During a normal breathing cycle, pressure changes are essential to the exchange of gases with the environment. Describe what type of pressure changes must occur during ventilation
What will be an ideal response?
The lungs and rib cage are designed to move, through the action of muscular contractions so that lung volumes can be changed. Prior to inhalation, the rib cage is moved upward and outward, pulling the lungs with it, to increase the volume of both lungs. The contraction of the diaphragm pulls on the bottom of the lungs, also expanding volume. Since the gases inside the lungs distribute themselves evenly in a closed container, the gas pressure in the lungs decreases below atmospheric pressure, permitting air from outside the body to easily move in. When the muscles relax, the rib cage and lungs return to normal position, the lungs are "squeezed," which raises intrapulmonary pressure above atmospheric pressure, permitting exhalation to occur.
You might also like to view...
Which of the following statements regarding the infection of root hairs by Rhizobium species is incorrect?
A. Nodules begin to form in the roots as both plant and bacterial partners differentiate. B. Attachment of Rhizobium cells to plant root hair cells induce curling of the root hair. C. The presence of Rhizobium triggers the formation of syncytial cells. D. This is a mutualistic relationship between plant and bacteria.
Short hair (L) is dominant to long hair (l). If a shorthaired
animal of unknown origin is crossed with a long-haired animal and they produce one long-haired and one short-haired offspring, this indicates that a. the short-haired animal is pure-breeding. b. the short-haired animal is not pure-breeding. c. the long-haired animal is not pure-breeding. d. the long-haired animal is pure-breeding. e. none of these can be determined with two offspring.
Which individuals have the greatest fitness in an area where malaria is common?
A) individuals of any genotype who become infected with malaria before the age of five B) individuals homozygous for the sickle cell anemia allele C) individuals homozygous for the normal globin allele D) individuals heterozygous for the normal and sickle cell anemia alleles
tissues
What will be an ideal response?