Thorax 2(Heart) Flashcards
How many zones is the mediastinum divided into?
Mediastinum is divided into 4 zones
What is the inferior and superior zone of the mediastinum separated by?
Inferior and superior zone separated by transthoracic plane
What proportion does the heart occupy of the inferior mediastinum?
Heart occupies 2/3 of the inferior mediastinum
What does the arch of the aorta rise above in the superior mediastinum?
Arch of the aorta rises above the sternam angle in the superior mediastinum
What does the base of the heart lay on?
Base of heart lays on diaphragm
What is the pericardium?
Thin fibro-serous sac that surrounds the heart and the roots of the great vessels
What are the 2 different components of the pericardium?
- Fibrous pericardium
- Serous pericardium
What is the fibrous pericardium?
Thick connective tissue that surrounds the heart and roots of great vessels
What layers make up the serous pericardium?
- Parietal layer that lines the inner surface of the fibrous pericardium
- Visceral layer that adheres to the heart and constitutes the outer covering
What is present between the fibrous and serous pericardium?
Between these components, there is fluid to allow frictionless beating movement
What is pericarditis?
-Inflammation of the pericardium due to viral/bacterial infection, systemic illness and post myocardial infarction
What is pericardial effusion?
-Accumulation of fluid within the pericardial sac resulting in cardiac tamponade(Compression of the heart)
What is constrictive pericarditis
Thickening of the pericardial sac that implies compression of the heart and subsequent heart failure.
What intercostal space is the apex of the heart present in?
Apex is in the 5th intercostal space
What does auricle mean?
Little ear
What is the coronary sinus?
Coronary sinus is a collection. of veins to allow blood to enter right atrium
What are fossa ovalis?
When do they close?
Remnant of embryo to allow maternal foetal blood passage. Closes as an adult
What are crista terminalis?
Connection between opening orifice of inferior vena cava valve and superior vena cava valve
Where is the opening of the coronary sinus found?
Opening of coronary sinus found on posterior wall of right atrium
What do chordae tendineae attach to and what does this allow the formation of?
Chordae tendineae attach to the cusps of the tricuspid valve and papillary muscle
-This allows the formation of a network of trabeculae carneae
What is the septomarginal area important for?
Septomarginal area important for conduction
What is the ligamentum arteriosum?
Ligamentum arteriosum is an embryological remnant and holds the aorta and pulmonary artery close to each other
What do valves of the heart allow?
Valves of the heart allow blood to run in only one direction
How many valves are there in the heart and what are they?
4 valves in the heart
- 2 atrioventricular(Mitral and bicuspid)
- 2 arterial valves(Pulmonary and aortic
What do the atrioventricular valves gurantee?
2 atrioventricular valves guarantee that the blood do not return from the ventricles to the atria
What do the arterial valves avoid?
2 arterial valves avoid reflux of blood from the two arteries that leave the heart
What are the most common problems associated with valves?
- Insufficiency
2. Stenosis
What is insufficiency in regards to valves?
poor functioning of the valves
What is stenosis in regards to valves?
Narrowing of the orifice due to inability of the valve to fully open
What are murmurs?
Murmurs are unusual sounds heard between heartbeats
What is the main vessel leaving the heart?
Main vessel leaving the heart is ascending aorta; it branches(apart from the coronary arteries) supply the rest of the body
What do the right and left brachiocephalic veins form?
-Right and left brachiocephalic veins form the superior vena cava that flows into the heart from above
Where does the inferior vena cava flow in for the heart from and what is its major tributaries?
The inferior vena cava flows into the heart from below and its major tributaries air from the lower limbs and posterior abdominal structures
What is the sinoatrial node(SAN) an instigator of?
-Sino-atrial node(SAN) is the instigator of contraction of both right and left atrium
What is the atrioventricular node(AVN)?
-Atrio-ventricular node(AVN) is essentially a jump allowing conduction from atria to ventricles
What does electrical conduction pass down in the heart to the apex and what does it allow?
Electrical conduction passes down purkinje fibres allowing ventricles to contract
What does the autonomic nervous system(ANS) control and what is it increased and inhibited by?
The autonomic nervous system controls the rate of contraction and speed of conductivity
- Increases by the sympathetic part of the ANS
- Inhibited by the parasympathetic part of the ANS
What is an example of a parasympathetic nerve?
Vagus nerve
What does the right vagus nerve pass down and how does it supply vocal chords?
Right vagus nerve passes down and when it reaches the right subclavian artery, it branches and loops around posteriorly to help supply vocal chords(Recurrent laryngeal nerve)
Where does the left vagus loop and what does it branch to give?
Left vagus nerve loops underneath the arch of aorta
-Gives branches of to help supply vagal cardiac branch
What does the deep cardiac plexus supply?
Deep cardiac plexus supplies over the carina(Bifurcation of the trachea)
What nerve carries heart pain?
Sympathetic nerves carry pain
-Heart attacks cause crushing chest pain
What zone does the right coronary artery supply?
Right coronary artery supplies posterior zone
What zone does the left coronary artery supply?
Left coronary artery supplies anterior zone
What do coronary sulcus seperate?
Coronary sulcus separates atria from ventricles
What do the anterior and posterior interventricular sulcus separate?
The posterior and anterior interventricular sulcus separates the two ventricles.
What is blood drained by from heart muscle?
Blood is drained from the heart muscle by the great, middle and small cardiac veins
What do the great, middle and small cardiac veins contribute to and what does it do?
These vessels contribute to the coronary sinus, that in turn, empties in to the right atrium
