Muscles Of Respiration Flashcards
Define a muscle (inc primary and secondary function)
Primary function: bring movement by contraction
Secondary function: not primarily responsible but assists in initiating and providing movement
What muscles are on the external anterior thoracic wall?
The external intercostal muscles
What is the origin (superior attachment) of the external intercostal muscles?
Arises from the lower border of the rib
Where do external intercostal muscles insert (inferior attachment)?
Attach to the upper border of the rib
What innervates the external intercostal muscles?
Intercostal nerves - numbered sequentially according to intercostal space
How many external intercostal muscles do we have?
11 on each side
How do intercostal muscles assist intercostal spaces?
Keep the rigid: prevent bulging on expiration and being drawn in on inspiration
What kind of muscle is the diaphragm?
Primary muscle of respiration
What muscles are found on the internal anterior thoracic wall?
Internal intercostal muscles
What is the origin on he internal intercostal muscles?
Arise from ridge on inner surface of inferior aspect of each rib and from corresponding costal cartilage
What is the insertion of the internal intercostal muscle?
The upper border of rib below origin
What is the innervation of the internal intercostal muscle?
The intercostal nerves
What are the actions of the internal intercostal muscles?
Intercostal connected with costal cartilage elevate ribs
Lateral and posterior portions of muscle depress ribs
Which way do the fibres on the lateral and posterior portion of the internal intercostal muscles run?
Fibres run obliquely
What is the relationship of the fibres of the internal intercostal muscles to the external intercostal muscles?
The internal i.m fibres run perpendicular to the external i.m
Name two accessory muscles on the inner anterior thoracic wall?
Innermost intercostal muscles
Transversus thoracic muscles
What is the origin of the innermost intercostal muscles?
Arise from the lower border of rib
What is the insertion of the innermost intercostal muscle?
Attach to he upper border of the rib below origin
What is the origin of the transversus thoracic muscle?
Posterior surface of lower portion of body of sternum and xiphoid process
What is the insertion of the transversus thoracic muscles?
Attach to the inner surface of costal cartilages 2-6
What are the actions of the innermost intercostal muscles?
Elevate the ribs
What is the action of the transversus thoracic muscles?
Depress the ribs