Thorax 3: The heart, internal structure and surface anatomy Flashcards
Name the layers of the heart and their functions
Myocardium - cardiac muscle
Endocardium - lines the chambers and valves
pericardium - simple squamous epithelium that secretes serous fluid
What secretes serous fluid into the pericardial space
the squamous epithelium of the pericardium
what brings deoxygenated blood into the right atrium?
IVC
SVC
coronary sinus
Describe the direction of the outflow tract of the right atrium
the tricuspid valve faces anterior and medially to the left
What is the purpose of musculi pectinati?
it roughens the wall of the right atrium from the crista terminalis into the auricle
this strengthens the walls of the right atrium without thickening it
What is the crista terminalis?
the boundary between the rough and smooth walls of the right atrium
What forms the posterior wall of the atria
the interatrial septum
Where is the SA node located
close to the opening of the SVC on the superior side of the crista terminalis
Where is the AV node located
on the septum between the opening of the coronary sinus and tricuspid valve
describe the outflow tract of the right ventricle
up and backwards via the infundibulum to the pulmonary trunk
what is the role of the infundibulum
Smooth part of the wall to create laminar flow
What roughens and strengthens the walls of the ventricles
Trabeculae carne
what is the septomarginal trabecula?
part of the trabeculae carne that bridges the anterior papillary muscle with inferior portion of the interventricular septum
describe the shapes of the ventricles
the right is crescent shaped and the left is round due to the bulge in the interventricular septum
how many cusps do each papillary muscle send chordae tendinae to?
2
what links the pulmonary artery and the arch of the aorta
ligamentum arteriosum
what is the relation of the pulmonary trunk to the aorta
posterior to aorta
what are the 3 cusps of the pulmonary valve
anterior right and left
what does competence of the mitral and tricupsid valves rely on
papillary muscles
how many pulmonary veins are there?
4
where are musculi pectinae found in the left atrium
left atrium
what is found posterior to the left atrium?
oesophagus and descending thoracic aorta f
what makes up the intraventricular wall of the left ventricle?
membranous and muscular portions from 4 embryological regions
what is special about the right and left aortic cuspids
they contain sinuses that form the opening of the coranory arteries
what is the cardiac skeleton?
it is a fibrous right that supports the valves and myocardium
what is the purpose of the cardiac skeleton
it separates electrically the myocardium of the atria and the ventricles to prevent the spread of the impulse between them
what is the only point of conduction between the atrium and ventricles?
AV Bundle of His
What happens during systole
the atria relax and fill with blood
ventricles contact and force blood out
mitral and tricuspid valves close
what causes the first heart sound
closure of the mitral and tricuspid valves during systole
what happens during diastole
AV valves open and ventricles relax and fill with blood passively
Atria contact
aortic sinuses fill as blood falls back against the aortic valve
what causes the second heart second
closure of aortic and pulmonary valves during diastole
what causes an extra heart sound
calcification of aortic and pulmonary valves
where would you listen to the aortic valves
2nd right intercostal space
where would listen to pulmonary valves
2nd left intercostal space
where would listen to tricuspid valves
4/5th interspace left
where would listen to mitral flow
5th left interspace mid clavicular line
what are the 4 corners of the heart?
2nd left CC
3rd Right CC
6th Right CC
5th left interspace
