Cardiac output, heart rate, stroke volume, factors affecting heart rate,
yes, makes the pumping of the heart more efficient during aerobic exercise
Can ventricular hypertrophy be a good thing for the heart?
decreases
Does vasodilation increase or decrease afterload?
Negatively Chronotropic
Factors that decrease heart rate are called ____ _______
autonomic innervation and hormones
Heart rate can be affected by ______ and _______.
HR x SV (heart rate x stroke volume)
How do you calculate cardiac output?
Beta 1 receptors
Norepinephrine released by sympathetic neurons binds to ____ receptors
Stimulate Calcium entry, increasing force and duration of ventricular contractions
Positive inotropic agents typically stimulate ____ , thus causing _______
EDV
Preload is determined by the = _____ (what value)
stroke volume
The amount of blood pumped out of each ventricle during a single beat is the __________. end-diastolic volume cardiac output end-systolic volume stroke volume
glossopharyngeal N IX and vagus N X
The cardiac centers in the medulla oblongata monitor baroreceptors and chemoreceptors innervated by the __________. accessory N XI and hypoglossal N XII trochlear N IV and trigeminal N V glossopharyngeal N IX and vagus N X facial N VII and vesitbulocochlear N VIII
acts on conducting and contractile cells, increasing the rate they depolarize and therefore increase Heart Rate
Caffeine has effects on cardiac conducting cells and contractile cells that are similar to those of NE. What effect would drinking large amounts of caffeinated drinks have on the heart?
the amount of blood pumped out of one heart ventricle in a single heartbeat
Define stroke volume
increases
Does Sympathetic stimulation increase or decrease contractility of muscle cells?
Decreases
Does parasympathetic stimulation increase or decrease contractility of muscle cells?
Increases
Does the presence of hormones E, NE, glucagon, and TH increase or decrease contractility of muscle cells?
increases
Does vasoconstriction increase or decrease afterload?
drugs treating hypertension ( high blood pressure)
Drugs treating what condition are negatively inotropic. (contractility)
increased sympathetic activity to the ventricles
During exercise, the most important control mechanism to increase cardiac output is __________. increased end-systolic volume increased body temperature increased acetylcholine release from the vagus nerve increased sympathetic activity to the ventricles
positively chronotropic
Factors that increase heart rate are called _____ _______
Positivity inotropic
Factors that strengthen heart contraction are called ______
negatively inotropic
Factors that weaken heart contraction are called ______
pulmonary circuit
Right ventricular hypertrophy is a result of resistance from the ___________ circuit
leads to more rapid depolarization and increases heart rate
Stretching of the cardiac pacemaker cells of the Sa node leads to ______ and _____ heart rate.
positive inotropic effect
Sympathetic stimulation has a _____ _______ effect on contractility.
shortens repolarization and accelerates rate of depolarization
Sympathetic stimulation releases NE, which shortens ____ and accelerates ______. (in pacemaker cells.
autonomic activity and circulatory hormones
Under normal circumstances, the factors responsible for making delicate adjustments to the heart rate as circulatory demands change are __________. nerve activity and muscular activity cardiac output and stroke volume autonomic activity and circulatory hormones all of the listed factors
interferes with movement of blood through the heart
Valvular malfunction in the heart __________. interferes with ventricular contraction causes an increase in the amount of blood pumped out of each ventricle interferes with movement of blood through the heart increases the cardiac output
when the muscle wall becomes too thick and the narrowing of the chamber results in les. room in the chamber.
When can ventricular hypertrophy be a bad thing?
atria receives more blood, the walls stretch
When venous return increases the atria ______ and the walls are _____.
in the SA node
Where do the most dramatic effects of sympathetic or parasympathetic stimulation take place in the body?
parasymathetic nervous system
Which autonomic nervous system dominates in a healthy, resting individual?
sympathetic nervous system
Which division of the autonomic nervous system would increase heart rate?
ACh (acetylcholine)
Which neurotransmitter does the parasympathetic nervous system release that affects heart rate?
NE
Which neurotransmitter does the sympathetic nervous system release that affects heart rate?
increased stretch on the ventricle
Which of the following could increase the strength of the contraction of a ventricle? parasympathetic stimulation lower venous return increased stretch on the ventricle negative inotropic drugs, such as beta blockers
stroke volume
Which of the following is measured in milliliters per beat? stroke volume end-systolic volume heart rate intermodal pathway
digitalis
Which of the following medications serves as a positive treatment by interfering with the removal of calcium ions from the sarcoplasm of cardiac muscle cells? acetylcholine digitalis beta blockers verapamil
Sympathetic effects dominate in a resting healthy adult.
Which of the following statements about autonomic tone is FALSE? Sympathetic effects dominate in a resting healthy adult. Resting heart rate will be 70-80 beats per minute. ACh and NE are released at the nodes. Parasympathetic rates dominate in a resting healthy adult.
increase
An increase in afterload cause ____ of ESV
amount of blood in each ventricle at the end of ventricular diastole
What is EDV?
decreases
An increase in Contractility of cardiac muscle cells ____ ESV
decrease
A decrease in afterload cause ____ of ESV?
decreases
A decrease in contractility of muscle cells ____ ESV
restricts blood flow
Any factor that ______ through the arterial system increases afterload.
increase afterload
Damage to the semilunar valve will do what to afterload?
tachycardia
Decreased parasympathetic (vagus) stimulation to the heart results in a situation known as __________. stenosis bradycardia carditis tachycardia
Cardiac output is the amount of blood pumped by the left ventricle in 1 minute.
Define cardiac output.
by changing ionic permeabilities of cells in the conducting system
How do the sympathetic and parasympathetic divisions alter heart rate? ( What causes their effects)?
through changes in the rate at which impulses are generated
How does the SA node affect heart rate?
EDV-ESV (End Diastolic Volume - End Systolic Volume)
How to calculate stroke volume?
the amount of blood pumped out of the left ventricle in one minute
How would you define cardiac output? the amount of blood pumped out of the atria and ventricles in one minute the amount of blood pumped out of both ventricles in one minute the amount of blood pumped out of the left ventricle in one minute the end-diastolic volume plus the end-systolic volume
increased ESV and reduced SV
Hypertension increases afterload, resulting in ______ ESV and ______ SV?
decreases
If EDV decreases, SV _____
increases
If EDV increases, SV ______
increases
If ESV decreases, SV _____
decreases
If ESV increases, SV _____
decreases
If filling time decreases, EDV_____
increases
If filling time increases, EDV _____
an insufficient amount of blood available to be moved into the aorta and systemic circulation
If the bicuspid valve is defective and valvular regurgitation occurs, the end result is which of the following? gushing of blood into the left ventricle, causing excessive pressure an overstretching of the left ventricle, causing a decrease in the force of contraction an insufficient amount of blood available to be moved into the aorta and systemic circulation All of the listed responses are correct.
decreases
If venous return decreases, EDV _____
increases
If venous return increases EDV ______
increases SV
If you increase afterload what happens to SV?
SV = EDV − ESV, so SV = 125 mL − 40 mL = 85 mL
Joe's end-systolic volume is 40 mL, and his end-diastolic volume is 125 mL. What is Joe's stroke volume?
systemic circuit
Left ventricular hypertrophy is a result of resistance from the __________circuit
ventricular hypertrophy ( enlargement of the ventricles)
Long term increase in afterload is associated with _________
block calcium movement or depress cardiac muscle metabolism
Negativity inotropic agents block ____ or depress _____
a decrease in heart rate
Parasympathetic stimulation from the vagus nerve results in __________. a decrease in heart rate an increased heart rate and cardiac output more forceful ventricular contractions no effect on the heart rate
negative inotropic effect
Parasympathetic stimulation has a ______ ____ effect on contractility.
extends repolarization, decreases spontaneous depolarization
Parasympathetic stimulation releases Ach, which extends _____ and decreases the rate of ______. ( in pacemaker cells)
ventricular efficiency over time
Physicians are interested in cardiac output because it provides a useful indication of __________. atrial efficiency in respect to time ventricular efficiency over time the amount of blood ejected by each ventricle valvular malfunctions
stroke volume
The difference between the end-diastolic volume (EDV) and the end-systolic volume (ESV) is the __________. stroke volume preload and afterload cardiac output cardiac reserve
the shorter the filling time
The faster the heart rate the _____ the filling time
larger preload
The greater the EDV , the ____ the preload
heart rate
What affects filling time?
preload, ventricular contractility, and afterload
What are the three factors that affect ESV?
effect on HR
What does chromotropic mean?
affects the conduction speed in the AV node
What does dromotropic mean?
effect of contractility of the heart
What does inotropic mean?
It increases heart rate
What effect does epinephrine have on the SA node? It increases heart rate. It decreases heart rate. It increases hyperpolarization. It increases the plateau.
- Increase stroke volume (The venous return fills the heart with blood, stretching the heart muscle. According to the Frank-Starling principle, the more the heart muscle is stretched, the more forcefully it will contract (to a point). The more forceful the contraction, the more blood the heart will eject with each beat (stroke volume). Therefore, increased venous return would increase the stroke volume (if all other factors are constant).
What effect would an increase in venous return have on the stroke volume?
slows heart rate, therefore lowering cardiac output (Stimulating the acetylcholine receptors of the heart would slow the heart rate (parasympathetic neurons release acetylcholine). Since cardiac output is the product of stroke volume and heart rate, a reduction in heart rate will lower the cardiac output (assuming that the stroke volume remains the same or doesn't increase).
What effect would stimulating the acetylcholine receptors of the heart have on cardiac output?
the amount of blood remaining in each ventricle at the end of ventricular systole
What is ESV?
70-80 bpm
What is a typical normal resting heart rate?
the opposing force that the LV has to overcome to push the blood out of the LV ( to open the aorta)
What is afterload?
Normal cardiac output at rest is about 5-7.5 L/min.
What is considered a "normal" cardiac output when resting? Please provide units.
the amount of force produced during a contraction, at a given preload.
What is contractility?
duration of ventricular diastole
What is filling time?
the degree of stretching in ventricular muscle cells during ventricular diastole
What is preload?
the more the ventricles are stretched the more forcefully they contract, up to a point
What is the frank starling law?
affects the ability of muscle cells to produce tension
What is the importance of preload?
The amount of blood returning to the heart through the veins
What is venous return?
enlargement of the ventricles
What is ventricular hypertrophy?
vasoconstriction and vasodilation
What two factors affect afterload?
venous return and filling time
What two factors affect preload?
All of the listed responses are correct.
Which of the following statements is part of Starling's law of the heart? The greater the ventricular stretch, the more forceful the contraction. An increase in venous return will increase blood flow into the heart. A slightly larger and better-contracting heart will increase stroke volume. All of the listed responses are correct.
During ventricular systole, the papillary muscles contract to keep the AV valves shut and prevent them from swinging up into the atria.
Which of the following statements is true? If you increase ESV, then you will increase SV. During ventricular systole, the papillary muscles contract to keep the AV valves shut and prevent them from swinging up into the atria. If you increase heart rate, then you will increase SV. None of the listed statements is true.
Not enough time to fill completely with blood, so little blood leaves the heart. No blood gets to tissues (The heart pumps in proportion to the amount of blood that enters. A heart that beats too rapidly does not have sufficient time to fill completely between beats. Thus, when the heart beats too fast, very little blood leaves the ventricles and enters the circulation, so tissues suffer damage from inadequate blood supply.)
Why is it a potential problem if the heart beats too rapidly?
when EDV is as large and ESV is as small
You get the largest stroke volume when EDV is ____ and ESV is ____
cardioinhibitory center
_____ center controls the parasympathetic neurons that slow heart rate
cardioacceleratory center
_______ center controls sympathetic neurons that increase heart rate?