The Cardio System Flashcards
Where is the heart situated?
Between the two lungs
What is the apex and where is it located?
The apex is the pointed end of the heart,
It is formed by the tip of the left ventricle
And it rests on the diaphragm
What is the pericardium?
It is the membrane that surrounds and protects the heart.
It also holds the heart in place
What is the outer fibrous pericardium?
It is a dense irregular connective tissue.
It prevents overstretching of the heart.
It provides protection
It anchors the heart in place
What is the inner serous pericardium?
It is a thinner delicate membrane that forms a double layer around the heart.
What are the 3 layers of the heart wall?
Epicardium
Myocardium
Endocardium
What is the epicardium?
It is known as the visceral layer of serous pericardium.
It is the thin transparent outer layer of the wall.
What is the myocardium?
It is the middle layer of the heart.
It is cardiac tissue muscle.
The majority of the heart is myocardium.
What is the endocardium?
It is the thin layer of the simple squamous epithelium that lines the inside of the myocardium.
It covers the valves and the tendons attached to the valves.
What are the cardiac muscle fibres?
They are the cells.
They are involuntary, striated and branched.
The tissue is arranged in interlacing bundles of fibres.
What are the 4 chambers of the heart?
The right atrium
The left atrium
The right ventricle
The left ventricle
What is the thin partition called between the right and left atrium called?
The interatrial septum.
What is the thin partition called between the left and right ventricle called?
The interventricular septum.
Which 3 veins does the right atrium receive deoxygenated blood from?
The superior vena cava (SVC)
The inferior vena cava (IVC)
The Coronary sinus
What does the superior vena cave do?
It brings back deoxygenated blood back to the right atrium from parts of the body above the heart.
What does the inferior vena cava do?
It brings back deoxygenated blood back to the right atrium from parts of the body below the heart.
What does the coronary sinus do?
It brings back deoxygenated blood back to the right atrium by draining blood from most of the vessels supplying the wall of the heart.
What is the circulation of the blood around the heart?
Deoxygented blood comes through the SVC, IVC and Coronary sinus and goes in to the right atrium
Through the tricuspid valve, into the right ventricle
Then goes through the pulmonary valve, into the pulmonary artery to the lungs to become oxygenated
Comes back in through the pulmonary veins into the left atrium
Goes through the bicuspid valve into the left ventricle
Goes through the aortic valve to the aorta to the rest of the body
Where are the atrioventricular valves?
They are between the atria and the ventricles
How many cusps does the bicuspid and tricuspid valves have?
Bicuspid has 2
Tricuspid has 3
What is another name for the bicuspid valve?
The mitral valve
How is the movement of blood controlled by the heart?
By opening and closing of the valves
And
The contraction and relaxation of the myocardium
How does the pressure go through the heart?
It goes from the high pressure areas to the low pressure areas
The pressure is related to the size and volume of the chambers
What is coronary circulation?
It’s the blood flow of the vessels in the myocardium
Where do the left and right coronary sinus originate?
At the branches of the ascending Aorta
Why do the arteries branch and branch again?
To deliver oxygen and nutrients throughout the heart muscle
What is controlled by the coronary sinus?
Deoxygenated blood that carries carbon dioxide and waste
What does the conduction system consist of?
Specialised cardiac muscle tissue that generates and distributes action potentials
What are the 5 components of the conduction system?
The Sinoatrial (SA) node
The Atrioventricular (AV) node
The bundle of his
Bundle branches
Purkinje fibres
Where is the SA node located and what does it do?
It is located in the right atrial wall
It begins cardiac excitation
Where is the AV node located and what does it do?
It is located in the interatrial septum
It is there to slow down the action potential, allowing the atriums to empty the blood
What is the bundle of his also known as?
The AV bundle
What happens after the action potential reaches the AV node?
The action potential enters the bundle of his in the interventricular septum
What happens during a normal cardiac cycle?
The two atrias contract
Then the two ventricles relax
Then the two ventricles contract
Then the two atrias relax
Plus the systole and diastole of both the atrias and ventricles
What is the phrase for contraction?
Systole
What is the phrase for relaxation?
Diastole
What is cardiac output?
It is the volume of blood ejected per minute from the left ventricle into the aorta
What is the equation for cardiac output?
Cardiac output = stroke volume x heart rate
Where does the regulation of heart rate originate?
In the cardiovascular (CV) center in the medulla oblongeta
What other regulators are there?
The Cardiac accelarator nerves
Vagus (X) nerves
Baroceptors
Chemoreceptors
What are the 5 age related changes in the heart?
1) Reduced maximum cardiac output
2) Changes in nodal and conducting cells
3) Reduced elasticity of the cardiac skeleton
4) Progressive atherosclerosis
5) Replacement of damaged cardiac muscle by scar tissue
