A&P2 Ch.20 mastering part a
The heart beats approximately ________ times each day.
100,000
Which chamber receives oxygenated blood from the pulmonary circuit?
16
The ________ valve prevents backward flow into the left atrium.
Bicuspid
________ is to slow heart rate as ________ is to fast heart rate.
Bradycardia; tachycardia
During the plateau phase of the cardiac action potential which ion is entering the cardiac muscle cell?
Calcium
Pacemaker cells in the SA node
Can spontaneously depolarize
Which of the following will receive electrical impulses next after the structure indicated by the red arrow?
Interventricular septum
When the semilunar valves close the AV valves then
Open
Depolarization of the atria corresponds to the EKG's
P wave
Identify the structure labeled "8."
Papillary muscles
The visceral pericardium is the same as the
Pericardium
Blood leaves the right ventricle by passing through the
Pulmonary valve
The duration of the ventricular action potential is approximately equal to the __________ interval in the electrocardiogram.
Q-T interval
Abnormally slow depolarization of the ventricles would most change the shape of the ________ in an ECG tracing.
QRS complex
Into which chamber of the heart will blood flow next after the vessel indicated by the red arrow?
Right atrium (The small cardiac vein empties into the coronary sinus, which drains into the right atrium)
The arrow indicates the pericardial cavity. What term best describes the membrane on both sides of the cavity?
Serous pericardium (The serous pericardium includes both the visceral and parietal layers and completely lines the pericardial cavity)
Analysis of the electrocardiogram can reveal all of the following except the
Stroke volume
As a result of the long refractory period in the cardiac action potential cardiac muscle cannot exhibit
Tetany
Blood flowing into the heart from the venae cavae flows next through the ________ valve.
Tricuspid
The foramen ovale in the fetal heart is located in the
interatrial septum
Blood returning to the heart from the pulmonary circuit first enters the
left atrium
Blood returning to the heart from the pulmonary circuit first enters the __________.
left atrium
Blood is supplied to the left atrium by the
left coronary artery
The circumflex branch and the anterior interventricular artery are branches of the
left coronary artery
The right pulmonary veins carry ________ blood to the ________ .
oxygenated; left atrium
The following is a list of vessels and structures that are associated with the heart. 1. right atrium 2. left atrium 3. right ventricle 4. left ventricle 5. venae cavae 6. aorta 7. pulmonary trunk 8. pulmonary veins What is the correct order for the flow of blood entering from the systemic circulation?
5, 1, 3, 7, 8, 2, 4, 6
The papillary muscles function to __________.
prevent the AV valves from reversing into the atria
Contractions of the papillary muscles
prevent the atrioventricular valves from reversing into the atria
Which of the following are involved in the pulmonary circuit?
right ventricle, pulmonary trunk, left atrium
The __________ valve prevents backward flow of blood into the left ventricle.
Aortic
The right atrium receives blood from the
systemic circuit
Blood is supplied to the myocardium by
the coronary arteries
In cardiac muscle
the fast depolarization phase of the action potential is the result of, increased membrane permeability to sodium ions.
Intercalated discs serve to transfer ________ from cell to cell.
the force of contraction, action potentials, electrical signals, ionic currents
Compared to the right ventricle
the left ventricle has all the following characteristics, except that it, pumps a greater volume
Tetanic muscle contractions don't occur in a normal cardiac muscle because
the refractory period lasts until the muscle relaxes.
The heart pumps approximately ________ liters of blood each day.
8,000
Pacemaker cells isolated from the SA node generate action potentials at ________ beats per minute.
80-100
Cardiac muscle cells and skeletal muscle cells differ in a few ways. Which of the following is not one of them?
Cardiac muscle cells lack transverse tubules
The P wave of the electrocardiogram is closely followed by __________.
Contraction of both atria
The first blood vessels to branch from the aorta are the ________ arteries.
Coronary
Identify the structure labeled "6."
Cusp of the tricuspid valve
If there is a complete block between the SA node and the AV node how would the ECG be affected?
The rate of P waves will be faster than the rate of QRS complexes
In cardiac muscle
about 20 percent of the calcium ion required for contraction comes from outside the cell.
The long plateau phase of the cardiac muscle action potential is due to
calcium channels remaining open.
The term used to describe fluid collecting in the pericardial cavity that restricts the movement of the heart is known as
cardiac tamponade
The function of an atrium is to
collect blood then pump it to the ventricle
The interventricular sulci and coronary sulcus
contain arteries, contain veins, contain fat, are grooves on the surface of the heart
As blood leaves the right ventricle it passes through the ________ and then into the pulmonary trunk.
conus arteriosus
The ________ deliver(s) blood to the myocardium.
coronary arteries
The great and middle cardiac veins drain blood into the
coronary sinus
Artery is to ________ as vein is to ________.
efferent; afferent
If the pacemaker cells in the SA node become more permeable to potassium ions the
heart rate will decrease and cells will hyperpolarize
