37 - Thoracic Walls

Question 1

Tissue types in the breast 1) 2) 3) 4) 5) 6)

Answer 1

1) Glandular 2) Fibrous 3) Adipose 4) Blood vessels 5) Nerves 6) Lymphatics

Question 2

Anatomical delineation of breast

Answer 2

From lateral border of sternum to mid-axillary line From second to sixth rib.

Question 3

Name for elongated part of breast towards armpit

Answer 3

Superolateral extension or axillary tail

Question 4

Why are most carcinomas of the breast found in the upper outer quadrant?

Answer 4

Because this quadrant has the most glandular tissue, because of the axillary tail of the breast.

Question 5

Muscles that breast overlies

Answer 5

2/3 of breast overlies pec major 1/3 of breast overlies serratus anterior

Question 6

How do breasts sit against torso?

Answer 6

Retro-mammary space separates breast and underlying muscle. This is where breast implants can be inserted.

Question 7

Blood supply of breasts 1) 2) 3)

Answer 7

1) Medial breast gets branches from internal thoracic arteries. 2) Superior aspect of breast gets branches from lateral thoracic artery, which is a branch of axillary artery, which is from the subclavian artery. 3) Lateral breast gets branches from posterior intercostal.

Question 8

Blood supply of medial breast

Answer 8

Medial breast gets branches from internal thoracic arteries.

Question 9

Blood supply of superior lateral breast

Answer 9

Superior aspect of breast gets branches from lateral thoracic artery, which is a branch of axillary artery, which is from the subclavian artery.

Question 10

Blood supply of lateral breast

Answer 10

Lateral gets branches from posterior intercostal arteries (lateral mammary branches)

Question 11

Venous drainage of breasts 1) 2) 3)

Answer 11

1) Medial - Internal thoracic vein 2) Lateral - Lateral mammary vein, which drains to lateral thoracic vein, which drains to axillary vein, which drains to subclavian vein

Question 12

Lymphatic drainage of breasts 1) 2) 3)

Answer 12

Drain to: 1) Axillary 2) Intercostal 3) Parasternal lymph nodes

Question 13

Components of sternal complex 1) 2)

Answer 13

1) Manubrium (superior) 2) Sternum (inferior)

Question 14

Ribs whose costal cartilage articulate with sternal complex

Answer 14

Upper 7 ribs

Question 15

Ribs whose costal cartilage join costal cartilage of rib immediately superior

Answer 15

Ribs 8, 9 and 10

Question 16

Ribs whose costal cartilage doesn’t articulate with anything

Answer 16

Ribs 11 and 12 (floating ribs)

Question 17

Answer 17

Question 18

Answer 18

Question 19

Description of two articular facets of tuberculae

Answer 19

Medal facet is smooth, articular. Lateral facet is rough, attachment for ligament of intercostal muscle

Question 20

Which part of rib are the tuberculae near?

Answer 20

Vertebral end (near head with articular facets

Question 21

Number of articular facets on vertebral head of rib

Answer 21

Two (both smooth)

Question 22

Orientation of rib bodies

Answer 22

Almost vertical (therefore have superior and inferior aspects)

Question 23

Structures on inferior border or ribs

Answer 23

Costal groove. Contains (in superior to inferior order) intercostal vein, intercostal artery, intercostal nerve

Question 24

Shape of first rib 1) 2) 3)

Answer 24

1) Shorter, more curved, flatter than other ribs. 2) Very deep groove for subclavian vessels. 3) Single articular facet on head, as only articulates with T1 vertebra.

Question 25

Defining characteristics of T vertebra 1) 2)

Answer 25

1) Facets on body and transverse processes for ribs. 2) Long, almost vertical spinous process 3) Body has articular facets for ribs on posterolateral superior and inferior surfaces.

Question 26

How do ribs join to vertebrae?

Answer 26

Join two adjacent vertebrae.

Question 27

Name for joints between ribs and vertebrae

Answer 27

Costovertebral joints and costotransverse joints

Question 28

Which parts of vertebrae do ribs attach to?

Answer 28

To body at costovertebral joints. To transverse processes at costotransverse joints.

Question 29

Costotransverse joints

Answer 29

Ribs join transverse process with a three-part costotransverse ligament

Question 30

Can ribs be dislocated from vertebral column?

Answer 30

No. Rib will break before costotransverse or costovertebral joints break

Question 31

Locations of apertures of thorax 1) 2)

Answer 31

1) Superior aperture is bounded by rib 1. 2) Inferior aperture is bounded by rib 12 posteriorally, rib 11 and 12 laterally, costal cartilage of ribs 7-10 anteriorally, xiphoid body.

Question 32

Superior aperture of thorax 1) 2) 3)

Answer 32

1) Bounded by rib 1. Runs around interior aspect of rib 1. 2) Covered by supra-pleural membrane (or Sibson's fascia) 3) There is an opening for airways, etc.

Question 33

Inferior aperture of thorax 1) 2)

Answer 33

1) Bounded by diaphragm. 2) Lateral and medial arcurate ligaments are posterior baoundaries. 3) Bounded laterally by ribs 11 and 12. 4) Bounded anteriorally by costal cartillage of ribs 7-10, and xiphoid process

Question 34

Lateral and medial arcurate ligaments 1) 2) 3)

Answer 34

1) In inferior aperture of thorax. 2) Lateral arcurate ligament overlies quadratus lumborum 3) Medial arcurate ligament overlies psoas

Question 35

Diaphragm anatomical delineation 1) 2) 3)

Answer 35

1) Posterior - Rib 12 2) Lateral - Rib 11 and 12 3) Anterior - Costal cartilage of ribs 7-10

Question 36

How does the diaphragm attach to vertebrae?

Answer 36

With right and left cruses. Right crus joins to L1, L2, L3. Left crus joins to L1, L2

Question 37

Origin and insertion of diaphragm

Answer 37

Circumferential origin. Central insertion.

Question 38

Answer 38

Question 39

Shape of diaphragm

Answer 39

Two domes. Right dome is higher than left

Question 40

Objects passing through diaphragm 1) 2) 3)

Answer 40

1) Oesophagus passes through muscular diaphragm, about at midline at T10. 2) IVC passes through central tendon right of midline at T8 3) Aorta passes behind diaphragm between crura at T12, slightly left of midline

Question 41

Vertebra where oesophagus passes through diaphragm

Answer 41

T10

Question 42

Vertebra where IVC passes through diaphragm

Answer 42

T8

Question 43

Vertebra where aorta passes behind diaphragm

Answer 43

T12

Question 44

Innervation of diaphragm

Answer 44

Left and right phrenic nerves innervate respective domes of diaphragm

Question 45

Layers of intercostal muscles

Answer 45

1) External intercostal 2) Internal intercostal 3) Innermost intercostal

Question 46

Direction of muscle fibres in external intercostal muscle

Answer 46

Downwards, forwards ('front pocket muscles')

Question 47

Function of external intercostal muscles

Answer 47

When contract, elevate and expand ribcage. Involved in inspiration.

Question 48

Makeup of external intercostal muscles

Answer 48

Muscle on posterior and lateral aspects. Intercostal membrane on anterior aspect

Question 49

Direction of muscle fibres in internal intercostal muscles

Answer 49

Downwards, outwards ('back pocket muscles')

Question 50

Makeup of internal intercostal muscles

Answer 50

Anterior, lateral aspects are muscular. Posterior aspect is intercostal membrane

Question 51

Function of internal intercostal muscles

Answer 51

Stabilise ribs during movement

Question 52

Direction of muscle fibres in innermost intercostal muscles

Answer 52

Downwards

Question 53

Distribution of innermost intercostal muscles

Answer 53

Mostly lateral. Some on posterior and anterior, but not many

Question 54

Where does neurovascular bundle in costal groove run relative to intercostal muscles?

Answer 54

Lies between internal and innermost intercostal muscles

Question 55

What does the neurovsacular bundle in costal groove supply?

Answer 55

Supplies rib inferior to rib in which groove runs. Can have collateral branches to supply superior rib (these are smaller than main branch)

Question 56

When inserting an intercostal needle, where do you insert it?

Answer 56

At inferior part of intercostal space. Better to hit smaller, less vital collateral branches of neurovascular bundle than main neurovascular bundle (which is at the superior part)

Question 57

Innervation of ribs

Answer 57

Anterior ramus of thoracic spinal nerve becomes intercostal nerve. Intercostal nerve innervates anterior skin, collateral nerves supply posterior and lateral skin.

Question 58

Dimensions of thorax that change during inspiration

Answer 58

Vertical, lateral, anterior-posterior directions

Question 59

Muscles of respiration

Answer 59

Any muscle attaching to ribs can potentially affect respiration. (EG: sternocleidomastoid, scalenes, abdominal muscles)

Question 60

How can anterior-posterior dimensions of thorax be changed?

Answer 60

Elevate upper 7 ribs.