L1.2 Thoracic Wall Flashcards
1
Q
What defines the thoracic wall?
A
Thoracic cage + coverings
2
Q
Function of the thoracic wall
A
- Protects, and forms the mechanical basis of breathing
3
Q
True, false and floating ribs
A
- 1-7 (true) → attach directly to the sternum via own costal cartilage
- 8-10 (false) → Attach to costal cartilage of ribs above
- 11 & 12 (floating) → Have no ANT attachments (contributes to mobility of thoracic cage)
4
Q
Typical and atypical ribs
A
- 3-9 (typical)
- curved & flat
- Head → has multiple facets (S & I & articular)
- INF aspect has the costal groove (vessels run through it)
- 1, 2, 10-12 (atypical)
- e.g. 1:
- Grooves for subclavian vessels, scalene tubercle
5
Q
Sternum
A
- Manubrium, body, xyphoid
- 1st rib articulation at manubrium
- 2nd rib articulation b/w manubrium and body
- Sternal angle of Louis: Angle b/w manubrium & body
6
Q
Distinction of the thoracic vertebrae
A
- Distinction are the rib articulations
- S/I demi-facets
- 2 points of rib articulations
- Coronal → permits rotation
7
Q
External intercostal muscles
A
- From ribs above to below, antero-inferiorly
- Medially continues as external intercosatal membrane
- For ribs elevation
8
Q
Internal intercostal muscles
A
- Fibres direction opposite of external intercostal muscles
- Run throughout the length
- For ribs depression, BUT MED helps elevation
9
Q
Innermost intercostal muscles
A
- Fibres direction same as internal
- Fragmented, not full length, deficient POS (exposes N)
- Functionally same as internal
10
Q
Intercostal vessels
A
- VAN (Sup → Inf)
- B/w internal & innermost muscles
- Nerves are just extension of spinal Nerve (Ventral Ramus)
- Branches off to supply skin → define dermatomes
11
Q
Features of the breasts
A
- Mammary glands under skin on ANT thoracic wall (on fascia SUP to pec maj)
- 15-20 lobules which contains alveoli at the end of duct
- Alveoli secretes milk into duct systems
- Each lobule drained by single duct (lactiferous duct → opens directly on nipple)
12
Q
What is the retromammary space?
A
- area which can be opened up for implants
- B/w pec maj & mammary glands
13
Q
Location of breasts
A
- 1/3 breast on serratus ANT laterally
- Rest MED to LAT border to sternum (Ribs 2-6)
14
Q
Features of the nipple
A
- In 4th intercostal space in mid-clavicular line
- Only applies for nulliporous women (women with no baby)
- Surrounded by S.M → erects it
- No fat/hair/sweat glands
15
Q
Areola
A
- Pigmented area around nipple
- Sebaceous gland → oil for lubrication
16
Q
Is it harder or easier to check for cancers in younger or older women
A
- Younger women with dense tissues → harder to identify breast cancer growing
17
Q
BS to the breasts
A
- MED → internal thoracic A (mammary A) from behind sternum
- LAT → branches of intercostal A & Subclavial A
18
Q
Venous drainage
A
Same as BS
19
Q
Lymphatics of the breasts
A
- Subareolar plexus → parasternal/axillary nodes (75% to axillary) → subclavian trunk → R.lymphatic duct/Thoracic duct
20
Q
Breast cancer
A
- Derived from glandular epithelium in lobules, appeared as jagged mass on mammogram
- Could damage suspensory ligament → could invert nipple, skin thickened or dimpled
- Anchors lobules to fascia
- Cancer cells can lodge in nodes → metastases → can be palpated
21
Q
Breast cancer in men
A
- Still can get breast cancer
- Usually no glandular development
- Only small duct development → but cancer can arise from the epithelium of the duct
22
Q
Thoracic dermatome landmark
A
- T4 - teets
- T10 - Bellybutton
23
Q
What do muscles of the ribs help to do
A
- Muscles of the ribs protect & aids in breathing
24
Q
Muscles of the ribs assisting in elevation and depression
A
- Pec maj/min → when humerus is fixed
- Seratus ANT → when scapular is fixed
- Both expands thoracic cage when contracted → helps get extra air in
- Serratus POS
- SUP → elevate ribs (inspiration)
- INF → depress ribs (expiration)
