Other Muscles Flashcards
Diaphragm
internally placed, domeshaped muscle that forms a partition between the thoracic and abdominopelvic cavities; most important muscle associated with breathing
What are the origin points of the diaphragm?
cartilages of lowest ribs, lumbar vertebrae
What are the insertion points of the diaphragm?
central tendon
What are the actions of the diaphragm?
prime muscle of inspiration (flattens on contraction)
Internal intercostals
lie deep to the external intercostals, and their muscle fibers are at right angles to the external intercostals
What are the actions of the internal intercostals?
depresses ribs for forced expiration
External intercostals
extend inferomedially from the superior rib to the adjacent inferior rib; assist in expanding the thoracic cavity by elevating the ribs during inhalation
What is the action of the external intercostals?
raises ribs for inspiration
Superior rectus
located superiorly and attaches to the anterosuperior part of the sclera
What is the action of the superior rectus?
rotates eyeball superiorly and medially (elevates and adducts)
Inferior rectus
attaches to the anteroinferior part of the sclera
What is the action of the inferior rectus?
rotates eyeball inferiorly and medially (depresses and adducts)
Medial rectus
attaches to the anteromedial surface of the eye and pulls the eye medially
What is the action of medial rectus?
rotates eyeball medially (adducts)
Lateral rectus
attaches to the anterolateral surface of the eye
What is the action of the lateral rectus?
rotates eyeball laterally (abducts)
Superior oblique
passes through a pulleylike loop called the trochlea; depresses the eye and turns laterally
What is the action of the superior oblique?
rotates eyeball inferiorly and laterally (depresses and abducts)
Inferior oblique
attaches to the posterior part of the eye and pulls the posterior part of the eye when contracting
What is the action of the inferior oblique?
rotates eyeball superiorly and laterally (elevates and abducts)
