Cardiovascular system

Which of the following patients will have a lower concentration of ADH in their blood? Select one: a. An injured person who has lost significant amount of blood b. All the patients c. A professional athlete after a short walk d. A person with high blood pressure e. A person with a congenital disease that cause a decrease activity of baroreceptors

The correct answer is: A person with high blood pressure Low blood pressure = release of ADH which stimulates water reabsorption in the kidneys = rise in blood pressure a. would result in low blood pressure, high ADH c. Would have normal blood pressure, regular ADH e. Baroreceptors signal for high blood pressure. No baroreceptors = brain thinks low blood pressure = releases ADH

Which of the following statements relating to the graph is false? a. The activity shown in these curves depends on the opening or closing of voltage-gated channels. b. All the statements are true. c. The dip in the blue curve as it approaches 0.30 seconds is due to the closing of calcium channels. d. The activity shown in these curves reflects the movement of negatively charged ions e. The red curve depicts an action potential for ventricular muscle

False: The activity shown in these curves reflects the movement of negatively charged ions The activity reflects the movement of positively charged ions

Which of the following scenarios is more likely to trigger a response of the parasympathetic system? Select one: a. Watching a scary movie b. A significant loss of blood c. All of the choices will trigger the parasympathetic system d. A relaxing massage e. An aerobic, energetic workout

The correct answer is: A relaxing massage Sympathetic NS = fight or flight Parasympathetic NS = rest and digest

Which of the following represents the correct order in which action potentials spread from the atria to the ventricles during a normal heartbeat in the mammalian heart? Select one: a. Atrioventricular node --> Purkinje fibers --> bundle of His b. Purkinje fibers --> bundle of His --> atrioventricular node c. Sinoatrial node --> Purkinje fibers --> bundle of His d. Atrioventricular node --> bundle of His --> Purkinje fibers e. Sinoatrial node --> ventricular muscle cells --> Purkinje fibers

The correct answer is: Atrioventricular node --> bundle of His --> Purkinje fibers

Which of the following statements is true about the SA node? Select one: a. Ca+2 voltage-gated channels are responsible for its depolarization b. Transmits action potentials to the ventricles via the bundle of His and Purkinje fibers c. Requires stimulation by neurotransmitters to initiate action potentials d. Controls the rate at which the atria fill with blood e. The SA node is directly responsible for depolarization of the ventricles as gap junctions link the atria to the ventricles

The correct answer is: Ca+2 voltage-gated channels are responsible for its depolarization Signal transmissions initiate at SA node, spread through atria's, and then are delayed at AV node. Bundle branches (first His then Purkinje) pass signal to heart apex then spread throughout ventricles b. SA-> atria, AV->Ventricles c. SA node does not require stimulation d. The Atria fills with blood passively. It is dependent on the pressure in the veins e. Not directly responsible. SA->atria->AV->ventricles. Also no gap junctions between atria and ventricles.

Which of the following mechanisms is responsible for returning blood from the feet to the heart? Select one: a. Rhythmic contraction of the smooth muscle in veins b. Contraction of skeletal muscles surrounding veins c. One way valves in the arteries d. Elastin and collagen absorbing and releasing cardiac output force. e. Gravity

The correct answer is: Contraction of skeletal muscles surrounding veins Skeletal muscle contractions (and gravity) help veins and lymphatic vessels carry blood and fluid back to the heart Gravity help veins carry blood from above the heart, skeletal muscles help veins carry muscle from below the heart

Which of the following factors generated by an overworked muscle tissue will increase blood circulation? Select one: a. High rate of ADP hydrolysis b. High oxygen levels c. High conversion of lactic acid to pyruvate d. All the factors e. High CO2 concentration

The correct answer is: High CO2 concentration

What advantages does a mammal's circulatory system have over an arthropod circulatory system? Select one: a. In a mammal's circulatory system, blood vessels can control the delivery of O2 to specific tissues based on need. b. An arthropod circulatory system relies on hemoglobin rather than on myoglobin. c. An arthropod circulatory system is a closed loop and therefore does not require a heart for pumping blood. d. None of the choices are true. e. Since the arthropod circulatory system is a closed loop, the blood pressure is maintained at a high level throughout the body.

The correct answer is: In a mammal's circulatory system, blood vessels can control the delivery of O2 to specific tissues based on need. b. Hemoglobin is an oxygen transport protein found in red blood cells. Myoglobin is a protein that also binds oxygen, but it binds more tightly and is found specifically in muscle cells for storing oxygen. Mammalian circulatory systems uses hemoglobin c. An arthropod circulatory system is an open system and therefore does not require a heart for pumping blood. e. Arthropods have a closed circulatory system, which allows for lower hydrostatic pressure Mammalian circulatory systems are close loop, which allows for blood pressure to be high enough to effectively deliver O2 and nutrients in large and more active animals.

Moving from the arteriole toward the venule end of the capillary beds: A. The osmotic pressure of the blood decreases B. The blood hydrostatic pressure increases, resulting in net water loss to the surrounding tissues C. The blood hydrostatic pressure decreases, resulting in fluid loss towards the venous side D. Net fluid loss at the arterial side exceeds fluid uptake at the venous side

The correct answer is: Net fluid loss at the arterial side exceeds fluid uptake at the venous side Arterial end = net outward force Venule end = net inward force A. Osmotic (inward) pressure remains the same; Blood (outward) pressure decreases B. The blood hydrostatic pressure decreases, resulting in net water gain from the surrounding tissues C. The blood hydrostatic pressure decreases, resulting in net inward force (fluid gain) towards the venous side

Select the correct order of the blood flow through the human circulatory system Select one: a. Aorta, right atrium, AV valve, right ventricle, SL valve, pulmonary artery. b. Vena cava, AV valve, right atrium, SL valve, right ventricle, pulmonary artery. c. Vena cava, left atrium, AV valve, left ventricle, SL valve, pulmonary artery. d. Vena cava, right atrium, AV valve, right ventricle, aortic valve, pulmonary artery. e. Pulmonary vein, left atrium, AV valve, left ventricle, semilunar valve, aorta.

The correct answer is: Pulmonary vein, left atrium, AV valve, left ventricle, semilunar valve, aorta. Oxygenated blood a. Oxygenated blood exits through the aorta to the rest of the body, flow would not start there. b-d Vena cava, right atrium, AV valve, right ventricle, semilunar valve, pulmonary artery. Deoxygenated blood

The cardiac muscles of the atria and ventricles that contract synchronously are able to do so because of the cardiac muscles unique properties, such as A. Intrinsic pacemaker activity throughout each chamber B. cell communication via gap junctions C. the autorythmicity of the SA node and the AV node D. the AV node imposes a 0.1 second delay before firing an AP E. More than 1 of the above

The correct answer is: cell communication via gap junctions Cardiac muscle cells are connected by gap junctions, which allows rapid spread of action potentials. All other statements are true, but do not contribute to the synchronous contraction of atria and ventricles.

In the cardiac cycle of humans, blood pressure in the arteries is at its maximum when the _______ are _______ during _______. Select one: a. ventricles; contracting; systole b. atria; contracting; diastole c. atria; contracting; systole d. ventricles; relaxing; systole e. ventricles; relaxing; diastole

The correct answer is: ventricles; contracting; systole Contracting (systole) raises blood pressure, Relaxing (diastole) lowers blood pressure Direction of blood flow: Veins to atria, ventricles to arteries. Ventricles contracting increases blood pressure in the arteries, while the atria fills passively