The Heart Flashcards
Cavities in the chest
2 x pleural cavities
Media steinum
Location of heart
Within media steinum, in pericardial sac
Does the pericardium attach to the diaphragm?
Yes
What limits diaphragmatic descent?
The central tendon of the diaphragm attaches to the pericardium
Structure of pericardium
Outer fibrous sheath
Serous pericardium lies interior to fibrous sheath
Parietal and visceral serous pericardium
Orientation of the heart
Right side lies anterior to left side
Atria lie to the right of ventricles
Location of the anterior atrioventricular sulcus
Between right atrium and right ventricle
Location of anterior interventricular sulcus
Between right centricle and left ventricle
Alternate name for the anterior atrioventricular sulcus
Coronary sulcus
Structure of the heart in utero
Foramen ovali is a hole in the sinus venorum
Allows passage of blood from the right atrium to the left atrium
What does the foramen ovali become after birth?
Fossa ovalis
Why does the foramen ovalii exist in utero?
Baby doesn’t breathe, so no point pumping blood to lungs.
Features of the right ventricle
All interior wall is grooved (trabeculae carnae)
Area below pulmonary trunk is smooth (comus arteriosus or infundibulum)
Part of trabeculae carnae on each wall (3) projects to the middle of ventricle, joins (forms papillary muscle)
Pulmonary trunk with pulmonary valve
Function of papillary muscle
Join with tricuspid valve with tendons called chordae tendinae
Features of right atrium
Exterior wall is grooved (musculi pectinati)
Interior wall is smooth (sinus venarum)
Coronary sinus and fossa ovalis on interior wall
Tricuspid valve
Left atrium
Completely smooth-walled (except for left atrial appendage, which has ridges)
Has fossa ovalis
Receives 4x pulmonary veins from lungs
Left ventricle
Thickest wall
Has trabeculae carnae
BIcuspid/mitral valve
2 papillary muscles connect with mitral valve with chorda tendinae
Fibrous skeleton of the heart
Anchors atrial and ventricular muscle masses
Sits between atria and ventricles
Electrically isolates atria and ventricles
Features of the fibrous skeleton of the heart
2x trigones - Bicuspid, tricuspid valves
2x coronets - PUlmonary valve, aortic valve (semilunar)
How do the atria and ventricles electrically operate?
As a syncitium
What do the atrial surface of the bicuspid and tricuspid valves look like?
Smooth
What do the ventricular surfaces of the bicuspid and tricuspid valves look like?
Rough, because of chordae tendinae attachments
Configuration of aortic and pulmonary valves
Pulmonary valve is closer to edge
Aortic valve closer to centre
Role of chordae tendinae
DO NOT open or close valves
Papillary muscles pull on valve cusps via chordae tendinae, hold cusps closed
Differences between semilunar valves and atrioventricular valves
3 cusps in semilunar valves
Cusps of semilunar valves attach to blood vessel (aorta, pulmonary trunk)
Semilunar valves do not have attached chordae tendinae
Where is the sinoatrial node located?
Right atrium
Top of cristae terminalis
Base of superior vena cava
Nerve supply of the ehart
Sympathetic and parasympathetic supply
Cardiac plexus is at the base of the heart
How does an electrical impulse travel through the heart?
SA node pacemaker cells generate action potential
Action potential stops at cardiac fibrous skeleton (insulated)
AV node transmits impulse to ventricles (slows impulse slightly)
Impulse travels down bundle of His
Purkinje fibers branch through ventricles
Blood vessels of the heart
Coronary arteries and veins
Pulmonary trunk
Aorta
Location of pulmonary trunk
Emerges from right ventricle
Splits into left/right arteries
Structure of aorta
1st part - Ascending aorta
2nd part - Aortic arch
Structure of aortic arch
Arches upwards, posterior, to the left
Ends up on the left-hand side of the vertebral column, becomes the descending thoracic aorta
What does the aorta become when it pierces the diaphragm?
The abdominal aorta (from the thoracic aorta)
Location of the right coronary artery
Anterior surface of the heart
In atrioventricular groove
Area supplied by right coronary artery
Right atrium, right ventricle
Conduction tissue of the AV, SA node
Location of the left coronary artery
Posterior side of the heart
Posterior atrioventricular groove
Interventricular groove
Do the right and left coronary arteries anastomose?
Yes
In two places
Major arteries of the heart
Left/right carotid
Left/right subclavian
Number of branches off aortic arch
Three
First arteries to branch off the aorta
Coronary arteries
Branch from just after the aortic valve
Names of 3 branches form aorta
1 - Brachiocephalic trunk
2 - Left common carotid
3 - Left subclavian
Branches from brachiocephalic trunk
Right common carotid
Right subclavian
Where do the pulmonary trunks travel in relation to the aortic trunk?
Underneath
Area supplied by descending thoracic aorta
Everything above diaphragm
Branches from the descending thoracic aorta
Pericardial
Intercostal
Bronchial
Oesophageal
Number of branches from the descending thoracic aorta
4
Internal jugular veins
Venous equivalent of common carotid arteries
Path of IVC
Pierces central tendon of diaphragm
Path of SVC
From internal jugular veins
Path of veins in relation to arteries
Anteriorally mirror the path of arteries
Vein associated with the common carotid arteries
Internal jugular veins
Vein associated with the subclavian arteries
Subclavian veins
What forms the brachiocephalic veins?
Fusion of internal jugular vein, subclavian vein
What do the left and right brachiocephalic veins form?
Superior vena cava
Role of azygous veins
Drain thorax into SVC
What does the final azagous vein drain into?
Arches into the back of the SVC
