Anatomy of heart Flashcards
Where does coronary sinus bring blood to right atrium from
From the cardiac muscle itself
What is Crista terminalis
Ridge on inside between atrium and right auricle
From SVC to IVC
Posterior to the wall is smooth
Fossa ovale
Marks location of embryonic foramen ovale, which allowed blood to bypass the lungs in feral circulation
Atrioventricular orifice
Communication with ventricle
Closed by tricuspid valve
Musculi pectinati
Anterior to crista terminalis, the walls are roughened by bundles of muscle fibres
Right auricle
Ear-like, conical, muscular pouch overlapping the aorta
In what direction does blood flow from right atrium to right ventricle
Horizontal and anterior direction
Conus arteriosus
Outflow tract which leads to the pulmonary trunk
How do is tricuspid valve formed
Formed by a fold of endocardium and connective tissue
Trabeculae carnae
Muscular, irregular structures
A few trabeculae carnae are known as papillary muscles
What are the importance of papillary muscles
When ventricle contracts, papillary muscles contract preventing the cusps from turning inside out into the atrium as inta-ventricular pressure rises
3 papillary muscles
Anterior - largest
Posterior - may consist of 1-3 structures
Septal - inconsistent (small or absent)
Septomarginal trabecula
Bridge between lower interventricular septum and base of anterior papillary muscle
Carries a portion f the cardiac conduction system to anterior wall of right ventricle
From how many pulmonary veins does blood enter the left atrium
4
Surfaces of left ventricle
Anterior, diaphragmatic, left pulmonary surfaces and apex
What is the aortic vestibule guarded by
Aortic valve
What is the cardiac skeleton
Collection of dense, fibrous tissue in the form of four rings which interconnect in a plane between the atria and ventricles
What’s does the cardiac skeleton do
Helps maintain integrity of openings and provides attachments for cusps
Separates muscular wall of atria from ventricles p, as well as electrically isolating the ventricles
Locus of superior vena cava
Inferior half within pericardial sac
Passes through fibrous pericardium at CC2 and enters right atrium
Locus of inferior veins cava
Passes through diaphragm at T8 and enter fibrous pericardium
Short portion within the pericardial sac before entering right atrium
What two portions is the chest cavity divided into
Mediastinum
Lateral pleura and lungs
Subdivisions of mediastinum
Superior mediastinum Inferior mediastinum Anterior mediastinum Posterior mediastinum Middle mediastinum
What is pericardium
Fibro-serous sac that encloses the heart and the roots f the great vessels
Functions of pericardium
Restrict excessive movement of the heart as whole
Serve as a lubricant container on which the different parts of the heart can contract
What are the walls of heart composed of
Wall are composed of cardiac muscle
Covered externally with a serous pericardium
Lined internally with layer of endothelium
How are muscle fibres arrsndged
Whorls and spirals
What are cardiocytes connected by
Connected by intercalated discs
Forming a cardiac syncytium to enable transmission of electrical impulses through the network and coordinate contraction of the myocardium
