WEEK 1 LECTURE FINISHED Flashcards
What is the pericardium? What are the 2 types?
A double walled membranous sac that encloses the heart. The outer layer is fibrous and anchors the heart to the diaphragm to assist in maintaining its position in the mediastinum.
The 2 types are fibrous and serous
What is fibrous pericardium?
Surrounds the heart, attaches to the central tendon of the diaphragm. It is lined by a serous membrane called the serous pericardium.
What is serous pericardium?
It is a double layered sac that encloses the heart. It has a layer of serous fluid between its layers.
The outer layer is called the parietal layer, which is continuous with the inner layer and lines the fibrous pericardium; the visceral layer. Between these 2 layers is serous fluid. The visceral layer is also known as the epicardium or the outmost layer of the heart tissues.
What is the purpose of the serous pericardium?
Its double layered walls create a cavity that is filled with serous fluid. This helps to prevent friction rubbing of the heart on the fibrous pericardium.
What is atria latin for?
Hall
What is ventricle latin for?
Little belly
What does the SVC drain blood from?
The head, neck, thorax and arms
What does the IVC drain blood from?
Anything below the diaphragm
What are the 4 sides/ surfaces of the heart?
Diaphragmatic - inferiorly
Sternocostal - anteriorly
Right pulmonary
Left pulmonary
Explain the diaphragmatic surface of the heart.
Mostly inferior
Mainly relates to the central tendon of the diaphragm
Formed by mainly the left ventricle and partially the right ventricle
Explain the sternocostal surface of the heart
Found anteriorly.
Formed mainly by the right ventricle.
Explain the left pulmonary surface of the heart
Formed mainly by the left ventricle.
Forms the cardiac impression on the left lung
Explain the right pulmonary surface of the heart.
Formed mainly by the right atrium
What are the 4 borders of the heart?
Right
Inferior
Left
Superior
Explain the right border of the heart (shape, formed by, extends between which 2 structures?)
Slightly convex.
Formed by the right atrium
Extends between SVC and IVC
Explain the inferior border of the heart (Orientation, formed by)
Nearly horizontal
Formed mainly by the right ventricle and slightly by the left
Explain the left border of the heart (formed by, position)
Formed mainly by the left ventricle
Slightly by the left auricle
Explain the superior border of the heart (formed by, what enters on the right?)
Formed by the right and left atria and auricles in the anterior view
Emerging from the superior border, ascending aorta and pulmonary trunk
The SVC enters on the right
Describe the auricle:
Ear like Muscular pouch Like an 'add on room' Increases the atriums capacity Overlapping the ascending aorta
At what level is the pulmonary semilunar valve?
3rd costal cartilage
How many cusps does the pulmonary semilunar valve have? What are they called?
3
Anterior
Right
Left
What are the names of the pulmonary veins that enter the left atrium?
Superior right and left
Inferior right and left
At what level is the mitral valve?
Posterior to the sternum at the level of 4th costal cartilage
At what level is the aortic valve found?
3rd intercostal space on the left side of the sternum
How many sinus does the aortic semilunar valve have?
3
Right
Left
Posterior
Where does the right coronary artery branch off the aorta?
In the right aortic sinus
Where does the left coronary artery branch off the aorta?
In the left aortic sinus
Describe the chord tendineae
String like processes that attach the margins of the mitral valve and tricuspid valves leaflets to projections on the walls of the ventricles called papillary muscles.
Help to stop the valves from being opened by blood pushing against them
What are papillary muscles?
Conical projections of muscle attached to the ventricle walls. When the ventricles contract the papillary muscles contract and pull on the cusps of the valves, stopping them from forced into the atrium.
How many papillary muscles are in the right ventricle?
3
How many papillary muscles are in the left ventricle?
2
What is endocardium? Where is it found?
A thin internal layer, lining the heart and also its valves. It is lined by endothelium tissue, extremely flattened epithelial cells.
What is myocardium?
A thick middle layer composed of cardiac muscle cells.
What is epicardium?
A thin external layer, formed by the visceral layer of the pericardium.
What nerve supply affects the blood supply to the heart muscle?
Both PNS and ANS
What do the coronary arteries do?
Carry blood to the heart muscle itself/Most of the myocardium
Which coronary artery is usually dominant and in what % of the population? What % have left or equal dominance for blood supply?
The right coronary artery is dominant in 75%.
The left is dominant in 10% of people
They are equally dominant in 15% of people
Where does the right coronary artery arise from? Where does it travel to anteriorly and how does it get to the posterior aspect of the heart?
It arises from the right aortic sinus of the ascending aorta, and runs in the atrioventricular groove/ coronary groove. It gives off the SA nodal branch and the right marginal artery then turns left to continue in the coronary groove to the posterior aspect of the heart.
How many branches does the right coronary artery give off anteriorly and what are they called?
2
Sinoatrial nodal branch
Right marginal branch
What happens to the right coronary artery at the crux of the heart? (what is the crux of the heart?)
The crux of the heart is the junction of the septum and walls of the 4 heart chambers.
At this point the right coronary artery gives off the atrioventricular nodal branch.
What happens to the right coronary artery in the posterior interventricular groove?
It gives off the posterior interventricular artery.
What does the right coronary artery do near the apex of the heart?
Anastomoses with the left coronary artery.
What does the right marginal branch of the heart supply?
Supplies the right border, running towards the apex but not reaching it.
What does the posterior inter ventricular artery supply?
Both ventricles as well as giving off branches to the interventricular septum.
What does the right coronary artery supply?
Right atrium Most of right ventricle Part of the left ventricle Part of the interventricular septum. SA node (60% of people) AV node (80% of people)
Where does the left coronary artery arise from? Where does it pass between to enter the anterior aspect of the heart?
Left aortic sinus of the ascending aorta. It passes between the left auricle and the pulmonary trunk in the coronary groove
What happens to the left coronary artery at the end the coronary groove?
It branches into anterior interventricular branch and the circumflex branch.
What is the pathway and supply of the anterior interventricular branch of the left coronary artery?
It passes along the interventricular groove to the apex of the heart. It turns around the inferior border of the heart and anastomoses with the posterior interventricular branch of the right coronary artery.
It supplies both ventricles and the interventricular septum.
In many people the anterior interventricular branch can give rise to a lateral branch which descends on the anterior surface of the heart.
What is the pathway and supply of the circumflex artery? Where does it terminate?
It follows the coronary groove around the left border of the heart to the posterior surface. It gives off the left marginal artery which follows the left margin of the heart and supplies the left ventricle. It terminates on the posterior surface of the heart and often anastomoses with the posterior interventricular branch of the right coronary artery.
What does the left coronary artery supply?
Left atrium Most of the left ventricle Part of the right ventricle Part of the interventricular septum SA node (40% of people) AV node (20% of people)
Arterial supply to the heart:
RIGHT CORONARY ARTERY: Anteriorly: - SA nodal branch - Right marginal branch Posteriorly: - AV nodal branch - Posterior Interventricular Artery
LEFT CORONARY ARTERY: Anteriorly: - Anterior interventricular branch Laterally and Posteriorly: - Circumflex branch - Left marginal branch
What is the venous drainage of the heart?
Mostly drained by vessels which drain into the coronary sinus, but partly by some vessels which drain directly into the right atrium.
What is the coronary sinus?
It is the main vein of the heart
Runs from left to right along the poster coronary groove
Has a rudimentary, non functional valve.
What is the great cardiac vein also known as. Where does it drain from?
Anterior interventricular vein
Is the tributary of the coronary sinus. It begins near the apex of the heart and ascends with the anterior interventricular branch of the left coronary artery. At the coronary groove it runs around the left side of the heart to reach the coronary sinus.
It drains areas supplied by the left coronary artery.
What is the middle cardiac vein also known as?
The posterior interventricular vein
Drains most of the heart supplied by the right coronary artery.
What lymph nodes drain the heart?
Tracheobronchial lymph nodes
What is the nerve supply to the heart?
Sympathetic - Cardiopulmonary splanchnic nerves. Sympathetic stimulation increases the heart rate and the force of contraction and increases blood flow through the coronary arteries.
Parasympathetic - vagus nerve
Stimulation slows the heart rate, reduces the force of the heart beat and constricts the coronary arteries
Surface anatomy of the heart:
Right side:
3rd costal cartilage - 6th costal cartilage
Left side:
2nd costal cartilage - 5th intercostal space
Apex:
Level of 5th intercostal space in the mid-axillary line.
Surface positions of the major heart valves:
Tricuspid valve: Posterior to the body of the sternum, 4th and 5th intercostal spaces.
Pulmonary valve: 3rd costal cartilage on the left
Bicuspid valve: Posterior to the body of the sternum, 4th costal cartilage
Aortic valve: Posterior to the left side of the sternum, 3td intercostal space
Describe the pulmonary trunk:
5cm long and 3 cm wide.
A continuation of the right ventricle.
Divides into right and left pulmonary arteries.
Describe the pulmonary arteries:
At what level do they arise from the pulmonary trunk?
The right and left pulmonary arteries arise from the pulmonary trunk.
This occurs at the level of the sternal angle.
How many pulmonary veins are there on each side?
2
Where does the arch of the aorta sit in relation to the oesophagus?
Arches in the poster direction on the left hand side of the trachea and oesophagus and superior to the left main bronchus.
What are the branches of the arch of the aorta from right to left?
Brachiocephalic, left common carotid, left subclavian
Where does the brachiocephalic trunk arise on the aorta? Where does it sit when it ascends and what does it split into?
Posterior to the manubrium, anterior to the trachea and posterior to the left brachiocephalic vein.
Ascends superolaterally to reach the right side of the trachea and and right sternoclavicular joint where it divides into the right common carotid and right subclavian arteries.
Where does the left common carotid branch from the aorta?
Arises posterior to the manubrium, posterior and slightly to the left of the brachiocephalic trunk.
