thoracic wall

Question 1

origin of intercostals

Answer 1

inferior border of rib above

Question 1

insertion of intercostals

Answer 1

superior border of the rib below

Question 2

nerve innervation of intercostals

Answer 2

thoracic intercostal nerves T1-T-11

Question 3

muscle action of EXTERNAL intercostals

Answer 3

draw the ribs SUPERIORLY to assist with inhalation

(increases space in the thoracic cavity)

Question 4

muscle action of INTERNAL intercostals

Answer 4

draw the ribs inferiorly to assist with exhalation

(decreases space in the thoracic cavity)

Question 5

origin of diaphragm

Answer 5

costal attachment: inner surface of lower six ribs

lumbar attachment:
upper 2 or 3 lumbar vertebrae

sternal attachment: inner part of xiphoid process

Question 6

insertion of diaphragm

Answer 6

central tendon

Question 7

nerve innervation of diaphragm

Answer 7

phrenic nerve C3, C4, C5 (keep me alive!)

Question 8

main action of the diaphragm

Answer 8

draw down the central tendon of the diaphragm

increase the volume of the thoracic cavity during inhalation