The Thorax

Question 1

How many true pairs of ribs are there?

Answer 1

7

Question 2

How many false ribs are there?

Answer 2

3

Question 3

How many floating ribs are there?

Answer 3

2

Question 4

What is the name of the joint where the head and tubercle of the rib meets the body of the thoracic vertebrae?

Answer 4

Costovertebral joints

Question 5

How many vertebrae do the ribs attach to?

Answer 5

12

Question 6

What is the joint classification of the costotransverse joints?

Answer 6

Synovial plane joint

Question 7

What ligaments are associated with the costotransverse joint?

Answer 7

Lateral and superior costotransverse

Question 8

What is the orientation of the external intercostal muscle fibres?

Answer 8

Run below and in front of the rib above and below them

Question 9

What is the orientation of the internal intercostal muscle fibres?

Answer 9

Run inside from the bottom of the costal grooves to the superior borders of the ribs lower than them

Question 10

Which nerve supplies the intercostal muscles?

Answer 10

Intercostal nerve

Question 11

What are the articulating surfaces of the sternocostal joints?

Answer 11

1st costal cartilages with manubrium of sternum

2nd – 7th pairs of costal cartilages with sternum

Question 12

What is the function of serratus anterior?

Answer 12

Allows forward and upward rotation of arm and pulls scapula forward and around rib cage

Question 13

What are the attachments of subcostales, levatores costarum and transversus thoracic?

Answer 13

Internal surface of lower ribs near their angles

Superior borders of 2nd or 3rd ribs below

Question 14

What are the attachments of levorates costarum?

Answer 14

Transverse processes of T7 - 11

Subjacent ribs between tubercle and angle

Question 15

What are the attachments of transversus thoracic?

Answer 15

Posterior surface of lower sternum

Internal surface of costal cartilages 2 - 6

Question 16

Name all the parts of the sternum.

Answer 16

Manubrium
Body
Xiphoid process

Question 17

What are the typical ribs?

Answer 17

3rd to 9th

Question 18

Name the parts of a typical rib?

Answer 18

Head
Neck
Tubercle
Body

Question 19

Describe the true ribs

Answer 19

They attach directly to the sternum through their own costal cartilages

Question 20

Describe the false ribs

Answer 20

Their cartilages are connected to the cartilage of the rib above them; thus their connection with the sternum is indirect

Question 21

Describe the floating ribs

Answer 21

The rudimentary cartilages of these ribs do not connect even indirectly with the sternum; instead they end in the posterior abdominal musculature

Question 22

Describe the head of a typical rib

Answer 22

Wedge shaped and has two facets, separated by the crest of the head; one facet for articulation with the numerically corresponding vertebra and one facet for the vertebra superior to it

Question 23

Describe the neck of a typical rib

Answer 23

Connects to the head of the rib with the body at the level of the tubercle

Question 24

Describe the tubercle of a typical rib

Answer 24

Located at the junction of the neck and body; a smooth articular part articulates with the corresponding transverse process of the vertebra, and a rough non-articular part provides attachment for the costotransverse ligament

Question 25

Describe the body of a typical rib

Answer 25

Thin, flat, and curved, most markedly at the costal angle where the rib turns anterolaterally. The angle also democrats the lateral limit of attachment of the deep back muscles to the ribs. The concave internal surface of the body has a costal groove paralleling the inferior border of the rib, which provides some protection for the intercostal nerve.