In inspiration, the diaphragm
contracts, descends, increases the volume and decreases the pressure
within the thorax, and increases the abdominal pressure. The diaphragm
is lower when a subject is in the sitting posture than when in the
erect posture, and patients with difficulty in breathing are more
comfortable when sitting.
20-2 What is the vertebrocostal trigone?
20-2 The vertebrocostal trigone is a
variable interval between the costal and lumbar parts of the diaphragm.
The pleura may then be in close relationship to the suprarenal gland