Flashcards in Lecture 4 - Diaphragm; Mechanisms of breathing Deck (23):
Which Dome of the diaphragm is higher and why?
Right dome is higher
heart pushes the left dome lower
The diapgram is a thin sheet of muscle that lines the entire thoracic cavity - has a central tendon
What does contraction lead to?
tendon moving downwards
What are the attachements of the diaphragm:
Anteriorly: xiphoid process
Posteriorly: bumps into psoas major and qadratus lumborium (doesn't reach posterior wall)
Costal Margin:Inferior six ribs and costal cartilages
Lumbar vertebrae: L1-3/4 via Right crus and L1-2/3 via left crus)
note: crus = legs
Where is the median arcuate ligaemnt/
Right in the mid-line forms over the top of the descending aorta
The medial arcuate lig. is ov ver which muscle?
The lateral arcuate lig. is over which muscle?
What are the structures that pierce the diaphragm and where do they do so?
IVC - T8 (slightly to the right)
Oesophagus - T10 (midline posterior)
Aorta - T12
Right phrenic n.: through central tendon
Left phrenic: anterolateral (through muscle)
Azygous Vein: Right
Hemiazygous vein: Left
Sympathetic trunk: Lateral to the cura
The aorta passes behind the _____ _______ _______at T12
mnedian arcuate ligament
As diaphragm pushses downwards it _____pressure in the abdominal cavity
blood then wants to move to the lower pressure area = thoracic cavity
When the D contracts it pulls ____ __ ___ ____ and closes off the ______, stopping the contents of the _____ going up like the blood does
When the D contracts it pulls the left and right crus and closes off the oesophagus, stopping the contents of the stomach going up like the blood does
what innervates motor, sensory to central part and sensory to pericardium of diaphragm?
C 3,4,5 - keeps the diaphragm alive
Where is pain from central diaphragm referred?
Dermatomes over the neck and upper limb (C3,4,5)
The very lateral part of the diaphragm receives sensory supply from ...
the lower intercostal nerve
Pain here will be referred to the lower thoracic spinal segments
movement of air in and out of lungs is..
created by pressure gradient by change in dimensions
The lungs have to move in whatever direction the thoracic wall moves because of...
the surface tension produced by the pleura
True or False
The parietal pleura is firmed attached to the thoracic cage, including the diaphragm
The diaphragm expands the lungs by...
pulling down on them
The diaphragm is the main determinant of _____ respiration
If you elevate the upper ribs, (external intercostals) - you increase the _______ direction of the cage
Elevation of lower ribs cause a increase in the _______ dimension
Elevation of lower ribs cause a increase in the transverse dimension
What are the accessory respiratory muscles?
Scalene muscles - for sniffing
external intercostals - expanding
Internal intercostals - collapsing
The _______ muscles tense in forced expiration to force abdominal contents up to push the diaphragm up and reduce thoracic cavity
The adbominal muscles tense in forced expiration to force abdominal contents up to push the diaphragm up and reduce thoracic cavity