Muscles of respiration:exhalation
Transverse thoracic
Located in inner surface of sternum From lower half of inner sternum fibers course superiorly and laterally to insert on the inner surfaces of ribs 2-6
Rectus abdominis
Located in midline Fibers course inferior superior 2 vertical bundles lateral to midline to linea Alba Each bundle is enclosed by an aponeurotic sheath
Transverse abdominis
Located in the Anterolateral abdomen and just deep to the externals Deepest of the abdominal muscles Horizontal course
Suncostals
Located on the inner surface of the posterior aspects of the ribs Only in lower rib cage Same course as the internal intercostals Origin: second or third rib below the insertion and runs up and laterally from origin
Latissimus dorsi
May function to compress posterior aspect of abdomen Which increases abdominal pressure and moves diaphragm up
External oblique abdominis
Most superficial of the abdominal muscles Located in the anterolateral abdomen Attaches from the anterior half of the iliac crest Courses upward and laterally to the exterior surfaces and lower borders of the lower 8 ribs
Serratus posterior inferior
Attaches from spinous process of T11-T12 and L 1-2 Courses upward and laterally to insert into inferior borders of the last 4 ribs
Forced exhalation
Active process depends on abdominal musculature Decreases size volume of thoracic cavity to expel air
Internal oblique abdominis
Anterolateral and deep to the externals Attaches from the anterior 2/3 of the iliac crest and inguinal ligament Inserts into the lowest 3 or 4 costal cartilages and the abdominal aponeurosis Courses upward and medially
Quaderatus lumborum
Back muscles Located in posterolateral aspect of abdominal wall between 12th rib and iliac crest Attaches from the iliac crest and iliolumborum ligament Fibers course upward and medially to attach to L1-L4 and medial half of 12th rib
Abdominal aponeurosis
Broad tendinous sheet in the ventral abdominal wall that extends from the sternum to pubis
Quiet exhalation
Passive process depends on: Elastic recoil of lungs Return of diaphragm and ribs to rest position Depends on forces of gravity tissur elasticityamd rib untorquing
Compress the abdomen
Respiratory function of the internal oblique abdominis
Depresses the lower 4 ribs
Respiratory function of the serratus posterior inferior
Pull ribs downward and inward compressing the thoracic cavity and expelling air
Respiratory function of transverse thoracic
Internal intercostals
They fill the space between ribs almost to sternum in front and up to rib tubercles in back Courses from lower border of a rib above to the upper border of the rib immediately below Runs down and laterally in front Runs down and medially in back Sparse in upper thorax
Rectus abdominis External oblique abdominis Internal oblique abdominis Transverse abdominis
What are the abdominal muscles of exhalation
Quadratus lumborum Serratus posterior inferior Latissimus dorsi
What are the back muscles of exhalation
Transverse thoracic Subcostals Internal intercostals
What are the thoracic muscles of exhalation
Increases abdominal pressure which elevates the diaphragm
What happens when the abdomen a compressed
Encircles abdomen from lumbar area on one side to lumbar area on the other side Attaches into aponeurosis at midline Antagonist to diaphragm
What is the origin and insertion of the transverse abdominis
Respiratory: compress abdomen
What is the rectus abdominal function
Draws ribs together and helps lower rib cage
What is the respiratory function of internal intercostals
Draw the ribs together with the lower rib fixed and can draw the rib cage down
What is the respiratory function of subcostals
Compress the abdomen
What is the respiratory function of the external oblique abdominis
Pulls lowest rib down or fixed it down Anchors rib cage
What is the respiratory function of the quaderatus lumborum
Compressed the abdomen laterally and anteriorly
What is the respiratory function of the transverse abdominis
From pubic symphysis to xyphoid process and 5th -7th rib cartilages Enclosed in abdominal aponeurosis
Where is the rectus abdominis found and attached to?
