Internal appearance of the heart Flashcards
What are the three surfaces of the heart?
Sternocostal surface
Diaphragmatic surface
Posterior surface
What are the three borders of the heart?
Right border
Inferior border
Left border
What are the three sulci of the of the heart?
Coronary sulcus
Ant interventricular sulcus
Post. interventricular sulcus
What is the crista terminalis?
It is a vertical ridge extends on the wall of right atrium from SVC to IVC opening ,at the junction between right atrium & right auricle.
What does the crista terminalis correspond to?
To a groove called sulcus terminalis on the outer sutrface of the right atrium
What does the crista terminalis divide the right atrium into?
Posterior part and anterior part
What is the posterior part of the cavity of the right atrium?
It is smooth embriologically
Derived from sinus venosus
What is the the anterior part of the cavity of the right atrium?
Rough trabeculated by bundles of muscle fibres
Embriologically it is derived from primitive atrium
What are the fetal remnants of the cavity of the right atrium and where do they lie?
Fossa ovalis and anulus ovalis
Lie on the atrial spetum
What does the fossa ovalis represent?
Persistent septum primum of embryo. it is the site of foramen ovale in fetus
What does anulus ovalis respresent?
Septum secondum of the embryo
What are the openings to the right atrium?
SVC- no valve
IVC- guarded by a valve
Coronary sinus: lies between IVC & right antrioventricular orifice, it has a valve
Right atrioventricular orifice lies anterior to IVC opening , it is surrounded by a fibrous ring which gives attachment to the tricuspid valve
Small orificesof small veins
How does the cavity of the right ventricle communicate with the right atrium?
Through the right atrioventricular orifice
How does the cavity of the right ventricle communicate with the pulmonary trunk?
Through the pulmonary orifice
What are the three types of trabeculae carneae of the wall of the right ventricle?
Papillary muscles
Chordae tendineae
Moderator band
What is the infundibulum?
is a funnel-shaped part of the right ventricle which lies below the pulmonary trunk.
What is the valve on the right atrium known as?
Tricuspid valve
Why is it called tricuspid?
Guarded by 3- cusps
What is the tricuspid valve attached to?
The fibrous ring of the skeleton of the heart
What shape are the tricuspid valves?
Triangle
What are the base of the tricuspid valves attached to?
Atrioventriular orifice
What is the chordae tendineae attached to?
one end is attached to free margin of valve,
the other end is attached to the apex of the papillary muscle,
What are the papillary muscle ?
Conical muscular projection
What are the papillary muscle attached to?
Base attached to ventricular wall
What is the role of the valves. Chordae tendineae and papillary muscle?
The three structures form a functional unit, preventing backflow of the blood from the ventricle in to the atrium during systole
What forms the cusp of the semi-lunar valves? and how many cusps
The cusps are formed by folds of endocardium with some CT enclosed
3 cusps
What lies behind the left atrium?
Oblique sinus of serous pericardium lies behind it
What does the oblique sinus separate?
The LA and fibrous pericarium from oesphagus
What is the texture of the interior surface of the left atrium of the heart?
Smooth
What are the openings of the left atrium of the heart
4 pulmonary veins
open into the left atrium and have no valves
What guards the left atrioventricular orifice?
Mitral valve
How does the left ventricle communicate with the left atrium of the heart?
Through the atrioventricular o
How does the left ventricle communicate with the aorta of the heart?
Through the aortic orifice
What guards the atrioventricular orifice on LHS?
Mitral valve and has 2 cusps
How many cusps does the aortic valves have and what does it do?
3 -cusps each one bulges to form aortic sinus
How do the pulmonary and aortic valves work?
Forced apart as blood is ejected from contracting ventricle
As the contracting of the ventricle stop, the elastic recoil of the pulmonary trunk and aorta forces blood back toward the ventricle, and forcing the free margins together, closing the orifice
