Chapter 5 - The Heart And Heart Disease Flashcards
How does the structure of the left ventricle cause high pressure?
It has a thick muscular wall
What is the definition of an atheroma?
A fatty deposit which forms in the wall of an artery
Why is the heart made of two separate pumps?
So one side pumps deoxygenated blood to the lungs and one side pumps oxygenated blood to the rest of the body
What is the course the blood takes around the heart to the lungs?
- Deoxygenated blood enters the vena cava
- This travels to the right atrium
- Then into the right ventricle through the right valve
- Blood travels out of the pulmonary artery to the lungs
What happens throughout a diastole?
The heart is relaxed
The blood flows into the atria and into ventricles
Semilunar valves CLOSED
Atrio-ventricular valves OPEN
What happens throughout an atrial systole?
Atria contracts
Blood flows into the ventricles
Semilunar vales CLOSED
Atrioventricular valves OPEN
What happens throughout a ventricular systole?
The atria relaxes
Blood flows away from the heart through the pulmonary arteries
Semilunar valves OPEN
Atrioventricular valves CLOSE
What makes blood flow?
It’s moves from regions of higher pressure to lower pressure
Where in the heart is the atrioventricular valve?
Between the left atrium and ventricle
Between the right atrium and ventricle
What is the purpose of the atrioventricular valves?
Closure of them ensures when ventricles contract the blood flows towards the aorta and pulmonary artery.
Where abouts in the heart are the semilunar valves?
In the aorta and in the pulmonary artery.
What is the purpose of the semilunar valves?
To prevent back flow of blood into the ventricles when the pressure is greater in the vessels than the ventricles
Cardiac output = ?
Heart rate x stroke volume
What is the process of the cardiac cycle?
- SAN sends wave of electrical activity across the atria causing atrial contraction
- Non conducting tissue prevents immediate contraction of ventricles which prevents impulses reaching the ventricles
- AVN delays impulses whilst the blood leaves the atria and ventricles contract
- AVN sends waves of electrical impulses down the bundle of His
- Causing ventricles to contract from base up
What is an aneurysm?
A thrombus full of blood
