Musculo Skeletal Anatomy - Week 3 - Rib cage

Question 1

What are the main functions of the rib cage?

Answer 1

• Increases stability of the thoracic spine
  flexion and extension lateral bending
  and rotation
• Important function is ventilation

Question 2

What are the 3 main parts of the sternum and what are their articulations?

Answer 2

1. The manubrium
   Articulates with the clavicles (or collarbones) and the
   costal cartilages of the first pair of ribs.
2. The body
   * Individual costal cartilages from rib pairs 2–7 are also
   attached to the body

• The rib pairs 8–10 are also attached to the body, but by
  a single pair of cartilages shared with rib pair 7

3. Xiphoid process
   * Angles dorsally from the sternum

• The muscular diaphragm (muscle used in breathing)
  and the rectus abdominis muscle attach to the xiphoid
  process.

Question 3

What ribs are classified as true ribs and why?

Answer 3

Ribs 1-7 classified as true ribs
because they attached directly to
the sternum.

Question 4

What ribs are classified as false ribs and why?

Answer 4

Ribs 8 -10 are false ribs because they attach to the sternum through costal cartilage.

Question 5

What ribs are classified as floating ribs and why?

Answer 5

Ribs 11 and 12 are floating ribs no
articulation or attachment to the
sternum

Question 6

What are the features of typical ribs?

Answer 6

Head:
* Wedge shape and has two articular facets
* One facet articulates with the numerically
corresponding vertebra, and the other
articulates with the vertebra above

Neck
* Connects the head with the body

The body, or shaft
* flat and curved
* has a groove for the neurovascular supply
of the thorax

Question 7

What ribs are Atypical?

Answer 7

Ribs 1, 2, 10, 11 and 12

Question 8

Why is Rib 1 considered an Atypical rib?

Answer 8

• is shorter and wider than the other ribs
• only has one facet on its head for articulation
  with its corresponding vertebra

Question 9

Why is Rib 2 considered an Atypical rib?

Answer 9

• Thinner and longer than rib 1
• has a roughened area on its upper surface, from
  which the serratus anterior muscle originates

Question 10

Why is Rib 10 considered an Atypical rib?

Answer 10

• Only has one facet
• is shorter and wider than the other ribs

Question 11

Why is Rib 11 and 12 considered an Atypical rib?

Answer 11

• Only contain one facet, which is for articulation
  with their corresponding vertebra.
• Have no neck

Question 12

What are the names of the 2 joints that articulate with the posterior rib?

Answer 12

1. Costovertebral joint
2. Costotransverse joint