Osteology of the Trunk

Question 1

Trunk composition

Answer 1

Spinal column
Sternum
Ribs

Question 2

Trunk function

Answer 2

Support.

Protection of vital organs.

Question 3

Spinal column

Answer 3

Cervical spine: 7 cervical vertebrae
Thoracic spine: 12 thoracic vertebrae
Lumbar spine: 5 lumbar vertebrae
Sacrum: 5 Sacral vertebrae
Coccyx: 3-4 coccygeal vertebrae

Question 4

Typical vertebrae

Answer 4

Vertebral body
Vertebral arch
Spinous process 
Transvers processes 
Articular processes

Question 5

Difference in size of vertebral body in cervical, thoracic and lumbar.

Answer 5

Lumbar: Biggest
Thoracic: Middle
Cervical: Smallest

Question 6

Difference in size of vertebral foramen in cervical, thoracic and lumbar.

Answer 6

Cervical: Biggest
Thoracic: Middle
Lumbar: Smallest

Question 7

Differences in shape of spinous processes in cervical, thoracic and lumbar.

Answer 7

Cervical: C3-C6 short and bifid(two heads), C7 protruding.
Thoracic: Long, angled inferior.
Lumbar: Thick and flattened.

Question 8

Differences in shape of transverse processes in cervical, thoracic and lumbar.

Answer 8

Cervical: Ant. and post. tubercules surrounding a transverse
foramen.
Thoracic: Angled backwards, articular surfaces for the ribs.
Lumbar: Small pointed eminence fused with proc. costalis.

Question 9

C1

Answer 9

No body
No spinous process
Anterior arch

Question 10

Median sacral crest

Answer 10

Fusion of the spinous processes.

Synostosis between the sacral vertebrae (synchondrosis in babies).

Question 11

Coccyx

Answer 11

Fusion of 3-4 vertebrae. Has some mobility.

Question 12

Sacrum

Answer 12

Articulates with the L5 superiorly and coccyx inferiorly.

Question 13

Sternal angle

Answer 13

Between manubrium and sternal body. Fuses with age (lack of collagen, around 60 years).

Question 14

Sternum

Answer 14

Clavicle articulates with the clavicular notch on the sternum.
Sternum articulates with the costal cartilage of the ribs.
Ribs 8-12 don’t have direct contract with sternum.

Question 15

Ribs

Answer 15

12 pairs.
First 7: True ribs, attach to both spine and sternum.
Last 5: Floating ribs.
11-12: False ribs.

Question 16

Rib components

Answer 16

All ribs have mostly same structure, different length.
- Head (articulates posteriorly with spine)
- Neck
- Costal tubercle
- Shaft (Flat end of shaft articulates anteriorly with costal
cartilage)

Question 17

Xiphoid process

Answer 17

Bottom of sternum.