4. Interior of the heart Flashcards
which chamber of the heart makes up the base?
left atrium
Which has a thicker wall; right or left atrium?
left atrium
Through which vessels does the right atrium recieve deoxygenated blood?
superior and inferior vena cavae
What chamber of the heart makes up the right border?
right atrium
Which other vessel, apart from the vena cavae, drain into the right atrium?
coronary sinus
what are the pectinate muscles?
muscles in the wall of the atria
what are the crista terminalis?
vertical ridge of smooth myocardium in the right atrium
Name of foetal defect between right and left atria
foramen ovale
Purpose of foramen ovale in the foetus
allows a shunt of blood from the right to left atrium, bypassing the non-functional lungs
what happens to the foramen ovale after birth and what is the name of the wall it is in?
closes - interatrial septum
what does the interatrial septum separate?
the right and left atria
Name of marking of foramen ovale
fossa ovalis
what can occur if the foramen ovale remains open after birth?
deoxygenated and oxygenated blood can mix
what conditions can occur is the foramen ovale remains open? (3)
- Tricuspid valve stenosis
- Aneurysm
- Patent foramen ovale
Which ventricle wall has a triangular shape; R/L?
R
which ventricle forms the apex of the heart?
Left
which ventricle is thicker; R/L?
Left
What are trabeculuae carneae?
irregular muscular columns
where would you find the trabeculuae carneae?
ventricles
2 issues which are caused by leakage between heart chambers
- mixing of oxygenated and deoxygenated blood
2. change of pressure - damaging to heart and lungs
How many cusps does the tricuspid valve have?
3
How many cusps does the bicuspid/mitral valve have?
2
Another word for heart strings
chordae tendineae
Where are the chordae tendineae?
In the mitral and tricuspid valves
Where are the papillary muscles?
- ventricles
- attached to the chordae tendineae
role of papillary muscles
contract to prevent collapse of valves during ventricular systole
When in the cardiac cycle do the AV valves close?
ventricular contraction
2 categories of dysfunction of the heart valves
- Incompetence/regurgitation
2. Stenosis
What happens to the valves during incompetence dysfunction?
they do not close properly
What happens to the valves during stenosis dysfunction?
the valve is narrowed
which valve dysfunction causes backflow of blood?
incompetence
In stenosis, what must occur for the blood to eject through the heart?
the preceeding chamber must work harder to generate more forceful contractions
Effect of tricuspid regurgitation
Backflow of blood from the right ventricle to the right atrium
effect of mitral stenosis
Left atrium has to work harder to pump blood to the left ventricle
Function of semilunar valves
allow unidirectional blood flow out of heart
Structure of semilunar valves
crescent shaped cusps
where are the aortic sinuses?
from the wall of the aorta to the aortic valves
effect of aortic stenosis
left ventricle has to work harder to pump blood to the aorta
when do congenital malformations arise?
embryological development
how long do people have congenital heart malformations?
since they were born
2 common types of congenital heart malformations
- atrial septal defect (ASD)
2. Ventricular septal defect (VSD)
How does atrial septal defect arise?
incomplete closer of formane in interatrial septum
Blood flow in ASD
from left atrium to right atrium to right ventricle
Problems caused by ASD (2)
- Enlarged R atrium and ventricle
2. Dilated pulmonary trunk
how does ventricular septal defect occur?
incomplete closure of interventricular septum
blood flow in VSD
left to right ventricles
problems caused by VSD (2)
hypertension
cardiac failure
Consequences of patent ductus arteiosus
shortness of breath - congestive heart failure
Name of congenital abornmality where the arch of the aorta/descending aorta is locally contstricted
coarctation of aorta
where does coarctation of the aorta commonly occur?
inferior to the origin of the left subclavian artery
collateral circulation of the coarctation of the aorta
left sub. artery L. internal thoracic artery anterior intercostal artery posterior intercostal artery thoracic aorta
Where is a moderator band usually placed?
R ventricular apex between the papillary muscle and ventricular septum
what is a moderator band?
muscular band of tissue
Function of moderator band
Carries AV bundle to the papillary muscle - allows for faster conduction
Which muscles are on the inside wall of the right atria
pectinate muscles
Describe surface of inside of R Atrium
smooth
name of line of separation between inside and wall of atria
cristae terminalis
name of separation between the atria
interatrial septum
where does the fossa ovalis lie
in the interatrial septum
where is the opening for the coronary sinus, in relation to the fossa ovalis?
inferior
Name of muscle in the ventricular wall
trabeculae carnae
what do the chordae tendinae attach?
cusps and the papillary muscle
when do the chordae tendinae contract?
when the ventricles contract
role of chordae tendinae
prevents backflow of blood to the atria
how many cusps in the pulmonary valve?
3
how many cusps in the aortic valve?
3
Describe the wall and the interior surface of the left atrium
smooth
what separates the superior and inferior mediastinum? (2)
- sternal angle
2. intevertebral disc between 4th and 5th thoracic vertebrae
where does the anterior mediastinum lie between?
heart and sternum
what is contained within the anterior mediastinum
remnants of the thymus gland
what does the middle mediastinum contain?
heart and pericardial sac
what 3 arteries make up the arch of aorta (left to right)
- L. subclavian artery
- L. common carotid artery
- brachiocephalic trunk
where do the subclavian arteries supply?
upper limbs
where do the common carotid arteries supply?
head, neck and brain
what 2 arteries does the brachiocephalic bifurcate into, name the position also.
right subclavian artery - right
right common carotid artery - left
between which arteries does the trachea lie?
left common carotid artery and brachiocephalic trunk
where does the thoracic duct lie?
between the descending aorta and the azygous vein
Name 3 branches of the descending aorta
- bronchial arteries
- oesophageal arteries
- posterior intercostal arteries
role of thoracic duct
carries lymph back to venous system
flow of lymph through the thoracic duct
lower region, abdomen
posterior mediastinum
brachiocephalic vein