Heart and Fundamentals of Cardiovascular System (Middle Mediastinum) Flashcards
What is anterior border of the middle mediastinum?
- anterior margin of pericardium
What is posterior border of the middle mediastinum?
- posterior border of pericardium
What is lateral border of the middle mediastinum?
- mediastinal pleura of the lungs
What is superior border of the middle mediastinum?
- sternal angle at vertebrae T4
- transverse thoracic plane
What is inferior border of the middle mediastinum?
- superior surface of diaphragm
Where is the base and apex of the heart?
- base = superior surface of heart
- apex = inferior (bottom left) surface of the heart
Where are the auricles of the atrium?
- antero-medial portion of the atrium
- ⬆️ contractile force of the atrium
What does auricle mean in greek?
- ear like flap
What does the inferior pericardium fuse with?
- central tendon of diaphragm
What does adventitia mean in relation to blood vessels?
- tunica adventitia (also known as externia)
- outer layer of blood vessels
What part of the heart is dominant on the right border of the heart?
- right atrium
What part of the heart is dominant on the inferior border of the heart?
- right and left ventricle
What part of the heart is dominant on the superior border of the heart?
- right and left atrium
- great vessels
What are the fossa ovalis in the atrium?
- remnants of foramen ovale (shunt betweem atria)
- on atrial septum, seperating atrium
- do not have function once baby is born
What is the coronary sinus in the heart?
- collection of veins from coronary blood flow
- delivers de-oxygenated blood from heart to right atrium
What are pectinate muscles?
- muscle fibres arranged like a comb
- assists with increasing volume of right atrium
What are pectinate muscles?
- muscle fibres arranged like a comb - assists with increasing volume of right atrium
Where does the inferior vena cava drain blood from?
- abdomen and rest of body
Where do the right and left pulmonary veins, bringing oxygenated blood, attach to the heart?
- left atrium - left and right are both pairs of veins - left and right inferior and superior
Where do the right and left pulmonary veins, bringing oxygenated blood, attach to the heart?
- left atrium - left and right are both pairs of veins (4 in total)
What is the Intratrial septum?
- wall separating atrium
Where are the papillary muscles?
- papillary = finger like
- in left and right ventricles
- base attaches to ventricle wall
- apices attach to chordae tendineae
What is the function of the papillary muscles?
- contract and pull on chordae tendineae - opens and closes valve - ensures valve leaflets do not prolapse
What is the function of the papillary muscles?
- contract and pull on chordae tendineae - opens and closes valve - ensures valve leaflets do not prolapse
What are the trabeculae carnae?
- roughened ridges of muscle
- similar appearance to trabecular bone
What is the moderator band in the ventricles?
- part of the trabeculae carnae - important in facilitating conduction into ventricles
Which ventricle is larger, the right or left?
- left and has thicker wall - left due to increased pressure must work against
Which parts of the aorta lie within the middle, superior and posterior mediastinum?
- superior = arch of aorta - middle = ascending aorta - posterior = thoracic aorta
Where are the semi lunar valves?
- pulmonary artery and the aorta leave the ventricles
Where are the semi lunar valves?
- pulmonary artery and the aorta leave the ventricles
What do the aortic sinuses do?
- receive oxygenated blood from left ventricle
- blood leaves arotic valve (AV)
- AV closes and blood flows back through aortic sinuses
- this blood supplies left and right coronary arteries
What do the aortic sinuses do?
- receive oxygenated blood from left ventricle - supplies left and right coronary arteries which supply heart with blood
What does stenosis mean?
- narrowing of valves
What does regurgitation mean?
- incomplete closing of valves
What runs within the atrioventricular groove?
- left and right coronary arteries
Where do coronary arteries arise from?
- aortic sinuses - above aortic valve
Where is the sinu-atrial nodal branch of the coronary artery?
- bifurcation of the right coronary artery
Where is the sinu-atrial nodal branch of the coronary artery?
- bifurcation of the right coronary artery
What does the left coronary artery branch in to?
- left circumflex artery
- left marginal branch of circumflex artery
- anterior intraventricular branch of left coronary artery
- diagonal branch of anterior intraventricular branch
What does the left coronary artery branch in to?
- left circumflex artery - left marginal branch of circumflex artery - anterior intraventricular branch of left coronary artery - diagonal branch of anterior intraventricular branch
What determines the dominance of the coronary artery?
- coronary artery supplying posterior 3rd of intraventricular septum - artery supplying SA node
What % of the population have their SA node coming from the circumflex artery?
- 40%
What % of the population have their SA node coming from the circumflex artery?
- 40%
What main parts of the heart does the left coronary artery supply with blood?
- left atrium - left ventricle
What are anastomosis?
- communication/connection between coronary arteries - divisions of arteries
What are anastomosis?
- communication between coronary arteries - divisions of arteries
When a coronary artery becomes blocked or damaged what can this cause clinically?
- angina (chest pain) - myocardial infarction
When a coronary artery becomes blocked or damaged what can this cause clinically?
- angina (chest pain) - myocardial infarction
Where does the coronary sinus receive blood from in the heart?
- great vein - middle vein - small vein - posterior vein
Where does the coronary sinus drain the blood into?
- right atrium
What are the 2 parts of the outside of the heart?
1 - pericardium (outer) 2 - serous (inner) - referred to as a fibrous-serous sac
What are the layers of the fibrous-serous sac of the heart?
- visceral pleura = inner most layer around heart - pericardial space = middle layer - parietal pleura = outer layer lining pericardium
What is the outer layer of the pericardium composed of?
- dense irregular connective tissue
What are the 3 main functions of the pericardium?
1 - protection from infections and trauma 2 - anchoring the heart 3 - prevents overfilling of the heart
What is the Sinoatrial node?
- specialised myocardial cells
Where is the Sinoatrial node located?
- junction of superior vena cava and aright atrium
What does Sinoatrial node, also known as the pacemaker do?
- receives stimulation - spreads innervation through atria using gap junctions
What does Sinoatrial node, also known as the pacemaker do?
- receives stimulation - spreads innervation through atria using gap junctions
What is the atrioventricular node?
- specialised myocardial cells
Where is the atrioventricular node located?
- bottom of right atrium
Once AV node is happy ventricles have filled sufficiently, what does it do?
- send signals down bundle of His in interventricular septum - signal then spreads through Purkinje fibres
The heart comes under control of the autonomic system. What controls the para and sympathetic aspects of the heart?
- sympathetic = sympathetic trunk T1-T5 - parasympathetic = vagus nerve to SA node
Where is the superficial and deep cardiac plexus?
- superficial = arch of aorta - deep = bifurcation of trachea
If the foreman ovale does not close at birth, what can happen?
- causes a shunt - mixing of oxygenated and de-oxygenated blood
If the foreman ovale does not close at birth, what can happen?
- causes a shunt - mixing of oxygenated and de-oxygenated blood
If the ductus arteriosus does not close at birth, what can happen?
- called patent ductus arteriosus - causes lung congestion and complications
