Bones of the Trunk

• The purpose of this lecture is to study the Bones of the Trunk

Skeleton

• The Skeleton has two parts, the Axial Skeleton and the Appendicular Skeleton

Axial Skeleton

• The Axial Skeleton includes the Skull, Vertebral Column and Thorax

Appendicular Skeleton

• The Appendicular Skeleton includes the Upper and Lower Extremity

Bones of the Trunk

• Bones of the trunk consist of vertebrae, ribs, and the sternum (breastbone).

Columna Vertebralis – Spine

• The spine consists of 32-33 vertebrae.
• The Pars cervicalis consists of 7 vertebrae cervicales.
• The Pars thoracica consists of 12 vertebrae thoracicae.
• The Pars lumbalis consists of 5 vertebrae lumbales.
• The Pars sacralis is also know as the os sacrum and consists of 5 vertebrae sacrales.
• The Pars coccygea is also known as the os coccygis and consist of 3-4 vertebrae coccygeae.

Vertebra

• The corpus vertebrae is the vertebral body.
• The arcus vertebrae is the vertebral arch.
• The Foramen vertebrale is the vertebral foramen.
• The incisura vertebralis superior is the superior vertebral notch.
• The incisura vertebralis inferior is the inferior vertebral notch.
• The foramen intervertebrale is the intervertebral foramen.
• The processus articularis superior is the superior articular process with its facies articularis superior.
• The processus articularis inferior is the inferior articular process with its facies articularis inferior.
• The processus transversus is the transverse process.
• The processus spinosus is the spinous process.

Vertebrae Cervicales (7)

• The foramen transversarium is part #8.
• The tuberculum anterior et posterior is parts #3 and #4.
• Split processus spinosus II-VI is part #11.
• The atypical cervical vertebrae are 1., 2., 6., 7.

1st Cervical Vertebra - Atlas

• 1 - Arcus anterior
• 2 - Fovea dentis
• 3 - Arcus posterior
• 4 – Sulcus arteriae vertebralis
• 5 - Massa lateralis
• 6 – Facies articularis superior
• 7 – Facies articularis inferior
• 8 - Processus transversus
• 9 – Foramen transversarium

2nd Cervical Vertebra - Axis

• 1 - Dens
• 2 - Facies articularis anterior
• 3 - Facies articularis posterior
• 4 - Apex dentis
• 5 - Corpus
• 6 - Processus spinosus
• 7 - Facies articularis superior
• 8 - Processus et facies articularis inferior
• 9 - Foramen transversarium

6th Cervical Vertebra

• Tuberculum caroticum is the anterior tubercle.

7th Cervical Vertebra - Vertebra Prominens

• Long, unsplit processus spinosus which is palpable through the skin

Thoracic Vertebrae – Vertebrae Thoracicae (12)

• Fovea costalis are the costal facets.
• Typical vertebrae are Th2-Th9.
• The vertebrae have fovea costalis superior, fovea costalis inferior, and fovea costalis processus transversi.
• Long, pointing downwards processus spinosus.

Connection Between Typical Vertebrae and Ribs

• Ribs connect to typical vertebrae.

Thoracic Vertebrae

• Atypical – Th1, Th10-Th12
• Th1 has a full F.c. superior, half F.c. inferior, and present F.c. proc. transversi.
• Th10 has half F.c. superior, absent F.c. inferior, and present F.c. proc. transversi.
• Th11, and Th12 possess one full facet on the body, and absent F.c. proc. transversi.

Lumbar Vertebrae – Vertebrae Lumbales (5)

• Have processus costalis
• Have a short, straight processus spinosus

Sacral Vertebrae - Os Sacrum

• Consists of 5 fused vertebrae sacrales
• The basis ossis sacri faces upward, which includes the promontorium and processus articularis superior.
• The apex ossis sacri faces downward.

Sacral Vertebrae - Sacrum

• Has facies pelvica which is concave.
• The lineae transversae are in quantity four, (4).
• The foramina sacralia anteriora are in quantity four by 2, (4x2).

Sacral Vertebrae

• This part has facies dorsalis which is convex.
• Has crista sacralis mediana.
• Includes foramina sacralia posteriora (4x2).
• Have canalis sacralis.
• Consists of hiatus sacralis.
• Has cornu sacrale.

Sacral Vertebrae - Sacrum

• Has pars lateralis in quantity 2.
• Includes facies auricularis.
• Has tuberositas ossis sacri.

Tailbone – Os Coccygis (3-5)

• Has cornu coccygeum in quantity 2.

Thorax. Ribs – Costae (12x2)

• Costae verae (1st-7th)
• Costae spuriae (8th-12th)
• The 8th-10th ribs fuse together and with the 7th rib.
• Costae fluctuantes (11th-12th)

Typical Ribs (2-10)

• Consist of caput costae with facies articularis capitis costae and crista capitis costae.
• Includes collum costae.
• Consists of tuberculum costae with facies articularis tuberculi costae.
• Parts of the rib are the bone and the cartilago costalis.
• The corpus costae is flattened vertically.
• Has a margo superior which is rounded and margo inferior which is edgy.
• Consists of facies externa which is convex and facies interna which is concave, where the sulcus costae resides.
• Contains the angulus costae.

Atypical Ribs (1, 11, 12)

• The 1st rib is called costa prima.
• The body is flattened horizontally.
• Contains facies superior with tuberculum musculi scaleni anterioris (T), sulcus venae subclaviae (V), and sulcus arteriae subclaviae (A).
• Has facies inferior, margo internus, and margo externus with tuberculum costae/angulus costae.
• The 11th, 12th ribs possess absent crest, absent neck, absent tubercle, and a smooth angle.

Thorax. Breastbone – Sternum

• Manubrium sterni with incisura jugularis (1), incisura clavicularis (2), and incisura costalis (2).
• Corpus sterni has incisurae costales (6x2).
• Has processus xiphoideus and angulus sterni.