Human Phys unit 3

During a physical examination, Joe learns that his resting tidal volume is 550 mL; his average resting respiratory rate is 15 breaths per minute; his total lung capacity is 6,000 mL; and his anatomic dead space is 150 mL. Joe's resting alveolar ventilation is 72.0 L/min. 6.0 L/min. 4.2 L/min. 1.8 L/min. 0.5 L/min.

6.0 L/min.

Which of the following is true concerning the heart conduction system? Action potentials pass slowly through the Purkinje fibers. Action potentials pass slowly through the atrioventricular node. Action potentials pass slowly through the bundle branches. Action potentials pass slowly through the ventricle wall. Action potentials pass slowly through the atrioventricular bundle.

Action potentials pass slowly through the atrioventricular node

You embark on a hiking trip on Mt. Kilimanjaro (altitude = 19,000 ft; Atmospheric air pressure = 379 mmHg). As you ascend, what happens to the PO2 in the alveoli? No change from sea level, as long as we breathe in the same volume of air. Alveolar PO2 decreases. Alveolar PO2 increases.

Alveolar PO2 decreases.

Which of these is demonstrated by the oxygen-hemoglobin dissociation curve? The greater the PO2 of the blood, the greater the dissociation of O2 from hemoglobin. At normal resting systemic arterial PO2, hemoglobin is almost 100% saturated with oxygen. At normal resting systemic venous PO2, only about 75% of the hemoglobin is in the form of deoxyhemoglobin. More additional oxygen binds to hemoglobin when going from a PO2 of 60 to 100 mmHg, than is added when going from a PO2 of 40 to 60 mmHg. As PO2 increases, the saturation of hemoglobin with oxygen increases linearly.

At normal resting systemic arterial PO2, hemoglobin is almost 100% saturated with oxygen.

If the arterial blood pressure in the brain is suddenly decreased, the flow through arterioles in the brain will immediately fall and then which of these will occur next? Brain arterioles will constrict to accelerate blood flow through the brain capillaries. Brain arterioles will dilate due to a decrease in levels of CO2. Blood flow will remain at the new, lower level due to reactive hyperemia. Blood flow will rise to levels above normal due to excess O2 levels. Blood flow will return toward its original level due to flow autoregulation.

Blood flow will return toward its original level due to flow autoregulation.

Increased sympathetic stimulation causes vasodilation, bringing elevated blood pressure back to normal. True or False

False

Most of the blood entering the ventricle during diastole occurs while the atria are contracting. True or False

False

Jane donates a pint of blood to a blood bank. A few minutes later, which of the following would be increased compared to pre-donation values? Her stroke volume and total peripheral resistance Her heart rate and total peripheral resistance Her heart rate and mean arterial pressure The percentage of her cardiac output flowing to her kidneys The blood flow to her brain

Her heart rate and total peripheral resistance

Which of the following statements regarding the dissolving of blood clots is FALSE? Activation of the reactions that lead to blood clotting ultimately lead to blood clot dissolution. Tissue plasminogen activator (t-PA) is secreted by endothelial cells. Blood clots are digested by plasmin. Plasminogen is an inactive precursor of the enzyme plasmin. It involves aggregation of soluble fibrin fragments into fibrin.

It involves aggregation of soluble fibrin fragments into fibrin

Which of the following statements about blood clotting is FALSE? It is the formation of a thrombus. It occurs after formation of a platelet plug in a damaged vessel. It requires the presence of erythrocytes. It is a result of a cascade of enzyme activation. It involves positive feedback by thrombin.

It requires the presence of erythrocytes.

Type II alveolar cells are among the last cells to mature during fetal development. In babies born prematurely, type II alveolar cells are often not ready to perform their functions. Which of the following drugs would be most likely to help an infant with immature type II alveolar cells? Pulmonary surfactant A beta-adrenergic agonist A muscarinic agonist Histamine A beta-adrenergic antagonist

Pulmonary surfactant

Of the following pairs of locations, which two have most nearly the same Pco2? Pulmonary arterial blood: Pulmonary venous blood Alveolar air : Pulmonary arterial blood Alveolar air : Inside tissue cells Inside tissue cells : Alveolar air Pulmonary venous blood : Systemic arterial blood

Pulmonary venous blood : Systemic arterial blood

Which of the following statements about partial pressures of gases is TRUE? The Po2 in pulmonary arterial blood is greater than the Po2 in pulmonary venous blood. The Po2 in pulmonary venous blood is greater than the Po2 in tissue cells. The Po2 in pulmonary venous blood is greater than the Po2 in the alveoli. The Po2 in systemic venous blood is greater than the Po2 in systemic arterial blood. The Po2 in systemic arterial blood is less than the Po2 in tissue cells.

The Po2 in pulmonary venous blood is greater than the Po2 in tissue cells

Which of the following is NOT true for ventricular systole? The ventricles contract during ventricular systole. Blood flows through the aortic and pulmonary semilunar valves during ventricular systole. The atria contract during ventricular systole. The semilunar valves open during ventricular systole. The atrioventricular valves close at the beginning of ventricular systole.

The atria contract during ventricular systole.

The ventricles begin to fill during ventricular diastole. True or False

True

Which of the following is NOT an anticoagulant or stimulator of blood clot dissolution? Vitamin K Aspirin Thrombin Heparin Tissue plasminogen activator (t-PA)

Vitamin K

Baroreceptors are located in the... aorta and carotid arteries. aorta and carotid veins. aorta and subclavian arteries. aorta and common iliac arteries. aorta and subclavian veins.

aorta and carotid arteries

At what point of the cardiac cycle do the semilunar valves close? between the ventricular filling phase and the isovolumetric contraction phase between the ventricular filling phase and the isovolumetric relaxation phase between the isovolumetric contraction phase and the ventricular ejection phase between the ventricular ejection phase and the isovolumetric relaxation phase between the isovolumetric relaxation phase and the ventricular filling phase

between the ventricular ejection phase and the isovolumetric relaxation phase

Which of the following factors would NOT tend to increase systemic arterial blood pressure? increased sympathetic stimulation of the blood vessels increased blood volume increased venous return increased parasympathetic stimulation of the heart increased activity of the skeletal muscle pump

increased parasympathetic stimulation of the heart

The semilunar valves remain open throughout the __________ phase of the cardiac cycle. late ventricular systole atrial systole ventricular diastole early ventricular systole

late ventricular systole

Normally, the hydrostatic pressure difference between capillary fluid and interstitial fluid favors movement of fluid ________ a tissue capillary. The protein osmotic pressure difference between capillary fluid and interstitial fluid normally favors movement of fluid __________ a tissue capillary. into; into into; out of out of; out of out of; into

out of; into

What determines the net direction of net gas diffusion in the body? temperature the size of the gas molecule partial pressure differences the solubility of the gas in blood pH

partial pressure differences

During exercise, there is a decreased flow of blood to: the brain. the skin. the abdominal organs. the skeletal muscles the heart.

the abdominal organs.

What nerves conduct action potentials into the central nervous system? the vagus and glossopharyngeal nerves the phrenic nerve the thoracic spinal nerves cervical spinal nerves the phrenic and glossopharyngeal nerves

the vagus and glossopharyngeal nerves

Which of the following pathways carries inputs from the parasympathetic nervous system to the heart? the glossopharyngeal nerves the phrenic nerves cervical spinal nerves the vagus nerves thoracic spinal nerves

the vagus nerves

During which phase of the cardiac cycle do the atrioventricular valves open? ventricular systole ventricular diastole atrial diastole atrial systole

ventricular diastole

The atria remain in diastole throughout both the __________ phases of the cardiac cycle. early and late ventricular systole early and late ventricular diastole ventricular systole and ventricular diastole

ventricular systole and ventricular diastole

Which is an intermediary protein that enables platelets to adhere to collagen? Tissue plasminogen activator (t-PA) ATP von Willebrand factor (vWF) Arachidonic acid Activated protein C

von Willebrand factor (vWF)