Heart and Circulation Flashcards
Aidan
What is the heart?
The pump that generates blood flow around the system.
What is the arterial system?
The conductance vessels that carry the blood around the body.
What is microcirculation?
Where transfer of nutrients, waste and water occurs.
What is the venous system?
The capacity vessels, that store and return blood to the heart.
Two parts of the vena cava?
Superior and inferior
Flow of blood through the chambers of the heart with the two valves named?
Right atrium through tricuspid valve into right ventricle, (out into lungs), back into left atrium through mitral valve into left ventricle then (out into body)
What wall of the heart is thicker? and why?
Left handed wall is thicker as it has to pump blood a further distance than the right hand side.
What is the heart surrounded by?
The pericardial sac.
What is the pericardial sac?
fibrous tissue lined with a serous, slippy membrane that secretes a minuscule amount of lubricating fluid.
Where is the heart situated?
Lies centrally in the chest, between the lungs and pleura, in the mediostinum.
What stops the back flow of blood?
Valves
What stops the blood coagulating inside the heart/circulatory vessels
Endothelium.
What are the right and left auricles?
extensions of the right and left atria.
What structures/surfaces does the pericardial cavity (and the heart)..
Front = sternocostal, Bottom = diaphramatic surface.
base aligns itself with the spine.
what part of the heart forms the base
The left atrium
In what ways do blood vessels vary?
In number, in diameter, wall thickness, smooth muscle, elastic tissue, fibrous tissue
what are blood vessels lined by?
Endothelial cells.
when not in contact with endothelial cells what does blood start to do?
Blood starts to clot when not in contact with endothelial cells.
what can the endothelial cells that line the blood vessels do to regulate bloodflow etc.
They can release a selection of chemicals to regulate bloodflow.
what is systole?
contraction of the heart.
what is diastole?
relaxation of the heart.
List the veins that lead in to the right atrium
Superior vena cava
Inferior vena cava
Coronary sinus
What is the coronary sinus?
It is where venous blood drains back into the heart.
what is the atrial ventricular node?
The single point of electrical conductivity between atria and ventricles and rest is covered by an ‘insulating’ cartilaginous skeleton.
what leads out of the right atrium
Tricuspid valve to right ventricle
What was the foramen ovale?
Foramen ovale was an opening from right to left atrium that allowed oxygenated blood coming from the mother to by-pass the non-functioning foetal lungs.
What is the fossa ovalis?
It is the site of what was the foramen ovale in the embryo.
How many veins enter the left atrium?
FOUR pulmonary veins enter the heart via the left atrium.
left and right, Sup and Inf veins.
What does the aortic valve do?
Stop backflow.
what are papillary muscles connected to?
They are connected to the mitral valve by tendons
why are papillary muscles connected to the mitral valve?
Anchors the mitral valve and stops it being inverted by the pressure of the blood being pumped out of the heart.
What does LAB RAT stand for?
Left atrium bicuspid, right atrium tricuspid.
Why does the wall of the ventricle become smooth near the outflow?
To create laminar blood flow into the pulmonary trunk and aorta.
What word describes the shape of the cusps of the pulmonary and aortic valves?
Semi-lunar (half moon).
In which position are the valves in during systole?
open as blood passes through and forces the cusps against the vessel wall.
In which position are the valves during diastole?
elastic recoil in the pulmonary trunk and aorta forces blood between the cusps and the vessel wall, forcing the cusps to meet in the centre of each vessel.
When do the heart muscles receive oxygen.
Only during diastole (when relaxed)
Where do the coronary arteries start from?
The left and right coronary arteries arise from the aortic sinuses just above the valve cusps.
What causes angina?
Angina is when the body cannot match the blood supply of the heart with the amount of blood it needs. The pain is lack of oxygen and nutrients causing damage to the heart muscles.
Where do the anterior cardiac veins drain into?
They drain directly into the right atrium.
What do the veins in the heart converge into?
They converge on the coronary sinus which then enters the right atrium.
How do you measure the electrical activity of the heart?
Electro-Cardiograms (ECG’s)
what are Purkinje fibres?
These are what deliver the electrical impulses into the muscle walls.
What is the AV node?
The only point where the ‘insulating’ cartilaginous skeleton is compromised.
What is the S-A node and what is it regulated by?
The S-A node is the pacemaker of the heart and can be sped up or slowed down by the autonomic nervous system.
What is the bundle of His?
It is the ONLY ROUTE by which conduction may pass from the AV node.
Where does the AV node branch into?
It continues into the right and left bundle branches that spread the conduction through each ventricle.
Give examples of how other systems integrate with the cardiovascular system.
Blood is oxygenated in the lungs and blood volume is regulated by the kidneys.
