Cardiac cycle
Depolarization is associated with what?
a- relaxation
b- contraction
c- afterload
d- preload
b- contraction
What are two things we can change to alter cardiac output?
a- stroke volume and EDV
b- ESV and heart rate
c- heart rate and ejection fraction
d- heart rate and stroke volume
d- heart rate and stroke volume
BUT WAIT, I thought that the heart was myogenic and created it's own contractions?
Which of the following is not true of a closed circulatory system?
a- lower pressures than most other systems
b- flow is faster throughout this type of system
c- gives us the ability to control distribution of blood flow
d- found in humans
a- lower pressures than most other systems
what is the volume of blood left in the ventricle after contraction?
a- ejection fraction
b- end systolic volume
c- end diastolic volume
d- stroke volumeb- ESV
True or false-
Cardiac muscle cells are myogenic and depend on a signal from the sympathetic nervous system to contractWhat is an ECG?
a- a recording of the hears electrical activity
b- a recording of a single action potential
c- a recording of heart sounds
d- a recording of depolarization
a- recording of hearts electrical activity
What do nerves of the PNS and SNS release respectively?
a- acetylcholine (PNS), cortisol (SNS)
b- epinephrine (PNS), norepinephrine (SNS)
c- norepinephrine (PNS), cortisol (SNS)
d- acetylcholine (PNS), norepinephrine (SNS)
d- Ach (PNS) and NE (SNS)
a- elastic arteries
b- venules
c- capillaries
d- capacitance vessels
c- capillaries
What is a typical ejection fraction?
a- 25%
b- 80%
c- 60%
d- 15%
c- 60%
Where is the AV node located?
a- at the top right corner of the right atrium
b- throughout the ventricular wall
c- in the interatrial septum above the tricuspid valve
d- In the interventricular septum
c- interatrial septum above the tricuspid valve
What is true about the left ventricle?
a- It is identical to the right ventricle
b- Blood from the left ventricle flows into the pulmonary trunk
c- It receives blood from the systemic veins
d- It has a larger myocardium than the right ventricle
d- larger myocardium
What parts of the heart do cardio-stimulatory nerves innervate?
a- the entire heart
b- only the cells of the SA node
c- the cells of the SA and AV node
d- skeletal muscle cells
a- the entire heart
Which of the following is not found in the tunica interna?
a- thin sheet of connective tissue and proteins
b- simple squamous epithelium
c- internal elastic lamina
d- collagen covering
d- collagen covering
How much of the end-diastolic volume is contributed by atrial systole?
a- 50-60 mL
b- 30-60 mL
c- 20-40 mL
d- 80-90 mL
c- 20-40 mL
What is the main job of Purkinje fibers?
a- spread signal throughout the ventricular myocardium
b- they pass their signal on to the interatrial pathway
c- Initiate the heart beat
d- carry an action potential through the interventricular septum
a- spread signal throughout the ventricular myocardium
What is true about the cardiac cycle?
a- The only event that occurs within the cycle is systole
b- It is a series of events that allow blood to be moved around the heart
c- The atria and ventricles on the same side of the heart contract at the same time
d- Accounts for the diastolic contraction in the heart
B- a series of events that allow blood to be moved around the heart
What is another name for an effect that increases heart rate?
a- preload
b- positive chronotropic compound
c- positive inotropic compound
d- stimulatory nerve
b- positive chronotropic compound
What is not true about arteries?
a- they have high pressures due to systole of ventricles
b- elastic arteries are in greater abundance farther from the heart
c- elastic arteries work to maintain pressure during diastole
d- muscular arteries are responsible for vasomotion
b- elastic arteries are in greater abundance farther from heart
What are some examples of elastic arteries?
What does the isometric contraction in a cardiac cycle cause?
a- rapid decrease in intraventricular pressure
b- rapid increase in intraventricular pressure
c- slow decrease in intraventricular pressure
d- slow increase in intraventricular pressure
b- rapid increase in interventricular pressure
What is the biggest difference between skeletal muscle action potentials and SA node action potentials?
a- SA node depolarization is much slower in SA node cells than skeletal muscle cells
b- SA node depolarization is much more rapid than skeletal muscle cells
c- There is much faster efflux of K+ in SA node cells than skeletal muscle cells
d- SA node cells don't repolarize
a- SA Node depolarization is much slower
By about how much does the ventricle increase its blood volume with passive filling?
a- 120 mL
b- 60 mL
c- 25 mL
d- 40 mL
d- 40 mL
Which of the following does not increase stroke volume?
a- secretion of norepinephrine from sympathetic nerves
b- decreased afterload
c- decreased venous return
d- increased EDV
c- decreased venous return
a decreased venous return would lead to an increase in what volume?
What is not true about capillaries?
a- blood flows very fast through them due to their small diameter
b- only about 5% of the total blood volume is in the capillaries at any time
c- they are the only sight of gas exchange between blood and interstitial fluid
d- capillaries control flow with sphincters
a- blood flows very fast through them due to their small diameter
How do we calculate cardiac output?
a- CO = HR * SV
b- CO = SV/EDV * 100
c- CO = EDV - ESV
d- CO = .70 (HR)
a- CO = HR * SV
Where do cardiocytes get most of their Ca+?
a- their sarcoplasmic reticulum
b- they rely on interstitial Ca+
c- they don't use Ca+
d- hormones
b- they rely on Ca+ in the interstitial fluid