A: Heart Flashcards
Right atrium receives blood from:
Superior vena cava (returning blood from upper body)
Inferior vena cava (returning blood from lower body)
Coronary sinus (returning blood from heart wall)
Left atrium receives blood from:
Pulmonary veins
Trabeculae carneae?
Inflow part leads from atrium.
Systemic circulation
Left ventricle pumps oxygenated blood to aorta + tissues of body. Deoxygenated blood returns in veins to right atrium
Pulmonary circulation
Right ventricle pumps deoxygenated blood through pulmonary artery to lungs. Oxygenated blood returns to left atrium via pulmonary veins.
Surface borders of heart
Superior border = 3rd right costal cartilge –> 2nd left intercostal space
Right border = 3rd right costal cortilage –> 6th right costal cartilage
Left border = 2nd left intercostal space –> apex of heart (5th left intercostal space near midclavicular line)
Inferior border = 6th right costal cartilage –> apex of heart
Anterior surface:
Wall of right ventricle with some left ventricle and some right atrium.
Infundibulum of right ventricle is funnel shaped part of chamber which leads to pulmonary artery.
Anterior interventricular sulcus separates both ventricles.
Coronary sulcus separates atria from ventricles.
Inferior surface
Rests of fibrous part of diaphragm
Composed of wall of left ventricle + small part of right ventricle.
Posterior interventricular sulcus separates both ventricles.
Coronary sinus separates inferior + posterior surface.
Right pulmonary surface
Faces right lung + composed of right atrium
Left pulmonary surface
Faces left lung + composed of left ventricle and part of left atrium
Borders of heart
Right = right atrium with superior venae cava + inferior vena cavae
Left = left ventricle with arch of aorta + pulmonary trunk
Inferior = right ventricle with left ventricle at apex
Superior = right + left atria. Aorta + pulmonary trunk exit from this border + vena cava enters.
Obtuse margin
Separates anterior surface + left pulmonary surface. Composed of left ventricle + small part of left auricle.
Fibrous pericardium attachments?
Outer layer composed of connective tissue + forms wall of middle mediastinum. Attached to central tendon of diaphragm + attached to sternum by sternopericardial ligaments.
Serous pericardium
Inner visceral layer: adheres to heart + is continuous
Outer parietal layer: lines fibrous pericardium.
Small space between the two is pericardial cavity contain pericardial fluid.
Oblique pericardial sinus
Reflection of pericardium around large veins on posterior surface
Transverse pericardial sinus
Reflection around arteries + veins. Finger placed in transverse sinus separates arteries from veins + allows for control of blood leaving the heart.
What does phrenic nerve innervate in the heart?
Fibrous pericardium + parietal layer of serous pericardium.
Pericardial effusion?
Accumulation of excess fluid in pericardial activity.
Can occur due to pericarditis.
Can compress heart (cardiac tamponade) - fluid can be removed by inserting a needle into the pericardial sac through an intercostal space.
Coronary sulcus
Separates atria + ventricles
Encircles heart.
Anterior part separates right atrium from right ventricle
Posterior part separates left atrium from left ventricle.
Interventricular sulci
Separate right and left ventricles
Superior vena cava
Returns blood from upper body
Inferior vena cava + how does it enter heart
Returns blood from lower half of body. Passes through an opening in central tendon of diaphragm and opens into inferior part of right atrium
Pulmonary trunk
Leaves superior part of right ventricle. Winds up + backwards on left side of ascending aorta + divides under aortic arch into right + left branches.
Pulmonary veins enter?
Enter left atrium
Ascending aorta
Leaves left ventricle
Ligamentum arteriosum
Remains of embryonic connection between pulmonary trunk + aortic arch.
Branches of right coronary artery
- Artery to SA node
- Right marginal artery
- AV nodal branch
- Posterior interventricular artery/ posterior descending artery: descends in IV groove towards apex and supplies RV, LV, IV septum. Near apex it anastomoses with circumflex + anterior interventricular branches of LCA
RCA supplies:
RA, RV, LV, some of La, interatrial septum, part of IV septum, SA node, AV node
Branches of left coronary artery
- Anterior interventricular/ left anterior descending: runs along anterior interventricular groove to apex. At apex it turns around inferior border + anastomoses with posterior interventricular branch of RCA. Gives rise to the diagonal artery and supplies RV + LV + IV septum.
- Circumflex artery. Runs in coronary ground around left border of heart to posterior surface. Terminates on posterior aspect of heart + anastomoses with posterior interventricular branch of RCA. Gives rise to left marginal artery
LCA supplies
Most of LA, LV, part of RV, most of IV septum, SA node.
Which artery is most commonly affected by ischaemic heart disease
Anterior interventricular/ left anterior descending
Which 4 tributaries does the coronary sinus receive?
- Great cardiac vein
- Middle cardiac vein
- Small cardiac vein
- Posterior cardiac vein
Features of right atrium
Receives superior vena cava, inferior vena cava, coronary sinus
External = sulcus terminalis, internal = crista terminalis
Fossa ovalis
Pectinate muscles in auricle more pronounced in right atrium
Left atrium
Receives pulmonary veins, smaller auricle.
Right venticle
Anterior papillary muscle has attachment to interventricular septum - septomarginal trabecula. Carries part of conduction system to anterior wall of RV.
Pumps blood into pulmonary trunk
Left ventricle
Pumps blood into aorta
Aortic vestibule leads to aorta
Valve incompetence (regurgitation/ insufficiency)
Valve does not close properly, backflow of blood
Valve stenosis
Valve does not open fully –> hypertrophy of heart due to higher pressure needed to eject blood through narrowed valve.
Aortic valve stethoscope placement:
medial end of 2nd RIS
Pulmonary valve stethoscope placement:
Medial end of 2nd LIS
Mitral valve stethoscope placement:
Over apex of heart (5th LIS in midclavicular line)
Tricuspid valve stethoscope placement:
Lateral to sternum, near 5th LIS
Referred cardiac pain
Visceral pain from heart is carried mainly on left side in sympathetic system to spinal cord segments T1-T4.
Cardiac evaluation reveals left coronary dominance. What is meant by this?
The posterior interventricular branch arises from the left coronary artery.
In which groove does the Posterior interventricular branch of right coronary artery descend?
Interventricular groove
Explain the importance of ligamentum arteriosum
During embryology, the lungs are not functional so blood is shunted (through the ductus arteriosus) from pulmonary trunk into aortic arch, thus bypassing the lung
A surgeon opens the pericardium and then passes her fingers into the ‘Oblique pericardial sinus’. Describe where she should insert her fingers. Name the vessels which bound this space.
Pass her fingers under the apex of the heart and move upwards into a recess between the pericardium and the posterior surface (left atrium) of the heart.
Bounded by the pulmonary veins.
A man experiences chest pain during physical exertion. Following
examination, a diagnosis of angina pectoris is made. How do visceral afferent fibers from the heart reach the CNS?
Visceral afferent fibers (carrying pain) are carried with the sympathetic system to spinal cord segments T1-T4.
Name the part of the valve leaflet to which chordae tendinae are
attached.
To the free margin and ventricular surface of each AV valve leaflet.
Function of fossa ovalis
Remnant of foramen ovale
In the embryo, the lungs are not functional so blood is shunted through an opening in septum (foramen ovale) from right atrium into left atrium, thus bypassing the lungs. Oxygen exchange in the embryo occurs at the placenta and not lungs.
Where is the AV node located?
Lower part of interatrial septum
Where is SA node located?
At the junction of the superior vena cava and the right atrium
Identify this layer of the wall of heart and tissue present
Myocardium - cardiac muscle
Explain the anatomy of referred pain from the heart?
Pain from both the dermatomes T1-T4 and visceral afferents from the heart enter the spinal cord at the same level, the brain can interpret the pain impulse as coming from the skin of these dermatomes.
Why is pain from the heart sometimes felt in the left arm?
Because branches of the 2nd and 3rd intercostal (T2, T3) nerves
(intercostobrachial nerves) join with the medial cutaneous nerve of the arm.
What does coronary sinus separate
Inferior + posterior heart
What does posterior interventricular sulcus separate
Both ventricles
Superior vena cava surface markings:
Lateral to sternum, between lower border of 1st RCC and lower border of 3rd RCC
Surface markings of left brachiocephalic vein
Crosses midline, from left to right, posterior to manubrium of sternum.
What is the surface marking of the union of subclavian + internal jugular vein?
Behind medial clavicle
What do each of the recurrent laryngeal nerves loop around?
Right = right subclavian artery
Left = aortic arch
What type of nerve fibres are carried in the thoracic splanchnic nerves
Preganglionic sympathetic fibres
Visceral afferent fibres from abdomen
In the superior mediastinum, describe the position of the left vagus nerve relative to arteries.
Descends between left common carotid and left subclavian arteries.
Crosses left side of aortic arch.
Investigations were performed on a patient complaining of chest pain. They revealed decreased blood supply to the muscle of the diaphragmatic surface of the heart. Which coronary artery is most likely occluded in this patient?
Posterior interventricular branch of right coronary artery.
What tissue is drained by coronary sinus?
Wall of heart
Function of moderator band?
It carries part of the conduction system of the heart to the anterior wall of the RV.
Site of auscultation of four major valves
Aortic = medial 2nd RIS
Pulmonary = Medial 2nd LIS
Mitral = over apex (5th LIS in midclavicular line)
Tricuspid = lateral to sternum, near 5th LIS
