HUBS192 Lecture 5 - Cardiovascular system, Anatomy of the Heart, part 2 Flashcards
what are the 2 heart valves?
1) semilunar valve
2) atrioventricular valve
what is the function of the atrioventricular valve?
to prevent blood returning to the atria during ventricular contraction
what is the right side of the atrioventricular valve called?
tricuspid valve
what is the left of the atrioventricular valve called?
bicuspid/mitral valve
what is diastole and which valves are open and closed during this?
the filling phase of the heart where both atrioventricular valves are open and both the semilunar valves are closed
what is systole and what valves are open and closed during this?
the contraction phase of the heart where both atrioventricular valves are closed and both semilunar valves are open
what is the function of the semilunar valves?
to prevent blood from returning to the ventricles during diastole
what is the right side of the semilunar valves called?
pulmonary valve with 3 cusps
what is the left side of the semilunar valves called?
aortic valve with 3 cusps
when is the semilunar valve pushed open?
pushed open as blood is ejected out of the heart
when is the semilunar valve pushed closed?
closed as blood starts to flow
what is the chordae tendineae?
tiny white collagenic cords that anchor the cusps to the ventricular walls
what is the function of the chordae tendineae?
stopping the leaflets from slamming shut
what are the papillary muscles?
enlarged muscles in ventricles that are attached to chordae tendineae
where does the right coronary artery supply blood to?
supplies blood to the right ventricle and the right atrium (the right side of the heart)
where does the left coronary artery supply blood to?
supplies blood to the left ventricle and the left atrium
where does the circumflex artery supply blood to?
supplies blood to the left atrium and the left ventricle (left side of the heart)
what is the circumflex artery?
a branch off of the left coronary artery
what is the anterior inter-ventricular artery?
a branch off of the left coronary artery
where does the anterior inter-ventricular artery supply blood to?
supplies blood to the left and right ventricle
what is the coronary sinus?
collection of veins joined together to form a large vessel that collects blood from the myocardium
where does the coronary sinus supply blood to?
supplies blood to the right atrium
where does the small cardiac vein drain into?
drains the right ventricle into the coronary sinus
where does the great cardiac vein drain into?
the largest of the veins draining into the coronary sinus from the myocardium
what does LS stand for?
longitudinal section
what are the 6 features of the cardiac muscle cell structure?
- striated
- short, branched cells
- multi nucleated
- central nucleus
- cytoplasmic organelles packed at the poles of the nucleus
- interconnected with neighbouring cells via intercalated disks (ICDs)
what does ICDs stand for?
intercalated disks
what is the percentage of mitochondria in cardiac muscle?
mitochondria is 20% the volume of the cell
what is a feature of the sarcomeres in cardiac muscle?
cardiac muscle has irregular branched sarcomeres
what do mitochondria indicate?
mitochondria indicates oxygen (ATP) dependant metabolism
3 components of ICDs?
1) adhesion belts
2) desmosomes
3) gap junctions
what is the function of adhesion belts?
links actin to actin in a vertical portion
what is the function of desmosomes?
links cytokeratin with cytokeratin
what is the function of gap junctions?
provides electrochemical communication in a horizontal portion
what is the conduction system of the heart responsible for?
this system is responsible for the co-ordination of heart contraction and of the atrioventricular valve action
what is the function of autonomic nerves?
autonomic nerves alter the rate of conduction impulse generation
what is the function of the conduction system of the heart?
its actions greatly increase the efficiency of heart pumping
what is the function of the atrioventricular node?
the part of the electrical conduction system of the heart that coordinates the top of the heart by electrically conducting the atria and ventricles
what is the function of the sinoatrial node?
specialised myocardial structure that initiates the electrical impulses to stimulate contraction
what are inter nodal pathways?
bands of specialised myocytes
what is the atrioventricular bundle?
extension of the atrioventricular node from the atrium across the fibrous skeleton of the heart to the ventricles
what are the R&L bundle branches?
right and left bundle branches from the hearts ventricles
what are the function of R&L bundle branches?
transmit cardiac action potentials to the purkinje fibres
what are purkinje fibres?
network of fibres that receive conductive signals originating at the atrioventricular node and simultaneously activate the left and right ventricles
