Thoracic Wall

Question 1

How many ribs are there?

Answer 1

12 pairs

Question 2

How many are true ribs?

Answer 2

1-7 - reach the sternum

Question 3

How many are false ribs?

Answer 3

8-10 - reach costal cartilage above 11-12 are floating

Question 4

Where are the articulations of the ribs?

Answer 4

With vertebral column via head and tubercle (articular facets) With sternum - costal cartilage

Question 5

How many thoracic vertebrae?

Answer 5

12 - each rib joined to one vertebra

Question 6

Where is the sternum?

Answer 6

Anterior of the heart

Question 7

How is the sternum made up?

Answer 7

**** Jugular notch **** 3 parts: Manubrium, Body and Xiphoid process (xiphisternum) **** Sternal angle **** (important landmark)

Question 8

Which ribs attach to the Manubrium?

Answer 8

1st costal cartilages

Question 9

Which ribs attach to the sternal angle?

Answer 9

2nd costal cartilage

Question 10

Which ribs attach to the body of the sternum?

Answer 10

3-7th

Question 11

Where do the 8-10th ribs attach?

Answer 11

To the cartilage above

Question 12

What is the costal margin?

Answer 12

Outline of cartilage where the diaphragm is attached - the bottom most bit of ribcage

Question 13

Why is the sternal angle important?

Answer 13

Landmark for 2nd ribs

Question 14

What are the contents of the thoracic inlet?

Answer 14

Great vessels heading for neck and upper limbs - common carotid, internal jugular and subclavian Oesophagus, trachea, nerves, lymphatics

Question 15

What is the thoracic inlet formed from?

Answer 15

1st ribs, T1, Manubrium

Question 16

Where is the major capacity for thorax expansion?

Answer 16

Lower parts of thorax

Question 17

What is the diaphragm?

Answer 17

Formed from flat central tendon, with muscle radiating to costal margin and vertebrae

Question 18

How does the diaphragm function?

Answer 18

Dome flattens, ^ vertical diameter of chest Pulls costal margin up to ^ transverse and anteroposterior diameter

Question 19

What is the secondary role of the intercostals?

Answer 19

Stiffen the chest wall, improve efficiency of breathing movements

Question 20

How many layers of intercostal muscles are there?

Answer 20

3: external, internal, innermost

Question 21

What way are the EIM positioned?

Answer 21

Towards your pockets (/// on RHS) - from lower border of rib above, to rib below

Question 22

Where and by what are EIM replaced?

Answer 22

By anterior intercostal membrane at costo-chondral junction (rib-cartilage)

Question 23

What way are IIM positioned?

Answer 23

Towards back pockets (/// on LHS) - attachments anteriorly at sternum from lowerb order of rib above to rib below - replaced by membrane posteriorly

Question 24

What way are IM arranged?

Answer 24

Like plywood - with EIM and IIM forming right angles against each other

Question 25

How many intercostal nerves?

Answer 25

11 pairs - T1-11 (1 subcostal - T12) - have both motor and sensory functions

Question 26

Where do the intercostal nerves supply?

Answer 26

Intercostal spaces - lateral cutaneous branch(ant (both medial and lateral) and post)

Question 27

How is the vasculature arranged in the intercostals?

Answer 27

Arranged in neurovascular bundles - running just below rib deep into internal intercostal

Question 28

What are the implications of the neurovascular bundles IM, when a chest drain is needed?

Answer 28

A space where no nerves are present is needed - Safe area/triangle!

Question 29

Where is the safe triangle?

Answer 29

5th intercostal space ant to mid axillary line Ant. border of latissimus dorsi, lateral border of pectoralis major, line superior to nipple and apex below axilla

Question 30

Where does each IC artery anastamose?

Answer 30

At the end of the intercostal space - so either posterior (in front of vertebrae) or anterior (behind sternum)

Question 31

What does anastamose mean?

Answer 31

Joining of vessels that supply the same area e.g.: IC artery joins with a major artery (aorta) at end of IC space

Question 32

Where do the IC nerves come from?

Answer 32

ONLY from spinal cord

Question 33

What vessels supply blood to the thorax?

Answer 33

Subclavian artery supplies O2 by separating into internal thoracic artery (ITA) ITA separates into Anterior intercostal artery and musculophrenic artery

Question 34

What does the thoracic cavity contain?

Answer 34

Lungs - in each pleural cavity Mediastinum (between pleural cavities): Heart (pericardial sac), Great vessels, Oesophagus, Trachea, Thoracic duct and major lymph trunks, lymph nodes, Phrenic and vagus nerves

Question 35

Where does pec. major lie?

Answer 35

Begins at the top of humerus (intertubercular sulcus of humerus) Medial half of clavicle and anterior surface of sternum, first 7 cartilages

Question 36

What is the function of pec. major?

Answer 36

Adduction, medial rotation and flexion of humerus at shoulder joint

Question 37

What does adduction mean?

Answer 37

movement towards the mid-line of the body - also applies to movements inwards and across the body

Question 38

What are the structures with which the rib articulates?

Answer 38

Articular facets or tubercle - and on vertebrae called facets for articulation with head/tubercle

Question 39

Where is the scapula and what is it?

Answer 39

The shoulder blades - on shoulder towards back