Structure and anatomy of the heart Flashcards
Outline the movement of blood through the heart
- vena cava into right atrium
- through tricuspid AV valve
- right ventricle
- semi-lunar valves
- pulmonary artery
- lungs
- pulmonary veins
- mitral value
- left atrium
- left ventricle
- aortic valve
- aorta
What is the heart made out of?
Cardiac muscle
What is the difference between cardiac muscle and skeletal muscle?
Cardiac muscle does not get fatigued and need to rest
Why is the heart described as a double pump?
- blood is pumped through the heart twice
- first time deoxygenated blood is pumped to lungs
- Second time oxygenated blood is pumped to the body
What is the function of the coronary arteries?
Supply the heart muscle with oxygen and glucose in order to keep it contracting and relaxing all the time
What is the function of pericardial membranes?
Help to prevent the heart from over distending with blood
Is the wall of the left ventricle thicker than the right?
Yes
Why is the wall of the right ventricle thinner than the wall of the left ventricle?
- the right side only has to pump blood to the lungs which are close to the heart
- right side must only overcome resistance of the pulmonary circulation
Why is the wall of the left ventricle thicker than the wall of the right ventricle?
- the left side must provide sufficient force to overcome the resistance of the aorta and arterial systems of the whole body
- left side must move the blood under pressure to all extremities of the body
As the atrium fills with blood what happens to atrial pressure?
It increases
How is cardiac muscle described?
Myogenic
What does myogenic mean?
Heart muscle has its own intrinsic rhythm
As ventricular pressure increases, what happens to aortic pressure?
Why?
It increases
Blood flows into the aorta at high pressure
What is the sino-atrial node? and what is its function?
Region of the heart that initiates a wave of excitation that triggers the contraction of the heart
What is the sino-atrial node also known as?
The pacemaker region