The size of the thoracic cavity is increased by contractions of all of the following muscles except the
a. diaphragm.
b. external intercostals.
c. pectoralis minor.
d. external oblique.
Introduction:
Breathing is the movement of air from outside the body through the bronchial tree and into the alveoli and the reversal of this air movement allow gas exchange between air and blood. The cause for these movements is the change in the size of the thoracic cavity that result from skeletal muscle contractions.
Answer to Problem 1PL
Correct answer:
The correct answer is option (d) external oblique.
Explanation of Solution
Explanation for the correct answer:
Option (d)external oblique. The external oblique aids expiration by compressing abdominal contents which helps to raise the diaphragm. The external oblique originates at the anterior surface of ribs five to twelve. So, the correct answer is option (d).
Explanation for the incorrect answers:
Option (a) diaphragm. The diaphragm originates at the costal cartilages and ribs seven to twelve. Its insertion occurs at the central tendon of diaphragm.The diaphragm contraction flattens itself and thus, it expands the size of thoracic cavity. Therefore, option (a) in incorrect.
Option (b) external intercostals. External intercostal muscles originate at the inferior border of superior rib. These muscles tend to elevate ribs which expands the thoracic cavity during inspiration. Therefore, this option is incorrect.
Option (c) pectoralis minor. The pectoralis minor originates at the sternal ends of ribs three to five. This muscle elevates the 3rd and 5th ribs which aids in increasing the size of thoracic cavity. Therefore, this option is incorrect.
The correct answer is Option (d) external oblique because the external oblique aids expiration by compressing abdominal contents which helps to raise the diaphragm.
Want to see more full solutions like this?
Chapter 51 Solutions
Laboratory Manual For Human Anatomy & Physiology
- Selection of Traits What adaptations do scavengers have for locating and feeding on prey? What adaptations do predators have for capturing and consuming prey?arrow_forwardCompetition Between Species What natural processes limit populations from growing too large? What are some resources organisms can compete over in their natural habitat?arrow_forwardSpecies Interactions Explain how predators, prey and scavengers interact. Explain whether predators and scavengers are necessary or beneficial for an ecosystem.arrow_forward
- magine that you are conducting research on fruit type and seed dispersal. You submitted a paper to a peer-reviewed journal that addresses the factors that impact fruit type and seed dispersal mechanisms in plants of Central America. The editor of the journal communicates that your paper may be published if you make ‘minor revisions’ to the document. Describe two characteristics that you would expect in seeds that are dispersed by the wind. Contrast this with what you would expect for seeds that are gathered, buried or eaten by animals, and explain why they are different. (Editor’s note: Providing this information in your discussion will help readers to consider the significance of the research).arrow_forwardWhat is the difference between Uniporters, Symporters and Antiporters? Which of these are examples of active transport?arrow_forwardWhat are coupled transporters?arrow_forward
- How do histamine and prostaglandins help in the mobilization of leukocytes to an injury site? What are chemotactic factors? How do they affect inflammation process?arrow_forwardCompare and contrast neutrophils and macrophages. Describe two ways they are different and two ways they are similar.arrow_forwardDescribe the effects of three cytokines (not involved in the initial inflammation response). What cells release them?arrow_forward
- Human Anatomy & Physiology (11th Edition)BiologyISBN:9780134580999Author:Elaine N. Marieb, Katja N. HoehnPublisher:PEARSONBiology 2eBiologyISBN:9781947172517Author:Matthew Douglas, Jung Choi, Mary Ann ClarkPublisher:OpenStaxAnatomy & PhysiologyBiologyISBN:9781259398629Author:McKinley, Michael P., O'loughlin, Valerie Dean, Bidle, Theresa StouterPublisher:Mcgraw Hill Education,
- Molecular Biology of the Cell (Sixth Edition)BiologyISBN:9780815344322Author:Bruce Alberts, Alexander D. Johnson, Julian Lewis, David Morgan, Martin Raff, Keith Roberts, Peter WalterPublisher:W. W. Norton & CompanyLaboratory Manual For Human Anatomy & PhysiologyBiologyISBN:9781260159363Author:Martin, Terry R., Prentice-craver, CynthiaPublisher:McGraw-Hill Publishing Co.Inquiry Into Life (16th Edition)BiologyISBN:9781260231700Author:Sylvia S. Mader, Michael WindelspechtPublisher:McGraw Hill Education