movements of the chest

Question 1

Which muscles contribute to changing the dimensions and therefore the volume of the thoracic cavity?

Answer 1

Diaphragm

Intercostal muscles

Question 2

Which part of the diaphragm attaches tot he costal margin of the veretbrae(ribs)?

Answer 2

flat CENTRAL TENDON

Question 3

How do the muscles work to increase lung volume?

Answer 3

1-dome flattens to increase the VERTICAL diameter of the chest
2- the dome pulls the costal margin up to increase both the TRANSVERSE and ANTEROPOSTERIOR DIAMETERS
3-

Question 4

What is the role of the intercostal muscles?

Answer 4

stiffen chest wall to improve the efficiency of the breathing movements

Question 5

Describe the movement of the sternum to increase chest volume?

Answer 5

like a pump handle:

-moves anteriorly and superiorly to increase the ANTEROPSOSTERIOR dimension of the chest

Question 6

Describe the movement of the ribs to increase chest volume?

Answer 6

Moves in a bucket handle type movement:

-they elevate to increase the MEDIO-LATERAL dimensions of the chest

Question 7

What are the 3 layers of the intercostal muscles and how are they organised?

Answer 7

External intercostal muscles
Internal intercostal muscles
Innermost intercostal muscles

Organised like plywood at 90 degree angels to eachother

Question 8

Describe the structure of the external intercostal muscles?

Answer 8

orientated downwards and laterally diagnolly from the lower border of the rib above to the rib below

Question 9

Where along the ribs is intercostal muscel replace by intercostal membrane?

Answer 9

at the rib cartilage junction

Question 10

Where do the internal intercostal muscles attach to?

Answer 10

attachments begin anteriorly at the sternum from the lower border of the rib above to the rib below

the fibres are at right angles tot he external intercostal muscles

Question 11

What direction do the fibres of the innermost internal intercostal muscles travel in?

Answer 11

same direction as the internal intercostal muscels

Question 12

Where does the neurovascular bundles sit?

Answer 12

in between the innermost and internal intercostal muscles

Question 13

What do the intercostal nerves do?

Answer 13

innervate the intercostal spaces and the skin overlaying the intercostal spaces

Question 14

How many pairs of intercostal nerves are there?

Answer 14

11

-plus one sub -costal nerve below the 12 ribs

Question 15

What are the names of the branches of the intercostal nerves?

Answer 15

LATERAL CUTANEOUS BRANCHES- divide into the anterior and posterior

ANTERIOR CUTANEOUS BRANCH- divides into the medial and lateral branch

Question 16

What does the motor component of the intercostal nerves do?

Answer 16

allow the intercostal muscles to contract

Question 17

Describe the arterial supply to the intercostal spaces?

Answer 17

-from branches of the DESCENDING AORTA and from INTERNAL THORACIC ARTERIES

Question 18

Describe the venous supply to the intercostal space?

Answer 18

-from the AZYGOUS VEIN ot the INTERNAL THORACIC VEINS

Question 19

What is in the costal groove of a rib?

Answer 19

• Intercostal artery
• intercostal vein
• intercostal nerve

Question 20

What are the implications for putting a needle or chest drain through the chest wall and how do you minimise damage?

Answer 20

becasue of the vessels and nerves inthe intercostal space it means that they are vunerable to traumatic injury

-minimise damage to the blood vessels, muscle and breast tissue by inserting a chest drain into a area known as the safe area

Question 21

What are the boundaries of the safe area?

Answer 21

-anterior border of the Laissimus dorsi
-lateral border of the pectoralis major muscle
-abbove a line thats superior to the horizontal level of the nipple
below the apex of the axilla

Question 22

Where should the chest drain be inserted?

Answer 22

on the superior surface of the rib to avoid potential damage to the neurovascular bundle