Flashcards in cardio anat Deck (35):
What are the 3 branches of the arch of the aorta?
1. Brachiocephalic trunk.
2. Left common carotid artery.
3. Left subclavian artery.
What are the branches of the brachiocephalic trunk?
Right common carotid (LHS).
Right subclavian (RHS).
What is the ligamentum arteriosum a remnant of and what was its function in the foetus?
Remnant of the ductus arteriosum.
It's function was to shunt blood between the pulmonary trunk and the aorta in order to bypass the non-functioning lungs.
What branch does the left vagus nerve give off as it crosses the arch of the aorta?
The left recurrent laryngeal nerve.
Briefly describe the anatomical course of the right phrenic nerve.
Lies on large veins (brachiocephalic, SVC etc) and along the right side of the heart. Crosses in front of root of the lung.
Briefly describe the anatomical course of the left phrenic nerve.
Crosses the arch of the aorta and descends in front of the root of the lung.
What spinal roots is the phrenic nerve derived?
C3, 4 and 5 (cervical plexus).
What does the phrenic nerve supply?
Motor innervation to the diaphragm.
Sensory innervation to the pleura, peritoneum and pericardium.
Briefly describe the anatomical course of the left vagus nerve.
Crosses the aorta and behind the root of the lung. Breaks up into branches on the oesophagus (oesophageal plexus) and leaves the thorax as the anterior gastric nerve.
Briefly describe the anatomical course of the right vagus nerve.
Lies on the trachea and crosses behind the root of the lung. Breaks up into branches on the oesophagus and leaves the thorax as the posterior gastric nerve.
Does the phrenic nerve enter the diaphragm? If so where?
Yes. It pierces the central tendon of the diaphragm alongside the IVC on the right (T8).
Does the vagus nerve enter the diaphragm? If so where?
Yes. Through the oesophageal hiatus (T10).
What are the layers of the pericardium?
1. Outer fibrous layer.
2. Parietal serous layer.
3. Visceral serous layer.
What structures form the left border of the heart?
1. Left pulmonary artery.
2. Left auricular appendage.
3. Left ventricle.
What is the surface marking for the apex of the heart?
5th intercostal space in the mid-clavicular line.
What forms the right border of the heart?
The right sternal edge.
On what aspect of the heart would you find the left atrium?
The posterior aspect. It is closely related to the oesophagus.
Where is the RCA found?
In the atrio-ventricular sulcus.
Name the 3 main branches of the RCA.
1. Sino-atrial nodal branch.
2. Right marginal branch.
3. Posterior inter-ventricular branch
In 90% of hearts where does the posterior inter-ventricular artery arise from?
In 30% of hearts where does the posterior inter-ventricular artery arise from?
The circumflex artery.
In 20% of hearts where does the posterior inter-ventricular artery arise from?
The RCA and the circumflex artery.
Name the 2 main branches of the LCA.
2. Left anterior descending (LAD).
In what sulcus does the circumflex artery lie? What other large vessel can be found here?
Left atrio-ventricular sulcus.
The coronary sinus can also be found here. IT passes posteriorly and drains into the RA.
Where is the SAN located?
The upper aspect of the crista terminalis in the RA.
Where is the AVN located?
At what phase of the cardiac cycle do the coronary arteries fill?
Diastole; when the ventricles are relaxed.
What 2 spaces does the crista terminalis divide in the RA?
It divides the smooth walled atrium from the trabeculated auricle - ridges = musculi pecanti.
What is the Fossa Ovalis a remnant of?
The Foramen Ovale. In the foetus the foramen ovale shunted blood from the RA to the LA so as to bypass the lungs.
In the ventricles, what are the chordae tendinae attached to?
The valves (mitral or tricuspid) and the papillary muscles.
How do the mitral and tricuspid valves work?
They open passively when the atria contract and then close afterwards to prevent backflow. The papillary muscles and chordae tendinae work to keep the valves closed during ventricular contraction.
How do the atrial and pulmonary valves work?
They open passively when the ventricles contract. Towards the end of systole they close to prevent the back flow of blood. The pressure of blood on the valves keeps them closed.
How would you know if the atrial and pulmonary valves were incompetent?
You would get regurgitation of blood into the ventricles. This could be heard as a diastolic murmur.
Where can you hear the pulmonary valve?
Left of the sternum, 2nd intercostal space.