Diaphragm & etc.

Question 1

what is the esophageal hiatus?

Answer 1

oval opening for the esophagus in the diaphragm muscle.

Question 2

what is the aortic hiatus?

Answer 2

opening posterior in the diaphragm for the descending aorta.

Question 3

do movements of the diaphragm affect the aortic hiatus?

Answer 3

no because the aorta does not pierce the diaphragm.

Question 4

what is the sternocostal triangle?

Answer 4

small opening between the sternal and costal attachments of the diaphragm.

Question 5

why do people with dyspnea prefer sitting up?

Answer 5

because lung volume in this position is increased and the diaphragm is working with gravity.

Question 6

the diaphragm is the most superior when a person is in which position?

Answer 6

supine

Question 7

when the diaphragm contracts what happens?

Answer 7

the domes are pulled inferiorly, the abdominal viscera pushes inferiorly, the thoracic cavity volume is increased and the intrathoracic pressure is decreased.

Question 8

what is the posterior abdominal wall composed of?

Answer 8

five lumbar vertebrae and associated IV discs
posterior abdominal wall muscles - psoas, quadratus lumborum, iliacus, transversus abdominis, oblique muscles, diaphragm, fascia, lumbar plexus, fat, nerves, and vessels.

Question 9

what is the posterior abdominal wall covered with?

Answer 9

endoabdominal fascia between the parietal peritoneum and the muscles.

Question 10

what is the psoas fascia? what does it form?

Answer 10

covering for the psoas major muscle and thickens to form the medial arcuate ligament

Question 11

what is the thorcolumbar fascia?

Answer 11

thin, transparent, covers the thoracic parts of the deep muscles.

Question 12

what encloses the vertical deep back muscles (erector spinae?)

Answer 12

posterior and middle layers of the thoracolumbar fascia.

Question 13

what is the anterior layer of the thoracolumbar fascia?

Answer 13

covering for the anterior surface of the quadratus lumborum and thickens to be the lateral arcuate ligament.

Question 14

what is superior and inferior attachment of the psoas major?

Answer 14

transverse processes of the lumbar vertebrae, sides of bodies T12-L5 vertebrae and IV discs.

strong tendon to lesser trochanter of femur.

Question 15

what is the innervation and action of the psoas major?

Answer 15

anterior rami of lumbar nerves L1, L2, L3

inferiorly with iliacus - flexes thigh
superiorly - flexes vertebral column laterally
balances the trunk
flexes trunk when sitting

Question 16

what is the superior and inferior attachment of the iliacus?

Answer 16

superior 2/3rd of iliac fossa, ala of sacrum, anterior sacro-iliac ligaments.

lesser trochanter of femur and shaft inferior to it, to to psoas major tendon

Question 17

what is the innervation and action of the iliacus?

Answer 17

femoral nerve.

flexes thigh and stabilizes hip joint, acting with psoas major

Question 18

what are the superior and inferior attachments of the quadratus lumborum?

Answer 18

medial half of inferior border of 12th ribs and tips of lumbar transverse processes

iliolumbar ligament and internal lip of iliac crest

Question 19

what is the innervation and action of the quadratus lumborum?

Answer 19

anterior branches of T12-L1-L4 nerves

extends and laterally flexes vertebral column.
fixes 12th rib during inspiration.