Week 5- Cardiac structure and function Flashcards
Where does the right atrium receive blood from?
The inferior and superior vena cava
What side of the heart would you find the tricuspid valve?
right
What is the role of the epicardium?
serve as a lubricant outer coating
What does the myocardium provide?
muscular contractions that eject blood from the heart chambers
What does the endocardium serve as?
protective inner lining of the chambers and valves
Where does the heart receive its blood supply from?
coronary arteries
What is myocardial infarction (MI)?
-blockage of the coronary blood flow results in cell damage
What is the role of the sinoatrial node?
pacemaker that initiates depolarisation
What is the role of the atrioventricular node?
-passes depolarisation to ventricles
Why does the AV node allow for a brief delay in the depolarisation of the ventricles?
To allow for ventricle filling
What is the role of the bundle branches?
connect atria to the left and right ventricle
What is the role of the purkinje fibres?
spread the wave of depolarisation throughout the ventricles
Where do action potentials originate in the heart?
SA node
Once the action potential travels from the SA to the AV where is it passed to?
interventricular septum
What does the action potential travel along to reach the apex of each ventricle?
bundle branches
Where does the the purkinje fibres carry the action potential to and from?
from the bundle branches to the ventricular walls
What is the P wave showing in an ECG?
arterial depolarisation (SA and AV)
What does the QRS complex show in an ECG?
Ventricular depolarisation and arterial repolarisation
What is the T wave showing in an ECG?
Ventricular repolarisation
What is atherosclerosis?
Fatty plaque that narrows coronary arteries reducing blood flow to myocardium
What is myocardial ischemia?
reduced blood flow to the myocardium
How does exercise reduce the amount of myocardial damage from a heart attack?
-improves the hearts antioxidant capacity
-improves the function of ATP-sensitive potassium channels
What effect does the parasympathetic nervous system have on the regulation of heart rate?
-slows the heart rate by inhibiting the SA and AV node via the vagus nerve
What effect does the sympathetic nervous system have on the regulation of heart rate?
-increases heart rate by stimulating the SA and AV node via cardiac accelerator nerves
