Chest Muscles Flashcards
What is the origin of the external intercostal muscles?
Lower border of the rib above
What is the insertion of the external intercostal muscles?
Upper border of the rib below
What is the fiber direction of the external intercostal muscles?
Inferomedial (like putting hands in pockets)
What is the main action of the external intercostal muscles?
Elevates ribs during inspiration
What nerve supplies the external intercostal muscles?
Intercostal nerves (T1-T11)
How do external intercostal muscles contribute to respiration?
They increase thoracic volume by pulling the ribs upward and outward
How do the external intercostal muscles differ from the internal intercostal muscles?
External intercostals elevate ribs, while internal intercostals depress ribs (forced expiration)
Which of the following best describes the function of external intercostal muscles?
A) Depress ribs, B) Elevate ribs, C) Stabilize the diaphragm, D) Constrict bronchi
The external intercostal muscles are innervated by:
A) Phrenic nerve, B) Vagus nerve, C) Intercostal nerves, D) Recurrent laryngeal nerve
What is the orientation of the external intercostal muscle fibers?
A) Superomedial, B) Horizontal, C) Inferomedial, D) Perpendicular
During quiet inspiration, which muscles play a primary role?
A) External intercostals, B) Internal intercostals, C) Rectus abdominis, D) Sternocleidomastoid
The external intercostal muscles are located:
A) Between adjacent ribs, B) Between vertebrae, C) Inside the pleural cavity, D) Over the diaphragm
What is the origin of the transversus thoracis muscle?
Posterior surface of the lower sternum
What is the insertion of the transversus thoracis muscle?
Inner surface of costal cartilages of ribs 2-6
What is the fiber direction of the transversus thoracis muscle?
Superolateral (radiating outward from the sternum)
What is the main action of the transversus thoracis muscle?
Depresses ribs during forced expiration
What nerve supplies the transversus thoracis muscle?
Intercostal nerves (T2-T6)
How does the transversus thoracis muscle contribute to respiration?
Aids in expiration by pulling ribs downward
Where is the transversus thoracis muscle located?
Deep to the sternum on the inner surface of the thoracic wall
