Movements of the Thoracic Wall and Abdomen

Question 1

What are the functions of the thoracic walls?

Answer 1

protection and respiration

Question 2

What are the bones of the thorax?

Answer 2

ribs and costal cartilage, sternum, thoracic vertebrae and IVD

Question 3

What is the function of costal cartilage?

Answer 3

allows compression and expansion (elasticity)

Question 4

What is the anterior anchorage of the thoracic cavity?

Answer 4

sternum

Question 5

What is the posterior anchorage of the thoracic cavity?

Answer 5

12 thoracic vertebrae and IVD

Question 6

What are the different types of ribs?

Answer 6

true (1-7)
false (8-10) - no direct attachment to sternum via cartilage
floating (11-12) - no costal cartilage

Question 7

What type of bones are ribs?

Answer 7

flat bones (protection)

Question 8

What is the superior boundary of the thorax?

Answer 8

T1, 1st rib, manubrium, suprapleural membrane

Question 9

What is the lateral wall of the thorax?

Answer 9

ribs, intercostal muscles, intercostal space

Question 10

What is the posterior wall of the thorax?

Answer 10

12 thoracic vertebrae, IVD, rib heads and tubercles

Question 11

What is the inferior wall of the thorax?

Answer 11

diaphragm

Question 12

What are the 8 joints of the thoracic wall?

Answer 12

• sternoclavicular
• sternocostal
• costochondral
• manibriosternal
• xiphisternal
• interchondral
• intervertebral
• costovertebral

Question 13

External intercostal

Answer 13

P: external superior border of lower ribs
D: external inferior border of superior ribs
A: elevate ribs during forced inspiration
NS: intercostal

Question 14

Internal intercostal

Answer 14

P: inner superior border of lower rib
D: inner superior border of superior ribs
A: interosseous: depress ribs during forced expiration. Interchondral: elevates ribs during inspiration
NS: intercostal nerve

Question 15

What is the function of the external intercostal muscles?

Answer 15

increase the anteroposterior dimension of the thorax –> elevation of ribs at 2nd-6th costovertebral joints during inspiration

Question 16

What is the function of the internal intercostal muscles?

Answer 16

increase the transverse dimension of the thorax –> elevation of ribs at 7-10 costovertebral joints during inspiration

Question 17

What is the general function of the intercostal muscles?

Answer 17

maintain rigidity of intercostal spaces; resist negative pressure and prevent ribs from going inwards

Question 18

Diaphragm

Answer 18

P: inner rim of costal margin, posterior ab wall and L1
D: central tendon
A: central part descends during inspiration (primary muscle of inspiration)
N: phrenic

Question 19

What is the function of the diaphragm?

Answer 19

increase vertical dimension of thorax

Question 20

What are the posterior medial, posterior lateral, lateral and anterior boundaries of the diaphragm?

Answer 20

Posterior medial: vertebral column, left and right crus
Posterior lateral: medial and lateral arcuate ligaments
Anterior: xiphoid process of sternum
Lateral: 7-12 costal cartilages

Question 21

What are the three movements of the thoracic wall?

Answer 21

• increase in vertical dimension (diaphragm)
• increase in anteroposterior dimension (sternum moves forward)
• increase transverse dimension (ribs rise)

Question 22

Which joint is involved in the pump handle movement?

Answer 22

upper rib costotransverse joint rotation

Question 23

Which joint is involved in the bucket handle movement?

Answer 23

lower rib costotransverse joint gliding

Question 24

Rectus abdominis

Answer 24

P: pubic symphysis and pubic crest
D: xiphoid process and 5-7 costal cartilages
A: trunk flex, compression of abdominal viscera, stabilise pelvis tilt (antilordosis)
N: thoraco-abdominal

Question 25

External oblique

Answer 25

P: external surface of ribs 5-12 D: linea alba, pubic tubercle, lateral part of inguinal ligament, anterior 1/2 iliac crest A: trunk flex and rotation, compression and support abdominal viscera N: thoraco-abdominal

Question 26

Internal oblique

Answer 26

P: TCF, anterior 2/3 iliac crest, lateral inguinal ligament D: inferior border of ribs 10-12, linea alba, pectin pubis via conjoint tendon A: trunk flexion and rotation, comrpession and support abdominal viscera N: thoraco-abdominal nerve and 1st lumbar nerve

Question 27

Transverse abdominis

Answer 27

P: lateral 1/3 inguinal ligament, inner anterior 2/3 iliac crest, TCF, lower 6 costal cartilages D: linea alba, aponeurosis of internal oblique, pubic crest, pectin pubis via conjoint tendon A: compression and support abdominal viscera N: thoraco-abdominal nerve and 1st lumbar nerve

Question 28

Which muscles are involved in inspiration?

Answer 28

scalenes, sternocleidomastoid, pec major, pec minor, serratus anterior, external intercostals, erector spinae

Question 29

Which muscles are involved in expiration?

Answer 29

external obliques, rectus abdominis, internal obliques, transversus abdominis, internal intercostals