HUBS192 Lecture 5 - Cardiovascular system, Anatomy of the Heart, part 2

Question 1

what are the 2 heart valves?

Answer 1

1) semilunar valve

2) atrioventricular valve

Question 2

what is the function of the atrioventricular valve?

Answer 2

to prevent blood returning to the atria during ventricular contraction

Question 3

what is the right side of the atrioventricular valve called?

Answer 3

tricuspid valve

Question 4

what is the left of the atrioventricular valve called?

Answer 4

bicuspid/mitral valve

Question 5

what is diastole and which valves are open and closed during this?

Answer 5

the filling phase of the heart where both atrioventricular valves are open and both the semilunar valves are closed

Question 6

what is systole and what valves are open and closed during this?

Answer 6

the contraction phase of the heart where both atrioventricular valves are closed and both semilunar valves are open

Question 7

what is the function of the semilunar valves?

Answer 7

to prevent blood from returning to the ventricles during diastole

Question 8

what is the right side of the semilunar valves called?

Answer 8

pulmonary valve with 3 cusps

Question 9

what is the left side of the semilunar valves called?

Answer 9

aortic valve with 3 cusps

Question 10

when is the semilunar valve pushed open?

Answer 10

pushed open as blood is ejected out of the heart

Question 11

when is the semilunar valve pushed closed?

Answer 11

closed as blood starts to flow

Question 12

what is the chordae tendineae?

Answer 12

tiny white collagenic cords that anchor the cusps to the ventricular walls

Question 13

what is the function of the chordae tendineae?

Answer 13

stopping the leaflets from slamming shut

Question 14

what are the papillary muscles?

Answer 14

enlarged muscles in ventricles that are attached to chordae tendineae

Question 15

where does the right coronary artery supply blood to?

Answer 15

supplies blood to the right ventricle and the right atrium (the right side of the heart)

Question 16

where does the left coronary artery supply blood to?

Answer 16

supplies blood to the left ventricle and the left atrium

Question 17

where does the circumflex artery supply blood to?

Answer 17

supplies blood to the left atrium and the left ventricle (left side of the heart)

Question 18

what is the circumflex artery?

Answer 18

a branch off of the left coronary artery

Question 19

what is the anterior inter-ventricular artery?

Answer 19

a branch off of the left coronary artery

Question 20

where does the anterior inter-ventricular artery supply blood to?

Answer 20

supplies blood to the left and right ventricle

Question 21

what is the coronary sinus?

Answer 21

collection of veins joined together to form a large vessel that collects blood from the myocardium

Question 22

where does the coronary sinus supply blood to?

Answer 22

supplies blood to the right atrium

Question 23

where does the small cardiac vein drain into?

Answer 23

drains the right ventricle into the coronary sinus

Question 24

where does the great cardiac vein drain into?

Answer 24

the largest of the veins draining into the coronary sinus from the myocardium

Question 25

what does LS stand for?

Answer 25

longitudinal section

Question 26

what are the 6 features of the cardiac muscle cell structure?

Answer 26

• 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)

Question 27

what does ICDs stand for?

Answer 27

intercalated disks

Question 28

what is the percentage of mitochondria in cardiac muscle?

Answer 28

mitochondria is 20% the volume of the cell

Question 29

what is a feature of the sarcomeres in cardiac muscle?

Answer 29

cardiac muscle has irregular branched sarcomeres

Question 30

what do mitochondria indicate?

Answer 30

mitochondria indicates oxygen (ATP) dependant metabolism

Question 31

3 components of ICDs?

Answer 31

1) adhesion belts
2) desmosomes
3) gap junctions

Question 32

what is the function of adhesion belts?

Answer 32

links actin to actin in a vertical portion

Question 33

what is the function of desmosomes?

Answer 33

links cytokeratin with cytokeratin

Question 34

what is the function of gap junctions?

Answer 34

provides electrochemical communication in a horizontal portion

Question 35

what is the conduction system of the heart responsible for?

Answer 35

this system is responsible for the co-ordination of heart contraction and of the atrioventricular valve action

Question 36

what is the function of autonomic nerves?

Answer 36

autonomic nerves alter the rate of conduction impulse generation

Question 37

what is the function of the conduction system of the heart?

Answer 37

its actions greatly increase the efficiency of heart pumping

Question 38

what is the function of the atrioventricular node?

Answer 38

the part of the electrical conduction system of the heart that coordinates the top of the heart by electrically conducting the atria and ventricles

Question 39

what is the function of the sinoatrial node?

Answer 39

specialised myocardial structure that initiates the electrical impulses to stimulate contraction

Question 40

what are inter nodal pathways?

Answer 40

bands of specialised myocytes

Question 41

what is the atrioventricular bundle?

Answer 41

extension of the atrioventricular node from the atrium across the fibrous skeleton of the heart to the ventricles

Question 42

what are the R&L bundle branches?

Answer 42

right and left bundle branches from the hearts ventricles

Question 43

what are the function of R&L bundle branches?

Answer 43

transmit cardiac action potentials to the purkinje fibres

Question 44

what are purkinje fibres?

Answer 44

network of fibres that receive conductive signals originating at the atrioventricular node and simultaneously activate the left and right ventricles