Thorax 08: Heart Innervation and Function

Question 1

Where do cardiac visceral sympathetic efferents go to?

Answer 1

Smooth muscle in coronary arteries, cardiac myocytes, and pacemaker cells

Question 2

Where do cardiac visceral parasympathetic efferents go to?

Answer 2

Cardiac atrial myocytes and pacemaker cells. Does not go to coronary arteries and very sparsely goes to ventricular myocytes

Question 3

What branches of the vagus go to the heart?

Answer 3

Cervical and thoracic parasympathetic cardiac nerves

Question 4

What branches of the sympathetic trunk go to the heart?

Answer 4

Cervical and thoracic sympathetic cardiac nerves

Question 5

Cardiac plexus

Answer 5

A neural plexus located below and deep to the aortic arc, anterior to the bifurcation of the trachea

Question 6

Nerves that stem from the cardiac plexus go where in the heart?

Answer 6

Coronary arteries, myocytes, and pacemakers

Question 7

Sinoatrial node

Answer 7

A node at the junction of the vena cava and right atrium walls that originates all cardiac muscle electric potential

Question 8

Atrioventricular node

Answer 8

A node inside the atrioventricular septum that conducts SA potential into the ventricles

Question 9

How do electric potentials reach the AV node from the SA node?

Answer 9

They travel through the atria walls by conducting through atrial myocytes

Question 10

“lupp” sound

Answer 10

At the beginning of systole; the sound of the closing of the mitral and bicupsid valves

Question 11

“dubb” sound

Answer 11

At the end of systole; the sound of the closing of the two semilunar valves

Question 12

P wave

Answer 12

Atrial depolarization

Question 13

QRS complex

Answer 13

Ventricular depolarization

Question 14

T wave

Answer 14

Ventricular repolatization

Question 15

The ECG waves is the sum of what action potentials?

Answer 15

SA node, AV node, atrial myocytes, Bundle of His, Purkinje fibers, and vnetricular myocytes

Question 16

Preganglionic cardiac sympathetic cell bodies leave the CNS where?

Answer 16

T1-T4

Question 17

Do cardiac sympathetic cell bodies synapse at the cardiac plexus?

Answer 17

No

Question 18

Do cardiac sympathetic cell bodies use the dorsal or ventral ramus? Do they use white or gray ramus communicons?

Answer 18

Ventral ramus; white ramus communicons

Question 19

What are the actions of sympathetics on the heart?

Answer 19

On pacemaker cells: increase calcium conductance and increase heart rate
On cardiac myocytes: increase calcium conductance and increase rate and force of contractions
On coronary arteries: dilate arteries and relax smooth muscles

Question 20

Which nerve do cardiac parasympathetics primarily use?

Answer 20

Cranial nerve 10

Question 21

Do cardiac parasympathetic cell bodies synapse at the cardiac plexus?

Answer 21

No

Question 22

What is the role of the parasympathetics on the SA node?

Answer 22

Control it to prevent it from beating at its intrinsic rhythm of 100-110 bpm (instead 50-80 bpm)

Question 23

What do parasympathetics do to the pacemaker cells?

Answer 23

increase outward flow of K+ to hyperpolarize membrane and decrease rate

Question 24

What do parasympathetics do to cardiac myocytes

Answer 24

Decrease production of cAMP mostly on atrial myocytes

Question 25

Which nerve is used for nonsensory afferents from the heart?

Answer 25

Cranial nerve 10

Question 26

Which nerves are used for sensory afferents from the heart?

Answer 26

T1-T4. They use the same pathway as sympathetic efferents (Except use dorsal roots)

Question 27

Atrial systole

Answer 27

Part of the systole where the atrium contracts; atrial pressure increases slightly

Question 28

Isoventricular contraction

Answer 28

Part of the systole where the ventricle contracts without changing volume; ventricular pressure increases significantly

Question 29

Rapid ejection

Answer 29

Part of the systole where the ventricle squeezes out its blood rapidly; atria begin to fill up again

Question 30

Reduced ejection

Answer 30

Part of the systole where ventricle lets out blood more slowly' semilunar valves start closing; atria volume increases

Question 31

Isovolumetric relaxation

Answer 31

Part of the diastole where the ventricle relaxes without filling up with more blood. Aortic pressure dips up and atria are at max volume

Question 32

Rapid ventricular filling

Answer 32

Part of the diastole where blood flows through the atriaventrical valves and into the ventricles; atrial pressure decreases and ventricular pressure remains low

Question 33

Diastesis

Answer 33

Part of the diastole where blood flows into ventricles more slowly. All pressures stabilize

Question 34

What is the blood supply of cardiac myocytes?

Answer 34

Coronary arteries

Question 35

Coronary arteries

Answer 35

The blood supply of cardiac myocytes; they are epicardial and rise from the aortic arch just distal of the aortic semilunar valve; they fill during diastole

Question 36

Right coronary artery

Answer 36

A branch off of the right aortic sinus containing the atrial branch

Question 37

Left coronary artery

Answer 37

A branch off of the left aortic sinus containing LAD and circumflex

Question 38

Anterior Interventricular artery

Answer 38

LAD; comes off of the left coronary artery; most common and dangerous site of heart attacks

Question 39

Right dominant

Answer 39

If the posterior interventricular artery is a branch of the right coronary artery

Question 40

Left dominant

Answer 40

If the posterior interventricular artery is a branch of the circumflex artery

Question 41

What regions of the heart are supplied by the right coronary artery?

Answer 41

Right atrium, right ventricle free wall, posterobasal wall of left ventricle. If right-dominant, posterior third of intraventricular septum

Question 42

What regions of the heart are supplied by the left coronary artery?

Answer 42

Circumflex artery: left atrium, side and back of left ventricle. If left-dominant, posterion third of intraventricular septum LAD: apex of heart, anterior wall of left ventricle, anterior two-thirds of intraventricular septum, bundle branches of conducting system

Question 43

In order, what are the five common coronary artery occlusion sites?

Answer 43

1) Junction LAD and circumflex 2) LAD 3) Right coronary artery 4) Circumflex branch of left artery 5) Posterior intraventricular artery 1 and 2 are mostly fatal

Question 44

What area of the heart is affected by occlusion of the left anterior descending branch?

Answer 44

Anterior side

Question 45

What area of the heart is affected by occlusion of the left circumflex branch?

Answer 45

Left pulmonary side

Question 46

What area of the heart is affected by occlusion of the right coronary artery?

Answer 46

Posterior side

Question 47

Where does the left coronary artery originate from?

Answer 47

Left aortic valve sinus

Question 48

Where does the right coronary artery originate from?

Answer 48

Right aortic valve sinus

Question 49

Venae cordis minimae

Answer 49

Small veins tha draw blood from cardiac myocytes and dump it directly into the heart chambers

Question 50

What kind of metabolism do cardiac myocytesuse to produce ATP energy?

Answer 50

Oxidative phosphorylation

Question 51

What are the three branches of the right coronary artery?

Answer 51

Atrial branch, right marginal branch, posterior descending artery in right-dominant hearts

Question 52

What are the three branches of the left coronary artery?

Answer 52

Left anterior descending artery, left circumflex branch, left marginal branch. In left dominant hearts, the posterioe descending artery also branches off of the left coronary artery

Question 53

What are the three major cardiac veins?

Answer 53

Great cardiac vein, middle cardiac vein, smaller cardiac vein

Question 54

Great cardiac vein

Answer 54

A vein that drains the area perfused by the LAD

Question 55

Middle cardiac vein

Answer 55

A vein that drains the area perfused by the posterior descending artery

Question 56

Smaller cardiac vein

Answer 56

A vein that drains the area perfused by the marginal branch of the right coronary artery

Question 57

What are the components (in order) of the heart conducting system?

Answer 57

SA node, atrial myocytes, AV node, Bundle of His, bundle branches, Perkinje fibers, ventricular myocytes

Question 58

What is the main nerve responsible for controlling the heart?

Answer 58

Vagus nerve