Which of the following statements is true about the SA (sinoatrial) node? a. The action potential created by the pacemaker cells of the SA node directly stimulates the contractile cells of both the atria and ventricles. b. The rate of spontaneous depolarization of nodal cells is the fastest in the SA node. c. Pacemaker cells in the SA node form a pathway between the SA and AV nodes. d. The pacemaker cells, which establish the heart rate, are located only in the SA node.

Q: How is blood prevented from backflowing from the pulmonary trunk into the right ventricle? a.…

A: As the heart pumps blood, a definite series of valves open and close tightly. These valves ensure…

Q: The AV node delay: a. allows the atria and ventricles to depolarize and contract as a unit. b.…

A: The human heart consists of the left and right atria and the left and right ventricles. The heart…

Q: An ECG measures a. changes in electrical potential during the cardiac cycle. b. Ca2+…

A: Introduction: ECG or electrocardiogram is a machine that helps analyse the condition of the heart.…

Q: Within the T-P interval of the EKG... a. The 2nd heart sound is heard b. the semilunar valves are…

A: a. The 2nd heart sound is heard

Q: Compared to the ventricles, the atria ____.   A do not contract as many times per minute   B…

A: It also removes waste products from the body. It has three components: blood, heart and the blood…

Q: Which of the following sequences is truly a systemic circulation pathway? A Right ventricle →…

A: The cardiovascular system is also called a vascular system. The cardiovascular system consists of…

Q: The vessels that carry oxygen to the myocardium are called __________.   A pulmonary arteries   B…

A: Blood is the body fluid that flows in tube-like structures known as vessels and functions in the…

Q: Leaky Na+ channels in the cells of the SA Node do which of the following?   a-allow a slow…

A: d-allow a slow depolarization that eventually reaches the threshold for voltage-gated Ca2+ channels.

Q: The ascending aorta and pulmonary trunk develop from the embryonic:- a. bulbus cordis only. b.…

A: Ascending aorta refers to the part of the aorta that begins at the upper region of the left…

Q: The valves which allow blood to flow from the ventricles into the arteries and not in the opposite…

A: The valves are the muscular flap like structures that are present between the two chambers of the…

Q: The two factors that assist the relatively low venous pressures in propelling blood toward the heart…

A: The circulatory system in humans has the heart, blood vessels- arteries and veins, etc. mainly. The…

Q: All of the following are part of the cardiac conduction system except the: a. chordae tendineae b.…

A: The human heart is situated in the middle of the thoracic cavity in a space called the mediastinum.…

Q: Which of the following statements are true? (a) The left ventricle wall is thicker than the right…

A: It is related to the circulatory system

Q: At the time point indicated on the ECG ____.   A blood would be flowing from the ventricles into…

A: An electrocardiogram can be defined as the type of test in which the heart's electrical activity is…

Q: Which vessel would blood in the right coronary artery pass through next?   A anterior…

A: The circulatory system consists of three systems that work together; the heart (cardiovascular),…

Q: The function of structure X is to Select one: a. act as the pacemaker of the heart. b. initiate the…

A: Heart is located in the chest cavity and derived from mesodermal tissue. Heart is surrounded and…

Q: If the pressure in the ventricles is higher than the pressure in the atria, but lower than the…

A: Heart valves open and close in response to pressure changes inside the heart chambers. the fluid…

Q: Answer question from image

A: Cardiac catheterization is performed to evaluate heart function, the presence of heart disease, and…

Q: The QRS wave of an ECG is produced by. a. depolarization of the atria. b. repolarization of the…

A: ECG or electrocardiogram is a diagram or graph of the electrical activity of heart that is produced…

Q: ne symptom of right ventricular failure would be _____.   A difficulty breathing when lying in the…

A: The right ventricle moves deoxygenated blood from the heart back to the lungs to be resupplied with…

Q: It is generally accepted that a relatively low diastolic vascular pressure is more important than a…

A: Introduction The pressure of circulating blood against the walls of blood arteries is known as blood…

Q: The lining of the heart chambers is called the __________.   A endocardium   B myocardium   C…

A: The heart is the muscular organ that pumps blood throughout the body. It is made of cardiac muscle.…

Q: In a patient with _______ some of the oxygenated blood returning to the left atrium would be pumped…

A: The blood enters the heart's right atrium from the body, where it moves to the right ventricle and…

Q: Which is not true about our heart A. ventricular systole squeezes blood to the lungs and the body B.…

A: Heart is a muscular organ that helps puno blood to different body organs. It has four chambers,…

Q: After passing through the inferior vena cava blood passes through the A coronary sinus B posterior…

A: The cardiovascular system, also known as the circulatory system, is made up of a blood pumping…

Q: Which of the following cardiac tissues has the most rapid conduction velocity? A)The AV node. B)…

A: Purkinje fibre situated in both ventricle myocardium

Q: How would the left ventricle of a patient who had had high blood pressure for many years differ from…

A: Answer: Introduction: Left ventricular hypertrophy is expansion and thickening means hypertrophy of…

Q: It is generally accepted that a relatively low diastolic vascular pressure is more important than a…

A: The term blood pressure is used to describe the pressure exerted by the blood on the blood vessel in…

Q: When the ventricles contract with more force this causes the _____ volume to be larger and the ____…

A: Ventricles   The two large chambers present towards the bottom of the heart. The main function of…

Q: The short horizontal line between the P wave and the QRS complex indicates that   a-depolarization…

A: * The electro cardiogram will shows following waves  P wave  Q wave R wave  S wave  T wave  U wave…

Q: The heart’s internal pacemaker beats by: a. an internal implant that sends an electrical impulse…

A: The heart is a muscular organ in numerous animals, which siphons blood through the veins of the…

Q: Which statement about the normal electrocardiogram (ECG) tracing is false?   A The T wave…

A: The heart is depolarized at every beat to trigger its contraction. This electrical activity is…

Q: a) Referring to the Figure , which part of the heart's electrical conduction is known as the…

A: A pacemaker is a little gadget that is put under the skin in your chest to help control your pulse.…

Q: Which of the following would not increase Cardiac Output? A. increase blood epinephrine…

A: The amount of blood pumped by the ventricles in 1 minute is measured in terms of cardiac output…

Q: After the AV node depolarizes , the next event directly following is A) AV bundle depolarization C)…

A: After passing through the AV node, the electrical current then continues down the conduction…

Q: The left ventricular wall of the heart is thicker than the right wall in order to ________.   A…

A: Heart is muscle which pumps blood to all parts of your body to provide it with the oxygen and…

Q: Which of these events occurs during (ventricular) systole? A)Only the left ventricle contracts.…

A: Diastole and systole are two phases of the cardiac cycle. Systole occurs when the heart contracts to…

Q: What is the consequence of the prolonged plateau of depolarization in ventricular myocytes?   a-it…

A: the consequence of the prolonged plateau of depolarization in ventricular myocytes.

Q: At what point is the pressure in the ventricles increasing most rapidly?   A when both sets of…

A: The measurement of the blood pressure in the ventricles of the heart is known as ventricular…

Q: In which of the heart chambers would deoxygenated blood be found? A)left atrium and left ventricle…

A: Blood Circulation in Circulatory System: Through two large veins (inferior and superior vena cava)…

Q: Which of the events below does not occur when the semilunar valves are open?   A Ventricles are in…

A: The heart valves regulate the blood flow into and out of the heart. The normal human heart contains…

Q: f the sinoatrial node stopped generating action potentials the heart would _____.   A stop beating…

A: The heartbeat starts with an impulse generated by the sinoatrial node (SA node) also known as the…

Muscle Action

A change in the body or a bodily organ as a result of its functioning is referred to as an action. Muscle action can be defined as the specific movement of a bodily part generated by the contraction of a muscle. The muscle proteins actin and myosin are the important contractile proteins involved in muscle action. Muscle contraction, in addition to movement, serves several other important functions in the body, including posture, heat generation, and joint stability. Muscle contraction maintains posture, which includes standing and sitting.