Thoracic muscles

Question 1

What are the five muscles that make up the thoracic cage?

Answer 1

external intercostals, internal intercostals, innermost intercostals, subcostals, transverse thoracis

Question 2

Which muscles attach to the thoracic cage?

Answer 2

pectoralis major, pectoralis minor, serratus anterior, scalene muscles

Question 3

How many pairs of external intercostals are there?

Answer 3

11

Question 4

Which muscle of the abdomen are external intercostals continuous with?

Answer 4

external oblique

Question 5

What are the attachments of the external intercostals?

Answer 5

Originate at the lower border of the rib, inserting into the superior border of the rib below.

Question 6

What is the function of the external intercostals?

Answer 6

Elevates ribs, increasing thoracic volume

Question 7

The innervation of the intercostals if from_______

Answer 7

Intercostal nerves, T1-11

Question 8

Which of the intercostals runs inferoposteriorly?

Answer 8

Internal intercostals

Question 9

Which of the intercostals runs inferoanteriorly?

Answer 9

External intercostals

Question 10

Which muscle of the abdominal wall are the internal intercostals continuous with?

Answer 10

Internal intercostals

Question 11

What are the attachments of the internal intercostals?

Answer 11

Originates from the lateral edge of the costal groove and inserts into the superior surface of the rib below

Question 12

What is the action of the interosseous part of the internal intercostals?

Answer 12

reduces thoracic volume by depressing the ribcage

Question 13

What is the action of the interchondral part of the internal intercostals?

Answer 13

Elevate the ribs

Question 14

What spearates the innermost intercostals from the internal intercostals?

Answer 14

intercostal neurovascular bundle

Question 15

Where are the innermost intercostals found?

Answer 15

in the most lateral portion of the intercostal spaces

Question 16

What is the action of the innermost intercostals?

Answer 16

same as internal

Question 17

Which abdominal muscle is tranversus thoracic continuous with?

Answer 17

transversus abdominis

Question 18

What are the attachments of transversus thoracis?

Answer 18

From the posterior surface of the inferior sternum to the internal surface of costal cartilages 2-6.

Question 19

What is the action of transversus thoracis?

Answer 19

Weakly depresses the ribs

Question 20

Where are the subcostals found?

Answer 20

in the inferior portion of the thoracic wall

Question 21

Describe the subcostals

Answer 21

They comprise of thin slips of muscle, which run from the internal surface of one rib, to second and third ribs below. The direction of the fibres parallels that of the innermost intercostal.

Question 22

What is the action of the subcostals?

Answer 22

share the action of the internal intercostals