Heart physiology

Question 0

Define depolarization

Answer 0

Depolarization is the moving of the membrane potential of cells closer to 0mV and making the membrane potential positive causing an action potential

Question 1

What are the two types of Cardiac muscle cells

Answer 1

Contractile and Non contractile = autorythmic

Question 2

Define repolarization

Answer 2

Repolarization is the movement of membrane potential back towards the resting membrane potential, or more negative values

Question 3

What electrical event is associated with cardiac muscle contraction (systole)

Answer 3

Depolarization is during systole

Question 4

What electrical event is associated with cardiac muscle relaxation (Diastole)

Answer 4

Repolarization

Question 5

List the order of electrical impulses through the intrinsic conduction system of the heart

Answer 5

Sinoatrial node > atrioventricular node > atrioventricular bundle (Bundle of His) > bundle branches > purkinje fibers

Question 6

What are the sections called on an ECG

Answer 6

P wave > QRS complex > T wave

Question 7

What is happening during the P wave

Answer 7

Atrial depolarization

Question 8

What electrical event is occuring during the QRS complex

Answer 8

Ventricular depolarization

Question 9

What electrical event is occuring during the T wave

Answer 9

Ventricular repolarization

Question 10

Define the cardiac cycle

Answer 10

The cardiac cycle is the events that occur in the heart during one heart beat

Question 11

Concerning blood movement through the heart, does blood move from high to low pressure or low to high pressure

Answer 11

High pressure to low pressure

Question 12

What prevents blood backflow in the heart

Answer 12

Heart Valves

Question 13

What are the valves of the heart

Answer 13

Atrioventricular valves = Right side is Tricuspid , Left side is Bicuspid

Question 14

After the atria contract during the cardiac cycle, what event causes the atrioventricular valves to close

Answer 14

The ventricles start to contract increasing the pressure in the ventricles causing the valves to close to prevent backflow

Question 15

In what phase during the cardiac cycle are both the AV and Semilunar valves closed, blood volume is constant, and the pressure in the ventricles is increasing rapidly due to ventricular systole

Answer 15

Isovolumetric contraction phase

Question 16

What event occurs that forces the semilunar valves to open during the cardiac cycle

Answer 16

The pressure in the ventricles is equal to or greater than the pressure in the adjoining arteries.

Question 17

During ventricular ejection phase, what valves are open

Answer 17

Semilunar valves are open during the ejection phase. AV valves are closed to prevent backflow during contraction

Question 18

What causes a sharp increase in Aortic pressure after blood has been ejected from the ventricles

Answer 18

The recoiling of the Aortic blood vessel after the closing of the Semilunar valves. Think of a rubber band stretching and then released.

Question 19

What is a heart murmur

Answer 19

The backwards movement of blood within the heart

Question 20

Define auscultation

Answer 20

The listening of organ sounds with the use of a stethoscope

Question 21

Define blood pressure

Answer 21

Blood pressure is the force exerted on the blood vessel wall per unit area by the blood contained in the blood vessel

Question 22

Define Pulse

Answer 22

Pulse is the pulsating surges of blood as it moves through the arterial system when the heart relaxes and contracts. Equivalent to HR

Question 23

Define pulse pressure

Answer 23

Pulse pressure is the difference between the systolic blood pressure and the diastolic blood pressure

Question 24

What blood pressure is named first and is higher

Answer 24

Systolic over diastolic

Question 25

What is the equation for calculating Mean Arterial Pressure

Answer 25

MAP= diastolic + pulse pressure / 3 | What is pulse pressure = the difference between systolic - diastolic

Question 26

What are the units of measurement for MAP

Answer 26

mmHg = millimeters of Mercury

Question 27

What is happening during the Listening of Heart sounds; lub dub sounds

Answer 27

The first sound you hear is the AV valves closing and beginning of systole. The second sound you hear is the Semi Lunar valves close at the beginning of ventricular diastole

Question 28

Where is blood flowing during the isovolumetric contraction phase

Answer 28

Blood is not moving, but is staying in the ventricle waiting for ejection. Once the pressure reaches a high enough level then the ejection phase will occur

Question 29

During the ventricular ejection phase, which set of valves are open

Answer 29

Semilunar valves are open and AV valves are closed during ejection phase

Question 30

During the isovolumetric contraction phase, is the pressure higher or lower in the ventricles

Answer 30

Compare to the atria the pressure is higher in the ventricles, aided by the AV valves closed so blood doesn't backup into the atria Compared to the arteries the ventricles supply, the pressure is lower in the ventricles

Question 31

What is happening Mechanically in a healthy heart during the ST segment of ECG

Answer 31

The myocardium of the ventricles has depolarized leading to contraction of the ventricles, known as the ventricular ejection phase

Question 32

When our blood pressure is at its maximum, what is the condition of the AV valves and Semi lunar valves

Answer 32

Systolic pressure is when the left ventricle is contracting and the aorta is under the highest pressure. During ventricular ejection phase the left AV valve is closed and the Aortic Semilunar valve is open

Question 33

What event happens before blood pressure reaches its maximum

Answer 33

The electrical event that happens is the depolarization of the ventricles

Question 34

How do you compute HR from an ECG

Answer 34

Count the QRS spikes

Question 35

How do you compute the Stroke Volume

Answer 35

EDV - ESV or end diastolic - end systolic

Question 36

How do you compute Cardiac Output

Answer 36

CO = Heart rate x Stroke Volume or Heart rate x (EDV-ESV)

Question 37

What are the layer of the heart

Answer 37

``` Visceral Pericardium Epicardium Parietal pericardium Serous layer Fibrous Pericardium Pericardial sac ```

Question 38

What are the three layers of the heart wall

Answer 38

Outer layer = Epicardium Middle layer = Myocardium Inner layer = Endocardium

Question 39

What is the heart pacemaker node

Answer 39

Sinoatrial node is the hearts pacemaker node

Question 40

What valves of the heart under go the most pressure

Answer 40

The left side of the heart is under more pressure so the Bicuspid valve and the aortic semilunar valve are under the most pressure

Question 41

During what part of the cardiac cycle are both valves closed

Answer 41

during the isovolumetric contraction phase and isovolumetric relaxation phase

Question 42

Why does pressure rise in the atrium during the isovolumetric contraction phase

Answer 42

Atrial pressure rises briefly due to the pressure in the ventricles forcing blood against the AV bulge back into the atria taking up space causing increased pressure

Question 43

What muscles hold the valves in the heart in place

Answer 43

The papillary muscles hold the valves in place

Question 44

What is another name for the Bicuspid valve

Answer 44

Mitral valve or left Atrioventricular valve

Question 45

The blood in the Sup/Inf. vena cava enters into what chamber of the heart

Answer 45

Right Atrium

Question 46

What are the tendons that connect the valves to the papillary muscles

Answer 46

Chordae tendineae

Question 47

What are the only arteries in the body that carry deoxygenated blood

Answer 47

Pulmonary trunk/ arteries

Question 48

Which side of the heart has blood with low oxygen levels

Answer 48

Right side of the heart

Question 49

What side of the heart is the pump to the systemic circuit

Answer 49

Left Ventricle

Question 50

What is the general name given to the part of the heart where the great blood vessels are

Answer 50

The Base

Question 51

What blood vessels take blood away from the heart

Answer 51

Artery

Question 52

What vessels bring blood to the heart

Answer 52

Veins bring blood to the heart

Question 53

what layer of the heart gets its oxygen and nutrients from the blood that is directly flowing through the heart

Answer 53

Endocardium

Question 54

How does a red blood cell travel to and through the heart

Answer 54

Inf/Sup. vena cava > right atrium > tricuspid valve or right AV valve > right ventricle > pulmonary semilunar valve > pulmonary trunk

Question 55

What system of the body is the heart a part of

Answer 55

The cardiovascular system

Question 56

What is the name of the sac surrounding the heart

Answer 56

Pericardial sac

Question 57

What is the space in the thoracic cavity that the heart is located

Answer 57

Mediastinum

Question 58

What chambers of the heart receive blood from veins

Answer 58

Right and left atria

Question 59

What chamber of the heart rests just below the right second rib

Answer 59

Right atrium

Question 60

What are the characteristics of cardiac muscle tissue

Answer 60

Short branching cells, striations, one to two nuclei, intercalated discs that contain gap junctions and desmosomes

Question 61

What structure divides the two ventricles of the heart

Answer 61

Interventricular septum

Question 62

What circuit provides oxygenated blood to cardiac muscle tissue

Answer 62

Cardiac Circuit

Question 63

What circuit delivers oxygen poor blood to lungs

Answer 63

Pulmonary circuit

Question 64

What circuit provides oxygenated blood to the body's tissues

Answer 64

Systemic Circuit

Question 65

What are the names of the blood vessels that bring oxygenated blood to the heart

Answer 65

The four pulmonary veins = 2 left pulmonary veins + 2 R pulmonary veins

Question 66

What chamber of the heart receives oxygenated blood from the four pulmonary veins

Answer 66

The left atrium