2. Cardiac imaging & CVS anatomy Flashcards
List the different imaging techniques that can be used to assess cardiac structure and functioning
- X-rays
- Nuclear imaging (e.g PET)
- Cardiac MRI
- CT scanning
what is the CT pulmonary angiography?
This is an imaging technique that can be used to study the pulmonary arteries.
It can be used to identify blood clots or narrowing in the pulmonary arteries.
describe the flow of blood through the chambers of the heart, including the valves it goes through
Deoxygenated blood from the cells of the body enter the right atrium of the heart through the inferior and superior vena cava. the blood then flows to the right ventricle through the tricuspid valve. when the right ventricle contracts, the blood flows into the pulmonary artery through the pulmonary valve and to the lungs.
Oxygenated blood from the lungs enters the left atrium via the pulmonary vein. it then flows into the left ventricle through the mitral valve and then to the aorta through the aortic valve and to the rest of the body.
how many pulmonary veins are there?
4 - two from each lung
two on the right side and two on the left
what is the main difference between the left and right ventricle?
left ventricle is much thicker as it has higher pressure
describe the 3 layers of arteries
tunica intima - composed of an elastic membrane lining and smooth endothelium
tunica media - composed of smooth muscle and elastic fibres
tunica extern/adventitia - composed of collagen and elastic fibres(connective tissue)
how does size of arteries affect its structure?
large arteries e.g. aorta have more elastic tissue which allows it to expand.
medium sized arteries are more muscular as they are the distributing arteries
small sized arteries are also muscular as they are resistance vessels and control blood pressure
describe the structure of the aorta
The aorta is the largest artery in the body.The aorta is divided into four sections:
The ascending aorta, the aortic arch, the descending aorta and the abdominal aorta.
describe the sections of the aorta
- The ascending aorta begins at the opening of the aortic valve in the left ventricle of the heart. The coronary arteries branch off the ascending aorta to supply the heart with blood.
- The aortic arch curves over the heart, giving rise to branches that bring blood to the head, neck, and arms.
- The descending thoracic aorta travels down through the chest. Its small branches supply blood to the ribs and some chest structures.
- The abdominal aorta begins at the diaphragm, splitting into smaller arteries in the lower abdomen. Most of the major organs receive blood from branches of the abdominal aorta.
what is the function of the aorta?
The aorta is used to distribute oxygenated blood to all parts of the body.
Give the equation for Cardiac output
CO= HR x SV
Compare the HR, CO and SV in a 70kg under resting conditions and during exercise
At rest:
HR= 60-90bpm
SV= 55-83 ml/beat
CO= 5L/min
During exercise:
HR- 150-200bpm
SV= Up to 200ml/ beat
CO= 20-35L/ min
what are the 3 layers of the heart?
Epicardium - serous membrane, smooth outer surface of heart. contains loose connective tissue and adipose tissue.
Myocardium - middle layer composed of cardiac muscle cell and responsible for heart contracting
Endocardium - smooth inner surface of heart chambers
what are pectinate muscles?
muscular ridges in auricles and right atrial wall
what are trabeculae carnae?
muscular ridges and columns on inside walls of ventricles
what are auricles and what are their function?
One auricle is attached to each of the anterior surfaces of the outer-walls of the atria. Their purpose is to increase the capacity of the atrium, and so also increase the volume of blood that it is able to contain
what is the phrenic nerve?
The phrenic nerve is a mixed nerve that originates from the the neck (C3, C4, C5) and descends through the thorax to innervate the diaphragm, to allow contraction.
what is the function of the phrenic nerve?
It is important for breathing and is the only source of motor innervation to the diaphragm.
It passes motor information to the diaphragm and receives sensory information from it. There are two phrenic nerves, a left and a right one.
What is a pericardial effusion?
Pericardial effusion (“fluid around the heart”) is an abnormal accumulation of fluid in the pericardial cavity.
what is the effect of pericardial effusion?
Due to the limited amount of space in the pericardial cavity, fluid accumulation leads to an increase in pressure in the pericardial space which can negatively affect heart function.
A pericardial effusion with enough pressure to adversely affect heart function is called cardiac tamponade.
what are the 4 main valves in the heart?
- The mitral/ bicuspid valve (atrioventricular valve)
- The tricuspid valve (atrioventricular valve)
- The aortic valve (semilunar valve)
- The pulmonary valve (semilunar valve)
describe the location and function of the mitral valve?
The mitral valve is found in the left side of the heart, it connects the left atrium to the left ventricle.
It prevents a backflow of blood from the ventricles into the atria.
describe the location and function of the tricuspid valve?
The tricuspid valve is found in the right side of the heart and it connects the right atrium to the right ventricle.
It prevents a backflow of blood from the ventricles into the atria.
describe the location and function of the aortic valve?
The aortic valve is found at the base of the aorta and it’s used to prevent a back flow of blood form the arteries into the ventricles