Ch.20

What vessels empty into the left atrium?

4 pulmonary veins

What clinical effect would an incompetent pulmonary semilunar valve result in?

An incompetent pulmonary semilunar valve could result in less blood reaching the lungs.

How does someone get angina pectoris?

Angina pectoris is chest pain caused by reduced blood supply to cardiac muscle.

What part of the heart do blood vessels enter and exit the heart?

Blood vessels enter and exit from the base of the heart.

What is myocardiacinfarction?

Coronary artery disease can diminish myocardial blood flow resulting in the death of myocardial cells. This condition is known as a myocardial infarction. Often referred to as a heart attack.

What are the phases of actions potentials in cardiac muscles?

Depolarization phase : - voltage gated Na channels are open - voltage gated K channels close - voltage gated Ca channels begin to open Early repolarization and plateau phases - voltage gated Na channels close - voltage gated K channels open, causing early repolarization - voltage gated Ca channels are open, producing the plateau by slowing further repolarization Final repolarization phase - Voltage gated Ca channels close - Many voltage gated K channels open

If a patient presents with endocarditis, what part of the heart is affected?

Endocardium

What are pectinate mucles?

Muscular ridges on the interior surface of the auricles. (right atrium)

What is the drug you would give someone who presents with chest pains and accompanying symptoms?

Nitroglycerin

What is the biological pacemaker of the heart?

SA node

What is the sequence of electrical charge in the heart?

SA node --> AV node ---> atrioventricular bundle --> bundle of branches ---> Purkinje fibers

What is pulse pressure?

The difference between systolic and diastolic pressures is the pulse pressure felt as a throbbing over arteries.

What is the other name for visceral pericardium?

The epicardium is a thin layer of serous membrane covering the heart surface that is also known as the visceral pericardium.

What is the purpose of refractory period of the cardiac muscles?

The long refractory period ensures that contraction and most of relaxation are complete before another action potential can be initiated. This prevents tetanic contractions in cardiac muscle and is responsible for rhythmic contractions

What is the pericardial sac?

The pericardium is a sac that surrounds the heart and consists of the fibrous pericardium and the serous pericardium.The fibrous pericardium forms the outer layer of the pericardial sac and helps hold the heart in place. The serous forms the inner layer of the sac and reduces the friction as the heart beats and contains the following parts: The parietal pericardium lines the fibrous pericardium. The visceral pericardium lines the exterior surface of the heart. The pericardial cavity lies between the parietal and visceral pericardia and is filled with pericardial fluid, which reduces friction as the heart beats.

What happens when we have spontaneous opening of the sodium fast channels?

The spontaneous opening of sodium fast channels marks the beginning of depolarization of a myocardial cell.

Opening of which channel do we see the plateau phase of the action potential in a cardiac muscle?

Voltage-gated Ca+ channels are open, producing the plateau

What is a heart murmur?

abnormal heart sounds are called heart murmurs, can be caused by valve insufficiency & swirling of blood in the ventricle.

What is the purpose of the skeleton of the heart?

anchor the cardiac muscle fibers.

P Wave results from what?

atrial depolarization

What would be the action of the baroreceptor reflex in terms of blood pressure?

baroreceptors monitor the stretching of major arteries and veins caused by the pressure of the blood flowing through them. barorecepters in the carotid arteries and aorta detect an increase/decrease in blood pressure.

The great cardiac vein and medial cardiac vein empty into which part of the heart?

coronary sinus

What would increase carbon dioxide due to your heart rate?

heart rate and stroke volume increase, increasing blood flow to the lungs.

What is cardiac tamponade?

is a potentially fatal condition in which a large volume of fluid or blood accumulates in the pericardial cavity and compresses the heart from the outside.

What is stroke volume?

is the volume of blood pumped during each heartbeat (cardiac cycle) and it is equal to end diastolic volume minus end-systolic volume. stroke volume= end diastolic - end systolic Stroke volume depends on end diastolic volume, the contractility of the ventricle, the pressure required to pump blood into the aorta, venous return of blood to the heart.

Where is the cardio regulatory center of the brain?

medulla oblongata , where the sensory action potentials are integrated.

What is cardiac output

or minute volume- is the amount of blood pumped by the heart per minute CO=HR X SV

Where do you find the epicardium?

or visceral pericardium, is a thin serous membrane that constitutes the smooth, outer surface of the heart, also provides protection against the friction of rubbing organs

What is the purpose of pericardial fluid?

reduces friction as the heart beats.

Where do the superior and inferior vena cava empty into?

right atrium

What happened when the left atrial pressure exceeds the ventricle pressure?

the bicuspid (mitral) valve opens.

What are trebeculae carneae?

the interior walls of the ventricles contain larger, muscular ridges and columns called trabeculae.

What is the systemic circulation?

the left side of the heart pumps blood through the systemic circulation , which delivers oxygen and nutrients to all the remaining tissues of the body

What is the pulmonary circulation?

the right side of the heart receives blood from the body and pumps blood through pulmonary circulation, which carries blood to the lungs and returns it to the left side of the heart.

What is Tetrology of Fallot

these are found in tetrology of fallor : an interventricular septal defect, an aorta that emerges from both ventricles, a stenosed pulmonary valve, an enlarged right ventricle. Tetralogy of Fallot is a complex congenital cardiac malformation consisting of varying degrees of right ventricular outflow tract obstruction, ventricular septal defect, overriding aorta and rightventricular hypertrophy (although the latter is generally not present in fetal life).

In a normal EKG, what does the QRS complex result from?

ventricles depolarize (closure of AV valves)

What is the purpose of prescribing calcium channel blockers?

voltage gate Ca+ channel-blocking agents prevent the movement of Ca+ through voltage-gated Ca+ channels into the cell; for that reason they are called calcium channel blockers. (Tachycardia, and certain arrhythmia's)