Passage
When present in the bloodstream above a threshold partial pressure, a general anesthetic blocks the sensation of pain, induces a state of unconsciousness, and causes muscle paralysis. Many anesthetic agents are administered in their gaseous phase and are absorbed into the bloodstream through the lungs. The rate of diffusion V_gas of an anesthetic across the alveolar membrane with a surface area A and a thickness T is described by the Fick law of diffusion:
Vgas=DAΔPTEquation 1where D is the diffusion coefficient specific for the gas and ΔP is the partial pressure difference across the membrane.An inhaled anesthetic is described by its blood-gas partition coefficient, the ratio of the anesthetic's concentration in the blood to its concentration in the lungs when the partial pressures are equal. The concentration C of an anesthetic gas dissolved in blood is described by the Henry law of solubility:
C=kHPgasEquation 2where k_H is the solubility constant specific for the gas and P_gas is the partial pressure of the gas.Due to the paralytic effects of general anesthetics, mechanical ventilators are usually necessary to assist a patient's breathing during surgery. Positive-pressure ventilators are noninvasive and use external pumps to induce inspiration by forcing air into the lungs through a ventilation mask. Despite the paralytic effects of general anesthesia, patients are often capable of expiration without the active aid of a mechanical ventilator.
-Many inhalational anesthetics are thought to increase surface tension effects in the alveoli. Water with greater surface tension:

Question

Passage
When present in the bloodstream above a threshold partial pressure, a general anesthetic blocks the sensation of pain, induces a state of unconsciousness, and causes muscle paralysis. Many anesthetic agents are administered in their gaseous phase and are absorbed into the bloodstream through the lungs. The rate of diffusion V_gas of an anesthetic across the alveolar membrane with a surface area A and a thickness T is described by the Fick law of diffusion:

Vgas=DAΔPTEquation 1where D is the diffusion coefficient specific for the gas and ΔP is the partial pressure difference across the membrane.An inhaled anesthetic is described by its blood-gas partition coefficient, the ratio of the anesthetic's concentration in the blood to its concentration in the lungs when the partial pressures are equal. The concentration C of an anesthetic gas dissolved in blood is described by the Henry law of solubility:

C=kHPgasEquation 2where k_H is the solubility constant specific for the gas and P_gas is the partial pressure of the gas.Due to the paralytic effects of general anesthetics, mechanical ventilators are usually necessary to assist a patient's breathing during surgery. Positive-pressure ventilators are noninvasive and use external pumps to induce inspiration by forcing air into the lungs through a ventilation mask. Despite the paralytic effects of general anesthesia, patients are often capable of expiration without the active aid of a mechanical ventilator.
-Many inhalational anesthetics are thought to increase surface tension effects in the alveoli. Water with greater surface tension:

Quizplus · Accepted Answer

11ecba2d_12df_bcdf_a3bf_a91e83a7750f_MD0008_00 The surface tension of a liquid refers to the imbalance of intermolecular forces at its surface that makes its surface act as a thin, elastic film. Surface tension arises from cohesive forces (between like molecules) in a fluid. Water has relatively high surface tension compared to many liquids due its ability to form hydrogen bonds. The formation of water droplets is partly due to surface tension effects. Water molecules away from the liquid-air interface experience attractive intermolecular forces from all directions. Conversely, water molecules at the surface experience a net inward force. This decreases the surface area of the water and pulls it into an approximately spherical shape. Because high surface tension indicates high cohesive forces, water with greater surface tension creates droplets with smaller surface areas. (Choice A) Capillary action refers to the phenomenon of a liquid "climbing up" a thin glass tube due to relatively high adhesive forces (water to glass) compared to cohesive forces (water to water). Water with high surface tension would not travel farther in a thin glass tube because water is more attracted to itself than to the glass surface. (Choice B) Evaporation occurs when the kinetic energy of a molecule can overcome intermolecular forces at the surface of the liquid. Fewer evaporative events would occur because more energy would be required to break the greater cohesive forces of high surface tension water. (Choice C) Van der Waals forces are attractive forces between molecules that do not arise from covalent or ionic bonds. Common examples include dipole-dipole forces and hydrogen bonds. Therefore, water with greater surface tension will have stronger van der Waals forces. Educational objective: The surface tension of a liquid is a result of strong cohesive forces between its molecules. Surface tension creates a tendency to decrease exposed surface area due to a net inward force at the surface molecules.

Passage When Present in the Bloodstream Above a Threshold Partial Pressure