ANATOMY - Heart Flashcards
What are the four chambers of the mammalian heart?
Right atrium
Right ventricle
Left atrium
Left ventricle
Describe the blood flow through the heart
The right atrium receives deoxygenated blood from the caudal vena cava, cranial vena cava and azygos vein. This blood travels through the right atrioventricular (tricuspid) valve and into the right ventricle towards the pulmonary semilunar valve and into the pulmonary trunk to the lungs where the blood will be oxygenated. Oxygenated blood travels through the pulmonary veins to the left atrium and through the left atrioventricular (mitral) valve and into the left ventricle towards the aortic semilunar valve into the aorta and systemic circulation
What is the cardiac notch?
The region in which the heart is in direct contact with the thoracic wall
What is the name of the serous membrane surrounding the heart?
Pericardium
What are the three layers of the pericardium?
Fibrous pericardium
Parietal pericardium
Visceral pericardium
What is the name of the space between the parietal and visceral pericardium?
Pericardial cavity
What is the name of the fluid within the pericardial cavity?
Pericardial fluid
What are the three layers of the heart wall?
Epicardium
Myocardium
Endocardium
(T/F) The epicardium is the same as the visceral pericardium
TRUE.
What is the main component of the myocardium?
Cardiac muscle
What is the name of the connective tissue between the cardiac muscle fibres of the myocardium?
Endomysium
What kind of epithelium makes up the endocardium?
Simple, squamous epithelium (endothelium)
What is the most prominent feature of the right (atrial) surface of the heart?
Complete coronary groove
What are the two prominent features of the left surface of the heart?
Incomplete coronary groove (interrupted by pulmonary trunk)
Prominent left auricle
Which structure separates the left and right atria?
Interatrial septum
Which structure divides the heart into atria and ventricles?
Coronary groove
What is the significance of the left and right interventricular grooves?
Mark the position of the interventricular septum which separates the left and right ventricles
(T/F) The apex of the heart is formed by the left ventricle
TRUE
What are the six internal features of the right atrium?
Coronary sinus
Intervenous tubercle
Pectinate muscles
Fossa ovalis
Terminal crest
Right atrioventricular valve (tricuspid)
What is the function of the coronary sinus in the right atrium?
The coronary veins drain deoxygenated blood from the cardiac muscle into the coronary sinus which empties the blood into the right atrium
What is the function of the intervenous tubercle in the right atrium?
The intervenous tubercle directs blood from the cranial and caudal vena cavas towards the right atrioventricular valve (tricuspid) to reduce turbulent blood flow
What is the function of the pectinate muscles?
Pectinate muscles are muscular ridges located within the auricles which increase the surface area for more efficient blood flow
What is the fossa ovalis?
Fossa ovalis is a scar left behind by the foramen ovale of the foetal heart
Where is the sinoatrial (SA) node located within the right atrium?
The sinoatrial (SA) node is located at the terminal crest
Where is the atrioventricular (AV) node located within the right atrium?
The atrioventricular (AV) node is located cranial to the coronary sinus
Describe the structure of the right atrioventricular (tricuspid) valve?
The right atrioventricular (tricuspid) valve consists of three cusps attached to the wall of the right atrium by a fibrous annular ring. Each cusp has chordae tendinae which attach the cusps to papillary muscles continuous with the wall of the right ventricle
What is the function of the right atrioventricular (tricuspid) valve?
The right atrioventricular (tricuspid) valve prevents the backflow of blood from the right ventricle back into the the right atrium during ventricular contraction
What are the three main features of the right ventricle?
Trabeculae carnae
Trabeculae septomarginalis
Pulmonary semilunar valve
Right atrioventricular (tricuspid) valve is also within right ventricle
What are the trabeculae carnae of the right ventricle?
Trabeculae carnae are muscular ridges
What is the function of the trabeculae septomarginalis of the right ventricle?
Conduction fibres (bundle of His) run through the interventricular septum and branch into the trabeculae septomarginalis to innervate the papillary muscles
What is the function of the pulmonary semilunar valve?
The pulmonary semilunar valve prevents the backflow of blood from the pulmonary trunk back into the right ventricle when the ventricle relaxes
What are the two main features of the left atrium?
Pectinate muscles
Left atrioventricular (mitral) valve
Describe the structure of the left atrioventricular (mitral) valve?
The left atrioventricular (mitral) valve consists of two cusps attached to the wall of the left atrium by a fibrous annular ring. Each cusp has chordae tendinae which attach the cusps to the papillary muscles continuous with the wall of the left ventricle
What is the two main features of the left ventricle?
Aortic semilunar valve
Aortic sinuses
Left atriventricular (mitral) valve is partially within left ventricle
What is the function of the aortic semilunar valve?
The aortic semilunar valve prevents the backflow of blood from the aorta back into the left ventricle when the ventricle relaxes
What is the function of the coronary arteries?
Coronary arteries transport oxygenated blood to the heart tissue
What is the function of the coronary veins?
Coronary veins drain deoxygenated blood from the heart tissue into the coronary sinus into the right atrium
What are the two main coronary arteries?
Left coronary artery
Right coronary artery
Describe the pattern of the coronary circulation in carnivores and ruminants
The left and right coronary arteries originate at the left and right aortic sinuses located at the aortic semilunar valve. The left coronary artery travels along the left interventricular groove to supply the left ventricle and the circumflex branch of the left coronary artery travels along the coronary groove around the caudal margin of the heart and down the right interventicular groove to supply part of the right ventricle. The right coronary artery travels along the coronary groove around the cranial margin of the heart to supply the cranial portion of the right ventricle. The coronary veins drain deoxygenated blood into the coronary sinus where the blood can empty into right atrium and into the right ventricle followed by the pulmonary circulation to be oxygenated in the lungs
How does the pattern of the coronary circulation differ in horses and pigs?
In horses and pigs, the right coronary artery travels along the coronary groove around the cranial margin of the heart and down the right interventricular groove to supply the right ventricle
What is puncta maxima?
Puncta maxima is the points of the thoracic wall where each heart valve can be heard best
Where can the pulmonary semilunar valve be heard best?
Left ventral region of the third intercostal space
Where can the aortic semilunar valve be heard best?
Left dorsal region of the fourth intercostal space
Where can the left atrioventricular (mitral) valve be heard best?
Left ventral region of the fifth intercostal space
Where can the right atrioventricular (tricuspid) valve be heard best?
Right middle region of the fourth intercostal space
