The Structure & Function of the Heart Flashcards
What do we call the volume of blood pumped through each ventricle per minute?
cardiac output
What is the equation for cardiac output?
cardiac output = heart rate x stroke volume
What do we call the volume of blood pumped from the heart with each beat?
stroke volume
Which ventricle pumps the greater volume of blood?
They pump the same volume
Name the top two chambers of the heart.
atria
Name the bottom two chambers of the heart.
Ventricles
Name the valves between the ventricles and arteries.
semi lunar valves
What is the general name for the valves between the atria and ventricles?
atrio-ventricular
Name the valve between the left atrium and left ventricle.
Bi-cuspid
Name the valve between the right atrium and right ventricle.
atrioventricular
Where does blood travel to after the right atrium?
right ventricle
Where does the blood travel to after the right ventricle?
the lungs
Which blood vessel takes blood to the lungs?
pulmonary artery
Which blood vessel bring blood back to the heart from the lungs?
pulmonary vein
Which chamber in the heart does blood from the heart come back to?
left atrium
Where does blood travel to after the left atrium?
left ventricle
Where does blood travel to from the left ventricle?
the rest of the body
Which blood vessel carries blood from the heart to the rest of the body?
aorta
Which blood vessel carries blood back to the heart from the rest of the body?
vena cava
Which chamber in the heart receives blood from the rest of the body?
right atrium
In the heart, what happens to blood during diastole?
blood returning to the atria flows into the ventricles
In the heart, what happens to blood during atrial systole?
Remaining blood flows from atria into the ventricles
What effect does ventricular systole have on the atrio-ventricular valves?
causes them to close
In the heart, what happens to the blood during ventricular systole?
pumps blood from the ventricles to the arteries
What happens to the SL valves during ventricular systole?
opens to SL valves
What causes the SL valves to close?
higher pressure in the arteries during diastole
What is the cardiac output for the following person:
heart rate = 72 bpm
stroke volume = 70ml?
5040 ml/min OR
5.04 l/min
What term is used to describe the contraction of heart muscle?
systole
What term is used to describe the relaxation of heart muscle?
diastole
What causes the ‘lub dupp’ heart sounds heard through a stethoscope?
the opening and closing of the AV and SL valves
From where does the heart beat originate?
pacemaker
What is another name for the pacemaker?
SA node (sino-atrial node)
Where is the SA node located?
The wall of the right atrium (silly)
As impulses spread from the SA node across the atria, what does it cause?
atrial systole
After impulses have gone from the SA node through the atria, where do they go to next?
The atrio-ventricular node (AV node)
Where is the AV node located?
The centre of the heart
When impulses travel to the apex of the heart and up through the ventricles, what does it cause?
ventricular systole
What can be used to detect the impulses the heart generates?
electrocardiogram (ECG if you are a cheat!)
How do you calculate the heart rate of a person from an electrocardiogram? (3 steps)
- Find 2 obvious points that are easy to measure
- measure the time between these two points
- divide 60 by that time
Which part of the brain regulates the rate of the SA node?
The medulla
Name the 2 nerves associated with the autonomic nervous system.
sympathetic and parasympathetic
What term is used to describe the opposite effects of the sympathetic and parasympathetic nerves on the SA node?
antagonistic
What effect does the sympathetic nerve have on heart rate?
increases it
What effect does the parasympathetic nerve have on heart rate?
decreases it
Which neurotransmitter does the sympathetic nerve release?
noradrenaline
Which neurotransmitter does the parasympathetic nerve release?
acetylcholine
What is used to measure blood pressure?
A sphygmomanometer
During which stages of the cardiac cycle is blood pressure:
a) highest
b) lowest
a) ventricular systole
b) diastole
What is the average blood pressure for a young adult, like Mr Hill?
120/80
What is the scientific term for high blood pressure?
hypertension
How does a sphygmomanometer work? (3 steps)
- stops blood flow in artery
- blood starts to flow (detected by pulse = systole)
- blood flows freely (no pulse detected = diastole)