ECG Anatomy and Function Overview
40 Questions
2 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What does the P-wave in an ECG represent?

  • Atrial contraction
  • Ventricular repolarisation
  • Atrial depolarisation (correct)
  • Ventricular depolarisation

    • The T-wave indicates the depolarisation of the ventricles.

    False

    What does the QRS complex signify in a standard ECG?

    Ventricular depolarisation

    The _____ carries deoxygenated blood from the right ventricle to the lungs.

    <p>pulmonary artery</p> Signup and view all the answers

    Which layer is comparatively thinner in veins compared to arteries?

    <p>Tunica media</p> Signup and view all the answers

    Match the parts of the heart's electrical activity with their corresponding features:

    <p>P-wave = Atrial depolarisation QRS complex = Ventricular depolarisation T-wave = Ventricular repolarisation Systole = Ventricular contraction</p> Signup and view all the answers

    What determines the heart rate of an individual using an ECG?

    <p>Count the number of QRS complexes in a given time period.</p> Signup and view all the answers

    Differences in the shape of ECGs among individuals indicate normal function.

    <p>False</p> Signup and view all the answers

    What is the primary function of the sino-atrial node (SAN)?

    <p>To act as a pacemaker for the heart</p> Signup and view all the answers

    What percentage does the flow of blood into the ventricles increase by?

    <p>30 percent</p> Signup and view all the answers

    The walls of the ventricles are thinner than those of the atria.

    <p>False</p> Signup and view all the answers

    How many beats per minute does a normal human heart beat on average?

    <p>72</p> Signup and view all the answers

    The ventricles contract during diastole.

    <p>False</p> Signup and view all the answers

    The _______ fibres are responsible for conducting the action potential throughout the ventricular musculature.

    <p>Purkinje</p> Signup and view all the answers

    What prevents the backflow of blood into the ventricles during ventricular relaxation?

    <p>Semilunar valves</p> Signup and view all the answers

    The phase when the atria relax and the ventricles contract is called __________.

    <p>ventricular systole</p> Signup and view all the answers

    Which valve prevents the backward flow of blood from the ventricles to the atria?

    <p>Atrioventricular valve</p> Signup and view all the answers

    Match the following heart chambers with their functions:

    <p>Atria = Receive blood from veins Ventricles = Pump blood to arteries Tricuspid valve = Prevent backflow from right ventricle Bicuspid valve = Prevent backflow from left ventricle</p> Signup and view all the answers

    The atrial systole occurs when the SAN generates an action potential.

    <p>True</p> Signup and view all the answers

    What is the role of the atrio-ventricular node (AVN) in the heart?

    <p>It relays the action potential from the atria to the ventricles.</p> Signup and view all the answers

    What initiates the action potential that starts the cardiac cycle?

    <p>Sinoatrial node (SAN)</p> Signup and view all the answers

    Match the following components of the heart with their functions:

    <p>Sino-atrial node (SAN) = Pacemaker of the heart Atrioventricular node (AVN) = Relays electrical signals Purkinje fibres = Conducts signals to ventricles Semilunar valves = Prevents backflow to the heart</p> Signup and view all the answers

    The heart beats approximately 72 times every hour.

    <p>False</p> Signup and view all the answers

    What is the term for the cyclic sequence of events during a heartbeat?

    <p>Cardiac cycle</p> Signup and view all the answers

    What type of blood can be donated to persons with any other blood group?

    <p>O</p> Signup and view all the answers

    Individuals with AB blood group can accept blood only from AB donors.

    <p>False</p> Signup and view all the answers

    What are the two surface antigens that determine the ABO blood group?

    <p>A and B</p> Signup and view all the answers

    Group 'AB' blood contains ___ antibodies in its plasma.

    <p>nil</p> Signup and view all the answers

    Which blood group has anti-A and anti-B antibodies in plasma?

    <p>O</p> Signup and view all the answers

    A person with blood type O can receive blood from group A.

    <p>False</p> Signup and view all the answers

    What is the term for the destruction of RBC caused by incompatible blood transfusion?

    <p>clumping</p> Signup and view all the answers

    Match the blood groups with their corresponding characteristics:

    <p>A = Anti-B antibodies, can donate to A and AB B = Anti-A antibodies, can donate to B and AB AB = No antibodies, universal recipient O = Anti-A and anti-B antibodies, universal donor</p> Signup and view all the answers

    What is the primary role of fibrins in blood coagulation?

    <p>To form a network that traps blood components</p> Signup and view all the answers

    Prothrombin is the active form that converts fibrinogen into fibrins.

    <p>False</p> Signup and view all the answers

    What fluid is collected by the lymphatic system from the spaces between tissue cells?

    <p>lymph</p> Signup and view all the answers

    Calcium ions play a very important role in _____ process.

    <p>clotting</p> Signup and view all the answers

    Which enzyme is essential for the conversion of prothrombin to thrombin?

    <p>Thrombokinase</p> Signup and view all the answers

    The interstitial fluid is composed mainly of large proteins and formed elements of blood.

    <p>False</p> Signup and view all the answers

    What type of mechanism prevents excessive blood loss from the body?

    <p>coagulation</p> Signup and view all the answers

    Match the following components with their roles in the coagulation process:

    <p>Thrombin = Converts fibrinogen to fibrin Fibrin = Forms clots Prothrombin = Inactive precursor of thrombin Thrombokinase = Catalyzes the conversion of prothrombin</p> Signup and view all the answers

    Study Notes

    ECG and Cardiac Function

    • ECG measures the heart's electrical activity through multiple chest leads.
    • P-wave signifies atrial depolarization, leading to atrial contraction.
    • QRS complex indicates ventricular depolarization, initiating ventricular contraction and marked by the start of systole.
    • T-wave reflects ventricular repolarization, concluding systole.
    • Counting QRS complexes aids in determining heart rate.
    • Variations in ECG shape suggest possible heart abnormalities, making ECG clinically significant.

    Double Circulation and Blood Vessels

    • Blood circulates via arteries and veins, each comprising three layers: tunica intima (endothelium), tunica media (smooth muscle and elastic fibers), and tunica externa (fibrous connective tissue).
    • Right ventricle pumps deoxygenated blood into the pulmonary artery; the left ventricle pumps oxygenated blood into the aorta.
    • Blood returns oxygenated from the lungs via pulmonary veins to the left atrium, forming pulmonary circulation.
    • Valves prevent backflow, ensuring unidirectional blood flow.

    Cardiac Muscle Structure

    • The heart is composed entirely of cardiac muscles, with thicker ventricular walls than atrial walls.
    • Nodal tissue regulates heart muscle contractions, including the sino-atrial node (SAN) as the primary pacemaker, generating 70-75 action potentials per minute.
    • The atrio-ventricular node (AVN) and AV bundle distribute action potentials throughout the ventricles via Purkinje fibers.

    Cardiac Cycle

    • The cardiac cycle begins with all chambers relaxed (joint diastole).
    • Blood flows from atria to ventricles as tricuspid and bicuspid valves open.
    • SAN action potential triggers atrial contraction (atrial systole), increasing ventricular blood volume.
    • Action potential travels through the AVN and AV bundle, causing ventricular contraction (ventricular systole) after which both the atria and ventricles relax.
    • Cardiac cycles occur approximately 72 times per minute.

    Blood Groups and Transfusions

    • Blood types are classified primarily into ABO and Rh systems based on surface antigens A and B and corresponding antibodies in plasma.
    • Group A: A antigens, anti-B antibodies; compatible with A and O.
    • Group B: B antigens, anti-A antibodies; compatible with B and O.
    • Group AB: A and B antigens, no antibodies; universal recipient.
    • Group O: No antigens, anti-A and anti-B antibodies; universal donor.

    Blood Clotting Mechanism

    • Blood clotting, or coagulation, forms a scab and involves fibrin threads trapping dead cells.
    • Fibrinogen converts to fibrin through thrombin action, triggered by prothrombin in a cascade involving various plasma factors.
    • Platelet release during injury activates coagulation; tissue factors can also initiate the process.
    • Calcium ions are crucial for the clotting mechanism.

    Lymphatic System

    • Interstitial fluid, a result of blood capillary exchange, contains minerals similar to plasma.
    • The lymphatic system collects interstitial fluid (lymph), returning it to major veins, aiding in nutrient and gas exchange between blood and cells.

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Related Documents

    Body Fluids and Circulation PDF

    Description

    This quiz focuses on the standard ECG and its components, including the significance of the P-wave and QRS complex in heart function. Understanding these aspects is crucial for evaluating cardiac electrical activity. Test your knowledge on the different aspects of ECG readings and their interpretations.

    More Like This

    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser