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Anatomy & Physiology: Cardiovascular, Blood, and Respiratory Physiology

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Terms in this set (28)

  • What is a pressure gradient and how does it affect blood flow?

    A pressure gradient is the difference in pressure between two points. Blood flows from an area of higher pressure to lower pressure, driving circulation.

  • How does vessel radius affect resistance and blood flow?

    Resistance is inversely proportional to the fourth power of the vessel radius. Small changes in radius greatly affect resistance and flow; vasoconstriction decreases radius and flow, vasodilation increases them.

  • What is the difference between flow rate and velocity in blood vessels?

    Flow rate is the volume of blood passing a point per time, while velocity is the speed of blood flow. Velocity decreases as cross-sectional area increases.

  • What is Poiseuille’s Law in cardiovascular physiology?

    Poiseuille’s Law relates flow to pressure gradient, vessel radius, length, and viscosity. It shows that flow is highly sensitive to changes in vessel radius.

  • What distinguishes autorhythmic cardiac cells from contractile cells?

    Autorhythmic cells generate spontaneous action potentials to set heart rhythm. Contractile cells produce forceful contractions to pump blood.

  • Describe the plateau phase in the cardiac contractile cell action potential.

    The plateau phase is a prolonged depolarization caused by Ca2+ influx balancing K+ efflux, which extends contraction and prevents tetanus.

  • Why is the refractory period longer in cardiac contractile cells than in skeletal muscle?

    A longer refractory period prevents premature contractions and allows the heart to relax and fill properly before the next beat.

  • What is the pacemaker potential in cardiac autorhythmic cells?

    The pacemaker potential is a slow depolarization due to Na+ influx and decreased K+ efflux, leading to threshold and spontaneous action potentials.

  • Name the main components of the cardiac conduction system.

    Includes the SA node, AV node, AV bundle, bundle branches, and Purkinje fibers, coordinating heartbeats.

  • What do the P wave, QRS complex, and T wave represent on an ECG?

    P wave: atrial depolarization; QRS complex: ventricular depolarization; T wave: ventricular repolarization.

  • Define stroke volume and how it is calculated.

    Stroke volume is the volume of blood ejected by a ventricle per beat. Calculated as \(SV=EDV-ESV\).

  • What is cardiac output and its formula?

    Cardiac output is the volume of blood pumped per minute. Calculated as \(CO=HR \times SV\).

  • What is the Frank-Starling Law of the Heart?

    The heart pumps more forcefully when it is stretched more during filling, increasing stroke volume based on venous return.

  • What are inotropic effects on the heart?

    Inotropic effects alter the force of cardiac contraction, influencing stroke volume by changing contractility.

  • What factors affect venous return to the heart?

    Factors include skeletal muscle pump, respiratory pump, venous valves, blood volume, and venous tone.

  • What are the main structural differences among arteries, veins, and capillaries?

    Arteries have thick muscular walls; veins have valves and thinner walls; capillaries have thin walls for exchange.

  • What is mean arterial pressure (MAP) and how is it influenced?

    MAP is average blood pressure in arteries during one cardiac cycle. Influenced by cardiac output and peripheral resistance.

  • What is the baroreceptor reflex?

    A negative feedback mechanism where baroreceptors detect blood pressure changes and adjust heart rate and vessel diameter to maintain MAP.

  • What are the three types of capillaries and their characteristics?

    Continuous (tight junctions), fenestrated (pores), and sinusoidal (large gaps), differing in permeability.

  • What is colloid osmotic pressure and its role in capillary exchange?

    Pressure from plasma proteins that draws water into capillaries, balancing filtration and absorption.

  • What are the main components of blood plasma?

    Water, plasma proteins (albumin, globulins, fibrinogen), nutrients, gases, hormones, and waste products.

  • What are the primary functions of erythrocytes, leukocytes, and thrombocytes?

    Erythrocytes transport oxygen; leukocytes defend against infection; thrombocytes aid in blood clotting.

  • What is hematopoiesis and which cytokines regulate it?

    Hematopoiesis is blood cell formation regulated by cytokines like erythropoietin, thrombopoietin, and colony-stimulating factors.

  • What is the function of surfactant in the lungs?

    Surfactant reduces surface tension in alveoli, preventing collapse and aiding lung expansion.

  • What is Boyle’s Law and its relevance to breathing?

    Boyle’s Law states that pressure and volume are inversely related; lung volume changes cause pressure changes driving air flow.

  • How do the sympathetic and parasympathetic nervous systems affect bronchiole diameter?

    Sympathetic causes bronchodilation (increased airflow); parasympathetic causes bronchoconstriction (reduced airflow).

  • What is Dalton’s Law in respiratory physiology?

    Dalton’s Law states total pressure is the sum of partial pressures of individual gases in a mixture.

  • What factors affect the rate of gas diffusion across the respiratory membrane?

    Surface area, concentration gradient, barrier permeability, and diffusion distance.