The thorax:

Question 1

The thorax

Answer 1

Consists of thoracic cavity, its contents (organs) and the wall that surrounds it (ribs, sternum and vertebral column).
Formed by ribs and costal cartilages, supported by sternum and thoracic vertebrae

Question 2

Thoracic cavity

Answer 2

• Kidney shaped

- Part of trunk between neck and abdomen

Question 3

Thoracic cavity is divided into:

Answer 3

Mediastinum and Left and right pulmonary cavities

Question 4

Mediastinum

Answer 4

Mass of tissue that extends from sternum and costal cartilages ant. to bodies of thoracic vertebrae post. and from sup. thoracic aperture to diaphragm
> Contains heart

Question 5

Left and right pulmonary cavities

Answer 5

contain lungs and pleurae

Question 6

Layers of thoracic cavity:

Answer 6

1.Skin
2.Subcutaneous tissue - breasts
3.Fascia:
- Pectoral –> continuous with deep fascia
- Endothoracic –> deep to intercostal spaces and ribs,
and separates these structures from the pleura
Pleura is deeper than endothoracic fascia
4.Muscles
- Thorax, upper limb, abdomen, back and neck

Question 7

Skeleton of thoracic wall consists of:

Answer 7

12 pairs of ribs & associated costal cartilages

Question 8

12 pairs of ribs & associated costal cartilages

Answer 8

Intercostal spaces separate ribs and their costal cartilages from one another.
- Subcostal space below 12th rib.

Question 9

Types of ribs:

Answer 9

True (1-7) - cartilages articulate directly with the sternum
(vertebrosternal)
False (8-10) – indirect connection with sternum (vertebrochondral)
Floating (11-12) - do not attach to the sternum or other ribs
(vertebral). End in muscle of post. abdominal wall

Question 10

Classifications of ribs:

Answer 10

Typical (3rd - 9th) –> Have more or less identical features
Atypical (1st, 2nd, 10th-12th)

Question 11

Components of typical ribs :

Answer 11

Head (with 2 facets), neck, tubercle (with articular facet), body, costal angle, costal cartilages & costal groove

Question 12

Atypical ribs:

Answer 12

Only have one facet on head (only articulate with one vertebrae)
Rib 1 – short and curved, flat, has a scalene tubercle (for attachment of ant. Scalene muscle) also has grooves for scalene vessels
Rib 2 - Has tuberosity for serratus ant. attachment
Rib 10 – 12 - only has one facet on head
Rib 11-12 – no neck, no tubercle

Question 13

Vertebrae:

Answer 13

12 thoracic vertebrae & intervertebral discs in between

Question 14

Typical thoracic vertebrae

Answer 14

• 2 - 8
• Sup. and inf. costal facets on their bodies (demi facets) – heads of
  ribs.
• Costal facets on transverse processes (except inf. 2/3) – tubercles
  of ribs.
• Long, inferiorly slanting spinous process.

Question 15

Atypical vert.

Answer 15

• T1, T9 – 12
  they differ from typical thoracic vertebrae largely in respect of the type of articulation with the rib.
  o Have one whole facet instead of two
  o Only one rib articulates on these vert.

Question 16

Sternum:

Answer 16

1. Manubrium
   - Jugular notch
   - Clavicular notches
   - Costal notch 1
2. 2 Manubriosternal joint ( Sternal angle / Angle of Louis)
   - Intervertebral disc between T4 & T5
   - 2nd costal cartilage
3. Body (Level of T5 – T9)
   - Costal notches

3.Xiphoid process (T10 level)
Xiphisternal joint –> T9
- NB landmark for sup. Limit of liver, central tendon of diaphragm and inf. Border of the heart

Question 17

Thoracic apertures:

Answer 17

Openings in rib cage

1. Thoracic inlet. -- (Sup. Thoracic aperture)
      > Formed by: 
- T1
- 1st ribs
- Sup. Border of sternum 
     > Passes through it:
- Trachea
- Esophagus
- Nerves and BV’s
To get between thorax to head and neck

2. Thoracic outlet -- (inf. Thoracic aperture)
        > Formed by: 
Formed at bottom- closed by the diaphragm 
Borders:
- T 12
- Ribs 11 and 12
- Costal margins
- Xiphisternal joint 
        > Passes through it:
~Must pass through diaphragm
- Oesophagus
- Inf. Vena cava
- aorta

Question 18

Joints of thoracic wall p1

Answer 18

Question 19

Joints of thoracic wall p2

Answer 19

Question 20

Ligaments of thoracic wall

Answer 20

	Ant. & post. longitudinal --> Vert. column
	Head of rib 
      o	Radiate & 
      o	Intra-articular lig. 
	Costotransverse 
	Lat. & sup. costotransverse 
	Interchondral 
	Sternocostal 
-	Ant. & post. radiate sternocostal 
-	Intra-articular 
	Sternoclavicular 
-	 Ant. & post. sternoclavicular 
-	Costoclavicular