance
Normally, during moderate exercise, diastolic blood pressure _________; and at the same time systolic blood pressure ________.
Options:
increases or remains the same; decreases
decreases or remains the same; increases
increases or remains the same; increases
increases; remains the same.
decreases or remains the same; increases
Which of the following formulas is correct?
Options:
Mean arterial pressure = stroke volume X heart rate
Mean arterial pressure = cardiac output X heart rate
Mean arterial pressure = cardiac output X peripheral resistance
Mean arterial pressure = «(systolic pressure + diastolic pressure)
Mean arterial pressure = cardiac output X peripheral resistance
Due to Starling’s Law, an increased venous return leads to a/an:
Options:
increased force of contraction
decreased force of contraction.
increased QRS amplitude.
decreased QRS amplitude
increased force of contraction
Read the the following two statements and detemine the most appropriate assessment.
A. Effect of arteriolar vasoconstriction on systolic pressure
B. Effect of venoconstriction on systolic pressure
Options:
A is greater than B
B is greater than A
A is approximately equal to B
B is greater than A
Your subject breathes a gas mixture from a balloon. Which gas mixture causes the greatest increase in ventilation?
Options:
95% O2, 5% N2
21% 02, 0.04% CO2, 79% N2
100% O2
95% O2, 5% CO2
95% O2, 5% CO2
An individual with a normal resting tidal volume is given a drug for pain which also depresses his respiration. The breathing rate decreased from 20 breaths/min to 10 breaths/min. The change in ventilation or minute volume or of respiration would be approximately:
Options:
10 breaths/min.
5 liters/min.
500 ml/breath
none of the above
5 liters/min.
When a person hyperventilates, the amount of CO2 in their blood ______. This results in a/an _____ “urge to breathe”.
Options:
drops; increased
climbs; increased
drops; decreased
climbs; decreased
drops; decreased